Study On Technology Of Sequencing Batch Intensified Pretreatment Reactor And Sequencing Batch Biofilm Reactor For Leachate Treatment

The environmental problem caused by municipal solid waste has deteriorated environment more and more seriously along with domestic urbanization and economic development. As the main technology of municipal solid waste treatment in China, landfill product leachate which can endanger the environment seriously. Leachate is characterized by broad changing rang of water quantity and quality,high CODCr and ammonia nitrogen,low BOD5/CODCr value meaning,poor biological degradation ability,high density of poisonous and harmful substance. As for this, leachate treatment acknowledged as world problem which is difficult to solved.Because more and more attention has been drew to leachate pollution, relevant research increase gradually. Researchers concentrate on biological treatment technology especially because of considering the operating expenses as research on leachate treatment. Present project in practice and research verify that it is difficult to meet the requirement of discharging standard only by anaerobic or aerobic biological process without pretreatment. The issuing and implementation of"Pollution control standard of living solid waste landfill"(GB16889-2008), put forward newer and higher demand for leachate treatment. Developing new biological disposal craft and meeting the new standard, become a difficult subject that must be faced and solved.This thesis has summarized experience and lessons of biological technology of leachate treatment, relied on the experimental study of Heishizi landfill leachate treatment and its treatment performance, aimed at its insufficiency, and also basised on biological treatment technology and engineering principle, put forward the treatment craft idea of"Sequencing Batch Intensified Pretreatment Reactor (SIPR) and Sequencing Batch Biofilm Reactor (SBBR)", researched on its treatment efficiency,model proving and measures. Through the realization of nitrify and hydrolysis in SIPR, degrade substance with macromolecule or difficult to dissolve, to dissolvable substance with microorganism, which is easy to degrad and absorb with biological methold, improve the biological degraded ability by a relatively large margin. At the same time, SIPR has better denitrification performance, and can optimize carbon and nitrogen rate of outflow water, which can benefit the follow-up aerobic biological treatment. The follow-up aerobic biological treatment craft—SBBR has high removal performance of organic matter and nutrition salt, and has high ability of anti-shork and loading of water quantity and quality, and its out flow water quality is better and stable.Trough studying on SIPR and SBBR's influencing factor experiment, explore the more excellent operating mode,treatment way of the energy-efficient, improve the treatment performance to guarantee outflow water quantity. Practice has proved that though adopting the craft of"SIPR + SBBR", better removal performance of carbon and nitrification has been got. Density of outflow water's average CODCr,BOD5,ammonia nitrogen,TN,TP,SS,colority are lower than 179mg/L,26.8mg/L,95.8mg/L,35.2mg/L,134.9mg/L,2.75mg/L,27.3 mg/L,35 degree.Aiming at pursuing high efficiency,low energy consumption and better water quality, orthogonal experiment has been carried on in different temperature condition (normal temperature,lower temperature,higher temperature), the best operation parameter of SIPR/ first step SBBR/ second step SBBR is: HRT=2/4/2d,DO =0.75/2.0/2.5mg/L,Sequencing batch cycle is 6h ( normal temperature ) ; HRT=1.5/3/1.5d,DO=1.0/2.5/3.0mg/L,Sequencing batch cycle is 6h ( higher temperature); HRT=3d/6d/3d,DO=0.7/2.0/2.5mg/L,Sequencing batch cycle is 8h (lower temperature).Based on"Pollution control standard of living solid waste landfill"(GB16889-2008), average BOD5,TP,SS,colority,Hg,As,Cd,Cr,Cr6+ of SIPR-SBBR's outflow water can satisfiy the new discharging standard. Through researching on degradation mechanism of SIPR and SBBR, conclusion can be drew that SIPR has high removal performance of granule,colloidal particle and the organic matter which is difficult to degrade, SBBR has high efficiency of dissolvable organic substance's degradation. After SIPR's treatment, the ratio of organic matter difficult to be oxidized droped. While through SBBR, ratio of organic matter difficult to be oxidized rised by a large margin, increase the degree of difficulty for follow-up profundity chemistry treatment. Through treatment of SIPR-SBBR,TN/TP of leachate decrease, and ease the shortage of TP in leachate;CODCr/NH4+-N increase greadually,all of this can produce better nutration rate for proceed advanced treatment.Following-up craft of congealed deposition+ SBBR is designed to guarantee the outflow water quality of the discharging standard of"Pollution control standard of living solid waste landfill"(GB16889-2008). Congealed deposition has high removal performance to the contamination which has bad biological degradation, and SBBR has high quality of removing TN. SIPR+SBBR+congealed deposition+SBBR can satisfy the new discharging standard of"Pollution control standard of living solid waste landfill" (GB16889-2008).Combine with the biological filtration theory and studying of mixing bacterial denitrification dynamics, set up denitrification theory model of SIPR, carry on the analyzing and assimilating of model and the experimental data, the model calculating value fits better with the actual result. Two step SBBR's organic degrading dynamics model was set up too. Acorrding to this, guidance can be given to production experiment,for the sake of SIPR-SBBR's application into leachate treatment.