Study On Process Suitability Evaluation And Optimization Of Wastewater Treatment Plant In Pingliang Industrial Park

This paper takes the wastewater treatment plant of Pingliang Industrial Park in Gansu Province as the research object,and the suitability of its wastewater treatment process was evaluated by using the method combining with the analytic hierarchy process and fuzzy comprehensive evaluation.With the help of the GPS-X software platform,the process flow of the wastewater treatment plant was simulated and parameter optimized,so as to provide data reference for the actual management of the wastewater treatment plant in Pingliang Industrial Park.The main contents of this paper are as follows:?1?According to the present situation of technology evaluation of wastewater treatment plant,a reasonable evaluation index system of process applicability of wastewater treatment plant is constructed,and the index weight was determined by AHP.The process of wastewater treatment plant in Pingliang Industrial Park was evaluated by fuzzy comprehensive evaluation method.The results showed that the process suitability of the wastewater treatment plant was good,with a score of 89.39.On the basis of the evaluation results and the actual situation of the wastewater treatment plant,corresponding suggestions are given.?2?With the aid of GPS-X software platform,the operation of BBR biochemica pool was simulated approximately by using a series of two anoxic fully mixed flow reactors and a rotary biological contact reactor,the process model of the wastewater treatment plant in Pingliang Industrial Park was constructed.The parameters of the model were corrected by the sensitivity analysis method,so that the model can effectively simulate the operation of the wastewater treatment plant.?3?The single-factor simulation study of process parameters was carried out to analyze the influence of different sludge reflux ratio,internal reflux ratio,sludge discharge volume of secondary sedimentation tank and dissolved oxygen concentration of each section of the aeration tank on the effluent water quality.Combined with the economics of stable operation of the process,the optimal operating parameters for single-factor simulation were determined as follows:the sludge reflux ratio is 75%,the internal reflux ratio is 200%,the sludge discharge volume of the second settling tank is 250m³/d,and the dissolved oxygen concentration of the aeration tank is distributed in increasing form.?4?Completed the orthogonal simulation study of the process parameters.While ensuring the quality of the effluent water,by comparing the energy consumption and cost of different operating conditions,the optimal operating conditions of the wastewater treatment plant process were determined:the sludge reflux ratio is 80%,the internal reflux ratio is 200%,the sludge discharge volume of the second settling tank is 280m³/d,and the DO concentration of the aeration tank 1#⁴#is 0.6mg/L,0.6mg/L,1.2mg/L,1.4mg/L,respectively.Under this condition,the average effluent water quality of the one-month dynamic operation was COD:18.86mg/L,NH₃-N:0.61mg/L,TN:10.27mg/L,TP:0.26mg/L,compared with the actual operation of the wastewater treatment plant,the energy consumption and cost were reduced by 5.57%.