Reasearch On Energy Consumption And Energy-saving Measures Of Municipal Wastewater Treatment Plants

In recent years, our country is faced with the situation of water shortage and pollution. To build sewage treatment plants is the most direct, important and effective measure. As a result of the high energy consumption, low efficiency, high operating costs in operation process of sewage treatment plants, many of them are in a awkward position that can afford to build but not money to run. Consequently, there is very important practical significance to study on energy consumption and energy-saving measures for optimizing operation and management, reducing the running cost of sewage treatment plants.According to investigation for the actual operation condition of four sewage treatment plants, which are different processing technology, different scale, this paper researches constitution and distribution ratio of energy consumption, energy consumption characteristics and influencing factors of wastewater treatment plant. It establishes evaluation index system of energy consumption using the method of Analytic Hierarchy Process, proposes energy saving technical measures and effective ways to the processing unit of the sewage treatment plants. The main conclusion below:(1)Through specific energy consumption analysis of the four sewage treatment plants, energy consumption cost of unit sewage water treatment of the two design capacity100000tons is0.1662yuan per ton,0.2230yuan per ton; the two10000tons of plants cost0.2258yuan per ton,0.2431yuan per ton, indicating that the larger the processing scale is, the lower the total energy consumption is.The energy consumption of increased nitrogen and phosphorus removal in sewage treatment process is higher than ordinary two grade treatment process, indicating that the higher the processing degree, the higher energy cost.(2) The proportion of energy consumption of the sewage treatment plants is from high to low:biological treatment, pretreatment stage and sludge treatment stage, which respectively accounted for62.19%-71.14%,23.47%-25.11%,4.07%-13.85%of total energy consumption. The energy consumption of biological treatment stage mainly concentrates on the aeration system, and pretreatment stage is mainly consumed in water pump. (3) This paper establishes energy consumption evaluation index system using the Analytic Hierarchy Procpss. The main factors of energy consumption of sewage treatment plants are actual amount of sewage treatment, utilization rate of equipment, process stability, design and layout of WWTPs, control and management standards, etc. Apply energy consumption evaluation system in this paper for the energy consumption analysis and calculation of the four sewage plants. Energy consumption level from low to high:A, C, B, D. Computing result is fundamentally as same as the result of specific energy consumption analysis. The evaluation system can accurately judge the situation of energy consumption of sewage treatment plants.(4)The energy-saving and consumption-reducing measures of municipal sewage treatment plants are from sewage lifting system, aeration system, sludge treatment system and other aspects, mainly in rational design and layout of sewage plant; the lectotype and reformation of the main energy-consuming equipments, such as pumps, aeration equipment, flow pushing and mixing device and sludge treatment equipment and so on; the reinforce of the operation and management and control.