CN111592170A

CN111592170A - Preparation method of nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in excrement, sewage and biogas slurry wastewater

Info

Publication number: CN111592170A
Application number: CN202010710764.5A
Authority: CN
Inventors: 苏文雯; 苏文锦; 苏斌
Original assignee: Beijing Jinxiu New Technology Development Co ltd
Current assignee: Beijing Jinxiu New Technology Development Co ltd
Priority date: 2020-07-22
Filing date: 2020-07-22
Publication date: 2020-08-28
Anticipated expiration: 2040-07-22
Also published as: CN111592170B

Abstract

The invention relates to a preparation method of nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in feces, biogas slurry and wastewater, which is implemented by adding FeCl into₂·4H₂O and FeCl₃·6H₂Preparing a mixed solution from O, heating, ultrasonically vibrating and stirring; addition of NH₃.H₂O solution, reaction curing and cooling; performing magnetic separation and cleaning to obtain nano Fe₃O₄Magnetic fine particles; mixing nano Fe₃O₄Magnetic particles are stirred and dispersed in deionized water, ultrasonic oscillation is carried out, a coating agent aqueous solution is added, and reaction is carried out to ensure that Fe₃O₄Fully adsorbing, cooling and cooling to prepare the nano Fe₃O₄A magnetic fluid; preparing the mineral soil into suspension, and then adding the nano Fe₃O₄And (3) conducting ultrasonic oscillation dispersion on the magnetic fluid, then introducing the magnetic fluid into a crystallization reaction kettle for crystallization, and washing the magnetic fluid to be neutral to prepare the nano magnetic material loaded mineral soil. The nano magnetic material of the invention loads mineral soil, can prevent the nano magnetic material from aggregating in the treatment process, can greatly reduce the aggregation degree of the magnetic nano particles, form a magnetic composite material, and effectively reduce COD and heavy metals in wastewater.

Description

Preparation method of nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in excrement, sewage and biogas slurry wastewater

Technical Field

The invention belongs to the field of wastewater treatment materials, and particularly relates to a preparation method of nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in excrement, sewage and biogas slurry wastewater.

Background

In 2015, the discharge amount of COD and ammonia nitrogen of Chinese agricultural sources is 106867260 tons. The data show that the five-day biochemical oxygen demand (BOD5) of the wastewater in the farm is as high as 2000-8000 mg/L, and the COD is as high as 5000-20000 mg/L, and high pollutant content. Livestock and poultry breeding has become a main source of pollutants, particularly organic pollutants, and the contribution rate reaches nearly 40%. With the gradual enhancement of environmental protection consciousness, the treatment of excrement in farms becomes a problem to be solved urgently, and some components in the excrement are directly discharged without being treated to pollute the environment, so that the establishment of biogas digesters in some farms to utilize excrement has a good effect, but the random discharge of biogas digesters causes environmental problems such as lake and river eutrophication, soil and underground water pollution and the like. According to the renewable energy medium and long term development planning, the annual total utilization of methane in China can reach 440 hundred million m by 2020³The biogas utilization of rural residents reaches 300 hundred million m³。

The biogas engineering simultaneously consumes organic wastes and produces clean energy, and simultaneously produces a large amount of anaerobic digestion residues, namely biogas slurry. Especially in large and medium-sized aquaculture biogas projects, the biogas slurry and the biogas residues generated every day can reach hundreds of thousands of tons. If the biogas slurry cannot be reasonably treated, resources are wasted, and secondary pollution to the environment is caused. The biogas slurry is used as fertilizer or directly discharged, and the discharge reaches the standard and the requirement on safety is high. In fact, the biogas slurry still contains a certain amount of organic matters, ammonia nitrogen, total phosphorus and the like which do not reach the discharge standard of pollutants for livestock and poultry breeding (GB 18596-2001). The larger the scale of the farm is, the more the amount of the biogas residues generated is, the longer the outward transport distance is, the higher the cost is, and the worse the benefit is. The temperature in the south is high, the planting period is long, and the storage time of biogas residues and biogas slurry is short; the storage equipment is huge, the investment is large, the occupied area is large, and the risk of storing biogas slurry at high temperature in summer is large.

The existing treatment technologies of feces and biogas slurry can be divided into 2 categories, namely a traditional biochemical treatment method and a natural biological treatment method. The aerobic treatment method comprises an activated sludge method, a biological filter, a biological rotating disc contact oxidation method, an intermittent activated sludge method and the like.

The aerobic treatment method has the advantages of strong treatment capability, wide adaptability and the like. The treatment technology taking anaerobic fermentation as a core is an important means for reducing livestock and poultry manure organic matters and other pollutants. The biogas slurry is high-concentration organic wastewater after anaerobic fermentation and has the characteristics of complex pollution components, high concentration and the like. In the anaerobic fermentation process, carbon-containing organic matters are primarily degraded and removed, most of nitrogen sources are reserved, the carbon-nitrogen ratio (C/N) of the biogas slurry is disordered, the biochemical performance is reduced, and the difficulty in processing the biogas slurry is further increased. The microbial treatment method has the advantages of complex process structure, more mechanical equipment, large maintenance workload, large investment, high energy consumption, high operation and maintenance cost, greatly increases the cost burden of the breeding industry, and is difficult to bear by a small-scale farm.

As the excrement and the biogas slurry are high-concentration organic waste liquid, the COD value of the excrement and the biogas slurry reaches 30000-40000 mg/L, the post-treatment cost of the excrement and the biogas slurry is very high, the excrement and the biogas slurry need to be diluted, the cost of diluting clean water is added, and the treatment cost per ton is nearly 40 yuan. Such high processing costs are difficult to achieve and acceptable in industrial production. The reality is that most of the high-investment equipment facilities at the early stage are basically in an idle and stagnant state due to the problem of operation cost.

The natural biological treatment method mainly comprises a biological pond method and artificial wetland treatment. The biological pond method has the advantages of simple and convenient operation, high-efficiency decontamination and the like, but has a plurality of problems, including unreasonable structure of the biological pond, low purification load, common sedimentation problem and the like. The ecological pond treatment system has the application limitations that (1) the ecological pond treatment system occupies a large area and is suitable for being popularized in areas with large-area wastelands, (2) the actual hydraulic retention time is shorter than the designed hydraulic retention time due to the easy occurrence of a short flow phenomenon, (3) when the temperature is higher, odor is easy to generate, breeding mosquitoes disturb resident life, and (4) the removal effect of nitrogen and phosphorus is unstable. The wetland treatment method has the advantages of relatively low construction and operation cost, good effluent quality, simple and convenient operation and the like. But the land occupation is large, and the land occupation is difficult to be practically applied in the places where the land is scarce.

The purification mechanism of the land ecological treatment system for the sewage is that the filler (medium) in the system has huge specific surface area and is easy to form a biological membrane, and when the sewage flows through the surface of particles, pollutants in the sewage are intercepted through the actions of precipitation, filtration and adsorption. The land treatment system has the main limitations of (1) large occupied area which is 2-3 times of that of the traditional secondary biological treatment method, (2) sewage can block the treatment system to cause poor water permeability, (3) a water-resisting layer is required to be arranged at the bottom, and once the water-resisting layer is damaged, the sewage can permeate into natural soil to pollute underground water, (4) the sewage can generate short flow or is unevenly distributed on a water passing section, and (5) cold regions are easily influenced by freezing and tropical regions are easily subjected to malaria and other pathogens.

In addition, an adsorption method is adopted for sewage treatment technologies of dirt such as excrement and biogas slurry, and is an effective means for treating the excrement and the biogas slurry, and currently, activated carbon is generally adopted as an adsorbent for adsorption treatment of the biogas slurry in China, but the regeneration of the activated carbon is complex and high in cost, and is difficult to bear economically, so that the adsorbent becomes a key factor for influencing the adsorption treatment of the biogas slurry. The natural zeolite and mineral soil are water-containing alkali metal or alkaline earth metal framework aluminosilicate minerals, have strong ion exchange adsorption characteristics, and can improve the adsorption capacity of soil on ammonium ions, phosphate ions, potassium ions and the like. The use of zeolite and mineral soil has limitations, and firstly, the zeolite and mineral soil have low adsorption exchange capacity and frequent regeneration operation; secondly, the reaction rate of the zeolite and the mineral soil is slow in actual operation, and the water yield is small.

Meanwhile, nutrient elements such as nitrogen, phosphorus and potassium, which are rich in the culture manure and the biogas slurry, exist in a quick-acting state, have high absorption rate and are indispensable components in the plant growth process; the direct utilization or discharge to return to the field has the defects of high transportation cost, over-standard Chemical Oxygen Demand (COD), water body pollution, germ transmission and the like caused by the direct discharge of the excrement and the biogas slurry; the purified waste gas reaches the standard and is discharged, but the energy consumption in the purification process is large, the cost is high, and the waste of resources is caused; the culture manure and biogas slurry are resources, and should be recycled, and are changed into products through a series of scientific methods.

Disclosure of Invention

The invention aims to provide a preparation method of nano magnetic material loaded mineral soil for reducing COD and heavy metals in excrement sewage biogas slurry wastewater, a treatment method for treating excrement sewage biogas slurry by adopting the nano magnetic material loaded mineral soil, a liquid biological bacterial fertilizer and a solid biological bacterial fertilizer.

The technical scheme for solving the technical problems is as follows: a preparation method of nano magnetic material loaded mineral soil for reducing COD and heavy metals in feces, biogas and liquid wastewater comprises the following steps:

step (1), FeCl₂·4H₂O and FeCl₃·6H₂Dissolving O in equivalent deionized water respectively; wherein the content of the first and second substances,

FeCL₂·4H₂o and FeCl₃·6H₂The mass volume concentration ratio of O is 1: 1-1: 3.

step (2), mixing the two solutions prepared in the step (1), heating to 50-80 ℃, performing ultrasonic oscillation, and keeping magnetic stirring at constant temperature; preferably, the mixture can be heated to 60 ℃ and then ultrasonically vibrated for 5min, and the mixture is magnetically stirred at the constant temperature of 60 ℃, wherein the stirring speed is 1000 r/min;

step (3) of adding NH to the mixed solution of step (2)₃.H₂O solution, continuously dripping NH after the reaction solution is completely blackened₃.H₂O solution until the pH value of the solution is 10-12, preferably pH is 11.5, reacting for 0.5-3 hours, preferably for 1 hour, so that Fe₃O₄Fully curing, and then naturally cooling to room temperature; preferred NH₃.H₂The molar concentration of the O solution is 2moL/L (mass concentration of 25%);

step (4), washing with deionized water after magnetic separation to obtain nano Fe₃O₄Magnetic fine particles; the specific magnetic separation can be that the solution after reaction is placed on a magnet to accelerate the precipitation of magnetic particles; preferably deionized water for 1-2 hours;

step (5), nano Fe₃O₄Magnetic particles are stirred and dispersed in deionized water, and nano Fe₃O₄The mass percentage concentration of the magnetic particles in the deionized water is 10-50%, ultrasonic oscillation can be carried out for 15 minutes, aqueous solution of the coating agent is added at the temperature of 60-90 ℃, preferably 80 ℃, the mass volume concentration of the aqueous solution of the coating agent can be 60-150 g/L, and Fe is reacted to ensure that₃O₄Is sufficientAdsorbing, reacting for 30min, cooling, and making into nanometer Fe₃O₄Magnetic fluid, in particular nano-Fe₃O₄10 percent of nano Fe by mass₃O₄A magnetic fluid;

step (6), mineral soil is added into deionized water according to the mass volume ratio of 10-25g/L to prepare suspension, namely the mass volume ratio of the mineral soil to the deionized water is 10-25 g: 1L, adding nano Fe with the same mass as the mineral soil₃O₄And after the magnetic fluid is dispersed by ultrasonic oscillation, the dispersion time can be selected from 10 minutes, the magnetic fluid is introduced into a crystallization reaction kettle for crystallization, the temperature in the crystallization reaction kettle can be controlled at 90 ℃ for crystallization for 7 hours, and the product is washed to be neutral by deionized water to prepare the nano magnetic material loaded mineral soil.

