CN107176777A - A device and process for treating Fenton iron slime with anaerobic microorganisms - Google Patents

Abstract

The utility model provides an utilize anaerobic microorganisms to handle device of Fenton iron mud, includes upflow anaerobic sludge blanket reactor's barrel, is equipped with the fender in the barrel, and the triphase separator, the intaking links to each other its characterized in that with the barrel bottom: the barrel is provided with a hollow heat preservation cavity connected with the circulating water bath kettle. The technology for treating the Fenton iron mud by using the device comprises the following steps: and (3) putting the Fenton iron mud to be treated into a water inlet adjusting tank, operating the cylinder of the up-flow anaerobic sludge bed reactor, and controlling the hydraulic retention time, temperature and pH. The iron sludge mixed wastewater is introduced into the cylinder, ferric iron in the iron sludge is used for enriching the dissimilatory iron reducing bacteria through dissimilatory iron reduction, so that organic matters in the iron sludge and the wastewater are removed, and meanwhile, energy gas is generated. The technical scheme of the invention can achieve the following technical effects: the method realizes effective removal of organic matters in the iron mud, improves the removal rate of the chemical oxygen demand of the wastewater, and improves the yield of methane. Is especially suitable for treating aromatic hydrocarbon and hydrocarbon containing benzene, phenol and other components and organic waste water containing long chain fatty acid.

Description

A device and process for treating Fenton iron slime with anaerobic microorganisms

technical field

The invention relates to the field of solid waste recycling technology.

Background technique

The Fenton and Fenton-like oxidation process is a catalytic oxidation technology that has been gradually promoted in recent years. This process uses Fe ²⁺ and Fe ³⁺ to catalyze hydrogen peroxide under acidic conditions to generate strong oxidizing hydroxyl radicals ( OH) to convert difficult Oxidation of degraded components. The reaction can be carried out under normal temperature and pressure. The process is simple and has great potential for industrialization. It has been successfully applied to the treatment of printing and dyeing wastewater, oily wastewater, phenolic wastewater, coking wastewater, nitrobenzene-containing wastewater, and diphenylamine wastewater. middle. However, not only the oxidation reaction of hydroxyl radicals occurs during the Fenton reaction process, but also the flocs of ferric hydroxide also have a certain flocculation effect on organic matter and other pollutants, which inevitably produces a large amount of iron-containing sludge. Fenton sludge can be classified as hazardous solid waste, with a moisture content of about 80% even after dehydration, and contains a large amount of organic matter and heavy metals. If it is not handled properly, it will cause many hazards, such as: direct discharge of iron mud will silt up the river bed and seriously pollute the water body; iron mud contains a large number of bacteria and viruses, which will seriously endanger human health if it is directly exposed to the environment; if it is directly buried, The organic matter adsorbed and wrapped by iron slime flocs will be corrupted and foul-smelling, causing a series of environmental problems. Therefore, the treatment of Fenton iron slime has become the key to restricting the further promotion of Fenton technology.

Traditional Fenton iron slime disposal methods are mainly cement stabilization, incineration, solidification and other methods. Although the method of landfilling after sludge stabilization and immobilization can ensure that the solid waste is properly treated and prevents secondary pollution, it only reduces the toxicity and mobility of the waste, and does not eradicate the organic matter in the iron sludge. Corruption issue. Although the incineration method can completely oxidize organic matter into carbon dioxide and water, iron sludge contains a large amount of iron and some heavy metals, and the fly ash produced by incineration needs further treatment.

