| Dioscorea zingiberensis is the major raw material for producing saponin that is named as "the gold of medicine". Dioscorea zingiberensis is one of the main industries in Yunxi County Hubei province. A large number of wastewater stems from producing process. Saponin wastewater is a kind of acid wastewater which is high concentrated and difficult to be decomposed. It will pollute seriously to the environment if saponin wastewater is discharged directly. At present, there is not an appropriate process that can be used to treat saponin wastewater successfully in practical engineering because of the complex composition. The study just tries to search a feasible method to treat saponin wastewater by full-scale experiment.The total issue is mianly studied on the assorted process physical chemistry-biochemistry-ecotype. As the second half of the full issue, the thesis mainly studies on the combined process of two-phase anaerobic-aerobic- constructed wetland to treat saponin wastewater which has been pretreated. The process is applied to assure the quality of outflow can reach the first-grade national standards of discharge. According to two-phase anaerobic digestion process, the normal up-flow reactor acts as acidification phase reactor, and anaerobic bio-reactor with shock wave as the methane phase reactor. Anaerobic bio-reactor with shock wave can produce the methane in ambient temperature. It is the first time for anaerobic bio-reactor with shock wave to be used for high-concentration industrial wastewater treatment, which widens the application field for the research. The traditional jet agitator is used as the aerobic reactor. The constructed wetland is used as the advanced treatment in the process.After four months researches by full-scale experiment, the result of the experiment shows: activated sludge can be used as inoculated sludge. The culturing and domesticating bacterium phases can end in two months by means of one-time culturing. Two-phase anaerobic digestion system can be used to treat saponin wastewater successfully in ambient temperature. The 60.5% removal of COD can be obtained by Two-phase anaerobic digestion process under the condition of ambient temperature. The average removal of COD can be got 42.09% by hydrolysis acidification process and 47.79% can be got by anaerobic bio-reactor with shock wave process. The 90% removal of COD could be obtained by jet agitator process when the temperature is lower than 35℃. That the constructed wetland with horizontal subsurface flow is used as advanced treatment process is feasible. It assures the quality of outflow can reach the first-level national standards of discharge. The average removal percentage of COD, NH4 and TP in constructed wetland reach 47.79, 75.64 and 88.82 respectively. The relationship between hydrodynamic loss and lengthwise position of constructed wetland accords with linear equation. The efficiency of anaerobic process is obvious influenced by the pH value. The optimal pH value for hydrolysis acidification reactor ranges from 5.5 to 6.5. The treatment efficiency will be decreased obviously when the pH value is higher than 7. The optimal pH value for anaerobic bio-reactor with shock wave ranges from 6.8 to 7.2. The efficiency of anaerobic and aerobic process is obvious influenced by temperature: the efficiency of the total process will be increased obviously when the temperature arises. Unless corresponding technical measure is applied, the efficiency of aerobic process will be decreased markedly when the temperature higher than 35℃.The outflow quality that has been treated by the combined process attaints to the first-grade national standards of discharge. The cost of the treatment is 3.34 Yuan/m3. The research indicates that the best way for saponin wastewater treatment is to utilize the wastewater synthetically, which can decrease the cost of the treatment effectively.
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