CN104843864A - Method for improving stability of landfill leachate anaerobic granular sludge - Google Patents

Abstract

The invention discloses a method for improving the stability of landfill leachate anaerobic granular sludge; by adding glucose, NH4Cl and Na2SO4 into the landfill leachate, the COD concentration is 5000-7000mg/L, NH4<+>-N concentration is 50-1000mg/L, and SO4<2->concentration is 1000-3000mg/L. By adjusting the collaborative concentration of COD, NH4<+>-N and SO4<2->in the landfill leachate, the inhibition effect of the three on anaerobic microorganisms can be eased, and the stability of anaerobic granular sludge under the condition of landfill leachate is also improved, thus improving the efficiency of anaerobic treatment.

Description

A kind of method improving percolate anaerobic grain sludge stability

Technical field

The invention belongs to percolate anaerobic treatment field, relate to a kind of percolate water inlet pollutent that regulates and work in coordination with the method that concentration improves anaerobic grain sludge stability.

Background technology

Percolate is a kind of high concentrated organic wastewater of complicated component, and its character depends on the factors such as component of refuse, particle diameter, compaction and landfill time.Make a general survey of the present situation of domestic and international landfill leachate treatment, treatment process mainly contains biological process and physico-chemical process.Wherein biological process due to working cost low, product not easily causes secondary pollution, can be used as the advantages such as energy recovery and is widely adopted.

The biological treatment etc. that Biochemical method percolate mainly comprises anaerobic biological treatment, Aerobic biological process, anaerobic-aerobic combine.Anaerobic biological process is mainly for the organism in chemical composition and mineral ion.Because in percolate, organic content is high, wherein majority is bioavailable substances, adopts anaerobic process can effective degradation of organic substances, can bear larger impact load again.The topmost feature of anaerobic biological treatment is that energy consumption is low, and the surplus sludge volume of generation is few, and required nutritive substance is also less.Therefore anaerobic biological treatment is usually applied to the pretreatment stage of percolate.Anaerobic biological treatment method is varied, includes upflow anaerobic sludge blanket reactor (UASB), anaerobic biofilter (AF), expanded granular sludge bed (EGSB) and IC reactor etc.Wherein, UASB because its load is high, take up an area less, cost is low, surplus sludge volume is few advantage, in China's anaerobic treatment percolate, account for very large proportion.

Efficient stable, active anaerobic grain sludge is preferably the core of UASB reactor, but due to percolate complicated component, NH ₄ ⁺-N is higher, and C, N, S's is out of proportion, in the process for the treatment of refuse percolate, often occurs that Activity of Anaerobic Granular Sludges is poor, easily causes the phenomenon that reactor collapses.Therefore, improve the condition of anaerobic treatment, strengthen the stability of anaerobic grain sludge, thus the steady running ensureing reactor is significant.

Summary of the invention:

The technical problem to be solved in the present invention be to provide a kind of strengthen anaerobic grain sludge stability, the steady running ensureing anaerobic reactor, improve the method for the raising percolate anaerobic grain sludge stability of anaerobic treatment efficiency.

The present invention adopts following technical scheme to solve the problems of the technologies described above:

Improve a method for percolate anaerobic grain sludge stability, adopt response phase method to add glucose, NH in percolate ₄cl and Na ₂sO ₄, regulate COD, NH ₄ ⁺-N and SO ₄ ^2-collaborative concentration.

Described COD concentration adjustment is 5000 ~ 7000mg/L.

Described NH ₄ ⁺-N concentration adjustment is 50 ~ 1000mg/L.

Described SO ₄ ^2-concentration adjustment is 1000 ~ 3000mg/L.

Describedly add glucose, NH ₄cl and Na ₂sO ₄the opportunity that adds be before anaerobic treatment percolate water inlet in add.

The invention has the advantages that:

The present invention takes full advantage of COD, NH ₄ ⁺-N and SO ₄ ^2-being the pollutent in percolate, is again the feature in the requisite carbon source of anaerobion growth and breeding, nitrogenous source and sulphur source, before anaerobic treatment, changes COD, NH ₄ ⁺-N and SO ₄ ^2-concentration, has the influence of the anaerobic grain sludge in reactor: other restraining factors in (1) reduction percolate are on the impact of Activity of Anaerobic Granular Sludges; (2) granule sludge is made to have high mass transfer efficiency and not breakable characteristic; (3) settling property of granule sludge is improved.Thus strengthen the stability of anaerobic grain sludge, ensure the steady running of anaerobic reactor.

Accompanying drawing explanation

Fig. 1 is the structural representation of the embodiment of the present invention 1 simulation process experimental installation;

In Fig. 1,1 is reaction flask, and 2 is air collectors, and 3 is graduated cylinders, and 4 is constant water bath box;

Fig. 2 is the structural representation of the embodiment of the present invention 2 upflow-type reactor

In Fig. 2,1 is inlet flume, and 2 is peristaltic pumps, and 3 is water-distributing devices, and 4 is mud thief holes, and 5 is triphase separators, and 6 is water-sealed drainage bottles, and 7 is collection chambers, and 8 is gas absorption bottles, and 9 is effluent collection grooves, and 10 is constant water bath box.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is elaborated.

