[China Environmental Protection Online] The Beijing Municipal Bureau of Quality Supervision recently announced that the Beijing local standard "Energy Consumption Quota for Urban Sewage Treatment" will be implemented on March 1 next year to make the sewage treatment more reasonable in energy use and play a role in energy conservation and emission reduction. This is the first standard for the energy consumption quota of sewage treatment in China. The energy consumption of 91 sewage treatment plants in the city will be subject to review. After sewage treatment, it will reach the Class I Class B standard. It is estimated that the overall energy saving will be about 8%.

At least 800000 tons of sewage are directly discharged into the river every day

"There are still 800000 to 1000000 tons of sewage discharged directly in the city every day, and the actual sewage treatment rate is lower than that after the Olympic Games." An Gang, chairman of the Rural Committee of the Beijing Municipal People's Congress, pointed out that the overall situation of water pollution in the city is still serious.

It is reported that the overall water quality of the North Canal basin is still inferior to Class V. The small and medium-sized rivers outside the Fourth Ring Road, such as Xiaotaihou River, Xiaolong River, and Ba River, have sewage cross-flow, black and smelly, and various branches, ditches, ditches and roadside ditches are either dry or accumulate sewage. Many newly-built communities and units in the urban-rural fringe from the Fourth Ring Road to the Fifth Ring Road are not connected to the municipal pipe network, and sewage self-treatment facilities have not been built or installed, and sewage is directly discharged into the river. In rural areas outside the Fifth Ring Road, the coverage rate of sewage collection pipe network is very low; There is a large gap in sludge treatment capacity, and temporary treatment measures are blocked. More than 40000 tons of sludge are accumulated in Gaobeidian and Xiaohongmen sewage treatment plants.

In addition, the construction of sewage treatment plants lags behind the urban development. The self-built sewage treatment facilities in some residential areas have insufficient operating funds, aging equipment, and can not operate normally. Some planned sewage collection pipe networks are affected by demolition and other factors, and are difficult to implement. There are also broken pipes and headless pipes in some areas, which become blind areas and dead corners of sewage collection.

At the same time, "sewage treatment and sewage resource utilization should be placed at the same important level as air pollution prevention and control." The Rural Committee of the Beijing National People's Congress suggested that in 2015, the distribution, source and cause of direct sewage of 800000 to 1000000 tons should be identified first, a detailed account should be established, a treatment plan should be formulated one by one, and the network access project of sewage not connected to the pipe network community should be started. According to the actual scale of urban development and population growth, complete and moderately advanced urban drainage system planning and scientific sewage treatment facility construction planning shall be prepared, and the implementation time shall be determined.

In addition, many experts suggested that the proportion of sewage treatment fee should be increased within the current water price, and the ladder charging mode should be adopted simultaneously with the water price. Timely adjust the water price standard to gradually raise the sewage treatment fee to the competitive price level.

It shall comply with Class I Class B standard

In this regard, the Beijing Municipal Bureau of Quality Supervision announced on December 5 that the Beijing local standard "Energy Consumption Quota for Urban Sewage Treatment" will be implemented on March 1, 2015, so as to make the sewage treatment more reasonable use of energy and play a role in energy conservation and emission reduction. This is the first standard for the energy consumption quota of sewage treatment in China. The energy consumption of 91 sewage treatment plants in the city will be subject to review. After sewage treatment, it will reach the Class I Class B standard. It is estimated that the overall energy saving will be about 8%.

Li Yan, one of the drafters of the local standard "Energy Consumption Quota for Urban Sewage Treatment", said that Beijing Drainage Group and Beijing Drainage Association, which led the drafting of the standard, had previously collected and analyzed the data of 34 sewage treatment plants in Beijing and some sewage treatment plants in the country from 2009 to 2011, taking the average value of the three years as the limit value of the energy consumption quota and the optimal value as the advanced value. We have also carried out a one-year standard pilot project for 11 sewage treatment plants in Beijing, with an overall energy saving of about 8%. The new standard will be used to regulate the energy consumption of existing urban sewage treatment plants and provide energy consumption accounting standards for new sewage plants.

For example, the second phase of Qinghe Sewage Treatment Plant with a treatment capacity of 200000 cubic meters per day has completed the energy-saving transformation, reducing the total electricity consumption by 1.38 million kilowatt-hours, equivalent to 55 tons of standard coal, and saving 1.08 million yuan in electricity costs.

