CN101811796A

CN101811796A - Method for treating leachate

Info

Publication number: CN101811796A
Application number: CN200910259934A
Authority: CN
Inventors: 白振光; 原培胜; 李勇华; 赵瀛; 王成伟; 尹晓峰
Original assignee: 718th Research Institute of CSIC
Current assignee: 718th Research Institute of CSIC
Priority date: 2009-12-23
Filing date: 2009-12-23
Publication date: 2010-08-25

Abstract

The invention relates to a method for treating leachate, which is mainly used for treating town refuse landfill leachate and high-concentration industrial wastewater, and belongs to the technical field of environmental protection. A device for realizing the method comprises a regulating reservoir, a flocculation settling pond, an anaerobic reactor, a membrane bioreactor, a nanofiltration membrane and a reverse osmosis membrane, wherein the anaerobic reactor is an up-flow anaerobic sludge blanket (UASB) or an up-flow sludge blanket filter (UBF); and the membrane bioreactor comprises an anoxic zone and an aerobic zone. The method has high removing rate of CODcr, BOD5, suspended matters (SS) and ammonia nitrogen in the leachate; the device has the advantages of compact structure to reduce occupied land, convenient assembly, quick startup and reduction in debugging time; various membrane modules adopt a modular mode so as to contribute to maintenance and replacement; effluent meets the index requirements of 'Standard for Pollution Control on the Landfill Site of Municipal Solid Waste' (GB 16889-2008); and the effluent can be collected for recycling on occasions having low requirements on water quality.

Description

A kind of rubbish leachate treatment method

Technical field

A kind of rubbish leachate treatment method of the present invention is mainly used in townm refuse landfill percolate and high-concentration industrial-water and handles occasion, belongs to environmental technology field.

Background technology

Percolate is a kind of high density, unmanageable organic waste water, all can cause serious secondary environmental pollution to many-sides such as underground water, surface water, soil, atmosphere, biology on every side, and can enter human body directly or indirectly by food chain, the health of harm humans.

The character of percolate depends on multiple factors such as component of refuse, landfill time, weather condition, the general characteristics that have: (1) organic concentration height, chemical oxygen demand (COD) (CODcr) and biochemical oxygen demand (BOD) (BOD ₅) the concentration maximum can reach thousands of to several ten thousand mg/L; (2) metal content height; (3) change of water quality is big, and the composition of percolate and character constantly change with the prolongation of landfill yard usage period, and biodegradability worse and worse; (4) ammonia-nitrogen content height, variation range is big; (5) trophic factor is out of proportion, because the ammonia-nitrogen content height, the imbalance situation often appears in the ratio of C/N, and P lacks; (6) percolate can produce a large amount of foams when biochemical treatment, is unfavorable for that system normally moves.Because contain more hard-degraded substance in the percolate, generally after biochemical treatment, COD concentration is still in higher level, the water outlet standard index of " household refuse landfill sites pollution control criterion " (GB 16889-2008) is CODcr:100mg/l; BOD ₅: 30mg/l; SS:30mg/l; Ammonia nitrogen: 25mg/l.

Percolate water quality complexity, intractability is big, especially for the percolate with aged feature, the removal of its high nitrogen and hardly degraded organic substance is become difficult point.Percolate has become the seriously polluted and reluctant percolate of generally acknowledging in the world wide, at present each state all active research rationally, treatment process, method or equipment efficiently.

In patent 200820190500.6, adopt equalizing tank, flocculation sedimentation tank, membrane bioreactor, nanofiltration membrane and reverse osmosis membrane method that percolate is handled, the macromolecular substance of can not effectively degrading, biodegradability of organic matter is poor, make the biological degradation effect of subsequent film bio-reactor be subjected to very big influence, processing efficiency is low.The present invention has increased the anaerobic reaction stage, up-flow anaerobic sludge blanket (UASB) or upflow sludge blanket-strainer (UBF) have promptly been increased, larger molecular organics in the pollutent is degraded into small molecules by the anaerobic reaction stage, improved organic biodegradability, effective, the efficient condition that provides of moving of membrane bioreactor has been provided.

Summary of the invention

The objective of the invention is to have proposed a kind of rubbish leachate treatment method in order to solve the unmanageable problem of present percolate.

The objective of the invention is to be achieved through the following technical solutions.

