A kind of garbage leachate treatment process
Technical field
The present invention relates to the process method that a kind of percolate is handled.
Background technology
Garbage sanitary filling handle have that investment is little, working cost is low, operating equipment is simple, can process various types rubbish etc. characteristics, be China city at present and even the topmost mode of a lot of later on year refuse treatments.But sanitary landfill method exists a very crucial problem, the i.e. collection of percolate and handling problem.Percolate is rubbish a kind of high concentrated organic wastewater that diafiltration is come out owing to fermentation, rain drop erosion and surface water, underground water soak in stacking and landfill process.
Rubbish leachate treatment method comprises physico-chemical processes and biological process.The load of percolate is very high, and intractability is bigger, is difficult to reach processing requirements with a kind of method, is generally the combination of several method.The percolate of China is handled the roughly following three phases of experience, and promptly the percolate treating process stage is selected with reference to the municipal wastewater treatment plant treatment process in (1); (2) progressively be familiar with the characteristic of percolate after, progressively adjust percolate treating process; (3) along with environmental protection requirement more and more after the strictness, adopt the generally biological treatment+advanced treatment process stage.
At present, the domestic most of percolation liquid treating system that is moving, biological treatment is main with the ordinary student metallization processes, is aided with simple materialization and handles, state of the art is relatively backward, can not reach the designing treatment effect.Major cause is: 1. ammonia nitrogen concentration is high.The percolate ammonia nitrogen concentration generally from tens of to several thousand mg/L do not wait.Because the ammonia nitrogen of high density has certain restraining effect to biological treatment system, and the ammonia nitrogen of high density causes the C/N imbalance in the percolate, and biological denitrificaion is difficult to carry out, and it is up to standard to cause final outflow water to be difficult to.2. Technological adaptability is poor.Along with the prolongation of landfill time, nutritive element is seriously lacked of proper care, and percolate C/N descends, and biodegradability reduces, and capacity of resisting impact load is poor.It is the DT-RO reverse osmosis process that domestic another percolate is at present handled main process, but in this technology, the core product reverse osmosis membrane assembly for external product monopolization, costs an arm and a leg, and the one-time construction investment is higher than biological process, and working cost is high.Bad like the pre-treatment effect, the sewage pollution substrate concentration that gets into reverse osmosis system is high, increases the processing pressure of film, causes film to pollute easily, increases the cleaning and the replacement charge of film, does not reach the setting processing efficiency.Pollutent is effectively removed in addition, concentrates in the liquid concentrator, causes secondary pollution.
Chinese patent discloses the new solution that some percolates are handled; Wherein the patent No. is 2006100345178 and is called " a kind of garbage filter liquid processing method " to disclose the method that a kind of MBR of employing handles percolate; Percolate needed to adopt the two-stage catalytic oxidation carry out aerobic treatment before getting into the membrane biological reaction pond in this technical process, and according to needs intermediate sedimentation pond also between its specification sheets record aerobic treatment and the membrane biological reaction pond, the membrane biological reaction pond also comprises anaerobic zone, catalytic oxidation district and film treatment zone three parts; In fact percolate is not only carrying out denitrification+nitration reaction in two-stage catalytic oxidation step; And in the membrane biological reaction pond, carried out denitrification+nitration reaction again, and having only this technical scheme of employing, just can reach like the described treatment effect of specification sheets; So this technical scheme technical process is long; The various reaction tanks that need are more, and floor space is big, and investment is big; And this technical scheme adopts nanofiltration that the percolate of handling through the membrane biological reaction pond is further handled, and does not reach " household refuse landfill sites pollution control criterion " requirement (GB16889-2008).Another number of patent application is 2009100847445 and is called " a kind of treatment process of percolate and device " to disclose a kind of method that adopts the submerged membrane bioreactor that percolate is handled again; This method does not adopt operations such as corresponding denitrogenation, coagulation that percolate is handled in early stage; And contain a large amount of suspended substances, colloidal particle or other impurity in the percolate; Owing to through corresponding step it is not removed, sewage is when carrying out the biological treatment of submerged film, and a large amount of suspended substances, colloidal particle or other impurity can be adsorbed on the membrane module; Reduce membrane module processing efficiency and work-ing life, increased processing cost.
