CN110272146B - Method for treating landfill leachate by coupling high-aluminum-iron sludge and industrial waste of water plant - Google Patents

Abstract

The invention discloses a method for treating landfill leachate by coupling high-alumina iron sludge and industrial waste of a water plant, which is used for deodorizing and purifying the landfill leachate and comprises the following steps: (1) mixing the high-iron waste ore, the waste gypsum and the semi-hydrated gypsum, adding water for solidification, and then adding the mixture into an extruder to be processed into granular reactive filler; (2) loosely piling the prepared reactive filler into a plurality of percolation bodies, and sequentially percolating the landfill leachate through the plurality of percolation bodies to obtain primary treatment landfill leachate; (3) the high aluminum iron sludge waste material and waste sulfuric acid containing chlorine or chloride are mixed to prepare the siliceous sludge acidic aluminum ferric sulfate, and the production waste gas is introduced into the leachate for neutralization and alkalinity. And dissolving the siliceous mud acidic ferric aluminum sulfate into the primary treatment garbage percolation for reaction to form flocculent precipitate, and separating the flocculent precipitate to obtain the deodorized and purified garbage percolation liquid. The scheme of the invention has low cost, realizes the resource utilization of waste, is environment-friendly and is reliable and effective to implement.

Description

Method for treating landfill leachate by coupling high-aluminum iron sludge and industrial waste of water plant

Technical Field

The invention relates to the technical field of waste recycling, in particular to a method for coupling and treating landfill leachate by using high-alumina iron sludge and industrial waste of a water plant.

Background

At present, most domestic water plants mainly use aluminum-iron sulfate diacid, polyaluminium chloride, aluminum sulfate and the like as main water purifying agents, polyacrylamide, poly dimethyl diallyl ammonium chloride and the like are used as main water purifying agents, cities with poor water source quality correspondingly generate a large amount of high-aluminum-iron sludge, the high-aluminum-iron sludge has obvious aluminum toxicity and usually contains a large amount of impurities such as manganese, organic matters, algae, humic acid and the like, and the original motivation generated by the invention is that the high-aluminum-iron sludge is difficult to find and bury under the strict control of the current environmental protection policy; at present, sulfuric acid is required to adsorb moisture in chlorine gas in the production of chlor-alkali plants, a certain amount of sulfuric acid containing chlorine is produced as a byproduct, and the yield of the sulfuric acid is similar to the mud yield of water plants according to investigation. The chloric sulfuric acid has stronger oxidability and corrosivity, if the chloric sulfuric acid is used as common waste sulfuric acid for transportation and use, storage, transportation and production facilities are easy to damage, and the output quantity is limited, so that effective application cannot be found stably at present, and in addition, according to the existing strict environmental protection regulation, the high-concentration waste sulfuric acid is common dangerous waste in cities and also needs to be destroyed.

According to one of the current resource ideas: the method has the advantages that the reaction equipment is more, the purity is low, the waste residue amount is huge, the purpose is difficult to find when the dilute acid is simply used for regenerating the ferric aluminum sulfate and the ferric aluminum sulfate, the daily sludge amount of the urban waterworks is generally in the level of several tons to ten tons, the cost-efficiency ratio of industrial operation is poor, and the method has no practical value.

Experiments show that the aluminum sulfate and the chlorine ion can be simply mixed and stacked in a closed manner, the aluminum sulfate and the chlorine ion are converted into a compound of the aluminum ferric sulfate and the high-silicon cement by heat preservation and catalysis of the chlorine ion (the chloride is derived from reduction products of the chloride, hydrochloric acid and chlorine, and the chloride is commonly used as magnesium chloride and brine), but the reaction is not thorough, the generated waste residue and acid mist are more, the acidity of the product is higher (1% suspended matter solution is generally between 1 and 2), a small amount of organic chlorine is contained, and the application of the aluminum sulfate in the traditional industrial production cannot be met. That is to say, even if the total output of the waste materials in the two industries is balanced, and the production cost is about hundred yuan/ton and is far lower than the cost of landfill and destruction, the problems of cheap raw materials and equipment are only solved, the product quality is at a disadvantage, and the environmental protection problems of serious waste residues and waste gases are generated, namely: it has not sufficient practicability and does not satisfy the three elements of patent application. The problems of product quality and industrial waste are solved accurately, and a targeted market demand thought is needed.

