Study On Emulsifier Span Synthetic Wastewater Treatment

In the process of making emulsifier Span, raw materials like fatty acids were used. There would be a lot of oils and fats in the production wastewater discharge. Oil film will be developed on the surface of the water after the wastewater was discharged, leading deadth of organisms in waters because of critical lack of oxygen, oxygen in the atmosphere was hindered to tranfer into water. Therefore, treating this kind of wastewater was of great significance to protect water resources, maintain ecological balance, promote economic development.According to sorbitol oleate (Span) emulsifier contains high content of organic pollutants and the component is complex, the process of contact anaerobic, aerobic treatment and advanced treatment (coagulation, or O3 + BAF combining process) was used. A kind of the new concrete filler was invented in anaerobic and aerobic treatment for filming and domestication. Optimization of various parameters and comparison of the advantages and disadvantages between the different processes were done through experimental research.The optimal process of making concrete fillers was obtained by comparing the performances of steel meshes of different specifications, different ratios of cement and water, PVA added or not. The results showed that the thicker steel wire mesh were, the smaller size grids were, and the higher starching rate was. The larger cement water ratio was, the higher starching rate was. The more PVA was added, the higher starching rate was , the better anti-drop capabilities.Through anaerobic - aerobic exposure to the synthetic Span wastewater discussed access to anaerobic and aerobic training contact with domestication and pilot plant operating conditions. It took 52 days for anaerobic domestication and it took 11 days for aerobic domestication, indicating hanging film of concrete got filling fast. When the COD was high, ammonia nitrogen and COD simultaneously declined in assimilation in the form of ammonia was removed. Nitrification nitrifying bacteria played the major role when COD was below 100mg/L, ammonia and nitrite were oxidized into nitrate nitrogen. When the pollutant substrate concentration was low (COD was 1100mg / L or less), COD degradation was consistent with the first rank exponential decay equation. When pollutants substrate concentration was higher (COD was 2000mg / L or more), COD degradation was zero rank reaction in the initial stage and first rank reaction later.When COD of the influent was 5000mg / L, influent flow rate was 2L/h, the COD removal ratio after anaerobic - aerobic treatment was more than 95%, the effluent COD was about 150mg / L.Advanced treatment of coagulation and ozone pre-oxidation-BAF were studied to decide the optimal operation parameters. PAC was the best chemical agent comparing ferrous sulfate and cationic bleaching agents as used in coagulation. When the dosage of PAC was 1500mg/L, COD of the effluent could be less than 80mg / L, chroma less than 8 times, and it met the discharging standard requirements. When ozone dosage was 150mg / L, HRT of BAF was 6h, after the whole treatment, COD removal rate was 46.7%, COD of the effluent was less than 80mg/L chroma was less than 4 times, and it had met the recycling standard. The process of ozone pre-oxidation-BAF was chosen.