CN1329318C - Method for disposing refuse leachate of domestic refuse landfill - Google Patents

Abstract

The present invention relates to a method for disposing refuse leachate of a domestic refuse landfill. The method of the present invention comprises the following steps: the pre-aeration decreases the conductivity and the acid-base buffering degree of leachate; the refuse leachate is concentrated in an aeration tank to stay 9 days and aerate 2 hours every 4 hours, and the leachate is drained into a middle tank by a pump after pre-aeration treatment; a dish-tube-type reverse osmosis system is used for trapping most of pollutants in the leachate, the leachate which is treated by pre-aeration is input to the dish-tube-type reverse osmosis system by the pump, and the water molecules of the leachate pass through a reverse osmosis membrane through pressure, so that most of the pollutants are trapped. The method has a long-term, stable and reliable processing effect, and is suitable for domestic refuse landfills in different stages and water inflow quality in different seasons; the water quality of the effluent treated by the method is good without bacteria and suspended matters, the effluent reaches the first-level discharge limiting value of ' standards of a domestic waste sanitary landfill for controlling pollution' in China, wherein the suspended matters can reach water quality standards for domestic service water.

Description

Handle the method for the percolate of household refuse landfill sites

Technical field

Present method relates to the treatment process of high concentrated organic wastewater, specifically, relates to a kind of method of using the percolate of preaeration and disc tube reverse osmosis (dt-ro) technical finesse household refuse landfill sites.

Background technology

The percolate of household refuse landfill sites is the high concentration organic sewage that rubbish produces in the landfill process, be mainly derived from the interior moisture of precipitation, organic matter degradation and rubbish itself, contain 93 kinds of objectionable impuritiess according to surveying and determination, 22 kinds of emphasis control lists that have been put into China and American National Environmental Protection Administration are wherein arranged, wherein a kind can be directly carcinogenic, 5 kinds can be brought out carcinogenicly, in addition also contain plurality of heavy metal ion, bacterium, virus etc. in the percolate.Calculate with its pollution load, one ton of percolate is equivalent to 100～200 tons of municipal effluents to the contribution of environment.The domestic refuse of adding China is a mixed collection, be subjected to living condition, living habit, the influence in area and season is very big, make its composition very complicated, the water concentration and the water yield change bigger, relevant statistic data shows that the chemical oxygen demand COD of Chinese consumer waste landfill percolate is between 3000-50000mg/L, and ss suspended solid is about 2000mg/L, ammonia nitrogen is between 1000-3000mg/L, the pH value is between 4～9, also has halogenated aryl hydrocarbon in addition, pollution such as heavy metal and virus, as not handled, directly discharging will be to body of groundwater on every side, surface water body, soil and ecotope bring immeasurable pollution and harm, to the peripheral people's healthy generation serious threat.

Leachate quality is subjected to influence of various factors, as: rubbish composition, quantity of precipitation, landfill yard structure, landfill time etc.Different landfill percolates, COD from several thousand to several ten thousand, BOD ₅To several thousand, every index such as SS changes also very greatly from hundreds of.Generally speaking, inorganic component content and changes along with the continuity of landfill phase much larger than organic component content in the percolate, organic further degraded, the BOD/COD value reduces gradually, is unsuitable for biological degradation gradually, and also can continue to produce percolate 10～30 years after the landfill yard closing.

The percolate treatment plant that has built at present adopts traditional biochemical processing, and the processing of this technique functions originates from life sewage is extremely incompatible to this toxicity height of percolate, sewage that change of water quality is big.At present domestic more influential several big refuse tips as: the red temple mountain range of Foochow, the refuse tip, Chang'an in Chengdu, the A Suwei of Pekinese, six li village refuse landfills or the like all are the exemplary of biochemical treatment failure, because effluent quality does not reach design requirements, abandoned existing facility at present.The intractability of percolate is very big, and conventional treatment process is difficult to its processing is reached present national specified discharge standard.Even external technology can satisfy the also very few of first grade discharging requirement.The refuse landfill of China's requirement first discharge standard in 2002 is totally 4 according to statistics, and none example is up to standard; The compliance rate of secondary is less than 10% also, even if three grades of emission standards, compliance rate up to standard and basic also has only 59%.

Summary of the invention

The purpose of this invention is to provide that a kind of technology is reliable, the method for treatment effect reliable processing consumer waste landfill percolate steady in a long-term.

The method of the percolate of processing household refuse landfill sites of the present invention, its step comprises:

(1) adopt preaeration to reduce the specific conductivity and the soda acid buffer index of percolate: percolate is concentrated in the aeration tank, stopped 9 days, during this period, the 4 hours aerations in every interval 2 hours enter intermediate pool through the percolate after the preaeration processing with pump;

(2) employing disc tube reverse osmosis (dt-ro) system holds back the most pollution substances in the percolate: with pump the percolate after preaeration is handled is imported the disc tube reverse osmosis (dt-ro) system, make the water molecules in the percolate see through reverse osmosis membrane by pressure, all contaminants matter is held back.

The advantage of the method for the percolate of processing household refuse landfill sites of the present invention and positively effect:

1, treatment effect is steady in a long-term reliable, is applicable to the influent quality of household refuse landfill sites different steps and Various Seasonal;

2, effluent quality is good, no bacterium and suspended substance: water outlet can reach the first grade discharging limit value of China's " domestic refuse sanitary filling field pollute control criterion " in (GB16889-1997), wherein suspended substance (SS) can reach miscellaneous domestic water quality standard, its cost performance height.