The landfill leachate contains a large amount of ammonium bicarbonate, humic acid, heavy metals and sulfides, the BOD/COD ratio of the acidic early landfill leachate is high, the landfill leachate is treated more frequently by a simple biological method, and the physicochemical effect is poor; however, the neutral to weakly alkaline intermediate and late landfill leachate contains a large amount of difficultly degraded humic acid and particulate matters due to low BOD/COD ratio, so before biochemical treatment or membrane treatment and purification, physicochemical treatment is generally required, and the physicochemical effect is also good.

According to the common known content in the industry, the landfill leachate is mostly operated by using a pretreatment-materialization-biochemistry-secondary materialization-biochemistry-advanced treatment method, and the concentrated water of the membrane treatment method is difficult to treat at low cost and is widely questioned at present.

Before entering a biochemical step, the ammonium bicarbonate is required to be converted into ammonium sulfate, a sulfide is removed, and meanwhile, black humic acid and brown humic acid in humic acid are acidified and precipitated/aluminum ferric salt is flocculated and pre-precipitated. Then the solution is neutralized to the proper PH6-9 of the microorganism, because the biochemical main pressure lies in the stress of high ammonia nitrogen to the microorganism, the ammonium bicarbonate is often converted into ammonia water by a pre-stripping process, and the ammonia water is subjected to materialization after stripping. The problem difficult to solve is that when the lime is added for removing bicarbonate radical by preblowing, the actual dosage of the lime is greatly increased because the generated calcium carbonate embeds the lime particles.

The mechanism part is as follows: in the research on the coagulation characteristics of humic acid under the typical PH condition, Jinpenkang, Shexin and the like, which is reported by the university of Seisan architecture science and technology, 2011, (43) 2, 215-219, humic acid and aluminum are considered to form complex ions under the weak acid condition, and the humic acid is effectively flocculated after the PH7 and the high aluminum ion concentration; the water treatment university statement of the seventh meeting of chemical society of 2016 considers that pH5-6 has the best humic acid removal efficiency, and according to the best data of the American environmental protection agency, the pH5-6 is the best, and the iron ion flocculation removal capacity is known to be higher than that of aluminum ions under weak acidity; that is, it is preferable to use a flocculant containing a large amount of residual acid or an additional acid supplement in physical and chemical treatment.

In a large amount of literature and practical application, diatomite is usually added to improve the treatment effect of a flocculating agent on the landfill leachate, and the mechanism of the treatment effect is adsorption. There are also literature reports that diatomite is used in combination with an aluminum-iron flocculant to provide the best results in cleaning landfill leachate. The high-siliceous mud is a siliceous product obtained by dissolving out ferro-aluminum ion acid in a lamella in a clay mineral structure, has large specific surface area and density far higher than that of diatomite, and also has strong adsorption capacity. Therefore, it is theoretically feasible to retain the high-siliceous sludge obtained by reacting the high-alumino-ferric sludge of the waterworks with the waste concentrated sulfuric acid as an adsorbent and a flocculating constituent weighting agent.

It is understood that the waste sulfuric acid has been used alone in the acidification and use of leachate in landfills, and waterworks sludge is also often transported to landfills for disposal, with an average ton of about several tons to tens of tons per day, which means that these two waste materials are abundant. The weight ratio of the sum of the used neutralizer, the flocculant and the adsorbent to the landfill leachate is generally about 1-2%, and the sum is just matched with the magnitude order (hundreds of tons/day order) of the production of the landfill leachate, so that obviously, the neutralizer, the flocculant and the adsorbent can basically achieve complete coupling on the balance of supply and demand materials; from the economic balance, the two are coupled in a refuse landfill and simultaneously treat tap water plant sludge (waste solids), high-concentration waste sulfuric acid (hazardous wastes) and refuse leachate (waste liquid), the simple treatment cost is only slightly higher than the conventional landfill cost of the two, the refuse leachate is materialized nearly free, and the waste generated by the materialization can be placed in the refuse landfill on site, so that the environmental protection cost of three-party enterprises is greatly reduced, and the economic value and the social value are obvious; compared with the method for purchasing sulfuric acid and ferric aluminum sulfate to materialize the landfill leachate, the method has obvious advantages in performance.