Anaerobic biological treatment technology is one of the most effective technologies in the field of organic wastewater and waste treatment. The organic matter in wastewater and high-solid waste is finally transformed into water, carbon dioxide, methane, hydrogen sulfide, etc. through the co-metabolism of a variety of microorganisms. Iron is one of the essential elements for microbial growth, with an average content of about 5.6% in the earth's crust. It exists in the forms of Fe ⁰ , Fe ²⁺ , and Fe ³⁺ , among which Fe(III) minerals are the main forms. As the oldest respiration method of life on earth, iron respiration is the reduction of iron by microbial dissimilation, which plays an important role in the geological cycle of iron. In this process, microorganisms use Fe(III) as an electron acceptor to reduce Fe(III) to Fe(II) while oxidizing organic matter and obtain energy from it. Because the microbial dissimilatory iron reduction process is coupled with the oxidative degradation of organic matter, it has been gradually applied in biometallurgy, bioremediation of heavy metal (uranium, chromium, arsenic, etc.) polluted environments, and biodegradation of petrochemical organic sewage. It has been reported that the addition of ferric iron can promote the anaerobic fermentation efficiency of landfill leachate rich in sulfate ions and long-chain fatty acids; there are also studies on the effect of ferric iron on the process of anaerobic biogas production from cellulosic waste, and the study found that The addition of FeCl ₃ can strengthen the destruction of cellulose crystallinity by anaerobic microorganisms, and ferric iron has certain application prospects in the methane utilization of municipal solid waste, agricultural production waste, forestry production waste and other fields. However, there is no report on using Fenton iron sludge as a source of ferric iron to promote anaerobic digestion.

Contents of the invention

The invention proposes a technology for using anaerobic microorganisms to digest and treat Fenton iron slime. On the one hand, the advantages of anaerobic digestion are used to effectively remove organic matter in iron sludge; on the other hand, based on the reduction mechanism of dissimilated iron, ferric iron in iron sludge is used as the electron acceptor for microbial dissimilated iron reduction to strengthen anaerobic digestion Organic matter efficiency, increasing anaerobic methane production.

Concrete technical scheme is: a kind of device utilizing anaerobic microorganism to process Fenton's iron sludge, it is characterized in that: comprise and be provided with the cylindrical shell of the upflow type anaerobic sludge bed reactor with loam cake, in this cylindrical shell, bottom-up A sludge reaction layer and a sludge suspension layer are arranged in sequence, a fender is fixed above the cylinder body, a three-phase separator is fixed under the upper cover, and an outlet pipe is arranged above the cylinder body. The water inlet adjustment tank is connected to the bottom of the sludge reaction layer in the cylinder through the water inlet pump through the water inlet pipe. It is characterized in that: the cylinder is provided with a hollow heat preservation chamber, and the upper part of the circulating water bath is connected to the upper part of the hollow heat preservation chamber through the circulating water pipe i, while the lower part is passed through The circulating water pipe ii and the circulating water pump are connected with the bottom of the hollow insulation cavity.

A kind of technique utilizing above-mentioned device to utilize anaerobic microorganism to process Fenton's iron slime, comprises following operation:

1) get the Fenton iron slime to be treated and carry out dehydration, make the moisture content of iron slime after dehydration be at 80～90%, the best is 80%, measure the iron content of iron slime;

2) Put the treated iron sludge into the water inlet adjustment tank according to the mass ratio and fully mix it with the wastewater to be treated, so that the mass fraction of the iron sludge (calculated as ferric iron) is kept at about 10-20g/L, and the best is 20g /L;

3) Turn on the circulating water bath, maintain the temperature of the circulating water at 37°C, turn on the circulating water pump, let the circulating water enter the hollow insulation cavity through the circulating water pipe, and maintain the temperature inside the cylinder of the upflow anaerobic sludge bed reactor at 37°C;

4) Turn on the water inlet pump, so that the mixed waste water enters the barrel of the above-mentioned upflow anaerobic sludge bed reactor through the water inlet pipe, the reaction temperature is 30-40°C, the optimum is 37°C, and the hydraulic retention time is 24h;

5) The waste water passes through the sludge reaction layer to generate energy gas, and the generated gas is collected through a three-phase separator;

6) The treated effluent is discharged through the outlet pipe.

Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

① Combining the anaerobic digestion process with the disposal of Fenton's iron sludge, organic matter in Fenton's iron sludge can be effectively disposed of without additional energy input. ②Based on the reduction mechanism of dissimilated iron to effectively utilize ferric iron in iron sludge to enrich dissimilated iron-reducing bacteria. ③ The divalent iron dissolved by the reduction of dissimilated iron is directly related to the anaerobic reactor's ability to treat organic matter, and the dissolution of ferrous iron plays a positive role in the growth of microorganisms in the anaerobic reactor. ④ The dissolution of ferrous iron accelerates the granulation of sludge in the anaerobic reactor, improves the processing capacity of the reactor and the ability to change environmental conditions, that is, the stability of the reactor.