The invention relates to nano Fe₃O₄The magnetic fluid is also called magnetic liquid, is colloidal solution or suspension formed by dispersing nano magnetic particles in carrier liquid under the action of surfactant, and because the magnetic fluid has both magnetic property and fluidity and small size effect, quantum size effect, surface effect and macroscopic quantum tunnel effect of nano particles, the surfactant is mostly added in the preparation process of the traditional preparation method, which can cause other ions and impurities wrapped in the solution to be difficult to remove and clean, and Fe is difficult to clean₃O₄The loss is serious; the invention adopts the steps of firstly preparing Fe₃O₄The method of coating the stabilizer is selected after cleaning, so that the defects are overcome; in addition, the selection of the water-based magnetic fluid coating stabilizer is also important, one end of the water-based magnetic fluid coating stabilizer is required to be hydrophilic, the other end of the water-based magnetic fluid coating stabilizer is required to be connected with the nano-particles with positive charges, the magnetic nano-particles are dispersed in a liquid carrier with the help of the coating stabilizer, the high-strength magnetism and the good stability are realized at a certain temperature, and the particle size distribution of the magnetic nano-particles can be easily controlled; because of small toxicity, high hydrophilicity and controllability, the coating stabilizer is selected to obtain the water-based magnetic fluid with better performance.

The invention is based on nano Fe₃O₄After the coating stabilizer is added, the coating stabilizer is wound on Fe in the form of hydrogen bond or coordinate bond₃O₄Surface ofA protective film is formed to prevent the aggregation of nano particles, and simultaneously, the steric hindrance effect and the mutual repulsion between organic groups overcome the nano Fe₃O₄The self gravity of the particles and the magnetic attraction among the particles enable the particles to be stably dispersed in the base liquid, so that the dispersibility and the stability of the magnetic fluid are improved; therefore, the amount of the coating stabilizer has certain influence on the stability and the magnetic responsiveness of the magnetic fluid, and when the mass concentration of the coating stabilizer is about 150g/L, the modified Fe₃O₄The particle settling time is longest, the stability is best, and the magnetic response distance is also longest, so that the optimal mass concentration of the coating stabilizer is 60g/L-150 g/L.

The invention is based on the adsorption technology, has the characteristics of simplicity and high efficiency, is widely used for removing heavy metals in water and reducing COD (chemical oxygen demand) and SS (suspended solid) indexes, but a plurality of adsorbents (mineral substances (soil)) cannot be separated from a solution or are difficult to separate after being adsorbed and saturated, so that the application of the adsorbents is limited. Compared with the traditional filtration separation method, the method is simple and efficient, can conveniently and quickly realize solid-liquid separation, and can prevent the magnetic nanoparticles from aggregating in the synthesis process by adopting a method of loading the magnetic nanoparticles with mineral substances (soil) through a nano magnetic material because the magnetic nanoparticles are particularly easy to aggregate in the formation process and the magnetic performance of the magnetic nanoparticles is reduced after aggregation, wherein the aggregation degree of the magnetic nanoparticles can be greatly reduced by compounding the magnetic nanoparticles with the mineral substance (soil) material to form a magnetic composite material, the magnetic nanoparticles are embedded in another substance through symbiosis, and the magnetic nanoparticles are loaded on the pore walls of the porous material.

The nano magnetic material loaded mineral soil not only has the physicochemical properties of minerals, but also has magnetism, so that the nano magnetic material loaded mineral soil can be used as a magnetic targeting carrier material for wastewater treatment; the natural mineral soil and the zeolite have larger specific surface area and excellent ion exchange performance, the natural inorganic material has highly developed pore structure and larger specific surface area, has strong adsorbability on pollutants in wastewater and low price, but cannot carry out magnetic separation per se, and in the wastewater treatment process, because the particles are fine and suspended in the treated wastewater for a long time, the wastewater is difficult to separate and recover quickly; the magnetic separation technology is widely applied to production practice for separating magnetic impurities in solid substances such as ores and the like and magnetic metal impurity particles in wastewater of steel plants and aluminum plants, the effect is obvious, but the application in separation and purification of wastewater containing organic and inorganic pollutants is rare, because the organic and inorganic particles have no magnetism, the particles need to be adsorbed by a magnetic adsorption material and then separated by a magnetic separation method, in addition, the invention selects a nano magnetic material to load mineral substances (soil) to reduce the indexes of the pollutants based on considering the treatment cost of subsequent treatment of the excrement and the biogas slurry and the important role of the mineral substances (soil) in soil and fertilizers.

The invention relates to a preparation method of nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in excrement, biogas and liquid wastewater, which comprises the following step (2), wherein the two solutions are mixed, and Fe²⁺: Fe³⁺The molar ratio is =1: 1-2: 3. based on mixing Fe in solution²⁺And Fe³⁺Coprecipitated and converted into Fe₃O₄Then the nano magnetic nano Fe is obtained after treatment₃O₄Material, the main reaction is: fe²⁺+Fe³⁺+8OH^-= Fe₃O₄+4H₂O,Fe²⁺And Fe³⁺Should be 1: 2, but because the inert gas is not used for protection in the preparation process, Fe²⁺Is very easy to be oxidized into Fe³⁺Therefore, Fe should be properly increased during the preparation process²⁺The optimal scheme of the magnetic performance can be judged by the color of the reaction liquid according to experimental experience:

TABLE 1 Fe prepared in different molar ratios for different colors₃O₄Magnetic fluid property determination

Fe²⁺：Fe³⁺	Colour(s)	Magnetic property
			2：1	Green colour	Is lower than
1：1	Black color	Height of
			2：3	Black color	Is higher than
1：2	Reddish brown color	Is low in

As shown in Table 1, when Fe²⁺And Fe³⁺Fe prepared at a ratio of 1:1₃O₄Presents black color, high purity and strongest displayed magnetic performance, and in addition, Fe is prepared²⁺And Fe³⁺Adding small amount of dilute hydrochloric acid to prevent Fe²⁺And Fe³⁺Hydrolyzing; the invention takes into account Fe²⁺And Fe³⁺Generating nano magnetic Fe₃O₄Certain amount of Fe in the process of loading on the surface of loaded mineral (soil)²⁺Will be oxidized into Fe³⁺Adjusting Fe²⁺And Fe³⁺A ratio; meanwhile, considering the complex components of the excrement or the biogas slurry and Fe²⁺Is not stableAnd (4) sex. Selected FeCl₃·6H₂O and FeCl₂·4H₂O configuration Fe²⁺And Fe³⁺The mixed solution has proper molar ratio of Fe²⁺: Fe³ ⁺=1:1-2：3。

The invention relates to a preparation method of a nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in excrement, sewage and biogas slurry wastewater, which is characterized in that a coating agent in a coating agent aqueous solution is one or more than two of sodium oleate, polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, gelatin, sodium dodecyl benzene sulfonate, sodium laurate and L-glutamic acid.

The invention relates to a preparation method of nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in excrement, biogas and liquid wastewater, and further, the mass volume concentration of the aqueous solution of the coating agent is 60-150 g/L.

The invention provides a preparation method of nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in excrement, biogas slurry and wastewater, and further the mineral soil comprises one or two of sepiolite, serpentine, natural zeolite, clinoptilolite, 4A zeolite molecular sieve, 5A zeolite molecular sieve, NaP1 type zeolite molecular sieve, bentonite, attapulgite, kaolin, diatomite, rare earth and the like.

The invention also provides a method for treating the fecal sewage and biogas slurry, which comprises the following steps:

step (10), pretreating by a struvite method to obtain a struvite fertilizer and supernatant waste liquid;

and (20) adding the supernatant liquid obtained in the step (10) into a reaction tank, adding the nano magnetic material loaded mineral soil when the concentration of the added liquid is 5.0-10.0g/L, starting a stirrer, stirring a water sample at the rotating speed of 100-500 r/min, continuously stirring for 20-40 min, and finally standing and precipitating to obtain the supernatant liquid meeting the production requirement of the liquid fertilizer.

The method for treating the fecal sewage and biogas slurry comprises the following steps:

step (101), filtering the feces and biogas slurry, injecting a certain volume of filtrate into the reaction tank, and adding the filtrate into the reaction tank

Adding phosphate into the reaction tank, and adjusting PO in the solution₄ ^3-：NH⁴⁺The molar ratio is 1: 1-1: 1.5; magnesium salt is added into the reaction tank to adjust Mg in the solution²⁺：NH⁴⁺The molar ratio is 1: 1-1: 1.5, stirring, continuously dropwise adding 1-5 mol/L NaOH into the reactor during stirring to control the pH value of the solution in the reaction tank to be 9.0-10.5, preferably 9.5-10.2, filtering the solution after reaction to obtain solid precipitate and supernatant waste liquid, wherein the solid precipitate is the struvite fertilizer.

The ammonia nitrogen, COD and BOD5 pollution indexes of the excrement and the biogas slurry are high, the BOC/COD value of the excrement and the biogas slurry is less than 0.20, and the microbial treatment condition is not met; aerobic microbial populations require BOD5 (C): n: p = 100: 5: 1, anaerobic microbial population requires BOD5 (C): n: p = 100: 6: 1, the carbon-nitrogen ratio (C/N) of the biogas slurry is disordered, and the biochemical treatment is high in cost and difficulty. The basic principle of treating the excrement and the biogas slurry by a struvite precipitation method is that a certain amount of magnesium salt and phosphorus salt are added into wastewater containing ammonia nitrogen to generate struvite precipitate under the alkaline condition,

the single struvite method is a chemical reaction method, and Mg is added²⁺And PO₄ ^3-The concentration is favorable for the reaction to proceed towards the formation of struvite. However, the addition of excessive phosphoric acid or phosphate will cause secondary pollution. The method is greatly influenced by chemical reaction conditions, has the defects of insufficient actual chemical reaction and large deviation from theoretical calculation, causes excessive reactants, especially excessive phosphoric acid, has large influence on soil and plant growth, has high relative cost of reactant materials and low ammonia nitrogen removal rate, and cannot be popularized in practical application.

The invention controls the reaction amount of the struvite method, controls the struvite method to reach the critical value of biochemical index after treatment, further removes COD and heavy metal by loading mineral soil with nano magnetic material, and further adopts the microbiological method to reach the optimal cost for treating the fecal sewage and the biogas slurry; that is, the present invention does not have the problem of excess reactant, and even if the reactant is in excess, the reactant can be used as a carbon source required by the subsequent biochemical reaction.

Selected n (Mg) of the invention²⁺)：n(NH⁴⁺) Is 1.25, n (PO)₄ ^3-)：n(NH⁴⁺) Is 1.15, and the ammonia nitrogen removal rate is highest when the stirring is 400 r/min.