The three waste resource coupling and balance of enterprises relate to the contents of a large number of subjects such as economics, environmental assessment, risk control and the like, and are not directly imaginable to professional chemical engineering technicians, so that the three waste resource coupling and balance of enterprises have the novel and creative premise of the invention. However, if the three are directly coupled, only the COD is effectively reduced, and the problem that the conventional inorganic flocculant and the waste acid materialized landfill leachate are used in the current landfill site and the odor is difficult to solve still can not be solved:

1. the landfill leachate has a large amount of malodorous gases such as hydrogen sulfide, ammonia gas, organic amine alcohol acid aldehyde ketone and the like which need to be purified, and a large amount of carbon dioxide and hydrogen sulfide are generated during physical and chemical acidification, so that a large amount of malodorous and virulent foams are generated, and the amount of malodorous and virulent foams needs to be greatly reduced. Specifically, the malodorous substances include alkaline malodorous substances (ammonia and amine which need to be acidified), acidic malodorous substances (hydrogen sulfide and organic acid which need to be alkalized) and malodorous substances (organic alcohol aldehyde ketone and hydrogen sulfide) which need to be oxidized.

2. The leachate has high humic acid and sulfur ion content and needs a large amount of aluminum-iron flocculating agent to remove, which results in high cost. If the tap water high-alumina iron sludge and the chlorine-containing sulfuric acid are used for physical and chemical treatment, the materials are possibly insufficient, and the odor and the virulent hydrogen sulfide are volatilized violently during acidification, so that the method has high risk.

At present, the landfill leachate deodorization and deodorization technology is used in a few landfill sites, and the industry considers that the main odors come from hydrogen sulfide, ammonia, organic alkyd ketoamine and the like, but the cost is high. In this respect, the inventive concept is to propose an efficient coupling process and to wish to be patented: two additional readily available waste materials may be used: waste gypsum, high-iron minerals and the like are used for pretreating landfill leachate, hydrogen sulfide and partial humic acid are removed in an alkaline atmosphere, a large amount of volatile hydrochloric acid and sulfuric acid mist generated in the production of a simple treatment agent is used for absorbing ammonia gas, organic amine and the like, and the supplementary oxidation is performed as necessary after the materialization.

It is clear that the removal of humic acid and hydrogen sulphide from gypsum and high iron minerals is readily known in the art, but coupled with the second treatment stage, the division of the industry to remove different types of pollutants is difficult to understand simply, and even if thought to be, it is difficult to achieve material balances and complete solutions for waste gas production. Thus, the problems of low cost and safety in odor reduction are solved, and the process route which is not detachable and integrally forms a substantial breakthrough is realized.

Disclosure of Invention

Aiming at the condition of the prior art, the invention aims to provide a method for coupling and treating the high-alumina iron sludge and the industrial waste in the water plant to the landfill leachate, which has the advantages of low cost, realization of resource utilization of wastes, environmental protection, reliable implementation and effectiveness.

