Research On Optimization Model And Performance Evaluation System Of Process Selection In Urban Sewage Treatment Plants In Northeast China

The choice of wastewater treatment process is one of the most important in the design step of sewage plants, whether can we select suitable wastewater treatment process directly determines the investment spending, processing conditions, whether meet the requirement of discharging standard indices and operation and management of sewage plants. The choice of process in traditional sewage treatment plants most depends on the personnel experience and subjective choice of designers, does not have an objective and fair evaluation method. It is necessary to set up a set of wide selected and convincing evaluation process for process optimization.First of all, this article widely researched 31 northeast wastewater treatment plants, found statistics of selection process, design scale, emissions targets and treatment effect of northern region, the analysis found that the selection process, CAST of A/O process in the most common, and the design scale large number of small and medium-sized sewage factory flat, but overwhelmingly superior in large and medium-sized sewage plant processing capacity. In addition, the wastewater plants except three sewage factory followed GB secondary standard, it also have a lot of room to improve on emissions standards.This paper uses the analytic hierarchy process(AHP), established the northern sewage plant process optimization evaluation model by analysising the main influence factors of sewage plant actual value, then quantified the qualitative indexes and weighted the advantages and disadvantages of comparison processes.Applied the model to the technique selection optimization of QingYuan sewage treatment plant, contrasted CASS process, A/O process, double oxidation ditch process and MSBR process, using analytic hierarchy process to calculate the weights of these processes for W=(0.267, 0.052, 0.052, 0.267, 0.052, 0.267)T, ultimately determined the CASS process is the most suitable and establish the formula of?=0.267a+0.052b+0.052c+0.095d+0.267e+0.267 f, then simplify the model.This paper has also established the performance evaluation system of sewage treatment plant and verified the results of AHP method, then compared the choice of technology process and the average values of other sewage plants horizontally. Performance evaluation method set up the standard values of the indicators on the dimension of each assessment score of sewage plant.Applied in the process optimization of DaHuo Fang sewage treatment plant, fitting the index regression equation of each sewage factory standard values, showed the selection processed were better than the standard, then gave suggestions according to the score of each dimension of process operation parameters. Through the comparison of dimension, found QingYuan sewage plant design needs to be improved in terms of construction cost, NanZaMu sewage plant SS dimension scores compared to be worse than other plants, finally concluded CASS and contact oxidation process have obvious advantages in terms of low energy consumption...