Application Studies On Two-stage Biological Treatment For Oil-polluted Water Processing

Petroleum-chemical polluted water features large drainage volume, high densities of petroleum and organic components, which makes it an industrial polluted water with great harm and huge difficulties to process, as well as the key point and difficulty for the aqua-environment pollution management.This thesis discusses the processing of oil-polluted water, based on the conventional three-method operation experience of petroleum-chemical polluted water processing and the national and international studies on the processing technologies of polluted water. Also, combined with the processing components and the volume and quality of the polluted water processed in polluted water processing factories nowadays, some operation indices are advanced such as for floatation tank, for aeration tank and for oxidation ditch. This helps to bring good drain water quality, steady working, easy operation and lower cost.Cascading horizontal flow and slope oil separator is taken in oil removal technique; partial pressurization and recurrent flow is taken in floatation technique. By fundamental principles and effective analysis, proper technique parameters and operation regulations are presented which remove oil and biological depressors efficiently, limit the oil proportion beneath 6mg/L in the second-stage floated water, and guarantee the normal operation of the biological treatment element. Based on contemporary theories and practical effects, parameters in the two-stage biological technique, serializing the aeration pool and the oxidation ditch, are discussed, as well as discoursed with analysis approach factor by factor. In addition, technique parameters and operation regulations suitable for this project are presented, which assures the steady operation of the instrument. And some emergency measures are presented.By the systematical tuning of all the components in the polluted water treatment as a whole, functions of elements are clarified along with some parameters in oil-polluted water treatment presented for this factory, such as mixture ratio, consistence of mixed liquid suspend solid (MLSS), sludge volume sedimentation ratio (SV), etc., which makes the water let out better than prescribed by the national standard. And problems existed and suggestions possible are pointed out.