In order to achieve the technical purpose, the invention adopts the technical scheme that:

the method for treating the landfill leachate by coupling the high-aluminum-iron sludge and the industrial waste of the water plant is used for deodorizing and purifying the landfill leachate and comprises the following steps:

(1) mixing the high-iron waste ore, the waste gypsum and the semi-hydrated gypsum, adding water for solidification, and then adding the mixture into an extruder to be processed into granular reactive filler;

(2) loosely piling the prepared reactive filler into a plurality of percolation dam bodies, and sequentially percolating the landfill leachate through the plurality of percolation bodies to obtain primary treatment landfill leachate, so as to realize primary odor reduction and pollution reduction under the alkaline condition;

(3) mixing high-alumina iron sludge from a waterworks and waste sulfuric acid containing chlorine or chloride, and then preparing acidic aluminum ferric sulfate containing siliceous sludge by a dry method, wherein acidic waste gas generated in the reaction is introduced into the secondary grade of the garbage percolate for reducing odor and reducing pollution to neutralize the odor of alkaline ammonia and amine; and dissolving the siliceous mud acidic ferric aluminum sulfate into the primary treatment garbage percolation for reaction, forming flocculation precipitate, and separating the flocculation precipitate to obtain the secondary treatment garbage percolation liquid subjected to deodorization and purification.

Further, in the step (1), the high-iron waste ore, the waste gypsum and the semi-hydrated gypsum are mixed, and an adhesion promoter is also added.

Preferably, the adhesion promoter is an acrylic amide.

Further, the high-iron waste ore in the step (1) is pyrite cinder, aluminum-extracting red mud or low-grade limonite.

Further, the specific surface area of the high-iron waste ore in the step (1) is more than 1 square meter per gram.

Further, the adding part ratio of the high-iron waste ore, the waste gypsum and the semi-hydrated gypsum in the step (1) is 1: 2: 1.

Further, the surface of the percolation body in the step (2) is also coated with an ecological bag or a non-woven bag.

Further, the water content of the high-aluminum iron sludge waste in the step (3) is 25-50%; the concentration of the waste sulfuric acid containing chlorine or chloride is more than 80 percent; the chlorine content of the waste sulfuric acid containing chlorine or chloride in the step (3) is 1-8%.

Further, garbage leachate is directly mixed at the side of the tank, and the safety amount of primary material mixing is not more than 0.5 ton, so that the material pile is prevented from blackening and the temperature is out of control; covering the heat-insulating layer after the temperature does not rise any more, standing and curing for 1-2 days to harden, and introducing waste gas into the landfill leachate to neutralize alkalinity.

Further, in the step (3), after the flocculation precipitate is separated, the landfill leachate is subjected to intermittent aeration treatment or oxidant is added to treat residual hydrogen sulfide and organic matters, so that the subsequent biological treatment after the physicochemical process is facilitated.

The idea mechanism of the scheme of the invention is as follows:

1. in the landfill leachate, the humic acid can be complexed and saturated by adding high-concentration calcium ions, and the flocculation adsorption removal capacity is obviously improved. The higher concentration calcium ions precipitate bicarbonate ions, which can greatly reduce the subsequent lime dosage for adjusting pH. The most cheap source of calcium ions is desulfurized gypsum of a thermal power plant, most of bicarbonate radical can be removed, and the complexing capacity of humic acid is passivated, so that the dosage of a flocculating agent is greatly reduced, and the mechanism of the method is similar to that of the method that humic acid is fixed by calcium and magnesium ions in nature. Further supplement high-iron minerals such as pyrite cinder, aluminum-extracting red mud, low-grade limonite and other common high-iron wastes, and can also greatly remove sulfur ions, heavy metals and the like. The special points are as follows: it is not suitable to use iron or ferrous ions, otherwise the ferrous sulfide colloid is difficult to be intercepted or flocculated by the waste gypsum percolation dam.

2. Adding lime into pretreated landfill leachate until the pH value is 9-11, blowing off ammonia nitrogen to be below 300 PPM, and then originally needing two steps of sulfuric acid neutralization and flocculating agent flocculation.

3. The side effect of the invention is that the waste gypsum is used, a large amount of sulfate ions are introduced into the pre-treated percolate, more hydrogen sulfide gas is generated once reducing atmosphere exists in the following biological treatment step, and the hydrogen sulfide gas is harmful to microorganisms, but the biotoxicity problem can be solved by simply putting high-iron mineral suspension for adsorption and precipitation, intermittently carrying out air stripping/absorption on the percolate in the biological tank, and the like during the biological tank treatment, and the technical improvement and the operation cost are very low.