Description of drawings

The present invention has 3 accompanying drawings, wherein:

Fig. 1 is a kind of device structure diagram of utilizing anaerobic microorganism to process Fenton's iron slime of the present invention.

Fig. 2 is the M-M section of Fig. 1 .

Fig. 3 is a schematic diagram of a process principle of using anaerobic microorganisms to treat Fenton's iron sludge in the present invention.

In Figure 1: 1. Water inlet regulating tank, 2. Water inlet pump, 3. Water inlet pipe, 4. Sludge reaction layer, 5. Suspended sludge layer, 6. Fender, 7. Outlet pipe, 8. Three-phase Separator, 9. Reactor upper cover, 10. Circulating water pipe i, 11. Circulating water bath, 12. Circulating water pump, 13. Hollow insulation cavity, 14. Cylinder body, 15. Circulating water pipe ii.

detailed description

(1) The application mechanism involved in the present invention is the dissimilation iron reduction mechanism. The dissimilation iron reduction mechanism is as shown in Figure 3. The life metabolism process of microorganisms needs respiration, and the life metabolism of dissimilation iron reducing bacteria takes organic matter as electron donors. Ferric iron is an electron acceptor. While oxidizing organic matter into carbon dioxide and water, it transfers electrons to ferric iron to reduce ferric iron to divalent iron, and in this process obtains energy for life growth. Compared with other anaerobic microorganisms, dissimilatory iron-reducing bacteria have a stronger ability to decompose and transform organic matter, especially macromolecules and refractory substances. The small molecules produced by the degradation of macromolecules can be used by methanogens to generate methane for energy recovery. Adding Fenton iron slime as a source of ferric iron into the anaerobic reactor will enrich dissimilated iron-reducing bacteria due to the reduction of dissimilated iron. When the wastewater flows through the sludge layer, the organic matter in the wastewater will be absorbed by the dissimilated iron-reducing bacteria. Oxidation produces carbon dioxide and water, and the dissimilatory iron-reducing bacteria use the obtained electrons to reduce ferric iron and obtain energy from it for life growth and energy metabolism.

(2) The present invention relates to a kind of upflow type anaerobic sludge bed reactor, and reactor as shown in Figure 1, is provided with the cylinder body 14 of the upflow type anaerobic sludge bed reactor with loam cake 9, and this cylinder body 14 is provided with hollow insulation chamber 13. The cylinder body 14 of the upflow anaerobic sludge bed reactor is sequentially equipped with a sludge reaction layer 4 and a sludge suspension layer 5 from bottom to top. A fender 6 is fixed on the inner top of the cylinder body 14 , and a three-phase separator 8 is fixed under the upper cover 9 . The top of the circulating water bath 11 is connected with the upper part of the hollow heat preservation chamber 13 through the water circulation pipe i-10 and the bottom of the hollow heat preservation chamber 13 is connected with the bottom of the hollow heat preservation chamber 13 through the water circulation pipe ii-15 and the water circulation pump 12 below. The water inlet adjustment tank 1 is connected to the bottom of the sludge reaction layer 4 in the cylinder body 14 through the water inlet pump 2 and the water inlet pipe 3 . When the water inlet pump 2 is turned on, the wastewater in the water inlet adjustment tank flows through the water inlet pump 2, the water inlet pipe 3, the sludge reaction layer 4 and the sludge suspension layer 5 in sequence, and finally flows out from the water outlet 7 for discharge.

(3) the present invention will be further described in conjunction with accompanying drawing 1 and example, utilize the technique of anaerobic digestion to process Fenton's iron slime as shown in Figure 2 to comprise the following steps:

Taking the landfill leachate as the wastewater to be treated, the chemical oxygen demand of the landfill leachate is 10000mg/L, and the concentration of ammonia nitrogen is 1800mg/L.

Turn on the circulating water pump 12, and the circulating water flows through the circulating water bath 11 through the circulating water pump 12, the circulating water pipe ii-15, the hollow insulation chamber 13, the circulating water pipe i-10 and returns to the circulating water bath to maintain an upflow anaerobic sludge bed The reactor barrel 14 temperature was 37°C.

Take the Fenton iron slime to be treated, carry out certain dehydration to reduce the iron slime volume, make the moisture content of the iron slime after dehydration be 80-90%, the best is 80%, the iron content of the iron slime is determined to be 40%, organic matter The content is 20%, and other substances include inorganic substances and heavy metal ions.