Summary of the invention
The technical problem that the present invention will solve is: provide that a kind of technical process is short and compact, processing efficiency is high, energy consumption is low and the garbage leachate treatment process of membrane module long service life, has solved the problem that exists in the above-mentioned prior art.
The technical scheme that solves the problems of the technologies described above is: a kind of garbage leachate treatment process, may further comprise the steps,
(1) percolate is collected the remittance equalizing tank; So that the leachate quality water yield is effectively regulated; Hydraulic load and organic loading in the landfill yard regulated in mainly acting as of equalizing tank; Alleviate the influence of impact load, reduce percolate to greatest extent and overflow influence surrounding environment to the percolate treatment facility;
(2) the equalizing tank water outlet promotes and gets into ammonia stripping reactor drum; With remove a large amount of free ammonias and part phenol, prussiate, sulfide and other be difficult to biochemical degradation, biochemical treatment is had the volatile matter inhibiting, that toxicity is big, carry out to help the stable of follow-up biochemical treatment;
(3) percolate carries out the coagulating sedimentation processing behind the ammonia stripping, and coagulating agent is Poly aluminum Chloride (PAC) or bodied ferric sulfate, and the coagulating agent addition is 100mg/L~800mg/L, ST 1~3h; Effect is to reduce that SS, colloidal particle and a small amount of COD and heavy metal ion impact follow-up biochemical load of processing in the percolate, improves operation stability;
(4) coagulating sedimentation water outlet entering anaerobic reactor carries out anaerobic treatment, consider that percolate COD concentration in early stage is high, so the coagulating sedimentation water outlet gets into anaerobic reactor; Reduce the COD load, percolate later stage COD concentration is low, and biodegradability is relatively poor; This moment the anaerobic reactor acidification that mainly is hydrolyzed; To improve the biodegradability of percolate, realize the flexibility that technology changes leachate quality, guarantee the stability of result;
(5) the anaerobic reactor water outlet gets into anoxic pond, Aerobic Pond and MBR reaction tank successively, and described MBR reaction tank to anoxic pond has mixed-liquor return, and the membrane module that uses in the reaction tank is a submerged for dull and stereotyped MBR membrane module, MBR form; Described anaerobic reactor water outlet is not less than 30h at anoxic pond HRT; Be not less than 60h at Aerobic Pond and MBR reaction tank HRT; MBR reaction tank to anoxic pond return current ratio of the mixed liquid is 3~5:1, and anoxic pond, Aerobic Pond and MBR reaction tank sludge concentration maintain 10000mg/L~15000mg/L; Anoxic pond, Aerobic Pond and MBR reaction tank are main biochemical treatment unit; Percolate mainly carries out denitrification denitrogenation in anoxic (A) pond; Mainly carry out the removal of organism and organonitrogen, ammonia nitrogen in aerobic (O) pond and MBR reaction tank, remove total nitrogen through the mixed-liquor return between MBR reaction tank and the A pond;
(6) water outlet of MBR reaction tank gets into reverse osmosis system, and described reverse osmosis system is a first-stage reverse osmosis, and reverse osmosis membrane selects rolled film, two sections of one-levels.To remove the difficult COD that removes of biochemical treatment, reach residual ammonia, metal and colourity, guarantee that water outlet is up to standard, the water outlet after the processing is directly discharged, and reverse osmosis concentrated liquid is back to equalizing tank.
Further technical scheme of the present invention is: the said Aerobic Pond of step (5) divides 2~5 lattice; Perforated wall connects, and last lattice are the MBR reaction tank, places the MBR membrane module; Aeration adopts blast aeration in described Aerobic Pond and the MBR reaction tank, and anoxic pond prevents the mud deposition through the diving alr mode.
Described step (1) percolate is in equalizing tank HRT >=90 day.
The described ammonia stripping of step (2) reactor drum is an Ammonia blowing-out tower, and the ammonia stripping process adopts air stripping, and the equalizing tank water outlet is at first through lift pump; Pump into the pH regulator pond, regulate pH to 9~11, remove deposition through vertical sedimentation basin; ST 1~3h, the settling tank water outlet pumps into Ammonia blowing-out tower and removes free ammonia nitrogen, and Ammonia blowing-out tower is packing tower or traverse baffle tower; Go up water inlet, bottom aeration, GWR 2500~5500:1 during stripping.
