CN100357201C

CN100357201C - Artificial leather effluent treating process

Info

Publication number: CN100357201C
Application number: CNB2005101231023A
Authority: CN
Inventors: 任洪强; 严永红
Original assignee: 南京大学
Priority date: 2005-12-15
Filing date: 2005-12-15
Publication date: 2007-12-26
Also published as: CN1810685A

Abstract

The present invention discloses a method for treating waste water of leatherette. According to the concentration of COD and DMF in waste water, a quality depended treatment method is adopted by selecting proper treatment technology. Waste water with high concentration of COD and DMF firstly enters a DMF recovery system for recovering DMF. After DMF is recovered, anaerobic treatment is carried out to the waste water; then ammoniacal nitrogen which is generated through hydrolyzation after the anaerobic treatment to DMF is removed through blowing desorption; subsequently, waste water after removing through blowing desorption and other technologic mixed waste leatherette water with low COD concentration are together treated by anoxic/ aerobic and coagulating sedimentation technology. The waste water which achieves the state standard of effluent discharge is discharged. The method has mature technique, convenient operation and management, and stable and reliable yielding water, and has good treatment effect especially on DMF substances whose content is high in waste leatherette water.

Description

A kind of method of leatheroid wastewater treatment

Technical field

The invention belongs to the Industrial Wastewater Treatment field, more particularly is the processing of leatheroid factory effluent.

Background technology

Leatheroid waste water composition complexity, variation water quality is big, mainly contains COD, SS, DMF pollutents such as (dimethyl formamides) in the waste water.Especially towards tower waste water COD and DMF concentration 30,000～100,000mg/L, the COD of the Cleaning Wastewater of coagulating pan, accumulator tank and recycling bin and DMF concentration are 15, about 000mg/L.DMF content is higher in this class waste water, and DMF is a kind of organic solvent, and price is higher, has higher reclamation and is worth.Overhead water COD and DMF are about 1600mg/L, and DMF content is still higher, can produce a large amount of ammonia nitrogens behind the DMF anaerobic hydrolysis.

Except that containing higher concentration DMF, also contain auxiliary agent, dyestuff etc. than the difficult degradation pollutent in the leatheroid waste water, the overall complicated component of waste water has certain degree of difficulty to art breading, and single physico-chemical process or biochemical process all are difficult to up to standard.

The leatheroid method of wastewater treatment generally mixes various waste water at present, adopts the anaerobic-aerobic treatment process, this treatment process water outlet COD, NH ₃-N concentration is higher, is difficult to reach the requirement of discharging standards, and the processing of leatheroid waste water must be considered the influence of a large amount of ammonia nitrogens to carrying out a biological disposal upon that produces behind the DMF anaerobic hydrolysis.

Summary of the invention:

The present invention seeks to: the various waste water at existing leatheroid production are handled respectively, to COD and DMF concentration 10, the above waste water of 000mg/L adopts minimizing and resource utilization, reduce the content of principal pollutant DMF in the waste water, adopt physical chemistry method to remove the ammonia nitrogen that the DMF anaerobic hydrolysis produces simultaneously, a large amount of ammonia nitrogens that produce behind the DMF of the processing of the leatheroid waste water consideration simultaneously anaerobic hydrolysis are to the influence of biological treatment.

Technical solution of the present invention is: a kind of method of leatheroid wastewater treatment, just select suitable treatment process to take branch matter treatment process according to COD in the waste water and DMF concentration, to COD and DMF concentration height 10, the above waste water of 000mg/L adopts minimizing and resource utilization, reduce the content of principal pollutant DMF in the waste water, as towards tower waste water COD and DMF concentration all 10, the waste water that 000mg/L is above, enter the DMF recovery system and reclaim DMF, reclaim back waste water and carry out anaerobic treatment, and the ammonia nitrogen that the posthydrolysis of DMF anaerobic treatment produces is carried out stripping remove.Waste water after stripping is removed utilizes anoxic/aerobic+coagulation-settlement process to handle with the leatheroid composite waste of other low COD and DMF concentration.

The leatheroid technology composite waste of other low COD concentration also can carry out anaerobic treatment by DMF recovery back waste water together.

Contain COD, the higher waste water of DMF concentration refers to towards the Cleaning Wastewater of tower water and coagulating pan, accumulator tank and recycling bin, the processing of DMF recovery system is through the plate-and-frame filter press extruding, and the waste water that squeezes out enters the DMF recovery system and is meant that distillation or alternate manner reclaim DMF.

Described ammonia-nitrogen desorption method is: utilize Ca (OH) ₂The pH value of waste water is adjusted to 10 ~ 11, and the stripping device adopts stripping tower, and gas-water ratio is 200 ~ 400: 1.

The anaerobic treatment reactor adopts rising streaming anaerobic reactor, 15 ~ 24 hours residence time.Anaerobic-aerobic loads biologic packing material in the pond, 2 ~ 4 hours anoxic residence time, 24 ~ 36 hours aerobic residence time.Anoxic pond DO is that 0.5mg/L, Aerobic Pond DO are 2.0 ~ 4.0mg/L.The anaerobic pond temperature is 15 ~ 35 ℃, and the temperature of anoxic, Aerobic Pond is 15 ~ 38 ℃.