Put the treated iron slime into the water inlet adjustment tank 1 at a certain volume ratio and fully mix it with the landfill leachate wastewater, so that the mass concentration of the iron slime (calculated as ferric iron) is kept at about 10-20g/L, which is the best 20g/L.

Turn on the water inlet pump 2, adjust the water inlet flow rate so that the hydraulic retention time is 24h, so that the mixed waste water in the water inlet adjustment tank 1 flows through the water inlet pump 2 and the water inlet pipe 3 in turn into the upflow anaerobic sludge bed reactor 14, The bottom-up influent water flow can play a stirring role to make the wastewater to be treated fully contact with the anaerobic microorganisms in the sludge reaction layer 4, and the dissimilatory iron-reducing bacteria in the anaerobic microorganisms will reduce the influent iron sludge through the dissimilatory iron reduction mechanism. The ferric iron contained in it is reduced to divalent, and energy is obtained from it, which improves the removal and transformation of macromolecules and refractory substances in landfill leachate, promotes anaerobic digestion, and increases methane production. At the same time, the anaerobic microorganisms in the sludge reaction layer 4 can be used to remove organic matter in the iron sludge.

When the wastewater passes through the sludge reaction layer 4, energy gases (carbon dioxide and methane) will be generated due to the anaerobic digestion of anaerobic microorganisms, and will be released in the sludge suspension layer 5, and the generated energy gases will be separated by the three-phase separator 8. collection, energy recovery.

The treated waste water finally flows out from the water outlet 7 for discharge.

The chemical oxygen demand removal efficiency of the landfill leachate treated by the technology of the present invention is 76%, and compared with the reactor without adding iron sludge, the chemical oxygen demand removal rate is increased by 10%, and the chemical oxygen demand of the effluent is reduced by 28%. Methane production increased by 14%.

Claims (2)

1. a kind of utilization anaerobe handles the device of Fenton iron mud, it is characterised in that：Including provided with taking the upper of lid (9) Sludge reaction layer (4) and dirt are sequentially provided with the cylinder (14) of flow anaerobic sludge bed reactor, the cylinder (14) from bottom to top Mud guard (6) is fixedly arranged above in mud superposed layer (5), the cylinder (14), three phase separator (8) is fixed on the upper lid (9) under, top is provided with outlet pipe (7) to the cylinder (14) outside；Intake regulating reservoir (1) through intake pump (2) by water inlet pipe (3) with Described interior sludge reaction layer (4) bottom of cylinder (14) is connected, it is characterised in that：The cylinder (14) is provided with hollow insulation chamber (13), it is connected and lower section with the top of the hollow insulation chamber (13) by circulating water pipe i (10) above recirculated water bath (11) It is connected by circulating water pipe ii (15) and water circulating pump (12) with the bottom of the hollow insulation chamber (13).

2. a kind of usage right requires that the utilization anaerobe of 1 described device handles the technique of Fenton iron mud, including following Process：

1) take pending Fenton iron mud to be dehydrated, make the iron cement moisture content after dehydration 80~90%, most preferably 80%, Determine the iron-holder of iron cement；

2) iron cement after processing is put into water inlet regulating reservoir (1) in mass ratio and be sufficiently mixed with pending waste water, make iron cement Mass fraction (in terms of ferric iron) is maintained at 10~20g/L or so, most preferably 20g/L；

3) recirculated water bath (11) is opened, it is 37 DEG C to maintain circulating water temperature, opens water circulating pump (12), makes recirculated water by following Ring water pipe (15) enters hollow insulation chamber (13), and it is 37 DEG C to maintain upflow anaerobic sludge blanket reactor cylinder (14) interior temperature；

4) intake pump (2) is opened, the waste water of mixing is entered the cylinder of above-mentioned upflow anaerobic sludge blanket reactor through water inlet pipe (3) Body (14), reaction temperature is 30-40 DEG C, and optimal is 37 DEG C, and hydraulic detention time is 24h；

5) waste water produces energy gas by sludge reaction layer (4), and the gas of generation is received by three phase separator (8) Collection；

6) water outlet after handling is discharged by outlet pipe (7).