The reaction based on the struvite has great influence on the stability, effect and cost of the whole system, and meanwhile, the struvite is greatly influenced by the complex components of the excrement and the biogas slurry, so that the control of the reaction parameters of the struvite is very important in the research process of the invention;

(1) the pH value has a great influence on the ammonia nitrogen index of the struvite and biogas slurry reduced by the struvite precipitation method, the difference between the existence form and the activity of each ion when the ion concentration product forming the struvite precipitate exceeds the corresponding solubility product is reflected, the precipitation reaction can only occur, when the pH value is less than 10.0, the ammonia nitrogen removal rate of the struvite and biogas slurry is increased along with the increase of the pH value, when the pH value is =10.2, the ammonia nitrogen removal rate of the struvite and biogas slurry is maximum and reaches 72.47%, and when the pH value is more than 10.2, the ammonia nitrogen removal rate of the struvite and biogas slurry is gradually reduced. The reaction mechanism shows that the ammonia nitrogen removal rate of the excrement and the biogas slurry is increased along with the increase of the pH and the forward reaction, and is reduced when the pH is more than 10.2 because Mg is contained in a medium-strong alkali system²⁺And OH^-、PO₄ ^3-Respectively generate Mg (OH)₂And Mg₃(PO₄)₂Decrease Mg in the solution²⁺And PO₄ ^3-The concentration of the organic fertilizer reduces the formation of struvite, so that the ammonia nitrogen removal rate of the excrement and the biogas slurry is reduced, and the optimum pH is determined to be 9.5-10.2 from the aspects of operation cost and treatment effect;

(2) and the ammonia nitrogen in the excrement and the biogas slurry is recovered by a struvite precipitation method, and the ammonia nitrogen removal effect is greatly influenced by the adding amount of different agents. The biogas slurry has complex components and is prepared according to a known proportion n (Mg)²⁺)：n(NH⁴⁺)：n(PO₄ ^3-) =1: 1:1, reaction, wherein the ammonia nitrogen removal rate of the feces and the biogas slurry is not ideal, and the ammonia nitrogen removal rate is improved by increasing the magnesium salt dosage according to the same ion effect; n (Mg)² ⁺)：n(NH⁴⁺) When the removal rate of ammonia nitrogen is increased from 1.0 to 1.20, the removal rate of ammonia nitrogen is increased from 56.32 percent to 73.34 percent, when n (Mg)²⁺)：n(NH⁴⁺) And when the removal rate is 1.25, the ammonia nitrogen removal rate reaches 76.58 percent at the maximum. Continue to increase n (Mg)²⁺)：n(NH⁴⁺) The ammonia nitrogen removal rate is rather decreased because of the excess Mg²⁺And PO₄ ^3-Formation of Mg₃(PO₄)₂So that the struvite precipitation is reduced; on the other hand, an excess of Mg is added² ⁺Increases the running cost and increases the hardness of the treated water, and therefore, the optimum n (Mg) is determined²⁺)：n(NH⁴⁺) Is 1.25; retention of n (Mg)²⁺)：n(NH⁴⁺) =1.25, since raw water contains a certain amount of phosphorus, n (PO) can be reduced appropriately₄ ^3-)：n(NH⁴⁺) When the amount of the ammonia nitrogen is increased from 0.65 to 1.15, the removal rate of the ammonia nitrogen in the excrement and biogas slurry is increased from 56.21 percent to 76.97 percent, and PO is continuously increased₄ ^3-The ammonia nitrogen removal rate is reduced by the adding amount of the catalyst;

(3) in addition, because the proportion of phosphate is larger in the cost of treating the ammonia nitrogen wastewater of the excrement and the biogas slurry by the struvite precipitation method, the dosage of the phosphate can be reduced to reduce the dosage cost on the premise of ensuring the treatment effect, and therefore, n (Mg)²⁺)：n(NH⁴⁺)：n(PO₄ ^3-) = 1.25: 1: 1.15; the reaction time is properly prolonged, the struvite crystallization effect is facilitated, the crystal development is promoted, the precipitate is separated out, and the ammonia nitrogen removal rate is 67.76% when the reaction is carried out for 20min, which indicates that the struvite precipitation reaction can be completed in a short time. The removal reached a maximum of 76.31% at 40min, after which the removal was reduced, presumably by precipitation back-dissolution. The ammonia nitrogen concentration is high when the reaction starts, the reaction mass transfer driving force is large, and the reaction is rapid. Along with the reaction, the ammonia nitrogen concentration of the excrement and the biogas slurry is reduced, the mass transfer driving force is reduced, and the reaction is slowed down. Although the reaction time has a large influence on the particle size of the struvite precipitate, the growth of the particle size of the precipitate has little influence on the ammonia nitrogen removal rate, so the reaction time is determined to be 40min;

(4) stirring rotating speed has great influence on ammonia nitrogen removal, mainly reflects that shearing force caused by different speed gradients is different, when the rotating speed is 100r/min, the ammonia nitrogen residual quantity of excrement and biogas slurry is reduced to 1025mg/L, and the removal rate is only 57.8%. The ammonia nitrogen removal rate gradually increases with the increase of the stirring speed, and the removal rate reaches the maximum value of 76.58% at 400 r/min. Because the stirring rotating speed is small, the turbulence degree is low, the medicament mixing effect is relatively poor, the possible collision frequency among ions is relatively small, the precipitate generation amount is small, the stirring rotating speed is increased, although the possible collision frequency among the ions is improved, the hydraulic shearing action weakens the crystallization, the crystals are fine, the struvite precipitate is not easy to settle, the ammonia nitrogen removal effect is further influenced, and the energy consumption is large due to the overhigh rotating speed, therefore, 400r/min is selected as the optimum rotating speed.

The method for treating the fecal sewage and biogas slurry comprises the following steps of₃PO₄、Na₂HPO₄、K₂HPO₄、Na₂HPO₄、K₂HPO₄、Na₃PO₄、K₃PO₄、NaH₂PO₄、KH₂PO₄One or more than two; the magnesium salt is MgO, Mg (OH)₂、MgCL₂6H₂O、MgSO₄、Mg(NO₃)₂One or more than two.

The invention also provides a liquid biological bacterial fertilizer which comprises the following raw materials in parts by weight: 1000 parts of supernatant obtained by the method for treating the manure and biogas slurry, 10 parts of EM probiotics, 50-100 parts of molasses, 10 parts of food industry waste liquid, 20 parts of humic acid, 3 parts of urea and 2 parts of monopotassium phosphate.

The invention adopts food industry waste liquid such as waste milk, amino acid waste liquid or bean curd factory water.

The invention also provides a preparation method of the liquid biological bacterial fertilizer, which comprises the following steps:

step (100), weighing raw materials according to the liquid biological bacterial fertilizer, dividing supernate into two parts, and adding

Adding molasses, and stirring to uniformly mix with the supernatant;

step (200), sequentially adding EM probiotics, food industry waste liquid, humic acid, urea and potassium dihydrogen phosphate according to parts by weight, intermittently stirring by adopting an electric spiral stirrer, and supplementing a first part of supernatant;

and (300) covering with cloth, fermenting, and obtaining the liquid biological bacterial fertilizer after foaming is stopped.

The EM probiotics can adopt conventional commercially available EM probiotics, and the content of microorganisms in the EM probiotics is 200 hundred million/g. The EM probiotics are mainly used for oxidizing and decomposing various toxic and harmful pollutants, purifying water quality and purifying environment through comprehensive actions such as oxidation reduction and the like; meanwhile, a large amount of beneficial substances which are easily absorbed by the passive plants, such as amino acids, organic acids, various vitamins, growth promoting factors, antibiotics and the like, can be generated, so that a benign ecological environment is created. The cultured and domesticated EM probiotics can be oxidized, decomposed and removed to remove various toxic and harmful pollutants such as phenol, cyanogen, benzene, naphthalene, lignin, ammonia nitrogen and the like. The purification capacity of a sewage treatment system is improved, the treatment efficiency is improved, the sludge production is reduced, and the sewage treatment cost is reduced; purifying the water quality of rivers, lakes and ponds to prevent eutrophication; purifying and repairing percolate, chemical and heavy metal polluted soil and petroleum polluted soil; eliminating foul smell, inhibiting proliferation of harmful pathogenic bacteria, and cleaning sewage.

The invention also provides a solid biological bacterial fertilizer which is prepared from 1000 parts by weight of the liquid biological bacterial fertilizer, 1-10 parts by weight of drought-resistant water-retaining agent and 10-50 parts by weight of modified mineral soil adsorbent compound fertilizer slow-release agent; the modified mineral soil adsorbent compound fertilizer slow release agent comprises an acetic acid solution, a modifier, a slow release agent and mineral soil, wherein 50-100g/L of the modifier is dissolved in the acetic acid solution; the mass ratio of the slow release agent to the mineral soil is 1/20-1/10; the mass ratio of the modifier to the premixed material of the mineral soil and the slow release agent is 1: 4-1: 12.

The preparation method of the solid biological bacterial fertilizer comprises the steps of weighing the raw materials in parts by weight, obtaining the raw materials according to the proportion, adopting a modified mineral soil adsorbent composite fertilizer slow release agent (physical adsorption), then utilizing a drought-resistant water-retaining agent (water absorption grease) to carry out chemical adsorption, and mainly utilizing the salt adsorption capacity of the modified mineral soil adsorbent to reduce the interference of the water absorption times of the drought-resistant water-retaining agent (water absorption grease).

Specifically, liquid biological bacterial manure is led into a magnetic dispersion machine with vacuum, the rotating speed is 1000r/min, modified mineral soil adsorbent compound fertilizer slow release agent with the formula amount is slowly added, stirring and adsorption are carried out under vacuum negative pressure and normal temperature, the specific vacuum negative pressure can be 0.05mpa, and stirring and adsorption are carried out for 2 hours at normal temperature (about 25 ℃); adjusting the rotating speed to 1000r/min, slowly adding the drought-resistant water-retaining agent (water absorbing grease) with the formula amount again, stirring and adsorbing for 2 hours at the normal temperature under the vacuum negative pressure of 0.05mpa to prepare the drought-resistant water-retaining agent and the composite mineral soil for adsorption to prepare the solid biological bacterial fertilizer.

The method is based on the adoption of physics (modified mineral soil adsorbent) and chemistry (drought-resistant water-retaining agent (water absorption ester)) to completely absorb the sewage and waste liquid and prepare the solid biological bacterial fertilizer, thereby solving the problems of direct discharge pollution, liquid transportation cost and storage safety. Adsorption methods can be divided into physical adsorption, chemical adsorption, exchange adsorption; physical adsorption mainly utilizes Van der Waals force, has small adsorption heat close to liquefaction heat, no selectivity and relatively small adsorption multiple, but has excellent salt resistance and excellent salt water adsorption capacity and can be a monomolecular layer or a polymolecular layer; compared with physical adsorption, chemical adsorption acting force depends on hydrogen bonds, released heat is large, a monomolecular layer is strong in selectivity, large in adsorption multiple (clear water), excellent in salt resistance and easy to biologically damage.

According to the solid biological bacterial fertilizer, the modifier is one or more than two of xanthan gum, chitosan, oligosaccharide, chitin, glucose, carboxymethyl chitosan, carboxymethyl fructose, carboxymethyl chitose, carboxymethyl inulin, carboxymethyl oligosaccharide, polyvinylpyrrolidone and the like.

The solid biological bacterial fertilizer further comprises an ammonia nitrogen slow-release agent and a phosphorus activator in a mass ratio of 1:1, wherein the ammonia nitrogen slow-release agent is any one or more of dicyandiamide, hydroquinone, thiourea, N-butyl thiophosphoryl triamide (nBPT) and Phenyl Phosphorodiamidate (PPD); the phosphorus activator is one or more of rare earth, oxalic acid, tartaric acid, citric acid, malic acid, humic acid and EDTA.

The manure and the biogas slurry are rich in nutrient elements such as nitrogen, phosphorus and potassium, exist in a quick-acting state, have high absorption rate and are indispensable components in the plant growth process. The seedling burning phenomenon can be caused by the excessive direct utilization of the excrement and the biogas slurry, mainly the seedling burning caused by high ammonia nitrogen, so that the nitrogen in the excrement and the biogas slurry needs to be inhibited and released; by adopting the ammonia nitrogen slow release agent and the phosphorus activator, the main components of the ammonia nitrogen slow release agent are urease inhibitor, nitrification inhibitor and other auxiliary components, which can inhibit the activity of urease in soil and inhibit the nitrification and denitrification of microbial flora such as nitrobacteria and the like, thereby further achieving the purposes of slowing down the decomposition speed of nitrogen, reducing the volatilization of ammonia and the loss of nitrate and nitrite, reducing the pollution to the environment and simultaneously well improving the utilization rate of nitrogen. The complex of the phosphorus activator and the organic-inorganic substance in the soil micro-ecological environment can reduce the fixation of phosphorus and activate slow-acting phosphorus to be converted into quick-acting phosphorus, thereby improving the utilization rate of phosphate fertilizer; phosphorus is one of essential nutrient elements for plant growth and development and is a non-renewable resource, the phosphorus generally exists in a salt form, the utilization rate is low, the phosphorus utilization rate is improved by adopting a phosphorus activator, and the mineral soil and zeolite have the advantages of porosity, large specific surface area, light weight, strong adsorption capacity, ammonium ion adsorption, capacity of improving the utilization rate of a phosphate fertilizer, soil fertility and fertilizer efficiency increase.

