Selection Of PVC Pipe Based On Leachate Immersion Experiment

Leachate is usually extracted from landfill and transported through pipes to the corresponding treatment facilities for subsequent treatment.In the process of migration,it is easy to cause pipe blockage,or even pipe burst,which poses a secondary environmental threat to groundwater and surface water.It is of practical significance to study the factors influencing the scale formation in the leachate transportation pipeline and select the suitable pipe material on this basis.By designing leaching experiment,this study choose common drainage pipe PVC dip in two age groups(young and old)in the leachate,a number of basic indicators of leachate cycle,including calcium and magnesium ions,chloride ion,REDOX potential,dissolved oxygen and pH,and the combination of PVC material performance characterization,contrast samples material leaching after change,discuss the possible causes of formation scaling.The grey target decision method was used to select four different kinds of PVC pipes,including100%PVC,85%PVC+15%TPU(polyurethane),75%PVC+14%TPU(polyurethane)+11%PET(polyester),60%PVC+23%PET(polyester)+17%TPU(polyurethane).The pipes with the best comprehensive performance were selected to guide the selection of leachate drainage system.The main conclusions of the study are as follows :(1)the scale formation of PVC sample after leaching in young leachate is large,which may be caused by chemical precipitation and microbial metabolic activities.(2)the content of calcium ions in leachate is the most important factor causing scaling,followed by pH.(3)the preferred order of the four kinds of PVC materials to be selected is 85% PVC + 15 % TPU(polyurethane)>100%PVC > 60% PVC + 23% PET(polyester)+ 17% TPU(polyurethane)> 75% PVC +14% TPU(polyurethane)+ 11% PET(polyester).