The described anaerobic reactor of step (4) is UASB or UBF, and triphase separator is established on top, and HRT is not less than 70h in anaerobic reactor.
Because adopt technique scheme, the present invention has following beneficial effect:
1, technical process is short and compact, processing efficiency is high: the present invention is directed to the percolate water quality characteristics, and materialization processing and biological processing unit reasonable combination, technical process is short and compact.The ammonia stripping effectively reduces ammonia nitrogen concentration; Guarantee follow-up nitrated/denitrifyingly carry out continuously; Coagulating sedimentation is effectively removed portion C OD, salinity, metal and ammonia nitrogen, reduces the toxicity to follow-up biochemical treatment on the one hand, reduces the contamination probability to follow-up MBR, r-o-on the other hand.Anaerobism, nitrated, denitrification and MBR technology are adopted in biochemical treatment, and wherein MBR is the integrated MBR of submerged, and there is mixed-liquor return in MBR reaction tank to denitrification pond.MBR is owing to the crown_interception of film, but effectively catching nitrifier and hardly degraded organic substance degradation bacteria improve it and remove efficient, and can keep high sludge concentration in anoxic pond, Aerobic Pond and the MBR reaction tank; Keep sludge activity, improve capacity of resisting impact load, after MBR effectively moves; Can remove most of organism, its removal efficient to SS also can reach more than 95%, effectively protects follow-up reverse osmosis membrane not contaminated; And reduce follow-up feed water by reverse osmosis pressure, and delay reverse osmosis membrane and pollute, increase reverse osmosis membrane working time; It is less to produce concentrated liquid measure, and Pollutant levels are low in the liquid concentrator, also handles well.
2, energy consumption is low: flow process of the present invention is short, and hydraulic hoist is less; The MBR form is a submerged in addition, leans on gravity or suction water outlet, and the required drive expense is far below the external placed type MBR that leans on the pump supercharging.
3, high, the long service life of membrane module processing efficiency: the present invention has adopted operations such as corresponding denitrogenation, coagulation that percolate is handled in earlier stage; Impurity such as a large amount of suspended substances of containing in the percolate, colloidal particle have been removed; Sewage is when carrying out the submerged Membrane Bioreactor for Wastewater Treatment; Be difficult on the membrane module by contaminating impurity, the membrane module processing efficiency is high, long service life; In the existing in addition garbage leachate treatment process; Generally believe that tubular fibre formula MBR membrane module treatment effect is better; Basically all be to select tubular fibre formula MBR membrane module for use, this kind film is prone to fracture of wire, is prone to pollution, cleans frequently, safeguards inconvenient, membrane lifetime weak point, and MBR membrane module of the present invention is a plate type membrane assembly; The characteristics that have antipollution, be prone to cleaning, the cleaning interval are long, stable, the membrane module life-span is long, the working order of suitable high sludge concentration.
4, compare with disc tube reverse osmosis (dt-ro) (DT-RO r-o-) technology: existing reverse-osmosis treated percolate engineering; Two-pass reverse osmosis is generally adopted in r-o-; The membrane module usage quantity is big, makes an investment in to account in the total investment of engineering than large portion, and operation and maintenance cost is also higher.The present invention is because of there being MBR, pre-treatment such as ammonia stripping, and the pollutent major part has obtained removing, adopts first-stage reverse osmosis can reach the water outlet requirement, can practice thrift the reverse osmosis membrane investment.
Below, in conjunction with embodiment the technical characterictic of a kind of garbage leachate treatment process of the present invention is further described.
Description of drawings
Fig. 1: the garbage leachate treatment process schema of the embodiment of the invention one.