Embodiment 1:

The inventive method is used to carry out the experiment of percolate simulation process, as shown in Figure 1, reaction flask 1 and air collector 2 all adopt the band plug glass serum vials of 500mL, the methane that anaerobic reaction produces is entered into by airway and the air collector 2 that mass concentration is the NaOH solution of 3% is housed, then can displace the liquid of same volume, measure by graduated cylinder 3 methane content that the liquid volume flowed out from air collector 2 is generation.

According to the principle design experiment water inlet Pollutant levels combination of Responds Surface Methodology Box-Behnken Design, wherein: COD 1000mg/L, 3500mg/L, 6000mg/L; NH ₄ ⁺-N 100mg/L, 2050mg/L, 4000mg/L; SO ₄ ^2-100mg/L, 1550mg/L, 3000mg/L.

The preparation of simulated wastewater: utilize glucose, NH ₄cl and Na ₂sO ₄preparation COD, NH ₄ ⁺-N and SO ₄ ^2-concentration be respectively the simulated wastewater of 6000mg/L, 920mg/L and 2820mg/L.In simulated wastewater, 0.9g glucose is equivalent to 1g COD, 3.29g NH ₄cl is equivalent to 1g NH ₄ ⁺-N, 1.48g Na ₂sO ₄be equivalent to 1g SO ₄ ^2-.

Prepared by experiment percolate: utilize glucose, NH ₄cl, Na ₂sO ₄by stoste COD, NH ₄ ⁺-N and SO ₄ ^2-concentration be adjusted to 6000mg/L, 920mg/L and 2820mg/L respectively.

Nutritious mother liquid and each 1mL/L of micro-mother liquor is all added in simulated wastewater and experiment percolate.Nutritious mother liquid and micro-mother liquor as follows:

The formula of nutritious mother liquid: NH ₄cl 170g/L; KH ₂pO ₄37g/L; CaCl ₂2H ₂o 8g/L; MgSO ₄4H ₂o9g/L.

The formula of trace element mother liquor:

FeCl ₃4H ₂o 2000mg/L; CoCl ₂6H ₂o 2000mg/L; MnCl ₂4H ₂o 500mg/L; CuCl ₂2H ₂o30mg/L; ZnCl ₂50mg/L; H ₃bO ₃50mg/L; (NH ₄) 6Mo ₇o ₂₄4H ₂o 90mg/L; Na ₂seO ₃5H ₂o100mg/L; NiCl ₂6H ₂o 50mg/L; EDTA 1000mg/L; 36%HCl 1mL; Resazurin 500mg/L.

Inoculation anaerobic grain sludge TSS is 80.70g/L, VSS be 58.00g/L, VSS/TSS is 0.72.

Experimental procedure:

1, in reaction flask 1, inoculation 100mL contains 5.8gVSS anaerobic grain sludge and 200mL experiment wastewater, pass into nitrogen 3min, nitrogen flow controls as 300mL/min, after evacuation of air, bottleneck seals with rubber plug with overlapped mouth rapidly, insert airway and be connected to draining air collector 2, a water shoot separately established by air collector 2 mouthfuls, is connected in graduated cylinder 3.

2, anaerobic reaction bottle 1 is put into constant water bath box 4 and is started experiment after shaking up, and every 24h records graduated cylinder 3 internal drainage volume in experimental period, namely every day methane production, terminate test till the not aerogenesis.COD, NH of each group of waste water is measured after experimental period ₄ ⁺-N and SO ₄ ^2-concentration, and calculate accumulative methane production.

3, before experiment starts, each group experiment all eluriates mud 3d with the waste water that experiment condition is identical.

4, experimental result is carried out response phase method analysis, utilize Design Expert 8.0.6 software carry out equation model and solve optimum solution.

5, test by above-mentioned steps 1-4 as experiment wastewater by simulated wastewater, experiment percolate and percolate stoste respectively.

Experimental result:

Based on response phase method interpretation, show that prioritization scheme is COD, NH ₄ ⁺-N and SO ₄ ^2-initial concentration be respectively 6000mg/L, 920mg/L and 2820mg/L, corresponding accumulative methane production should be 676.48mL, and COD clearance is 96.50%, NH ₄ ⁺-N clearance is 40.61%, SO ₄ ^2-clearance is 75.10%.

Confirmatory experiment result shows:

Accumulative methane production 589.75mL, the COD clearance 94.09%, NH of simulated wastewater experimental group ₄ ⁺-N clearance 39.31% and SO ₄ ^2-clearance 74.37%, is respectively 12.82%, 2.50%, 3.20% and 0.97% with the relative error of predictor; Accumulative methane production 546.25mL, the COD clearance 80.63%, NH of experiment percolate experimental group ₄ ⁺-N clearance 27.92% and SO ₄ ^2-clearance 71.75%, is respectively 19.25%, 16.45%, 31.25% and 4.46% with the relative error of simulation equation predictor.Percolate stoste experimental group experimental result is accumulative methane production 107.80mL, COD clearance 44.45%, NH ₄ ⁺-N clearance 11.50% and SO ₄ ^2-clearance 34.11%.Initial COD, NH of changing in percolate are described ₄ ⁺-N and SO ₄ ^2-concentration has promoter action to anaerobic treatment percolate.