The present invention adopts " DMF recovery-anaerobism-ammonia-nitrogen desorption-anaerobic-aerobic (A/O) technology-coagulating sedimentation " art breading leatheroid waste water, the water outlet COD after the processing _Cr≤ 100mg/L; NH ₃-N≤15mg/L; Colourity≤40 times.

Mainly by pollutent contain high density DMF waste water reclamation-anaerobism pre-treatment after mixes with other waste water, after the processing of A/O-coagulation-settlement process, reach discharging standards.

Handler's fabricate-leather method of wastewater treatment of the present invention compared with prior art has following advantage:

1. consider pollutent resource utilization and minimizing, reclaim DMF, reduce the content of principal pollutant DMF in the waste water.

2. according to the height of Pollutant levels, the anaerobism preconditioning technique of high-concentration waste water is set, has solved anaerobic degradation and the ammonia nitrogen removal of leatheroid wastewater treatment the biggest problem DMF.

3. treatment system stability and high efficiency, the water outlet after the processing can be used as the water source of reuse water, has good economic benefits.

Description of drawings

Fig. 1 is the schematic flow sheet of inventor's fabricate-leather method of wastewater treatment.

Embodiment

Each main units comprises in inventor's fabricate-leather method of wastewater treatment flow process: main kind of waste water is: collect waste water A, overhead water B and other waste water C towards tower water, coagulating pan, accumulator tank and recycling bin.A kind of leatheroid method of wastewater treatment of the present invention may further comprise the steps:

(1) water collecting basin: collect the waste water A towards tower water, coagulating pan, accumulator tank and recycling bin, water collecting pool volume is not less than the maximum emission of any waste water wherein.

(2) equalizing tank 1: collect overhead water B, 18 hours adjusting time.

(3) equalizing tank 2: collect composite waste C, 15 hours adjusting time.

(4) DMF waste water press filteration system: the waste water that contains high density DMF in catchmenting is removed foreign material in the waste water through press filteration system, and the waste water after the press filtration enters the DMF recovery system.

(5) anaerobic pond: the pressurization of waste water in the equalizing tank 1 enters anaerobic pond, and anaerobic pond adopts the rising flow reactor, and fill or filled biomass filler not the inside, and to keep certain upflow velocity, anaerobic pond hydraulic detention time be 12 ~ 24 hours.

(6) efficient deamination system: comprise that pH regulator pond, soda acid add, stripping tower.Anaerobic pond water outlet pH adjusts to 10 ~ 11, and pressurization enters stripping tower, and the stripping gas-water ratio is 200 ~ 400, and the medicament of adjusting pH adopts Ca (OH) ₂And H ₂SO ₄

(7) anaerobic-aerobic system: composite waste carries out denitrification in anoxic pond, Aerobic Pond carries out nitration reaction, removes COD and NH in the waste water ₃-N.Anoxic pond DO is lower than 0.5mg/L, hydraulic detention time 2 ~ 4 hours; Aerobic Pond DO is 2.0 ~ 4.0mg/L, hydraulic detention time 18 ~ 36 hours.System's internal reflux ratio is 200% ~ 400%, and external reflux ratio is 50% ~ 100%.Biologic packing material is installed in the anaerobic-aerobic system or biologic packing material is not installed.

(8) coagulative precipitation tank: go out remaining organism in the anaerobic-aerobic system, water outlet reaches discharging standards or further advanced treatment and reclamation.

The preferred operational conditions of handler's fabricate-leather method of wastewater treatment of the present invention is: 18 hours anaerobic pond residence time, stripping gas-water ratio 300: 1, anoxic pond 3 hours, Aerobic Pond 24 hours, internal reflux ratio 300%, external reflux ratio 75%.

The basic equipment of cell process of the present invention is prior art, and specific processing condition all provide: comprise DMF recovery-anaerobism-ammonia-nitrogen desorption-anaerobic-aerobic (A/O) technology.

Enter respectively in the water collecting basin towards tower water, accumulator tank, coagulating pan, wash water, pump up to the plate-and-frame filter press filtration, filter residue is mixed coal and is burned, filtrate flows into the storage pond, be forced into the DMF that reclaims in the recovery tower in the waste water with water pump, after the recovery, waste water and other reclaim liquid and discharge with the form of overhead water.Overhead water is forced in the anaerobic pond with water pump from flowing to equalizing tank, and the DMF in the waste water decomposes by anaerobion, produces ammonia nitrogen, enters denitrification system, is mixed into equalizing tank 2 with other waste water after the denitrogenation, and the ammonia of stripping enters ammonia recovery system.Sanitary sewage, ground wash-down water, tanning water, water coolant, ash-flushing water etc. enter equalizing tank 2, the composite waste pressurization enters the anaerobic-aerobic system in the equalizing tank 2, waste water mixes with the internal reflux mixed solution in the anoxic pond, carry out denitrification, carry out nitrated in the Aerobic Pond, thereby organism and ammonia nitrogen in the removal waste water, mixed-liquor return is to anoxic pond in the Aerobic Pond.Through after the mud-water separation, sludge part is back to anoxic pond at second pond in water outlet in the anaerobic-aerobic pond, and supernatant liquor enters that coagulative precipitation tank further purifies the back discharging or as the water source of reuse water.Leatheroid waste water is through treatment scheme shown in Figure 1, and each structures handler fabricate-leather water treatment effect sees Table 1.