3, treatment system preaeration of Cai Yonging and disc tube reverse osmosis (dt-ro) (DTRO) system high efficiency are integrated, and floor space is little, and the disposal field floor space only is about 20% of a common biochemical processing process; Its level of automation height, easy to maintenance, easy to operate, and the removable use of equipment so that household refuse landfill sites can also move to other place use after closing, bring more economic benefit.

Embodiment

The method of the percolate of processing household refuse landfill sites of the present invention, its step comprises:

1, adopt preaeration to reduce the specific conductivity and the soda acid buffer index of percolate.Charge into air by the percolate of aerator in the aeration tank, because the air come-up is overflowed partial vulcanization hydrogen, ammonia, mercaptan, voltaile fatty acid volatile organic compoundss such as (as butyric acid, acetate etc.) from percolate, thereby specific conductivity is reduced, be the load of follow-up disc tube reverse osmosis (dt-ro) system reduction; And a large amount of acid volatilizable organic effusions make the pH value rising of percolate, and the HCO that the soda acid buffer index is played an important role ₃ ^-Ion changes CO gradually into ₃ ^2-Precipitate in conjunction with heavy metal ion, caused the reduction of percolate soda acid buffer index.

Intermittent aeration is adopted in preaeration of the present invention, and the hydraulic detention time (from percolate enter aeration tank to the time of discharging) of percolate in the aeration tank is 9 days, and every interval was carried out aeration in 4 hours 2 hours, and specific conductivity can reduce about 30%.Enter intermediate pool through the percolate after the preaeration processing with pump, so that the operation of the continous-stable of disc tube reverse osmosis (dt-ro) system is for further processing with being pumped into disc tube reverse osmosis (dt-ro) (DTRO) system then.

2, employing disc tube reverse osmosis (dt-ro) (DTRO) system (commercially available) can hold back the most pollution substances in the percolate: reverse osmosis is the phenomenon opposite with the naturally osmotic process, promptly under the ambient pressure effect, the process that solvent is separated out by semi-permeable membranes, the DTRO system utilizes the principle of reverse osmosis technology, make the water molecules in the percolate see through reverse osmosis membrane by pressure, most pollution substances are comprised the small molecules solute, hold back greater than molecule and the ion of 1nm as ammonia nitrogen etc., thereby reach the purpose that purifies percolate.Disc tube reverse osmosis (dt-ro) DTRO system is main in this technology to be removed COD, BOD, ammonia nitrogen and adjusts the pH value, the water outlet that guarantees the entire treatment system reaches related standards, the highest can reaching " urban sewage reutilization city miscellaneous water water quality standard " (GB/T 18920-2002).Because DT-RO film group has special hydromeehanics design, make it to be suitable for handling high opacity and the high waste water that contains the sand coefficient, the waste water SDI value that enters the film group can reach 20, also can reach 40 and contain the sand coefficient; The installation, maintenance of DT-RO treatment system is simple, and is easy to operate, the level of automation height; Because the pipeline that the DT-RO system adopts, zero spare part are standardized component mostly, installation, maintenance is more convenient.

After disc tube reverse osmosis (dt-ro) moves for some time, need clean system.Cleaning system comprises volume pump, medicine storing pot etc.Cleaning process has system to clean and two kinds of matting.

System flushing: the flushing of film group must be carried out when each system closing.The auto stop during system fault is also carried out cleaning procedure.The main purpose of flushing is to prevent that the pollutent in the percolate from depositing at membrane surface.Flushing is divided into two kinds, and a kind of is with the percolate flushing, and a kind of is the water purification flushing, and water purification can adopt the clear liquid after the system handles, and the time of two kinds of flushings is generally all at 2～5 minutes.

Matting: for keeping the diaphragm-operated performance, the film group should regularly be carried out matting.Used clean-out system divides acidic cleaner A and alkaline cleaner C (Beijing Tiandiren Environment-Tech Co., Ltd produces and sells), and the timed interval that alkalescence is cleaned is 100～200 hours, and the acid timed interval of cleaning is 200～400 hours.The main effect that alkalescence is cleaned is to remove organic pollution, and acid main effect of cleaning is to remove inorganic pollution.When cleaning, detergent solution is at film group system internal recycle, and to remove the pollution substance that is deposited on the diaphragm, scavenging period was generally 1～2 hour, but can stop at any time.Liquid discharge system after cleaning finishes is to the pre-treatment equalizing tank.Generally clean-out system being diluted to 5～10% backs uses.

Claims (1)

1, handle the method for the percolate of household refuse landfill sites, its step comprises:

(1) adopt preaeration to reduce the specific conductivity and the soda acid buffer index of percolate: percolate is concentrated in the aeration tank, stopped 9 days, during this period, the 4 hours aerations in every interval 2 hours enter intermediate pool through the percolate after the preaeration processing with pump;

(2) employing disc tube reverse osmosis (dt-ro) system holds back the most pollution substances in the percolate: with pump the percolate after preaeration is handled is imported the disc tube reverse osmosis (dt-ro) system, make the water molecules in the percolate see through reverse osmosis membrane by pressure, all contaminants matter is held back.