Embodiment 2

As shown in Figure 2, the inventive method carries out simulation application in UASB process percolate.Testing apparatus internal diameter 7.5cm, high 150cm, effective volume 5.3L.Take to intake bottom peristaltic pump 2, water-distributing device 3 is established in bottom.After triphase separator 5 is separated, mud is separated with liquid gas and falls back to mud district.Water outlet overflows to effluent collection groove 8 through water-sealed drainage bottle 6.Discharge through being equipped with after mass concentration is the gas absorption bottle 8 of 3%NaOH solution after gas enters collection chamber 7 by triphase separator 5.

Arrange 3 thief holes 4 (3) (3#, 2#, 1#) bottom testing apparatus from bottom to top, spacing 15cm, bottom 3# mouth is mud thief hole, and all the other are thief hole for subsequent use.Testing apparatus bottom is dipped in the constant water bath box 10 of 35 ± 2 DEG C, and submergence is highly 2/3 of testing apparatus height, to ensure the temperature condition that submergence sludge blanket is suitable.Simulated wastewater experiment percolate inputs in water-distributing device 3 by peristaltic pump 2, anaerobic grain sludge in testing apparatus and the simulated wastewater of input and percolate generation anaerobic biochemical reaction, and under the effect of current, doing up-flow motion, the final anaerobic gas produced enters collection and confinement of gases bottle 8 from the discharge of triphase separator 5 top vent pipeline and collects.

Testing sequence:

1, the simulated wastewater as the preparation of embodiment 1 method and experiment percolate is adopted, the two COD, NH ₄ ⁺-N and SO ₄ ^2-collaborative concentration is adjusted to 5610mg/L, 100mg/L and 1830mg/L respectively, and the two carries out contrast experiment respectively in the upflow-type reactor that two covers are identical.

2, inoculation 1.5L granule sludge in reactor, account for 30% of reactor volume, during normal operation, in reactor, sludge quality concentration is 16.42gVSSL ^-1.

3, seed sludge domestication 40d.

4, stable operation stage keeps influent COD, NH ₄ ⁺-N and SO ₄ ^2-collaborative concentration is respectively 5610mg/L, 100mg/L and 1830mg/L, and HRT remains 24h, and volumetric loading is 5.60kgCOD/ (m ³d).

5, every day is to Inlet and outlet water COD, NH of reactor ₄ ⁺-N and SO ₄ ^2-concentration measures, and investigates COD, NH ₄ ⁺-N and SO ₄ ^2-concentration is on the impact of granule sludge stability.

6, through the steady running after date of 29d, take mud by 3# thief hole, measure the concentration of mud, size distribution and settling velocity, evaluate optimum COD, NH that response phase method is determined thus ₄ ⁺-N and SO ₄ ^2-collaborative concentration is on the impact of anaerobic grain sludge stability.

Test-results

Change COD, NH of percolate water inlet ₄ ⁺-N and SO ₄ ^2-concentration, makes mud particle diameter many places between 0.9mm ~ 1.6mm, and granule sludge has high mass transfer efficiency and not breakable characteristic.The settling velocity of mud remains between 28.52m/h ~ 67.87m/h, belongs to the mud that settling property is good.

Above-mentioned two cover reactor performances are compared, granule sludge sludge concentration, particle diameter and settling velocity in the reactor being flow condition with experiment percolate are all better than the granule sludge in simulated wastewater experimental group reactor, and COD, NH of regulating percolate are described ₄ ⁺-N and SO ₄ ^2-concentration, can reduce other restraining factors in percolate to the impact of Activity of Anaerobic Granular Sludges, is conducive to the stable of granule sludge.

Claims (5)

1. improve a method for percolate anaerobic grain sludge stability, it is characterized in that: adopt response phase method to add glucose, NH in percolate ₄cl and Na ₂sO ₄, regulate COD, NH ₄ ⁺-N and SO ₄ ^2-collaborative concentration.

2. a kind of method improving percolate anaerobic grain sludge stability as claimed in claim 1, is characterized in that: described COD concentration adjustment is 5000 ~ 7000mg/L.

3. a kind of method improving percolate anaerobic grain sludge stability as claimed in claim 1, is characterized in that: described NH ₄ ⁺-N concentration adjustment is 50 ~ 1000mg/L.

4. a kind of method improving percolate anaerobic grain sludge stability as claimed in claim 1, is characterized in that: described SO ₄ ^2-concentration adjustment is 1000 ~ 3000mg/L.

5. a kind of method improving percolate anaerobic grain sludge stability as claimed in claim 1, is characterized in that: described in add glucose, NH ₄cl and Na ₂sO ₄the opportunity that adds be before anaerobic treatment percolate water inlet in add.