The Energy Resherch On The Oxidation Ditch Of The Urban Sewage Treatment Plant

The high cost of operation is the most common problem in the sewage treatment plant,it influences the effect of water pollution treatment directly, so the problem that saving energy and reducing consumption in the wastewater treatment process is the current one to be solved. Energy conservation means emission reduction, can reduce the carbon emissions in the energy consumption of one-time effectively,which has the important practical significance to the low carbor economy development that our country advocate at present.According to the practical research of some sewage treatment plants that using the oxidation ditch process in anhui province,this paper introduces the basic operation situation and the relevant technological process of the sewage treatment plant, investigates each processing unit equipment operation and energy consumption status in different oxidation ditch process in detail,and makes statistics that the total energy consumption in the operation of every sewage treatment plant.According to the index difference that different process and aeration equipment operation brings,it evaluates comprehensively the aeration mode of the oxidation ditch in some sewage treatment plant in Anhui province with analytic hierarchy process; At the same time it builds up the fuzzy control model system of the biochemical aeration period that cost the biggest energy with MATLAB software tools, explores and sums up the energy saving measures of reformation in the other treatment period, the research results and conclusions are as follows:(1)The practical processing is less than the design value of water level in the research of the the sewage treatment plant, which generally operates with high energy consumption that is more than half of the total energy consumption. Therefore, the research on the energy saving is focus on the section of biochemical aeration processing in the urban sewage treatment plant oxidation ditch process.(2) According to the calculation it obtains the power consumption of per ton water,the lowest ones are Chaohu sewage treatment plant and Hefei WangTang sewage treatment plant whose practical processing scale are60000m3/d and150000m3/d, thus it can be seen in the normal water load, the bigger the sewage treatment plant is, the power consumption of per ton water is lower.(3)It introduces the aeration combinations used in the urban sewage treatment plant oxidation ditch process combining with investigation and makes comparative analysis,from some angles containing maturity of process、economic benefits and the operation stability of the system.According to the calculation of the model it draws the conclusion:the surface aerator of down-umbrella and underwater-push is the best aeration combination.(4) According to the ahp model it draws that the weight of outlet water stability in index layer is the highest, about0.5309; the power consumption of per ton water is the second one, about0.1729, and in turn for the stability of equipment operation, the life of equipment, the power consumption of removing per COD,the difficulty of operation management, the power consumption of removing per sludge,the difficulty of construction.(5) Taking the field test to the certain city sewage treatment in Anhui province as plant-based, it uses MATLAB software tools to build a double-input and single-output fuzzy control model system,according to the result of model it adjusts the operation of aeration turn disc, and controls the concentration of the dissolved oxygen in the Orbal Oxidation Ditch in real-time, the effect of the energy saving test runs verification.(6) In addition to biochemical aeration segment, sewage treatment plant for ascension, the returning of sludge and treatment period of energy consumption were also a certain proportion of the total energy consumption occupy, all kinds of sewage pump are the main energy consumption equipment in the sewage treatment plant for ascension and the returning of sludge, its energy is wasted because the pumps are often not running in efficiently.It achieves energy-saving operation by streamlining reflux way to reduce there flux ratio and reduces the reflux time and other means in the returning of sludge.(7) Choosing efficient flocculant in sludge flocculation processing stage and determining the optimal dosing quantity through experiment to reduce the cost,at the same time it ensures that the dewatering machine operates normally in the efficient segments.