Embodiment
Embodiment one:
A kind of garbage leachate treatment process (referring to Fig. 1) may further comprise the steps,
(1) percolate collect is imported equalizing tank, equalizing tank hydraulic detention time (HRT) >=90 day is effectively to regulate the leachate quality water yield;
(2) the equalizing tank water outlet promotes and gets into ammonia stripping reactor drum, mainly removes a large amount of free ammonias, and described ammonia stripping reactor drum is an Ammonia blowing-out tower; The ammonia stripping process adopts air stripping, and the equalizing tank water outlet pumps into the pH regulator pond at first through lift pump; Regulate pH to 9~11, remove deposition through vertical sedimentation basin, about ST 2h; The settling tank water outlet pumps into Ammonia blowing-out tower and removes free ammonia nitrogen, and Ammonia blowing-out tower is packing tower or traverse baffle tower, goes up water inlet during stripping; The bottom aeration, GWR 5000:1, tail gas gets into the absorption tower removal behind the stripping;
(3) percolate carries out the coagulating sedimentation processing behind the ammonia stripping; Coagulating agent is Poly aluminum Chloride (PAC) or bodied ferric sulfate; The coagulating agent addition is 100mg/L~800mg/L, about ST 2h, with the SS in the further removal percolate, colloidal particle, a small amount of COD and metal;
(4) coagulating sedimentation water outlet entering anaerobic reactor carries out anaerobic treatment, reduces COD in the percolate, and described anaerobic reactor is UASB, and triphase separator is established on top, and HRT is not less than 70h in anaerobic reactor;
(5) the anaerobic reactor water outlet gets into anoxic pond, Aerobic Pond and MBR reaction tank successively, and described MBR reaction tank to anoxic pond has mixed-liquor return, and the membrane module that uses in the reaction tank is a submerged for dull and stereotyped MBR membrane module, MBR form; Anoxic pond, Aerobic Pond and MBR reaction tank are main biochemical treatment unit; Percolate mainly carries out denitrification denitrogenation in anoxic pond is denitrification (A) pond; Mainly carry out the removal of organism and organonitrogen, ammonia nitrogen in promptly nitrated (O) pond of Aerobic Pond and MBR reaction tank, remove total nitrogen through the mixed-liquor return between MBR pond and the A pond;
Said Aerobic Pond divides 4 lattice, and perforated wall connects, and last lattice are the MBR reaction tank, places the MBR membrane module, and aeration adopts blast aeration in described Aerobic Pond and the MBR reaction tank, and anoxic pond prevents the mud deposition through the diving alr mode,
Described anaerobic reactor water outlet is not less than 30h at anoxic pond HRT; Be not less than 60h at Aerobic Pond and MBR reaction tank HRT; MBR reaction tank to anoxic pond return current ratio of the mixed liquid is 3~5:1, and described MBR reaction tank to anoxic pond return current ratio of the mixed liquid is meant from the MBR reaction tank and is back to the mixed solution flow of anoxic pond and gets into the ratio of the discharge of sewage of anoxic pond from the anaerobic reactor water outlet that anoxic pond, Aerobic Pond and MBR reaction tank sludge concentration maintain 10000mg/L~15000mg/L; The membrane module that uses in the MBR reaction tank is dull and stereotyped MBR membrane module; This membrane module has antipollution, and the characteristics of easy care can operation continuously under high sludge concentration.At this technique unit, because the effect of damming of film can make and contain abundant nitrifier and denitrifying bacteria in the mud, sludge concentration is high; High to contaminant removal efficiency, water-fast power load impact, therefore; Do not need other aerobe processing units, compact construction, floor space is little;
(6) water outlet of MBR reaction tank gets into reverse osmosis system, further removes COD, ammonia nitrogen, salinity and colourity, guarantees that water outlet is up to standard; Water outlet after the processing is directly discharged; Reverse osmosis system is a first-stage reverse osmosis, and reverse osmosis membrane selects rolled film, two sections of one-levels; Reverse osmosis concentrated liquid is back to equalizing tank, the r-o-recovery 75%;
(7) coagulating sedimentation mud and biochemical treatment unit mud get into sludge thickener, further with after the plate-and-frame filter press dehydration, send into the landfill yard landfill.
The embodiment of the invention is not limited to the foregoing description, and the various variations of under the prerequisite that does not break away from aim of the present invention, doing all belong to protection domain of the present invention.
The embodiment of the invention one treatment effect is as shown in the table:
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