Study On Influence Factors Of Energy Saving On Aeration System And Measures Of Control Mode In Wastewater Treatment Plant

The important way of solving water pollution of the environment is sewage treatment,but most wastewater treatment plants(WWTP) exist problems of costing high of treatment and operation.The important reason is low efficiency and high energy of aeration system that is main consuming department. Under background of"energy conservation and emission reduction",through the analysis of the aeration system problem, sloution and countermeasure are proposed.That is very important significance for improving efficiency of wastewater treatment and reducing the operating cost. With aeration system of typical WWTP as the research object in this paper, through researching influence factors of OTR of microporous aeration equipment, the factors and extent are analysed. Through analysing the existing problems of aeration system of equipment and control mode,the references of energy consumption and control mode optimization in WWTP are provided.Through OTR test experiment of new and old aerator,the reasons of decline and operation costing are analysed, hat will provide theoretical guidance of WWTP aeration equipment daily operation and reducing the operating cost. The main conclusions are as follows:The result of experiment of affecting the typical WWTP aerator key factors of oxygen-supplement ability indicated that:1)Temperature influence of OTR has two sides. When the temperature of water is 15℃, OTR is the highest.In the medium and high temperature conditions, with the increase of temperature OTR is reduce. In the low temperature conditions, with the increase of temperature OTR is increase. In the condition of higher air flow,extent of Increase or reduction of OTR is increase.2)Air flow influence of OTR has a certain condition. In scope of 1 to 3m3/h, the increase of air flow will make OTR increase. But beyond 3m3/h, with the increase of air flow the extent of increase of OTR will be reduced.3)The experimental analysis indicated that the salinity effect for OTR is not negligible in a certain range. In salinity scope of 0 to 2500mg/L,the influence of the salinity can be ignore. When salinity exceed 2500mg/L, with the increase of salinity, OTR get higher .So the influence of the salinity cannot be ignore.The results of analysis of aeration system problem and the current control mode in typical WWTP indicated that: 1)Many WWTP have existed some problems of aeration equipment aging leak and aeration pipes blocked and shotage of online monitoring instruments of oxygen in aeration tank.2) In this respect of aeration system operation, most WWTP have existed problems that WWTP only have one aeration system monitoring index and are not quickly response for water inflow and water concentration. 4) Through observation of aeration effect in the aeration tank of WWTP and continuous monitoring of dissolved oxygen and other record,the running status of aeration equipment and the advantage and disadvantage of control model can be analysised.The result of analysis of the aeration equipment operation's cost indicated that:1) The contrast experiment of OTR of new aerator and running ten years' aerator indicated that, after a period of time the oxygen-supplement ability of aerator will decrease.The OTR drops of about 10%.2)If aerator that runs ten years in first-stage project of LiCunhe WWTP in the QingDao city replace for the new aerator of the same type, it will save 900000 yuan every year and the cost of replacement will be recovered in 14 months later.