The invention relates to the solid biological bacterial fertilizer, and further relates to a preparation method of the modified mineral soil adsorbent compound fertilizer slow-release agent, which comprises the steps of dissolving the modifier in an acid solution according to the mass-volume ratio of 50-100g/L, fully stirring and dissolving, weighing a premixture of the mineral soil and the slow-release agent (the mass ratio of the slow-release agent to the mineral soil is 1/20-1/10), adding the premixture of the modifier to the mineral soil and the slow-release agent (the mass ratio of the premixture of the modifier to the mineral soil to the slow-release agent is 1: 4-1: 12) into the solution, fully stirring at high speed (1000 r/min,60 min) to obtain a black paste solution, drying (60 ℃), grinding and crushing. Specifically, the acetic acid solution is a 1% acetic acid solution with a mass concentration selectable.

The invention relates to the solid biological bacterial fertilizer, and further the drought-resistant water-retaining agent is prepared from the following raw materials: acrylic acid, a modifier, an acetic acid solution, ammonium persulfate, methylene diacryloyl and ethanol; the mass ratio of the acrylic acid to the modifier is 9.0-11.0; the mass ratio of the methylene diacryloyl to the acrylic acid is 0.0016, and the mass ratio of the ammonium persulfate to the acrylic acid is 0.033; the mass volume ratio of the modifier to the acetic acid solution is 10-25 g/L; the adding amount of the ethanol is 50 percent of the volume of the total solution; the modifier is one or more than two of xanthan gum, chitosan, oligosaccharide, chitin, glucose, carboxymethyl chitosan, carboxymethyl fructose, carboxymethyl chitose, carboxymethyl inulin, carboxymethyl oligosaccharide, and polyvinylpyrrolidone.

Specifically, adding modifier into acetic acid solution (preferably acetic acid solution), placing in a reaction kettle equipped with a stirring device, heating in water bath, and adding N₂Stirring under the protection of the (1) to fully dissolve the modifier, adding ammonium persulfate, adding acrylic acid and methylene-bisacryloyl to start reaction after 30min, reacting for a certain time (4-6 h) at a constant temperature (60-70 ℃), stopping the reaction, adding 50% ethanol of the total solution volume into a reaction kettle, stirring at a high speed, slowly adding NaOH aqueous solution (preferably with the mass volume concentration of 20%) to adjust the pH value to 7.0, performing suction filtration, dispersing the precipitate in ethanol (the mass volume ratio of the precipitate to the ethanol is 300 g/L), stirring at a high speed, fully washing the precipitate, performing suction filtration, repeatedly washing for 3 times, soaking for 24h with a mixed solvent of ethanol and distilled water (the volume ratio is 4: 1), performing suction filtration, and performing vacuum drying and crushing on the filter cake to obtain the super absorbent resin, namely the drought water retention agent.

The invention adopts the physical (modified mineral soil adsorbent) to absorb the sewage by 200-one (100-one), the chemical (drought-resistant water-retaining agent (water absorption grease)) to absorb the sewage by 1250-one (1180-one), and the salt water absorption by 400-one (200-one).

The adsorption capacity of the modified mineral soil adsorbent on sewage is greatly influenced by parameters, the mass ratio of the modifier to the composite mineral soil (the premix of the mineral soil and the sustained-release agent) is 1: 4-1: 12, and the sewage absorption rate is more than or equal to 90 percent of the maximum sewage absorption rate; at room temperature, the sewage absorption rate is increased quickly from the beginning of adsorption to the adsorption reaction for 90min, and after 90min, the sewage absorption rate is increased slowly, and the adsorption tends to be balanced; the pH value of the liquid biological bacterial fertilizer in the system is less than or equal to 6.0, the pH value of sewage is an important factor influencing the adsorption effect, the pH value is less than or equal to 6.0, the sewage absorption multiple is highest, the sewage absorption rate is more than or equal to 90 percent of the total sewage absorption rate, the sewage absorption multiple is reduced along with the increase of the pH value of the solution, and the modified mineral soil adsorbent composite fertilizer slow-release agent and the drought-resistant water-retaining agent adopt acid solution to promote the sewage absorption rate of the mineral soil adsorbent.

The modifier adopted in the drought-resistant water-retaining agent is alkali-resistant and corrosion-resistant, is an environmentally-friendly amphoteric polyelectrolyte type flocculant, has excellent performances of good biocompatibility, salt resistance, antibacterial property, virus resistance, biological invasion prevention, degradability and the like, has selective antibacterial property, mainly inhibits escherichia coli, staphylococcus aureus, yersinia enterocolitica, salmonella typhimurium and listeria monocytogenes, and is suitable for environments with complicated components of feces and biogas slurry; preparing the high water absorption resin by taking the modifier as a raw material, wherein the parameters are as follows:

the super absorbent resin used for sewage is a micro-crosslinked type resin, and must have a suitable degree of crosslinking. When the dosage of the cross-linking agent is less, the cross-linking degree of the resin is small, the water solubility is good, the water absorption is low, the saline water resistance is poor, and the corrosion resistance and the biological invasion resistance are poor; meanwhile, the three-dimensional network enables the monomers and the free radicals to be surrounded by the network formed in the initial stage, the fluidity is weakened, the collision probability of the free radicals is reduced, the molecular weight of the grafted branched chain is increased, the water absorption rate, the saline resistance, the corrosion resistance and the biological invasion capacity of the resin are further improved, and the water absorption rate, the saline resistance, the corrosion resistance and the biological invasion capacity are maximized when the mass ratio of the MBAM to the AA is about 0.16%.

However, if the amount of the cross-linking agent is continuously increased, the cross-linking density of the resin is too high, the relaxation of the network is limited, water is difficult to enter the resin from the surface of the resin, the swelling degree of the resin is reduced on the contrary, and the water absorption multiple is reduced; when the amount of the initiator is small, the water absorption of the resin is not high. This is because less initiator generates fewer grafting points on the main chain of the modifier, which is not favorable for forming water-absorbing network, and the reaction speed is relatively slow, which affects the polymerization and crosslinking reaction; with the increase of the using amount of the initiator, the reaction rate is increased, active groups generated on the molecular chain of the modifier are increased, the formation of a three-dimensional network is facilitated, and the water absorption of the product is increased.

When the mass ratio of the initiator to AA is 3.3 percent, the resin has the highest water absorption rate, salt water resistance, corrosion resistance and biological invasion resistance; when m (aa): when m (modifier) < 9.0, the water absorption rate increases with the increase of the ratio, because with the increase of the monomer concentration, enough monomers can react with the free radicals on the molecular chain of the modifier, the graft copolymerization reaction is accelerated, the reaction is more sufficient, the formation of a three-dimensional network of the resin is facilitated, meanwhile, the water absorption performance of the generated resin is improved due to the increase of the hydrophilic carboxyl content, when m (AA): when m (modifier) > 10.0, the water absorption rate decreases as the ratio increases. This is probably because the more AA content, the higher molecular weight of the polymerized side chain, the higher viscosity of the system, which hinders the movement of molecules or free radicals and easily causes the polymerization, and at the same time, the polymer molecular chains are easily entangled, which improves the degree of crosslinking and further reduces the water absorption of the product. When m (aa): m (modifier) =9.0-11.0, the water absorption of the product is maximum, and the salt water resistance, corrosion resistance and biological invasion resistance are maximum.

Detailed Description

The principles and features of this invention are described below in conjunction with embodiments, which are included to explain the invention and not to limit the scope of the invention.

Example 1

Raw water is biogas slurry generated by anaerobic digestion of aquaculture wastewater in a certain Yinchuan cattle farm, filter cloth is used for filtering before the test to remove large-particle suspended matters in the biogas slurry, and the water quality of a water sample after filtering is shown in a table 1-1.

TABLE 1-1 test raw Water quality

Item	Unit of	Raw water index data
			pH		9.20
NH₃-N	mg/L	2685
			COD	mg/L	1972
BOD5	mg/L	240
			TP	mg/L	101
Electrical conductivity of	ms.cm^-1	39.80
			Turbidity of water	NTU	56.70
Total lead	mg/L	13.40
			Total cadmium	mg/L	1.08
Total mercury	mg/L	1.50
			Total chromium	mg/L	9.10
Arsenic (As)	mg/L	7.32
			Nickel (II)	mg/L	27.70

1. Firstly, the fecal sewage or biogas slurry is filtered, 1000mL of filtrate is injected into a reaction tank, and KH-containing KH is put into the reaction tank₂PO₄Adjusting PO in the solution₄ ^3-：NH⁴⁺=1:1 (molar ratio) and MgCL is put into a reaction tank₂6H₂O, adjusting Mg in the solution²⁺：NH⁴⁺= 1.1: 1 (molar ratio), stirring at a certain rotating speed of 200r/min, continuously dropwise adding 1mol/L NaOH into the reactor during stirring, respectively controlling the pH values of the solutions in the reaction tanks to be 9.5, and filtering the solutions after reacting for 30 min. The solid precipitate, i.e., struvite fertilizer F1, remained, and the supernatant liquid left behind was filtered for further processing.

TABLE 1-2 indexes of waste liquid before and after struvite or biogas slurry treatment by struvite method

Item	Unit of	Raw water index data	Index after treatment by struvite method	The index is reduced by percentage%
					pH		9.20	8.90	3.3
NH₃-N	mg/L	2685	298.2	90.6
					COD	mg/L	1972	1325.0	32.8
BOD5	mg/L	240	210	12.5
					TP	mg/L	201	74	63.2
Total lead	mg/L	13.40	0.85	93.7
					Total cadmium	mg/L	1.08	0.76	30.5
Total mercury	mg/L	1.50	1.19	20.7
					Total chromium	mg/L	9.10	8.5	65.9
Arsenic (As)	mg/L	7.32	6.85	64.4
					Nickel (II)	mg/L	27.70	26.10	5.7

TABLE 1-3 physical and chemical indexes of struvite fertilizer F1

Item	Unit of	Detecting a value
			Total nitrogen	%	≥12.0
All-phosphorus	%	≥18.0
			Soluble phosphorus	%	≥10.0
Calcium carbonate	%	≥30.0
			Potassium salt	%	≥2.0
Density of	g/cm³	≥1.65

2. Adding 1000mL of the supernatant obtained in the step 1 into a reaction tank, adding a magnetic-load 4A zeolite molecular sieve when the weight of the supernatant is 5.0g, starting a stirrer, stirring a water sample at the rotating speed of 100r/min, continuously stirring for 30min, standing for precipitation for 40min, extracting the supernatant by using an injection syringe, and then performing water quality analysis.