Each structures treatment effect table of table 1

The structures title	????COD			????BOD ₅			????NH ₃-N
	????COD			????BOD ₅			????NH ₃-N			Water inlet	Water outlet	Clearance (%)	Water inlet	Water outlet	Clearance (%)	Water inlet	Water outlet	Clearance (%)
	Equalizing tank 1	?1800	??1800	??-	??550	???550	????-	???15	??15	Water inlet	Water outlet	Clearance (%)	Water inlet	Water outlet	Clearance (%)	Water inlet	Water outlet	Clearance (%)	????-
Anaerobic pond	Equalizing tank 1	?1800	??1800	??-	??550	???550	????-	???15	??15	?1800	??1000	??44.4	??550	???300	????45.5	???15	??360	????-	????-
Anaerobic pond	The deamination system	?1000	??950	??5.0	??-	???-	????-	???360	??145	?1800	??1000	??44.4	??550	???300	????45.5	???15	??360	????-	????59.7
Equalizing tank 2	The deamination system	?1000	??950	??5.0	??-	???-	????-	???360	??145	?1200	??1200	??-	??600	???600	????-	???100	??100	????-	????59.7
Equalizing tank 2	Anoxic pond	?1200	??750	??37.5	??600	???250	????58.3	???-	??-	?1200	??1200	??-	??600	???600	????-	???100	??100	????-	????-
Aerobic Pond	Anoxic pond	?1200	??750	??37.5	??600	???250	????58.3	???-	??-	?750	??100	??86.7	??250	???20	????92.0	???-	??15	????85	????-
Aerobic Pond	Coagulative precipitation tank	?100	??60	??40.0	??20	???10	????50.0	???-	??-	?750	??100	??86.7	??250	???20	????92.0	???-	??15	????85	????-

Claims

1, a kind of method of leatheroid wastewater treatment, just select suitable treatment process to take branch matter treatment process according to COD in the waste water and DMF concentration, it is characterized in that to COD and DMF concentration that 10 the above waste water of 000mg/L adopts and is introduced into the DMF recovery system and reclaims DMF; Reclaim back waste water and carry out anaerobic treatment; The ammonia nitrogen that the posthydrolysis of DMF anaerobic treatment is produced carries out the stripping removal then; Waste water and other COD concentration after stripping is removed are lower than 10, and the leatheroid technology composite waste of 000mg/L carries out anaerobic-aerobic+coagulation-settlement process together again to be handled.

2, the method for leatheroid wastewater treatment according to claim 1 is characterized in that the anaerobic treatment reactor adopts rising streaming anaerobic reactor, 15 ~ 24 hours residence time.

3, the method for leatheroid wastewater treatment according to claim 1 is characterized in that loading biologic packing material in the anaerobic-aerobic pond, 2 ~ 4 hours anoxic residence time, 24 ~ 36 hours aerobic residence time.

4, the method for a kind of leatheroid wastewater treatment according to claim 1 is characterized in that anoxic pond oxygen level DO is that 0.5mg/L, Aerobic Pond DO are 2.0 ~ 4.0mg/L; The anaerobic pond temperature is 15 ~ 35 ℃, and the temperature of anoxic, Aerobic Pond is respectively 15 ~ 38 ℃.

5, the method for leatheroid wastewater treatment according to claim 1, it is characterized in that containing COD, the higher waste water of DMF concentration refers to towards the Cleaning Wastewater of tower water and coagulating pan, accumulator tank and recycling bin, COD concentration is 10, the waste water that 000mg/L is above, the processing of DMF recovery system is that the waste water that squeezes out enters the DMF recovery system and is meant distillation or distillation system through the plate-and-frame filter press extruding.

6, a kind of according to claim 1 or 5 method of leatheroid wastewater treatment is characterized in that described ammonia-nitrogen desorption method is: utilize Ca (OH) ₂The pH value of waste water is adjusted to 10 ~ 11.

7, a kind of according to claim 1 or 5 method of leatheroid wastewater treatment is characterized in that other COD concentration is lower than 10,000mg/L leatheroid technology composite waste, reclaim back waste water with DMF and carry out anaerobic treatment.

8, a kind of according to claim 1 or 5 method of leatheroid wastewater treatment is characterized in that installing in anoxic one aerobic system biologic packing material.

9, a kind of according to claim 1 or 5 method of leatheroid wastewater treatment is characterized in that described ammonia-nitrogen desorption method is: the stripping device adopts stripping tower, and gas-water ratio is 200 ~ 400: 1.