Experimental Reasearch On The Treatment Of The Straw Pulp Making Intermediate Wastewater By Microelectrolysis-Activated Sludge-Baf

Serious pollution to the aquatic environment, which is brought by the straw pulp making intermediate wastewater, has become the focus and difficulty problems of the prevention and control of industrial pollution. Therefore, the research on an economic and technical feasibility treatment process is becoming a new problem in the development of paper and pulp mill wastewater treatment process.Regarding the intermediate wastewater from a paper and straw pulp mill as the research subject, the pilot-experiment was carried out by the combination of Microelectrolysis-Activated Sludge with BAF to treat the intermediate wastewater which contains a number of toxic and difficult decompounded organic compounds. The effects of the technological factors of the different treatment processes on treatment results are studied and the optimal control parameters are to be selected.The main results were as follows:(1) The combination process, the effluent quality of which was relative stable with the fluctuant influent, has stronger resist impact load capability and adaptability to the change of wastewater quality. The COD removal is in the range of 79.49%⁸3.02%; The SCOD removal is in the range of 72.99%⁸0.60%; The COD removal is in the range of 79.49%⁸3.02%; The BOD₅ and SS removal is 90% above; The chroma removal is in the range of 79.49%⁸3.02%.(2) The microelectrolysis treatment unit did greater contribution than activated sludge and BAF treatment unit for pollutants removal efficiency. If the pollutants removal of the microelectrolysis treatment unit becomes bad, the activated sludge and BAF treatment unit have strong ability to further treatment for the pollutants.(3) For the Microelectrolysis treatment unit, the optimal control parameters are that pH equals to 5, DO equals to 5.5mg/L, HRT equals to 3h.For the Activated Sludge treatment unit, the optimal control parameters are that DO equals to 1.5mg/L, HRT equals to 5h,θc equals to 12d. For the BAF treatment unit, the optimal control parameters are that Gas Velocity equals to 4m/h, Filtration Speed equals to 4m/h, Reflux Ratio equals to 3:1.The COD removal efficiency of the combination of Microelectrolysis-Activated Sludge with BAF is not favorable. At the same time, the rising extent of B/C is small.On the basis of the results of the pilot-experiment, the research was carried out by the combination of Activated Sludge with BAF on the treatment for the wastewater treated by UASB.The main results were as follows:(1) The combination process of Activated Sludge with BAF, the effluent quality of which not only meets the requirements of The Discharge Standard Of Water Pollutions For Paper Industry but also does meet Shan Dong Province Along The Line Of South-North Water Transfer Water Pollutants Discharge Standards Systems, has stronger resist impact load capability and adaptability to the change of effluent quality of UASB.(2) The combination process of Iron-Carbon Activated Sludge with BAF, the effluent COD of which remains at the level of 100mg/L with the average being 89mg/L and minimum being 82mg/L that could be much better to satisfy the Shan Dong Province Along The Line Of South-North Water Transfer Water Pollutants Discharge Standards Systems, is more suitable for treating the straw pulp making intermediate wastewater than others.The above-mentioned research results provide technical guidance for treating the straw pulp making intermediate wastewater and have the vital significance to the abatement of the Chinese paper and straw pulp industry.