2.1 weighing 40g FeCl₂4H₂O and 54.2gFeCl₃6H₂O was dissolved in 1000ml of distilled water, respectively. Mixing the two solutions, heating to 60 deg.C, ultrasonically shaking for 5min, and magnetically stirring at 60 deg.C (rotation speed of 1000 r/min). Then 2moL/L NH is added₃.H₂O solution (25% concentration), continuously adding NH dropwise after the solution is completely blackened₃.H₂Reacting the O solution for 1 hour until the pH value of the solution is about 11.5 to ensure that the Fe₃O₄Fully curing, and naturally cooling to room temperature. Magnetic separation (placing the solution after reaction on a magnet to accelerate the precipitation of magnetic particles) and washing with distilled water for 1-2h to obtain nano Fe₃O₄Magnetic fine particles; stirring again to disperse the nano Fe₃O₄100g of magnetic particles are put into 1000mL of deionized water and ultrasonically shaken for 15min, and 60g of ethylene glycol is added into the aqueous solution at the temperature of 80 ℃. Reacting for 30min to make Fe₃O₄Fully adsorbing, cooling and preparing into nano Fe₃O₄10% by mass of magnetic fluid; adding 10g of 4A zeolite molecular sieve into 1000mL of deionized water to prepare suspension, and adding nano Fe₃O₄Dispersing 10g of magnetic fluid by ultrasonic oscillation for 10min, introducing a crystalloid reaction, crystallizing for 7h at 90 ℃ in a kettle, washing the product with distilled water until the pH value is 7, and drying to obtain Fe₃O₄The nano magnetic load 4A zeolite molecular sieve with the load of 10 percent, namely the nano magnetic material load mineral soil.

TABLE 1-4. indexes of wastewater before and after treatment of nano magnetic material loaded mineral soil

TABLE 1-5. Fe₃O₄And the magnetic performance parameters of the nano magnetic load 4A zeolite molecular sieve

Zeolite molecular sieve A0-4A; A1-Fe₃O₄(ii) a A2-example 1

3. (without heavy metal pollution) liquid biological bacterial manure F2

3.1 the liquid biological bacterial fertilizer F2 comprises the following raw materials in parts by weight: 1000kg of supernatant obtained in the step 2, 10kg of EM probiotics (commercially available), 50kg of molasses, 10kg of waste milk, 20kg of humic acid, 3kg of urea and 2kg of monopotassium phosphate;

the manufacturing steps are as follows:

(1) the large-scale pond for manufacturing the liquid fertilizer is thoroughly cleaned, and if the large-scale pond is not used for a long time, the large-scale pond is cleaned by bleaching water firstly, and then the bleaching water is washed by clear water.

(2) Adding 500kg of the supernatant obtained in the step 1 according to the formula, pouring molasses into the supernatant, and stirring the mixture with force to ensure that the molasses is completely mixed with the supernatant obtained in the step 1.

(3) The EM probiotic stock solution is added, and any commercially available EM probiotic can be selected.

(4) Sequentially adding molasses, waste milk, humic acid, urea and potassium dihydrogen phosphate according to the proportion, intermittently stirring by using an electric spiral stirrer, and supplementing and adding 500kg of the supernatant in the step 1.

(5) The band is covered with a cleaning cloth to prevent the invasion of insects.

(6) And (4) producing a large amount of bubbles after fermenting for about one week, and obtaining the liquid biological bacterial manure F2 after the foaming stops (about three weeks later).

TABLE 1-6 indexes of liquid biological bacterial manure

3.2 planting experiment of liquid biological bacterial manure F2

1) And test time: 05 months in 2017-10 months in 2017;

2) and a place: a phase change heat storage greenhouse vegetable base for a beautiful and beautiful road agricultural science and technology industrial park in Ningxia Yinchuan city.

3) And test design: seed soaking test and test treatment: CK, clear water (blank control); f2-1 is the liquid biological bacterial fertilizer F2 prepared from the fermentation biogas slurry in the step 3.

TABLE 1-7 application effect data of liquid biological bacterial manure

4. Taking 1000kg of the F2 liquid biological bacterial manure 3, 6.0kg of xanthan gum and acrylic acid super absorbent resin, 20kg of xanthan gum modified attapulgite adsorbent and N-butyl thiophosphoric triamide (nBPT) and 50kg of citric acid; the preparation process comprises the following steps: introducing F2 liquid biological bacterial manure into a magnetic dispersion machine with vacuum, rotating at 1000r/min, slowly adding a premix of xanthan gum modified attapulgite adsorbent and N-butyl thiophosphoryl triamide (nBPT), stirring and adsorbing for 2h at the normal temperature under the vacuum negative pressure of 0.05 mpa; regulating the rotating speed to 1000r/min, slowly adding the xanthan gum and the acrylic acid super absorbent resin according to the formula amount again, stirring and adsorbing for 2 hours at the normal temperature under the vacuum negative pressure of 0.05mpa, and preparing the xanthan gum and acrylic acid super absorbent resin and the attapulgite solid biological bacterial fertilizer F3.

4.1 preparation of Xanthan Gum modified Attapulgite adsorbent composite N-butyl thiophosphoric triamide (nBPT) and citric acid

Firstly preparing 1 percent acetic acid solution by mass fraction, then weighing 50g of xanthan gum to be dissolved in 1000mL of 1 percent acetic acid solution, fully stirring and dissolving,

a pre-mixture of 500g of attapulgite, 12.5g of N-butyl thiophosphoric triamide (nBPT) and 12.5g of citric acid is weighed and added into the solution, then the solution is fully stirred at high speed (1000 r/min) for 60min to obtain a black paste, and the black paste is dried at 60 ℃ and ground.

4.2 preparation of Xanthan Gum composite acrylic acid super absorbent resin

Weighing a certain amount of 50g of xanthan gum, adding the xanthan gum into 2000ml of 2% acetic acid solution, and placing the solution with stirringIn a reaction kettle, heating in water bath, and reacting in N₂Stirring under the protection of the (1) to fully dissolve the modifier, adding 16.5g of ammonium persulfate APS, stirring for 30min, adding 500g of acrylic acid and 0.8g of methylene bisacryloyl MBAM, reacting for 4h at a constant temperature of 60 ℃, stopping the reaction, adding ethanol with the volume of 50% of the total solution into a reaction kettle, stirring at a high speed, slowly adding 20% NaOH aqueous solution to adjust the pH value to 7.0, performing suction filtration to obtain a precipitate, dispersing 300g of the precipitate into 1000ml of ethanol, stirring at a high speed, fully washing the precipitate, performing suction filtration, repeatedly washing for 3 times, soaking for 24h by using 1000ml of a mixed solvent (the volume ratio is 4: 1) of ethanol and distilled water, performing suction filtration, performing vacuum drying on a filter cake, and crushing to obtain the xanthan gum composite acrylic acid super absorbent resin.

TABLE 1-8 indexes of xanthan gum modified attapulgite adsorbent

Item	Index (I)
		Appearance of the product	Yellow powder
Maximum water absorption multiple g/g (pure water)	200
		Water absorption multiple g/g (biogas slurry)	180
Absorption rate of methyl orange solution (concentration 50g/ml)	120
		Water absorption saturation time min	≤100

TABLE 1-9. Xanthan Gum composite acrylic acid super absorbent resin

Item	Index (I)
		Appearance of the product	Light yellow powder
Maximum water absorption multiple g/g (pure water)	1150
		Water absorption multiple g/g (biogas slurry)	200
Absorption rate of methyl orange solution (concentration 50g/ml)	600
		Water absorption saturation time min	≤100

TABLE 1-10. Xanthan gum, acrylic acid composite super absorbent resin and attapulgite solid biological bacterial manure F3

4.3 planting experiment of solid biological bacterial manure F3

1) And test time: 05 months in 2017-10 months in 2017;

3) And test design: planting test, test treatment: CK, 500kg of compound fertilizer (N15-P15-K15) is applied per mu; f3+ compound fertilizer (N15-P15-K15) =500kg is applied per mu, and base fertilizer, additional fertilizer, irrigation application and management conditions are the same

TABLE 1-11 experiment of application effect of solid biological bacterial fertilizer

Example 2

The raw water is biogas slurry generated by anaerobic digestion of aquaculture wastewater in a certain Yinchuan cattle farm, the biogas slurry is filtered by using filter cloth before the test to remove large-particle suspended matters in the biogas slurry, and the water quality of a filtered water sample is shown in a table 2-1.

TABLE 2-1 quality of raw Water

1. Firstly, the fecal sewage or biogas slurry is filtered, 1000mL of filtrate is injected into a reaction tank, and KH-containing KH is put into the reaction tank₂PO₄Adjusting PO in the solution₄ ^3-：NH⁴⁺= 1.25: 1 (molar ratio) and MgCL is put into a reaction tank₂6H₂O, adjusting Mg in the solution²⁺：NH⁴⁺= 1.15: 1 (molar ratio), stirring at a certain rotating speed of 600 revolutions per minute, continuously dropwise adding 1mol/L NaOH into the reactor during stirring, respectively controlling the pH values of the solutions in the reaction tanks at 10.2, and filtering the solutions after reacting for 30 min. The solid precipitate, i.e., struvite fertilizer F1, remained, and the supernatant liquid left behind was filtered for further processing.

TABLE 2-2 indexes of waste liquid before and after struvite or biogas slurry treatment by struvite method

Item	Unit of	Raw water index data	Index after treatment by struvite method	The index is reduced by percentage%
					PH		9.20	8.0	13.0
NH³-N	mg/L	2685	209.8	92.2
					COD	mg/L	1972	1127.0	43.0
BOD5	mg/L	240	196	18.30
					TP	mg/L	201	130.65	35.0
Total lead	mg/L	13.40	8.04	40.0
					Total cadmium	mg/L	1.08	0.78	27.8
Total mercury	mg/L	1.50	1.07	28.6
					Total chromium	mg/L	9.10	8.3	8.8
Arsenic (As)	mg/L	7.32	6.7	8.5
					Nickel (II)	mg/L	27.70	23.10	16.6

TABLE 2-3 physical and chemical indexes of struvite fertilizer F1

Item	Unit of	Detecting a value
			Total nitrogen	%	≥15.0
All-phosphorus	%	≥20.0
			Soluble phosphorus	%	≥14.0
Calcium carbonate	%	≥28.0
			Potassium salt	%	≥2.8
Density of	g/cm³	≥1.63

2. Adding 1000mL of the supernatant obtained in the step 1 into a reaction tank, adding 10g of a magnetic load 5A zeolite molecular sieve, starting a stirrer, stirring a water sample at a rotating speed of 500r/min, continuously stirring for 40min, standing for precipitation for 40min, extracting the supernatant by using an injection syringe, and then performing water quality analysis.

2.1 weighing 39.8g FeCl₂4H₂O and 54.0gFeCl₃6H₂O was dissolved in 1000ml of distilled water, respectively. Mixing the two solutions, heating to 60 deg.C, ultrasonically shaking for 5min, and magnetically stirring at 60 deg.C (rotation speed of 1000 r/min). Then 2moL/L NH is added₃.H₂O solution (25% concentration), continuously adding NH dropwise after the solution is completely blackened₃.H₂Reacting the O solution for 1 hour until the pH value of the solution is about 11.5 to ensure that the Fe₃O₄Fully curing, and naturally cooling to room temperature. Magnetic separation (placing the solution after reaction on a magnet to accelerate the precipitation of magnetic particles) and washing with distilled water for 2h to obtain nano Fe₃O₄Magnetic fine particles; stirring again to disperse the nano Fe₃O₄500g of magnetic particles are put into 1000mL of deionized water and ultrasonically shaken for 15min, and 100g of sodium acetate is added into the water solution under the condition of 80 ℃. Reacting for 30min to make Fe₃O₄Fully adsorbing, cooling and preparing into nano Fe₃O₄50% by mass of magnetic fluid; adding 100g of 5A zeolite molecular sieve into 1000mL of deionized water to prepare suspension, and adding nano Fe₃O₄Dispersing 50g of magnetic fluid by ultrasonic oscillation for 10min, introducing a crystalloid reaction, crystallizing for 7h at 90 ℃ in a kettle, washing the product by distilled water until the pH value is 7, and drying to obtain Fe₃O₄Nano magnetic load 5A zeolite molecular sieve with 25% loading

TABLE 2-4. wastewater indexes before and after treatment of nano magnetic material loaded mineral soil

TABLE 2-5. Fe₃O₄And the magnetic performance parameters of the nano magnetic load 5A zeolite molecular sieve

Zeolite molecular sieve A0-5A; A1-Fe₃O₄(ii) a A2-example 2

3. (without heavy metal pollution) liquid biological bacterial manure F2

3.1 the liquid biological bacterial fertilizer F2 comprises the following raw materials in parts by weight: 1000kg of supernatant obtained in the step 2, 10kg of EM probiotics (commercially available), 100kg of molasses, 10kg of waste milk, 20kg of humic acid, 3kg of urea and 2kg of monopotassium phosphate;

the manufacturing steps are as follows:

(3) Adding EM probiotic bacteria stock solution.