A kind of rubbish leachate treatment method of the present invention realizes that the device that this method comprises is: equalizing tank, flocculation sedimentation tank, anaerobic reactor, membrane bioreactor, nanofiltration membrane and reverse osmosis membrane; Wherein anaerobic reactor is up-flow anaerobic sludge blanket (UASB) or upflow sludge blanket-strainer (UBF); Membrane bioreactor comprises oxygen-starved area and aerobic zone;

1) percolate enters equalizing tank by the potential difference gravity flow, makes the concentration of all contaminations be in a kind of uniform state, prevents that the fluctuation of the water quality and the water yield from affecting greatly the subsequent disposal stage;

2) with water pump the percolate in the equalizing tank is promoted in the flocculation sedimentation tank, simultaneously flocculation agent is joined in the flocculation sedimentation tank, make impurity and heavy metal ion precipitation in the percolate, the direct landfill of throw out;

3) with 2) percolate that obtains enters up-flow anaerobic sludge blanket (UASB) or upflow sludge blanket-strainer (UBF) by the pump lifting mode, makes the macromolecular substance in the percolate be degraded into small-molecule substance, can improve organic biodegradability like this;

4) with 3) percolate that obtains is promoted to the oxygen-starved area of band floating stuffing in the membrane bioreactor by potential difference gravity flow or pump, carries out the anti-nitration reaction denitrogenation processing; Percolate enters aerobic zone then, under the dual function of hollow-fibre membrane negative pressure-pumping and active sludge, makes the removal of being degraded of wherein most of pollutent, and the part mud mixture is back to the oxygen-starved area and carries out denitrification;

5) with 4) percolate that obtains enters intermediate water tank, through making it pass through nanofiltration membrane by the high-pressure pump pressurization behind the strainer; The water outlet of nanofiltration membrane enters another intermediate water tank, and pressurization makes it pass through reverse osmosis membrane through high-pressure pump again, obtains percolation water afterwards.

Reach " household refuse landfill sites pollution control criterion " (GB16889-2008) effluent index through the percolation water that obtains after the above-mentioned steps, can be back to some occasion not high after the collection water quality requirement.

Beneficial effect

(1) the present invention is to the CODcr in the percolate, BOD ₅, suspended substance (SS) and ammonia nitrogen have high clearance;

(2) compact construction can be integrated in one or more casings according to field condition is all or part of during application, has reduced appropriation of land;

(3) easy for installation, start fast, shorten initial failure period;

(4) various membrane modules all are modular mode, are convenient to maintenance and replacing;

(5) level of automation height adopts PLC control and liquid crystal touch screen technology, the real-time control of implementation procedure and unattended;

(6) water outlet can reach " household refuse landfill sites pollution control criterion " (GB 16889-2008) effluent index requirement, can be back to some occasion not high to water quality requirement after the collection.

Description of drawings

Fig. 1 is a method flow diagram of the present invention.

Embodiment

The invention will be further described below in conjunction with drawings and Examples.

Rubbish leachate treatment method comprises equalizing tank, flocculation sedimentation tank, anaerobic reactor, membrane bioreactor, nanofiltration membrane and reverse osmosis membrane; Wherein anaerobic reactor is up-flow anaerobic sludge blanket (UASB); Membrane bioreactor comprises oxygen-starved area and aerobic zone;

1) be CODcr:12000mg/l with former water index; BOD ₅: 7000mg/l; SS:2000mg/l; The percolate of ammonia nitrogen: 4000mg/l enters equalizing tank by the potential difference gravity flow, carries out the adjusting of water quality, the water yield in the pond, makes the concentration of all contaminations be in a kind of uniform state, prevents that the fluctuation of the water quality and the water yield from affecting greatly the subsequent disposal stage;

2) with water pump the percolate in the equalizing tank is promoted in the coagulation reactor, simultaneously flocculation agent is joined in the coagulation reactor, make impurity and heavy metal ion precipitation in the percolate;

3) with 2) percolate that obtains enters up-flow anaerobic sludge blanket (UASB) by the pump lifting mode, makes the macromolecular substance in the percolate be degraded into small molecules, can improve organic biodegradability like this;

5) with 4) percolate that obtains makes it pass through nanofiltration membrane by the high-pressure pump pressurization, and pressurization makes it pass through reverse osmosis membrane through high-pressure pump again, obtains percolation water afterwards.

The index of the percolation water that obtains after the process above-mentioned steps is CODcr:70mg/l; BOD ₅: 20mg/l; SS:10mg/l; Ammonia nitrogen: 15mg/l.

Claims

1. rubbish leachate treatment method, it is characterized in that: the device of realizing this method comprises equalizing tank, flocculation sedimentation tank, anaerobic reactor, membrane bioreactor, nanofiltration membrane and reverse osmosis membrane; Wherein anaerobic reactor is up-flow anaerobic sludge blanket or upflow sludge blanket-strainer; Membrane bioreactor comprises oxygen-starved area and aerobic zone;

1) percolate enters equalizing tank by the potential difference gravity flow, makes the concentration of all contaminations be in a kind of uniform state;

2) with pump the percolate in the equalizing tank is promoted in the flocculation sedimentation tank, simultaneously flocculation agent is joined in the flocculation sedimentation tank, make impurity and heavy metal ion precipitation in the percolate, the direct landfill of throw out;

3) with 2) percolate that obtains enters up-flow anaerobic sludge blanket or upflow sludge blanket-strainer by the pump lifting mode, makes the macromolecular substance in the percolate be degraded into small molecules;