| Landfill leachate is a kind of persistent organic wastewater, which is produced inthe process of piling. Membrane bioreactor （MBR） is a new type of sewage treatment,which combines membrane separation technology with activated sludge technology.Now, MBR has been widely used in landfill leachate treatment. Membrane module isthe core component of MBR technology. The flat-sheet MBR, which has greatpotential for application in leachate treatment, has the characteristics of low energyconsumption, simple operation, easy to clean and high removal rate. While there arefew feasibility studies for flat-sheet membrane applied in industrial scale landfillleachate treatment.To study the feasibility of flat-sheet membrane applied in landfill leachate, a12m3/d equipment adopted the submerged flat-sheet MBR module was established inthis thesis to treat landfill leachate generated in a landfill, Liuzhou and operationcontinuously for5months. The treatment process of the equipment was "hydrolyticacidification+anoxia （A）/aerobic （O）/MBR+reverse osmosis （RO）". Through theremoval efficiency of COD, ammonia nitrogen （NH4+-N）, total nitrogen （TN） tostudy the stability and high efficiency of MBR system and compared with the oldtreatment process; On-line cleaning in site and lab cleaning were tested to findsuitable cleaning agent for flat-sheet MBR contamination during the disposal oflandfill leachate; The MBR effluent was treated by RO post-processing, according theeffluent water quality and RO running stability to confirm the feasibility of MBR forRO depth processing.The main research results were summarized as follows:1. The range of pH, COD and NH4+-N of the influent landfill leachate were7.84～8.57,4047～8827mg/L mg/L, and884～1787mg/L, respectively, the MLSS inMBR was8000～11000mg/L,the effluent COD and NH4+-N were624～2069mg/L,0.14～48.0mg/L, respectively, superior to the original "UASB+oxidation ditch "process when it was running at the same time.2. During the period of experimental device stable operation, TN removalefficiency was54.5%in A/O/MBR system, and the MBR effluent TN and NO2-was641mg/L,272mg/L, respectively, pH was at7.5to8.3, synchronous nitrificationdenitrification occurred in MBR system for TN removal.3. During the experiment, the transmembrane pressure （TMP） of MBR was less than0.03MPa and the membrane flux was in10L/（m2h）. it could operate for30daysthen the flux began to fall, serious membrane fouling was happened when it went to50th days, the membrane flux fell down to4.5L/（m2h）. The5%chelating agent Ahad the best cleaning effect, the membrane flux could return back to80％of the initialflux in the lab test; Chelating agent A was adopted for on-line cleaning, the membraneflux could return back to90％of the initial flux.4. The MBR effluent was treated by RO post-processing, during the4mouthsoperation period, RO system effluent COD <100mg/L, NH4+-N <25mg/L, TN<40mg/L,TP <3mg/L, and reached the landfill pollution control standard（GB16889-2008） of effluent standards. The RO membrane had barely polluted duringthe period, its membrane flux was maintained in20L/（m2h）, and the TMP was0.07MPa. |