(4) Sequentially adding molasses, amino acid waste liquid, humic acid, urea and potassium dihydrogen phosphate according to the proportion, intermittently stirring by using an electric spiral stirrer, and supplementing and adding 500kg of the supernatant in the step 1.

TABLE 2-6 indexes of liquid biological bacterial manure

3.2 planting experiment of liquid biological bacterial manure F2

1) And test time: 05 months in 2017-10 months in 2017;

TABLE 2-7 application effect data of liquid biological bacterial manure

Species of crop	The seed soaking concentration%	Seed soaking time h	Effect (contrast CK)
				Tomato	30	12	The stem height and the number of fibrous roots are respectively increased by 29.13 percent and 16.19 percent
Outdoor eggplant	100	24	The emergence rate is improved by 11.80 percent
				Corn (corn)	20	24	The bud length, stem thickness and root length are respectively increased by 1.82 times, 0.75 times and 1.95 times
Rice (Oryza sativa L.) with improved resistance to stress	100	10	The yield is improved by 7.63 percent, and the morbidity is reduced
				Radix bupleuri	100	24	The germination rate is improved by 31.35 percent
Oil peony	100	24	The germination rate is improved by 32.88 percent

4. Taking 1000kg of the F2 liquid biological bacterial fertilizer, 5.0kg of chitosan composite acrylic acid super absorbent resin and chitosan modified silicon in the amount of the mixture in the step 3

30kg of diatomite adsorbent Phenyl Phosphorodiamidate (PPD) and 30kg of humic acid; [ PREPARATION TECHNOLOGY ]: introducing the F2 liquid biological bacterial manure into a magnetic dispersion machine with vacuum, rotating at 1000r/min, slowly adding the premixture of chitosan modified diatomite adsorbent and Phenyl Phosphorodiamidate (PPD), stirring and adsorbing for 2h at the normal temperature under the vacuum negative pressure of 0.05 mpa; adjusting the rotation speed to 1000r/min, slowly adding the chitosan composite acrylic acid super absorbent resin with the formula amount again, stirring and adsorbing for 2h at the normal temperature under the vacuum negative pressure of 0.05mpa to obtain the chitosan composite acrylic acid super absorbent resin and diatomite

4.1 preparation of Chitosan-modified diatomaceous-earth adsorbent composite Phenyl Phosphorodiamidate (PPD) and humic acid

Firstly, preparing an acetic acid solution with the mass fraction of 1%, then weighing 100g of chitosan, dissolving the chitosan in 2000mL of 1% acetic acid solution, fully stirring and dissolving, weighing 1200g of diatomite, 30g of Phenyl Phosphorodiamidate (PPD) and 30g of humic acid, adding the premixture into the solution, fully stirring at a high speed (1000 r/min) for 60min, enabling the solution to be black paste, drying at 60 ℃, grinding and crushing;

4.2 preparation of Chitosan composite acrylic acid super absorbent resin

Weighing a certain amount of 100g of chitosan, adding the chitosan into 4000ml of 2% acetic acid solution, placing the mixture into a reaction kettle with a stirring device, heating the mixture in water bath, and adding N₂Stirring under the protection of the above to fully dissolve the modifier, adding 36.3g of ammonium persulfate APS, stirring for 30min, adding 1100g of acrylic acid and 1.76g of methylene bisacryloyl MBAM, reacting at a constant temperature of 60 ℃ for 5h, stopping the reaction, adding ethanol with the volume of 50% of the total solution into a reaction kettle, stirring at a high speed, slowly adding 20% NaOH aqueous solution to adjust the pH value to 7.0, performing suction filtration to obtain a precipitate, dispersing 1000g of the precipitate into 3000ml of ethanol, stirring at a high speed, fully washing the precipitate, performing suction filtration, repeatedly washing for 3 times, soaking for 24h by using 3000ml of a mixed solvent (the volume ratio is 4: 1) of ethanol and distilled water, performing suction filtration, performing vacuum drying on a filter cake, and crushing to obtain the chitosan composite acrylic acid super absorbent resin

TABLE 2-8 indexes of chitosan modified diatomaceous earth adsorbents

Item	Index (I)
		Appearance of the product	Grey powder
Maximum water absorption multiple g/g (pure water)	400
		Water absorption multiple g/g (biogas slurry)	320
Absorption rate of methyl orange solution (concentration 50g/ml)	280
		Water absorption saturation time min	≤60

TABLE 2-9. Chitosan composite acrylic acid super absorbent resin

Item	Index (I)
		Appearance of the product	Grey powder
Maximum water absorption multiple g/g (pure water)	1250
		Water absorption multiple g/g (marsh)Liquid)	480
Absorption rate of methyl orange solution (concentration 50g/ml)	800
		Water absorption saturation time min	≤30

TABLE 2-10 solid biological bacterial manure F3 made of chitosan composite acrylic acid super absorbent resin and diatomite

4.3 planting experiment of solid biological bacterial manure F3

1) And test time: 05 months in 2017-10 months in 2017;

3) And test design: planting test, test treatment: CK, 500kg of compound fertilizer (N15-P15-K15) is applied per mu; f3+ compound fertilizer (N15-P15-K15) =500kg is applied per mu, and base fertilizer, additional fertilizer, flushing application and management conditions are the same.

TABLE 2-11 application effect experiment of solid biological bacterial fertilizer

Example 3

The raw water is the breeding excrement of a Lingwu cattle farm, the large-particle suspended matters in the breeding excrement are removed by filtering with filter cloth before the test, and the water quality of the filtered water sample is shown in a table 3-1.

TABLE 3-1 quality of raw Water

Item	Unit of	Raw water index data
			PH		9.60
NH3-N	mg/L	3367
			COD	mg/L	2564
BOD5	mg/L	320
			TP	mg/L	167
Electrical conductivity of	ms.cm^-1	40.11
			Turbidity of water	NTU	57.30
Total lead	mg/L	11.50
			Total cadmium	mg/L	1.12
Total mercury	mg/L	1.16
			Total chromium	mg/L	8.90
Arsenic (As)	mg/L	7.33
			Nickel (II)	mg/L	26.5

1. Firstly, the fecal sewage or biogas slurry is filtered, 1000mL of filtrate is injected into a reaction tank, and KH-containing KH is put into the reaction tank₂PO₄Adjusting PO in the solution₄ ^3-：NH⁴⁺= 1.2: 1 (molar ratio) and MgCL is put into a reaction tank₂6H₂O, adjusting Mg in the solution²⁺：NH⁴⁺= 1.05: 1 (molar ratio) and stirring at a certain rotating speed of 800 rpm), continuously dropwise adding 1mol/L NaOH into the reactor during stirring, controlling the pH values of the solutions in the reaction tanks to be 10.0 respectively, reacting for 30min, and filtering the solutions. The solid precipitate, i.e., struvite fertilizer F1, remained, and the supernatant liquid left behind was filtered for further processing.

TABLE 3-2 indexes of waste liquid before and after struvite or biogas slurry treatment by struvite method

Item	Unit of	Raw water index data	Index after treatment by struvite method	The index is reduced by percentage%
					pH		9.60	7.9	17.7
NH₃-N	mg/L	3367	412.6	87.7
					COD	mg/L	2564	1253.8	51.1
BOD5	mg/L	320	224	30.0
					TP	mg/L	167	133.6	20.0
Total lead	mg/L	11.50	3.45	30
					Total cadmium	mg/L	1.12	0.83	25.9
Total mercury	mg/L	1.16	0.75	35.3
					Total chromium	mg/L	8.90	4.01	54.9
Arsenic (As)	mg/L	7.33	3.25	55.7
					Nickel (II)	mg/L	26.5	18.7	29.4

TABLE 3-3 physical and chemical indexes of struvite fertilizer F1

Item	Unit of	Detecting a value
			Total nitrogen	%	≥9.0
All-phosphorus	%	≥21.0
			Soluble phosphorus	%	≥12.0
Calcium carbonate	%	≥26.0
			Potassium salt	%	≥1.6
Density of	g/cm³	≥1.70

2. Adding 1000mL of the supernatant obtained in the step 1 into a reaction tank, adding magnetic load bentonite when 7.5g of the supernatant is added, starting a stirrer, stirring a water sample at a rotating speed of 300r/min, continuously stirring for 20min, standing for precipitation for 40min, extracting the supernatant by using an injection syringe, and then performing water quality analysis.

2.1 weighing 30g FeCl₂4H₂O and 60gFeCl₃6H₂O was dissolved in 1000ml of distilled water, respectively. Mixing the two solutions, heating to 60 deg.C, ultrasonically shaking for 5min, and magnetically stirring at 60 deg.C (rotation speed of 1000 r/min). Then 2moL/L NH is added₃.H₂O solution (25% concentration), continuously adding NH dropwise after the solution is completely blackened₃.H₂Reacting the O solution for 1 hour until the pH value of the solution is about 11.5 to ensure that the Fe₃O₄Fully curing, and naturally cooling to room temperature. Magnetic separation (placing the solution after reaction on a magnet to accelerate the precipitation of magnetic particles) and washing with distilled water for 1-2h to obtain nano Fe₃O₄Magnetic fine particles; stirring again to disperse the nano Fe₃O₄300g of magnetic particles are put into 1000mL of deionized water and ultrasonically shaken for 15min, and 150g of sodium dodecyl benzene sulfonate is added into the aqueous solution at the temperature of 80 ℃. Reacting for 30min to make Fe₃O₄Fully adsorbing, cooling and preparing into nano Fe₃O₄30% by mass of magnetic fluid; adding 25g of bentonite into 1000mL of deionized water to prepare suspension, and adding nano Fe₃O₄Dispersing 18 g of magnetic fluid by ultrasonic oscillation for 10min, introducing a crystalloid reaction, crystallizing for 7h at 90 ℃ in a kettle, washing the product by distilled water until the pH value is 7, and drying to obtain Fe₃O₄Nano magnetic load bentonite with load of 21.6 percent

TABLE 3-4. wastewater indexes before and after treatment of nano magnetic material loaded mineral soil

Tables 3-5.Fe₃O₄And magnetic performance parameters of the nano magnetic load bentonite

A0-Bentonite; A1-Fe₃O₄(ii) a A2-example 3

3. (without heavy metal pollution) liquid biological bacterial manure F2

3.1 the liquid biological bacterial fertilizer F2 comprises the following raw materials in parts by weight: 1000kg of supernatant in the step 2, 10kg of EM probiotics (commercially available), 50kg of molasses, 10kg of bean curd waste liquid, 20kg of humic acid, 3kg of urea and 2kg of monopotassium phosphate;

the manufacturing steps are as follows:

(3) Adding EM probiotic bacteria stock solution.

