Researches On The Best Cleaner Production Assessment And Its Wastewater Treatment Of Dioscorea Zingiberensis Industry

Due to the limitations of the Dioscorea zingiberensis growing conditions, thedioscorea zingiberensis industry are mainly located in Shiyan, Hubei and Shangluo,Shaanxi, which is the water source of the Middle-Route of the South-to-North WaterDiversion Project. A large amounts of water that is high salinity, high concentrations oforganic, is generated in the production process of the dioscorea zingiberensis. It’s difficultto treat this wastewater using conventional wastewater treatment, and then cause seriouswater pollution of the danjiangkou reservoir. Therefore, this paper adopts the method of"cleaner production+end-treatment to prevent and control the pollution of the dioscoreazingiberensis industry.The best cleaner production process of the dioscorea zingiberensis industry isdetermined by "scene investigation+model assessment": By mean of the sceneinvestigation, the status of cleaner production process of the dioscorea zingiberensisindustry is mastered, and the direct separation process, the SMRH, and the directseparation-plate frame filtration are screened out as the election process of the bestprocess, and it’s provide data support for follow-up assessment; This paper adopts thecombination of analytic hierarchy process and gray relational analysis to assess the cleanproduction process of the dioscorea zingiberensis industry on the basis of assessmentmethods currently used clean production. The analytic hierarchy process determines theindex weight, and the gray relational analysis is used to comprehensive assessment. Thedirect separation process is finalized as the best cleaner production.、This paper determines the combination of pretreatment+anaerobic treatment+aerobic treatment process to deal with the comprehensive wastewater that’s generated inthe direct separation process, on the basis of the wastewater quality and emissions. Thetest system could treat well dioscorea zingiberensis wastewater during its stable operation.When the influent COD concentration is about10000mg/L, the effluent CODconcentration of the test system could be basically stabilized around250mg/L, to meet therequirements of saponin industrial water pollutant discharge standards"(GB20425-2006).During the process of the test system startup, the UASB reactor goes through nurturing domestication stage and load improvement stage, and its effluent CODconcentration could be basically stabilized around1200mg/L until100days or so, and itsCOD removal rate is above80%, so the treatment effect is stabilized. During the processof the two contact oxidation ponds startup, it doesn’t go through load improvement stage,and directly goes through the nurturing domestication of sludge, and the effluent CODconcentration is basically stabilized around200mg/L until45days or so, while the CODremoval rate fluctuate within the range of70%to90%, so the treatment effect isstabilized.In addition, the test study found: In the test system, the adjustment of pH andtemperature affect seriously the treatment effect of the UASB, and the reactor couldhandle normally when the influent pH is basically stabilized in the range of6.5to7.0andthe inffluent temperature is basically stabilized in the range of33℃to37℃; Themaximum volumetric loading rate of the UASB is9kgCOD/(m3·d); The effluent VFAconcentration of UASB can really reflect its treatment effect and its effluen COD trend;The two contact oxidation ponds is very sensitive to the effluent stability of UASB, so theoperation of UASB should be attached great importanc in actual production.