On the basis of the engineering design, the invention correspondingly provides a method for pre-treating the landfill leachate at low cost by combining common urban industrial wastes:

1. one step before adding deamination nitrogen: taking the landfill leachate out of the collecting well into the regulating reservoir, and performing a pretreatment process of percolating effluent through a waste gypsum-high iron mineral reaction percolation dam group, wherein the percolation dam is used as a covering material of the landfill nearby after carbonate, sulfur ions and adsorbed humic acid are about to lose efficacy. The protection points are as follows: the high-iron content minerals are mainly porous materials, and the practicability is realized only when the specific surface area is generally more than 1 square meter/gram; because the waste gypsum (such as desulfurized gypsum, gypsum waste and the like) and the high-iron content minerals with large specific surface area are fine particles, the reaction materials are required to be loosely stacked, so that the mass transfer resistance of the materials in the material bag is low, and the infiltration dam can not be easily blocked by suspended matters in the infiltration liquid to effectively act. The method adopted in the process is as follows: the mixture of the two is added with cheap semi-hydrated gypsum (the waste gypsum can be fried at 130 ℃ and 180 ℃), then water is added for solidification, and an extruder is used for extruding into chemical filler-like particles. The weight ratio of the gypsum to the high-iron mineral is not strictly required and is generally 3:1-1:1, wherein the preferred high-iron mineral is low-grade limonite distributed in a large amount, and is mine waste at present. The non-woven fabric bags are also used as suspended matter filter cloth, and the percolation dam is generally built by high-permeability non-woven fabric bags.

Note: the specific surface area and the loose degree of the low-grade limonite are the first of common high-iron wastes, the capture capacity of the low-grade limonite on sulfur ions, humic acid, other organic acids and heavy metal ions is obviously superior to that of other high-iron minerals, the low-grade limonite does not contain salt, and the low-grade limonite does not react with gypsum after being simply mixed. The inferior choice is aluminum-extracting red mud which is rich in carbonate and the like, can react with gypsum, and high salinity is not beneficial to the subsequent biological treatment of the percolate.

The number of the reaction percolation dams in the regulating tank is generally more than 2, and the water inlet end and the water outlet end are ensured. The reaction percolation dam assemblies are alternately used in one pass by 2 or more so as to change the material bag. Effluent is required to be replaced by most of sulfate radicals in bicarbonate, chromaticity, COD, sulfide ions, heavy metals and the like are obviously reduced, the technology can be used for connecting the existing technology of spraying a landfill leachate deodorant (commonly EM bacteria, hydrogen peroxide, ozone and carboxylic acids) under the film covering of a landfill leachate regulating tank, and the using amount of the deodorant is obviously reduced; and the conventional process of adding lime to blow off ammonia nitrogen and then adding a flocculant for pretreatment or skipping the denitrification step and directly adding the flocculant for pretreatment so as to enter a biological pond is facilitated. The function is as follows: the dosage of lime, flocculating agent and the like can be greatly reduced, and a large amount of carbon dioxide and toxic hydrogen sulfide gas generated by acidification during flocculation can be greatly reduced. The cost is far lower than that of the industrial product treatment.

2. A transformation materialization step: the cyclone sedimentation tank is preferably used in the flocculation, and the original physicochemical treatment system can be reserved. In the traditional scheme, a neutralizing agent, a flocculating agent and an adsorbent are changed into a siliceous sludge acidic aluminum ferric sulfate serving as a simple treating agent, wherein the siliceous sludge acidic aluminum ferric sulfate is prepared by simply mixing high aluminum ferric industrial waste (such as high aluminum ferric sludge in a waterworks) and waste sulfuric acid containing chlorine and chloride (such as waste sulfuric acid for drying chlorine in a chlor-alkali plant).