TABLE 3-6 indexes of liquid biological bacterial manure

3.2 planting experiment of liquid biological bacterial manure F2

1) And test time: 05 months in 2017-10 months in 2017;

TABLE 3-7 application effect data of liquid biological bacterial manure

Species of crop	The seed soaking concentration%	Seed soaking time h	Effect (contrast CK)
				Tomato	30	12	The stem height and the number of fibrous roots are respectively increased by 17.90 percent and 11.18 percent
Outdoor eggplant	100	24	The emergence rate is improved by 8.8 percent
				Corn (corn)	20	24	The bud length, stem thickness and root length are respectively increased by 1.43 times, 0.47 times and 1.52 times
Rice (Oryza sativa L.) with improved resistance to stress	100	10	The yield is improved by 6.01 percent, and the morbidity is reduced
				Radix bupleuri	100	24	The germination rate is improved by 19.75 percent
Oil peony	100	24	The germination rate is improved by 20.53 percent

4. Taking 1000kg of the F2 liquid biological bacterial fertilizer, 10.0kg of carboxymethyl oligosaccharide composite acrylic acid super absorbent resin, and 50kg of carboxymethyl oligosaccharide modified diatomite adsorbent composite dicyandiamide and hydroquinone in the formula 3; the preparation process comprises the following steps: introducing the F2 liquid biological bacterial manure into a magnetic dispersion machine with vacuum, rotating at 1000r/min, slowly adding the premix of the carboxymethyl oligosaccharide modified diatomite adsorbent composite dicyandiamide and hydroquinone, stirring and adsorbing for 2h at the normal temperature of vacuum negative pressure of 0.05 mpa; adjusting the rotation speed to 1000r/min, slowly adding the carboxymethyl oligosaccharide composite acrylic acid super absorbent resin with the formula amount again, stirring and adsorbing for 2 hours at the normal temperature under the vacuum negative pressure of 0.05mpa to obtain the carboxymethyl oligosaccharide composite acrylic acid super absorbent resin and the diatomite solid biological bacterial fertilizer F3

4.1 preparation of carboxymethyl oligosaccharide modified diatomaceous Earth adsorbent composite dicyandiamide and Hydroquinone

Firstly, preparing an acetic acid solution with the mass fraction of 1%, then weighing 75g of carboxymethyl oligosaccharide, dissolving the carboxymethyl oligosaccharide in 1000mL of 1% acetic acid solution, fully stirring and dissolving, weighing a premixture of 600g of diatomite, 20g of dicyandiamide and 20g of hydroquinone, adding the premixture into the solution, fully stirring at a high speed (1000 r/min) for 60min, wherein the solution is black paste, drying at 60 ℃, grinding and crushing;

4.2 preparation of carboxymethyl oligosaccharide composite acrylic acid super absorbent resin

Weighing certain 50g of carboxymethyl oligosaccharide, adding into 1000ml of 2% acetic acid solution, placing into a reaction kettle equipped with a stirring device, heating in water bath, and adding into N₂Stirring under the protection of (1), fully dissolving carboxymethyl oligosaccharide, adding 16.5g of ammonium persulfate APS, stirring for 30min, adding 500g of acrylic acid and 0.8g of methylene bisacryloyl MBAM, reacting for 4h at a constant temperature of 60 ℃, stopping the reaction, adding ethanol with the volume of 50% of the total solution into a reaction kettle, stirring at a high speed, slowly adding 20% NaOH aqueous solution to adjust the pH value to 7.0, performing suction filtration to obtain a precipitate, dispersing 300g of the precipitate into 1000ml of ethanol, stirring at a high speed, fully washing the precipitate, performing suction filtration, repeatedly washing for 3 times, soaking for 24h by using 2000ml of mixed solvent (volume ratio of 4: 1) of ethanol and distilled water, performing suction filtration, performing vacuum drying on a filter cake, and crushing to obtain the carboxymethyl oligosaccharide composite acrylic acid super absorbent resin

TABLE 3-8 indexes of adsorbent of carboxymethyl oligosaccharide-modified diatomaceous earth

Item	Index (I)
		Appearance of the product	White powder
Maximum water absorption multiple g/g (pure water)	180
		Water absorption multiple g/g (biogas slurry)	160
Absorption rate of methyl orange solution (concentration 50g/ml)	130
		Water absorption saturation time min	≤65

TABLE 3-9. carboxymethyl oligosaccharide composite acrylic acid super absorbent resin

Item	Index (I)
		Appearance of the product	White powder
Maximum water absorption multiple g/g (pure water)	1200
		Water absorption multiple g/g (biogas slurry)	400
Absorption rate of methyl orange solution (concentration 50g/ml)	450
		Water absorption saturation time min	≤65

TABLE 3-10. carboxymethyl oligosaccharide composite acrylic acid super absorbent resin and diatomite solid biological bacterial manure F3

4.3 planting experiment of solid biological bacterial manure F3

1) And test time: 05 months in 2017-10 months in 2017;

TABLE 3-11 application effect experiment of solid biological bacterial fertilizer

Example 4

The raw water is the breeding excrement of a Lingwu cattle farm, the breeding excrement is filtered by filter cloth before the test to remove large-particle suspended matters in the breeding excrement, and the water quality of the filtered water sample is shown in table 1.

TABLE 4-1 quality of raw Water

Item	Unit of	Raw water index data
			pH		9.60
NH₃-N	mg/L	3367
			COD	mg/L	2564
BOD5	mg/L	320
			TP	mg/L	167
Electrical conductivity of	ms.cm^-1	40.11
			Turbidity of water	NTU	57.30
Total lead	mg/L	11.50
			Total cadmium	mg/L	1.12
Total mercury	mg/L	1.16
			Total chromium	mg/L	8.90
Arsenic (As)	mg/L	7.33
			Nickel (II)	mg/L	26.5

1. Firstly, the fecal sewage or biogas slurry is filtered, 1000mL of filtrate is injected into a reaction tank, and KH-containing KH is put into the reaction tank₂PO₄Adjusting PO in the solution₄ ^3-：NH⁴⁺= 1.5: 1 (molar ratio) and MgCL is put into a reaction tank₂6H₂O, adjusting Mg in the solution²⁺：NH⁴⁺= 1.5: 1 (molar ratio) and stirring at a certain rotating speed of 800 rpm), continuously dropwise adding 1mol/L NaOH into the reactor during stirring, respectively controlling the pH values of the solutions in the reaction tanks at 10.5, and filtering the solutions after reacting for 30 min. The solid precipitate, i.e., struvite fertilizer F1, remained, and the supernatant liquid left behind was filtered for further processing.

TABLE 4-2 indexes of waste liquid before and after struvite or biogas slurry treatment by struvite method

Item	Unit of	Raw water index data	Index after treatment by struvite method	The index is reduced by percentage%
					PH		9.60	9.0	6.3
NH3-N	mg/L	3367	483	85.6
					COD	mg/L	2564	1299.7	49.3
BOD5	mg/L	320	236	26.3
					TP	mg/L	167	143.9	13.8
Total lead	mg/L	11.50	5.25	54.3
					Total cadmium	mg/L	1.12	0.79	29.5
Total mercury	mg/L	1.16	0.97	19.6
					Total chromium	mg/L	8.90	4.73	46.9
Arsenic (As)	mg/L	7.33	3.89	46.9
					Nickel (II)	mg/L	26.5	19.4	26.8

TABLE 4-3 physical and chemical indexes of struvite fertilizer F1

Item	Unit of	Detecting a value
			Total nitrogen	%	≥8.8
All-phosphorus	%	≥19.8
			Soluble phosphorus	%	≥11.5
Calcium carbonate	%	≥24.0
			Potassium salt	%	≥1.8
Density of	g/cm³	≥1.60

2. Adding 1000mL of the supernatant obtained in the step 1 into a reaction tank, adding the magnetic load sepiolite when 8.0g of the supernatant is obtained, starting a stirrer, stirring a water sample at a rotating speed of 200r/min, continuously stirring for 35min, standing for precipitation for 40min, extracting the supernatant by using an injection syringe, and then performing water quality analysis.

2.1 weighing 50g FeCl₂4H₂O and 50gFeCl₃6H₂O was dissolved in 1000ml of distilled water, respectively. Mixing the two solutions, heating to 60 deg.C, ultrasonically shaking for 5min, and magnetically stirring at 60 deg.C (rotation speed of 1000 r/min). Then 2moL/L NH is added₃.H₂O solution (25% concentration), continuously adding NH dropwise after the solution is completely blackened₃.H₂Reacting the O solution for 1 hour until the pH value of the solution is about 11.5 to ensure that the Fe₃O₄Fully curing, and naturally cooling to room temperature. Magnetic separation (placing the reacted solution on a magnetAccelerating the precipitation of magnetic particles) and washing with distilled water for 1-2h to obtain nano Fe₃O₄Magnetic fine particles; stirring again to disperse the nano Fe₃O₄400g of magnetic particles are put into 1000mL of deionized water and ultrasonically shaken for 15min, and 105g of polyvinylpyrrolidone is added into an aqueous solution at the temperature of 80 ℃. Reacting for 30min to make Fe₃O₄Fully adsorbing, cooling and preparing into nano Fe₃O₄Magnetic fluid with the mass percentage of 40 percent; adding 17.5g of sepiolite into 1000mL of deionized water to prepare suspension, and adding nano Fe₃O₄Dispersing the magnetofluid 7.0 g by ultrasonic oscillation for 10min, introducing into a crystalloid reaction, crystallizing at 90 ℃ in a kettle for 7h to obtain the product, washing the product with distilled water until the pH value is 7, and drying to obtain Fe₃O₄Nano magnetic load sepiolite with loading capacity of 16%

TABLE 4-4. wastewater indexes before and after treatment of nano magnetic material loaded mineral soil

Item	Unit of	Index after treatment by struvite method	Index of processed nano magnetic load sepiolite	The index is reduced by percentage%
					PH		9.0	8.0	11.1
NH3-N	mg/L	483	325	32.7
					COD	mg/L	1299.7	181.5	85.30
BOD5	mg/L	236	54.68	76.8
					TP	mg/L	143.9	123.5	14.2
Total lead	mg/L	5.25	0.56	89.3
					Total cadmium	mg/L	0.79	0.09	88.60
Total mercury	mg/L	0.97	Not detected out	100
					Total chromium	mg/L	4.73	0.57	87.9
Arsenic (As)	mg/L	3.89	0.44	88.68
					Nickel (II)	mg/L	19.4	0.20	98.9

TABLE 4-5. Fe₃O₄And the magnetic performance parameters of the nano magnetic load sepiolite

A0-sepiolite; A1-Fe₃O₄(ii) a A2-example 3

3. (without heavy metal pollution) liquid biological bacterial manure F2

3.1 the liquid biological bacterial fertilizer F2 comprises the following raw materials in parts by weight: 1000kg of supernatant in the step 2, 10kg of EM probiotics (sold in the market), 50kg of molasses, 10kg of waste milk liquid, 20kg of humic acid, 3kg of urea and 2kg of monopotassium phosphate;

the manufacturing steps are as follows:

(3) Adding EM probiotic bacteria stock solution.

