关键词： 填埋场渗滤液；矿化垃圾；生物反应床；
Design of a landfill leachate treatment process
Abstract: This case was a phase of Chongming domestic waste comprehensive treatment plant landfill leachate treatment engineering. This case was designed  according to "Shanghai integrated wastewater discharge standard" (DB31/199-2009) secondary standards. Principle is harmless, reduction and recycling. The rationality and efficiency are important, in order to achieve economic benefit, social benefit and environment benefit unification. Leachate treatment is the final link in sanitary landfill, if low standard, not only bring immeasurable on the surrounding environment pollution and hazard, a threat to human body health, but also makes sanitary landfill lose its original meaning[3]. As a result, the landfill leachate treatment is particularly important[4].
Combined lots of domestic and foreign development of garbage leachate treatment results in recent years[5]. Pretreatment - merge process was chosen because in economic terms, operation mode flexibility and on water quality assurance, is an ideal treatment program. After comparing the technical feasibility, environmental impact, operational management, and other aspects of economic indicators, This design choice of the "aged refuse bioreactor bed + single-stage reverse osmosis" program. When it came to technical feasibility, the program level of advanced technology, high reliability, simple equipment.Also,this program was environment friendly and it was easy to operated and managed. Mineralized garbage bed belongs to the natural substrate from the purification system, its structure mainly includes supporting layer and water layer, water distribution, sewerage systems. The key point of mineralized garbage bed design is to choose the bed body waste layer thickness. Reaction bed treatment effect, hydraulic loading and the investment cost is determined by the thickness of bed layer. The smaller the thickness, the higher hydraulic loading, the lower the cost of investment, but the effluent water quality decline.
Design process is: landfill pump pumping the leachate regulating pool. Leachate in regulating pool after storage and anaerobic degradation, waste water are pumped into primary mineralization bed. Through the integrated processing of mineralized refuse bed, gravity artesian water into the tank level set, pool sewage level set by the pumped into secondary mineralization bed garbage and gravity artesian water pool into the secondary set, 2 sets in sewage pool by the pumped into level 3 mineralized garbage bed, gravity artesian water pool into level 3 sets. Level 3 in the collecting basin sewage pump into the single stage reverse osmosis systems, reverse osmosis system treated effluent into clear water reserviors, clear water reserviors Yangtze river or the direct discharge of water reuse. Concentrate into the reverse osmosis system concentrated tank, thick liquid pool of water injection into the landfill area or into the basin. Set inside the pool laid 1.5 mmHDPE membrane, water pump set two sets, one with a case. Reverse osmosis system penetrating fluid recovery was 75%, treatment of water of 150 t/d.There were three aged refuse bioreactor bed because landfill leachate with a high concentration of organic matter, complex composition, containing a large number of viruses, bacteria and other characteristics, many types of pollutants, high concentration and concentration range, the concentration can vary in different months several times. Single-stage aged refuse bioreactor bed load limited. After reading a lot of previous experimental studies conclude that refuse to take three mineralized bed bioreactor effluent elasticity receiving higher water quality standards and guaranteed. After three mineralized refuse bio-reaction bed and a single-stage reverse osmosis system treated leachate organic load can be achieved NBOD5=10.18kgCODcr/(m3•d),  NCODcr=3.81kgBOD5/(m3•d), Nss=0.38kgss/(m3•d), NNH3-N=1.02kgNH3-N/(m3•d), Achieved "Shanghai Integrated Wastewater Discharge Standard" (DB31/199-2009) the second emission standards. Aged refuse bioreactors were designed three beds in the same size as the entire processing chain safety pre-high levels, to ensure water quality, and in the construction, maintenance and parts ancillary aspects of simple and convenient. Mineralized waste bed area of approximately 1782m2 (about 66m × 27m), depth of 4m, are all dam structures. Sump size is 18m × 5.6m × 3.4m, reinforced concrete. Clean water tank, concentrated liquid pool size is 10m × 5.6m × 4m, reinforced concrete. Structures investment costs 8.8292 million yuan. 填埋场渗滤液处理的工艺设计+CAD图纸(2):http://www.youerw.com/huaxue/lunwen_9017.html