The production process of the simple treatment medicament comprises the following steps:

the method is characterized in that water plant high-alumina iron sludge with the water content of 25-50% and waste sulfuric acid containing chlorine and chloride ions with the concentration of more than 80% are used for simple mixing, stirring and stacking, the temperature is rapidly increased at the moment, a stirring field is selected beside a landfill leachate pool, so that a small amount of escaped acid mist can be absorbed by ammonia gas and organic amine volatilized by the leachate (the method is convenient for the conventional air extraction equipment to carry out combined gas collection-absorption on the leachate pool and the production of simple treatment medicaments, and the step has a partial deodorization function); the safety amount of the material mixing at one time is not more than 0.5 ton, so that the blackness of a material pile and the out-of-control temperature are avoided; covering the heat-insulating layer after the temperature does not rise any more, standing for curing for 1-2 days, and solidifying to dissolve, and pumping the slurry liquid for use.

The waste sulfuric acid is generally controlled to contain 1-8% of chlorine or chloride ions as a complex catalyst for dry reaction, more than 5% of the waste sulfuric acid can be generally selected to realize both reaction speed and deodorization, the reaction speed is high due to overhigh content, and the byproduct hydrochloric acid and sulfuric acid mist for deodorization of the film covering space of the landfill leachate regulating reservoir are obviously thickened, so that the acid mist can not be completely absorbed. The proportion of the high aluminum iron sludge and the sulfuric acid is 1:1.5-1:3 according to the total mole number of the aluminum iron and the sulfuric acid, namely the sulfuric acid is excessive at the step of synthesizing the flocculating agent according to the acidification dosage requirement, and the proper excessive sulfuric acid is also beneficial to dissolving out more aluminum iron and increasing the specific surface area of the siliceous sludge.

A large amount of sulfur ions in the landfill leachate are removed in the first step through the first two-step scheme; the second step removes a large amount of volatile ammonia and organic amine in the landfill leachate, and the combination of the volatile ammonia and the organic amine can also realize the deodorization of the landfill leachate, which is a key technical breakthrough.

On the basis, a third step can be added for further optimization:

3. the third step is an auxiliary step: because the concentration of sulfate radicals in the leachate is increased by the pretreatment, the control of controlling the concentration of sulfide ions in the biological reaction tank needs to be increased, and the hydrogen sulfide can be simply blown off or oxidized by adopting an intermittent aeration method and treated. If necessary, an oxidant can be added after the second step of treatment to further remove the organic alcohol and the aldehyde. Esters, residual hydrogen sulfide, and pre-oxidation of organics to enhance the performance of the biological treatment step.

By adopting the technical scheme, compared with the prior art, the invention has the beneficial effects that: the scheme of the invention solves the problems of huge lime consumption and great release of hydrogen sulfide in the physicochemical step in the conventional ammonia nitrogen stripping of the landfill leachate, and increases the safety of pretreatment and physicochemical treatment; in addition, the scheme of the invention fully realizes the on-site resource treatment of the waste materials of the landfill, reduces the expensive cost of the outsourcing medicament, and reduces the waste increment phenomenon generated by the outsourcing medicament in terms of total amount.

Detailed Description

The invention will be further described with reference to specific embodiments.

Example one

(1) Red pyrite cinder (specific surface area is more than 1 square meter/gram), gypsum mold fragments and semi-hydrated gypsum are added according to the weight ratio of 1: 2: 1, mixing, adding water, and extruding into granular filler;

(2) and (3) stacking the filler in loose ecological bags to form a percolation dam body, wherein the percolation dam body comprises 2 paths of water inlet ends and 1 path of water outlet ends of the landfill leachate. The purpose of selecting the ecological bag is that the water permeability of the ecological bag can enable the landfill leachate to slowly permeate through the ecological bag step by step. Then collecting the landfill leachate at a water outlet end for ion detection, comparing the ion concentration with the ion concentration of the landfill leachate at the upstream of a water inlet end, detecting that the carbonate in the landfill leachate is removed by more than 65 percent, and the sulfide ions are removed by more than 50 percent, and apparently, the water color of the landfill leachate is obviously changed from black-brown turbidity to brown and is clearer, which shows strong pre-purification capacity of a percolation dam body;

the lime blowing-off process is added to the discharged water, so that the lime consumption is obviously reduced, and obvious benefits are formed.