TABLE 4-6 indexes of liquid biological bacterial manure

3.2 planting experiment of liquid biological bacterial manure F2

1) And test time: 05 months in 2017-10 months in 2017;

3) And test design: seed soaking test and test treatment: CK, clear water (blank control); f2-1 is the liquid biological bacterial fertilizer F2 prepared from the fermentation biogas slurry of the above 3

TABLE 4-7. liquid biological bacterial manure application effect data

Species of crop	The seed soaking concentration%	Seed soaking time h	Effect (contrast CK)
				Tomato	30	12	The stem height and the number of fibrous roots are respectively increased by 16.50 percent and 11.09 percent
Outdoor eggplant	100	24	The emergence rate is improved by 8.6 percent
				Corn (corn)	20	24	The bud length, stem thickness and root length are respectively increased by 1.49 times, 0.43 times and 1.58 times
Rice (Oryza sativa L.) with improved resistance to stress	100	10	The yield is improved by 7.01 percent, and the morbidity is reduced
				Radix bupleuri	100	24	The germination rate is improved by 18.99 percent
Oil peony	100	24	The germination rate is improved by 20.78 percent

4. Taking 1000kg of the F2 liquid biological bacterial fertilizer, 7.5 kg of carboxymethyl fructose composite acrylic acid super absorbent resin, 10kg of carboxymethyl fructose modified rare earth adsorbent composite dicyandiamide, 50kg of thiourea and malic acid in the step 3; the preparation process comprises the following steps: introducing the F2 liquid biological bacterial manure into a magnetic dispersion machine with vacuum, rotating at 1000r/min, slowly adding the premix of the carboxymethyl fruit shell sugar modified rare earth adsorbent composite dicyandiamide, thiourea and malic acid, stirring and adsorbing for 2h at the normal temperature of vacuum negative pressure of 0.05 mpa; adjusting the rotation speed to 1000r/min, slowly adding the carboxymethyl chitose composite acrylic acid super absorbent resin with the formula amount again, stirring and adsorbing for 2 hours at the normal temperature under the vacuum negative pressure of 0.05mpa to obtain the carboxymethyl chitose composite acrylic acid super absorbent resin and the rare earth solid biological bacterial fertilizer F3

4.1 preparation of carboxymethyl fructose-modified rare earth adsorbent composite dicyandiamide, thiourea and malic acid

Firstly, preparing an acetic acid solution with the mass fraction of 1%, then weighing 40g of carboxymethyl chitose, dissolving the carboxymethyl chitose in 1000mL of 1% acetic acid solution, fully stirring and dissolving, weighing a pre-mixture of 480g of rare earth, 12g of dicyandiamide, 12g of thiourea and 24g of malic acid, adding the pre-mixture into the solution, fully stirring at a high speed (1000 r/min) for 60min, enabling the solution to be black paste, drying at 60 ℃, grinding and crushing;

4.2 preparation of carboxymethyl chitosan Compound acrylic acid super absorbent resin

Weighing certain 90 g of carboxymethyl chitosan, adding into 2000ml of 2% acetic acid solution, placing in a reaction kettle with a stirring device, heating in water bath, and adding into N₂Stirring under the protection of the above, fully dissolving carboxymethyl chitose, adding 29.7g of ammonium persulfate APS, stirring for 30min, adding 900g of acrylic acid and 1.44g of methylene bisacryloyl MBAM, starting reaction, reacting at a constant temperature of 60 ℃ for 4h, stopping reaction, adding ethanol with the total solution volume of 50% into a reaction kettle, stirring at a high speed, slowly adding 20% NaOH aqueous solution to adjust the pH value to 7.0, performing suction filtration to obtain a precipitate, dispersing 900g of the precipitate into 3000ml of ethanol, stirring at a high speed, fully washing the precipitate, performing suction filtration, repeatedly washing for 3 times, soaking for 24h by using 3000ml of a mixed solvent (volume ratio of 4: 1) of ethanol and distilled water, performing suction filtration, performing vacuum drying on a filter cake, and crushing to obtain the carboxymethyl chitoseSugar-compounded acrylic acid super absorbent resin

TABLE 4-8 indexes of carboxymethyl fructose modified rare earth adsorbents

Item	Index (I)
		Appearance of the product	Brown powder
Maximum water absorption multiple g/g (pure water)	240
		Water absorption multiple g/g (biogas slurry)	170
Absorption rate of methyl orange solution (concentration 50g/ml)	140
		Water absorption saturation time min	≤60

TABLE 4-9. carboxymethyl fructose composite acrylic acid super absorbent resin

Item	Index (I)
		Appearance of the product	Brown powder
Maximum water absorption multiple g/g (pure water)	1180
		Water absorption multiple g/g (biogas slurry)	500
Absorption rate of methyl orange solution (concentration 50g/ml)	550
		Water absorption saturation time min	≤45

TABLE 1-10. carboxymethyl chitosan composite acrylic acid super absorbent resin and rare earth solid biological bacterial fertilizer F3

4.3 planting experiment of solid biological bacterial manure F3

1) And test time: 05 months in 2017-10 months in 2017;

TABLE 4-11 application effect experiment of solid biological bacterial fertilizer

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A preparation method of nano magnetic material loaded mineral soil for reducing COD and heavy metals in feces, sewage and biogas slurry wastewater is characterized by comprising the following steps:

step (1), FeCl₂·4H₂O and FeCl₃·6H₂Dissolving O in equivalent deionized water respectively;

wherein FeCl₂·4H₂O and FeCl₃·6H₂The mass volume concentration ratio of O is 1: 1-1: 3;

step (2), mixing the two solutions prepared in the step (1), heating to 50-80 ℃, performing ultrasonic oscillation, and keeping magnetic stirring at constant temperature;

step (3) of adding NH to the mixed solution of step (2)₃·H₂O solution, continuously dripping NH after the reaction solution is completely blackened₃.H₂O solution until the pH value of the solution is 10-12, and reacting for 0.5-3 hours to obtain Fe₃O₄Fully curing, and naturally cooling to room temperature;

step (4), washing with deionized water after magnetic separation to obtain nano Fe₃O₄Magnetic fine particles;

step (5), nano Fe₃O₄Magnetic particles are stirred and dispersed in deionized water, and nano Fe₃O₄The mass percentage concentration of the magnetic particles is 10-50%, the coating agent aqueous solution is added under the condition of ultrasonic oscillation and 60-90 ℃, and the reaction is carried out to ensure that Fe₃O₄Fully adsorbing, cooling and cooling to prepare the nano Fe₃O₄A magnetic fluid;

step (6), mineral soil is added into deionized water according to the mass-volume ratio of 10-25g/L to prepare suspension, and then nano Fe with the same mass as the mineral soil is added₃O₄Dispersing the magnetic fluid by ultrasonic oscillation, introducing the dispersed magnetic fluid into a crystallization reaction kettle for crystallization, washing the product to be neutral by deionized water, and preparing the nano magnetic material negativeCarrying mineral soil.

2. The method for preparing the nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in the wastewater of the manure, the biogas and liquid as well as the liquid according to claim 1, wherein the two solutions in the step (2) are mixed, and Fe²⁺: Fe³⁺The molar ratio is =1: 1-2: 3.

3. the method for preparing the nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in the wastewater of the manure, the biogas slurry and the wastewater according to claim 1, wherein the coating agent in the coating agent aqueous solution is one or more than two of sodium oleate, polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, gelatin, sodium dodecyl benzene sulfonate, sodium laurate and L-glutamic acid.

4. The method for preparing the nano magnetic material loaded mineral soil for reducing COD (chemical oxygen demand) and heavy metals in the manure, sewage and biogas slurry wastewater according to claim 1, wherein the mass volume concentration of the coating agent aqueous solution is 60g/L-150 g/L.

5. The method for preparing nano magnetic material loaded mineral soil for reducing COD and heavy metals in wastewater of manure sewage biogas slurry according to claim 1, wherein the mineral soil comprises one or two of sepiolite, serpentine, natural zeolite, clinoptilolite, 4A zeolite molecular sieve, 5A zeolite molecular sieve, NaP1 type zeolite molecular sieve, bentonite, attapulgite, kaolin, diatomite and rare earth.

6. A method for treating manure and biogas slurry is characterized by comprising the following steps:

and (20) adding the supernatant liquid obtained in the step (10) into a reaction tank, adding the nano magnetic material-loaded mineral soil prepared by the preparation method of any one of claims 1 to 5 according to 5.0 to 10.0g/L, starting a stirrer, stirring a water sample at the rotating speed of 100r/min to 500r/min, continuing stirring for 20 to 40min, and finally standing and precipitating to obtain the supernatant liquid for liquid fertilizer production.

7. The method for treating fecal sewage biogas slurry according to claim 6, wherein the struvite pretreatment comprises the steps of:

Adding phosphorus salt to adjust PO in the solution₄ ^3-：NH⁴⁺The molar ratio is 1: 1-1: 1.5; magnesium salt is added into the reaction tank to adjust Mg in the solution² ⁺：NH⁴⁺The molar ratio is 1: 1-1: 1.5, stirring, continuously dropwise adding 1-5 mol/L NaOH into the reactor in the stirring process to respectively control the pH values of the solutions in the reaction tanks to be 9.0-10.5, filtering the solutions after reaction to obtain solid precipitates and supernatant liquid, wherein the solid precipitates are struvite fertilizers.

8. The method of claim 7, wherein the phosphorus salt is H₃PO₄、

Na₂HPO₄、K₂HPO₄、Na₂HPO₄、K₂HPO₄、Na₃PO₄、K₃PO₄、NaH₂PO₄、KH₂PO₄One or more than two; the magnesium salt is MgO, Mg (OH)₂、MgCL₂6H₂O、MgSO₄、Mg(NO₃)₂One or more than two.

9. The liquid biological bacterial fertilizer is characterized by comprising the following raw materials in parts by weight: 1000 parts of supernatant obtained by the manure and biogas slurry treatment method of any one of claims 6 to 8, 10 parts of EM probiotics, 50-100 parts of molasses, 10 parts of food industry waste liquid, 20 parts of humic acid, 3 parts of urea and 2 parts of monopotassium phosphate.

10. The preparation method of the liquid biological bacterial fertilizer is characterized by comprising the following steps:

step (100), weighing each raw material according to the liquid biological bacterial fertilizer of claim 9, dividing the supernatant into two parts,

adding molasses into the first part of supernatant, and stirring to uniformly mix with the supernatant;

sequentially adding EM probiotics, food industry waste liquid, humic acid, urea and potassium dihydrogen phosphate according to the weight parts, intermittently stirring by adopting a stirrer, and supplementing a second part of supernatant;

11. A solid biological bacterial fertilizer, which is characterized by comprising 1000 parts by weight of the liquid biological bacterial fertilizer of claim 9, 1-10 parts by weight of drought-resistant water-retaining agent and 10-50 parts by weight of modified mineral soil adsorbent compound fertilizer slow-release agent; the modified mineral soil adsorbent compound fertilizer slow release agent comprises an acetic acid solution, a modifier, a slow release agent and mineral soil, wherein 50-100g/L of the modifier is dissolved in the acetic acid solution; the mass ratio of the slow release agent to the mineral soil is 1/20-1/10; the mass ratio of the modifier to the premixed material of the mineral soil and the slow release agent is 1: 4-1: 12.

12. The solid biological bacterial fertilizer as claimed in claim 11, wherein the modifier is one or more of xanthan gum, chitosan, oligosaccharide, chitin, glucose, carboxymethyl chitosan, carboxymethyl fructose, carboxymethyl chitose, carboxymethyl inulin, carboxymethyl oligosaccharide and polypyrrolidone; the acetic acid solution is 1% by mass; the slow release agent comprises an ammonia nitrogen slow release agent and a phosphorus activator in a mass ratio of 1:1, wherein the ammonia nitrogen slow release agent is any one or more of dicyandiamide, hydroquinone, thiourea, N-butyl thiophosphoryl triamide (nBPT) and Phenyl Phosphorodiamidate (PPD); the phosphorus activator is one or more of rare earth, oxalic acid, tartaric acid, citric acid, malic acid, humic acid and EDTA.

13. The solid biological bacterial fertilizer as claimed in claim 11, wherein the preparation method of the modified mineral soil adsorbent compound fertilizer slow release agent comprises the steps of dissolving the modifying agent in an acetic acid solution according to a mass volume ratio of 50-100g/L, fully stirring and dissolving, weighing and adding a pre-mixture of the mineral soil and the slow release agent into the solution, fully stirring the pre-mixture of the modifying agent, the mineral soil and the slow release agent at a high speed to obtain a black paste, drying, grinding and crushing.

14. The solid biological bacterial fertilizer as claimed in claim 11, wherein the drought-resistant water-retaining agent is prepared from the following raw materials: acrylic acid, a modifier, an acetic acid solution, ammonium persulfate, methylene diacryloyl and ethanol; the mass ratio of the acrylic acid to the modifier is 9.0-11.0; the mass ratio of the methylene diacryloyl to the acrylic acid is 0.0016, and the mass ratio of the ammonium persulfate to the acrylic acid is 0.033; the mass volume ratio of the modifier to the acetic acid solution is 10-25 g/L; the adding amount of the ethanol is 50 percent of the volume of the total solution; the modifier is one or more than two of xanthan gum, chitosan, oligosaccharide, chitin, glucose, carboxymethyl chitosan, carboxymethyl fructose, carboxymethyl chitose, carboxymethyl inulin, carboxymethyl oligosaccharide and polyvinylpyrrolidone.