It is reported that the energy consumption of 91 sewage treatment plants in the city will be reviewed, and the sewage plants with a daily treatment capacity of 10000 to 100000 tons are the key energy-saving transformation objects. At the same time, according to the standard, the effluent index of the treated water of the sewage treatment plant should meet the Class I Class B standard, which is equivalent to the Class IV non-polluting water quality standard.

It is reported that the energy consumption of 91 sewage treatment plants in the city will be reviewed, and the sewage plants with a daily treatment capacity of 10000 to 100000 tons are the key energy-saving transformation objects. At the same time, according to the standard, the effluent index of the treated water of the sewage treatment plant should meet the Class I Class B standard, which is equivalent to the Class IV non-polluting water quality standard.

Sewage treatment plants should also save energy and reduce consumption

The conclusion that the sewage treatment plant undertakes the important task of improving the water environment, but it is an energy-intensive enterprise, occupying the top ten of the energy-intensive industries, is very surprising, but more worrying is that China has not yet realized this problem, and the construction of sewage treatment plants still follows the existing model.

Recently, Qu Jiuhui, an academician of the CAE Member and a researcher of the Ecological Environment Research Center of the Chinese Academy of Sciences, Ke Bing, deputy director of the China Agenda 21 Management Center of the Ministry of Science and Technology, Wang Kaijun, a professor of Tsinghua University and vice president of the School of Environment, Yu Gang, a professor of Tsinghua University, Wang Hongchen, a professor of Renmin University of China and vice president of the School of Environment, Yu Hanqing, a professor of the University of Science and Technology of China, and other six influential experts appealed, It is not advisable to exchange high energy consumption for the reduction of water pollutants. The society should pay more attention to the high energy consumption of sewage treatment plants, formulate standards, give policies, guide their treatment technology upgrading, improve energy efficiency and ultimately achieve energy self-sufficiency.

Wang Hongchen pointed out that the energy consumption of the sewage treatment plant is mainly electricity consumption. The power consumption per cubic meter of sewage treatment is 0.2-0.3 kilowatt-hour, and the electricity cost accounts for about 50-70% of the sewage treatment cost. At present, there are 16000 sewage treatment plants in the United States, accounting for about 3% of the total power consumption of the whole society. In cities, the power consumption of sewage treatment often exceeds 10% of that of the whole city.

At present, there are more than 3500 sewage treatment plants in China, and the energy consumption accounts for about 0.3% of the electricity consumption of the whole society. With the national control of the high-energy consumption industry and the rapid increase of the scale of sewage treatment, the energy consumption of sewage treatment plants in China will continue to increase, and will gradually close to the level of the United States. On the one hand, high energy consumption leads to higher cost of sewage treatment, exacerbating the current energy crisis; On the other hand, some small and medium-sized sewage treatment plants are difficult to operate, and the emission reduction benefits of sewage treatment plants cannot be brought into normal play.

Wang Kaijun said that most of the existing sewage treatment plants in China need to be upgraded. If the upgrading and upgrading continue to be carried out in the mode of high energy consumption and high material consumption, the sewage treatment industry will face more unsustainable problems.

Experts said that the current energy consumption of traditional sewage treatment plants is high, but the sewage also contains great potential. The research report shows that there are 200 billion kilowatt-hours of electricity hidden in the sewage of the United States, which can meet more than 10% of the energy demand of the United States.

Wang Kaijun said that the anaerobic process of sewage treatment can effectively solve the problem of high energy consumption, but among the existing sewage treatment plants in China, there are about 50 using anaerobic process, of which less than 30 are in operation. The development of sewage treatment technology in China deviates from the international development trend. Wang Hongchen, who worked for Beijing Drainage Group for a long time, said that according to his work experience, the self-sufficiency rate of energy in a sewage treatment plant with a standard anaerobic digestion system can normally reach 20-30%.

Compared with the emphasis on energy conservation and consumption reduction in other industries, the society still pays no attention to the energy consumption of sewage plants. The experts suggested that from the policy level, the sewage treatment plant should be given appropriate incentives for energy conservation and consumption reduction, and at the same time, the energy consumption standards of the sewage treatment plant should be timely introduced to guide its technical upgrading and development towards energy self-sufficiency.