After the stripping process, the process enters a physicochemical stage, the physicochemical effect is obviously superior to that of the traditional aluminum ferric sulfate dihydrate, the slag settling speed is higher, and the odor of hydrogen sulfide is obviously reduced because heavy slag does not need air floatation.

(3) Adding the physicochemical flocculation/adsorbent into the primary treatment garbage percolation for reaction, then forming flocculation precipitate, and separating the flocculation precipitate to obtain garbage percolate subjected to deodorization and purification; the physicochemical flocculation/adsorbent is formed by simply mixing, stirring and stacking high-alumina iron sludge of a water plant with the water content of 50% and waste sulfuric acid with the concentration of 85%, wherein the temperature is quickly increased, the heat dissipation speed is flexibly controlled to ensure that the temperature is not higher than 90 ℃, the safety quantity of primary material mixing is not more than 0.5 ton, and the stirring field is generally selected beside a landfill leachate pool so as to facilitate absorption of a little escaped acid mist by ammonia and organic amine volatilized by the leachate (gas collection-absorption by using conventional air extraction equipment). Covering the heat-insulating layer after the temperature does not rise any more, standing for curing for 1-2 days, and then dissolving after hardening, and pumping the slurry-like liquid for use; in addition, 5 percent of chloride ions in the waste sulfuric acid are used as a complex catalyst for dry reaction, the proportion of the high-aluminum iron sludge and the sulfuric acid is 1:2 according to the total mole number of aluminum and iron and the mole number of sulfuric acid, and the product is gray hard block and can be dissolved in water to become suspension liquid.

This embodiment discovers that leachate deodorization effect is better at big trial.

Example two

(1) Mixing 1 part by weight of low-grade limonite powder (the specific surface area is more than 5 square meters per gram and is similar to mud), 2 parts by weight of desulfurized gypsum, 1 part by weight of semi-hydrated gypsum and an adhesion promoter (a proper amount of polyacrylamide solution), and extruding and solidifying to prepare loose flocculation mixture filler;

(2) filling materials are put into ecological bags with branches serving as frameworks, loose infiltration dams are built, the dosage of reactants is the same as that of the embodiment, 3 times are also set, and the ecological bags are selected to enable garbage leachate to slowly permeate step by step due to water permeability. And then collecting the landfill leachate at a water outlet end for ion detection, comparing the ion concentration with that of the landfill leachate at the upstream of the water inlet end, detecting that the carbonate in the landfill leachate is removed by more than 80 percent, the sulfide ions are removed by more than 75 percent, apparently, the water color of the landfill leachate is obviously changed from black-brown turbidity to light-brown clarity, and the removal rate of the COD is monitored to be close to 70 percent. The comparison shows that the pre-purification capability is obviously better than that of the case I, and the flocculating suspension capability of the auxiliary agent-polyacrylamide also plays a good role.

The effluent goes through the lime blowing-off process, the lime consumption is obviously reduced, and obvious benefits are formed.

After the stripping process, the process enters a physicochemical stage, the physicochemical effect is obviously superior to that of the traditional aluminum ferric sulfate dihydrate, the slag settling speed is higher, and the odor of hydrogen sulfide is obviously reduced because heavy slag does not need air floatation.

(3) Adding the physicochemical flocculation/adsorbent into the primary treatment garbage percolation for reaction, then forming flocculation precipitate, and separating the flocculation precipitate to obtain garbage percolate subjected to deodorization and purification; the physicochemical flocculation/adsorbent is formed by simply mixing, stirring and stacking water plant high-alumina iron sludge with the water content of 40% and chlorine-containing waste sulfuric acid with the concentration of 85%, at the moment, the temperature is quickly raised, the heat dissipation speed is flexibly controlled to ensure that the temperature is not higher than 90 ℃, the safety amount of primary material stirring is not more than 0.5 ton, and the stirring site is generally selected beside a landfill leachate pool so as to facilitate absorption of a little escaped acid mist by ammonia gas of volatilized leachate (gas collection-absorption of conventional air extraction equipment). Covering the heat-insulating layer after the temperature does not rise any more, standing for curing for 1-2 days, and dissolving after hardening, and pumping the slurry-like liquid for use; in addition, 3% of chloride ions are supplemented in the chlorine-containing waste sulfuric acid in the mode of industrial magnesium chloride to serve as a complex catalyst for dry reaction, the proportion of the high-aluminum-iron sludge and the sulfuric acid is 1:2 according to the total mole number of aluminum-iron-containing sludge and the mole number of sulfuric acid, and the product is gray hard blocks and can be dissolved in water to become a suspension.

In this example, the leachate deodorization effect was found to be slightly better than that of the example in the pilot plant, and it is estimated that the odor of the malodorous organic substances is also related to the oxidation of the small amount of chlorine volatilized from the chlorine-containing waste sulfuric acid. However, if the large-scale production is more prone to supplementing hydrogen peroxide after the second-stage physicochemical reaction, residual hydrogen sulfide, organic alcohol, aldehyde, ester and macromolecular organic matters are removed by a Fenton oxidation mechanism, and deodorization and biological further treatment are facilitated.

The foregoing is illustrative of the present invention, and it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (2)

1. The method for treating the landfill leachate by coupling the high-aluminum-iron sludge and the industrial waste of the water plant is used for deodorizing and purifying the landfill leachate, and is characterized in that: which comprises the following steps:

(1) mixing the high-iron waste ore, the waste gypsum and the semi-hydrated gypsum according to the weight ratio of 1: 2: 1, adding acrylic acid amide as an adhesion promoter, adding water for solidification, and then adding the mixture into an extruder to process into granular reactive filler;

the high-iron waste ore is pyrite cinder, aluminum-extracted red mud or low-grade limonite;

(2) loosely piling the prepared reactive filler into a plurality of percolation dam bodies, coating ecological bags or non-woven bags on the surfaces of the percolation dam bodies, and percolating the landfill leachate through the percolation dam bodies in sequence to obtain primary treatment landfill leachate, so as to realize primary odor reduction and pollution reduction under an alkaline condition;

(3) mixing high-alumina iron sludge from a waterworks and waste sulfuric acid containing chlorine or chloride, and then preparing acidic aluminum ferric sulfate containing siliceous sludge by a dry method, wherein acidic waste gas generated in the reaction is introduced into the secondary grade of the garbage percolate for reducing odor and reducing pollution to neutralize the odor of alkaline ammonia and amine; dissolving acidic aluminum ferric sulfate containing siliceous mud, adding the dissolved acidic aluminum ferric sulfate into primary treatment garbage percolation for reaction, forming flocculation precipitate, and separating the flocculation precipitate to obtain secondary treatment garbage percolation liquid subjected to deodorization and purification; carrying out intermittent aeration treatment or adding an oxidant to the secondary landfill leachate to treat residual hydrogen sulfide and organic matters;

the water content of the high-aluminum iron sludge is 25-50%; the concentration of the waste sulfuric acid containing chlorine or chloride is more than 80 percent; the chlorine content in the waste sulfuric acid containing chlorine or chloride is 1 to 8 percent;

the garbage leachate tank is directly mixed, and the safety quantity of once material mixing is not more than 0.5 ton, so that the material pile is prevented from blackening and the temperature is not out of control; covering the heat-insulating layer after the temperature does not rise any more, standing and curing for 1-2 days to harden, and introducing the waste gas into the landfill leachate to neutralize alkalinity.

2. The method for coupling and treating the landfill leachate by the high-alumina iron sludge and the industrial waste of the water plant according to claim 1, wherein the method comprises the following steps: the specific surface area of the high-iron waste ore in the step (1) is more than 1 square meter per gram.