The local standard of Jiangsu Province, Discharge Standard of Pollutants from Urban Sewage Treatment Plants (hereinafter referred to as the Standard), was officially implemented. On the same day, the Jiangsu Provincial Department of Ecology and Environment held a press conference to interpret the Standard.
reducing pollutant discharge from domestic sources
as an important basic project to improve environmental quality, urban sewage treatment plants are also an important source of pollutant discharge. At present, sewage treatment plants have been built in cities and counties in Jiangsu province, and the sewage treatment facilities in towns have been fully covered. More than 9 urban sewage treatment plants have been built in Jiangsu province, with a daily treatment capacity of about 21.6 million cubic meters. The total discharge of domestic pollutants accounts for nearly 4% of the province's total, which has a significant impact on the quality of regional water environment.
Jiangsu is located at the end of the Yangtze River and Huaihe River basins, which is a typical plain water network area with the highest water network density in China. Huang Wei, a first-class researcher at the Water Department of Jiangsu Provincial Department of Ecology and Environment, said that Jiangsu Province has a special situation, dense industry, dense towns and population, high development intensity, urbanization rate of 74%, total pollution discharge still at a high level, and the discharge intensity of major pollutants in the land area is 4-5 times that of the whole country, and the bottleneck of resources and environment continues to intensify. In recent years, influenced by climate change, the regional imbalance of water resources and water quality shortage have become increasingly prominent.
In p>219, the Jiangsu Provincial Government issued the Implementation Plan for the Construction of Eco-environmental Standard System in Jiangsu Province (218-222), which clearly put forward the formulation of pollutant discharge standards for urban sewage treatment plants. In 222, the General Office of the Jiangsu Provincial Government issued the Implementation Opinions on Accelerating the Construction of Urban Sewage Treatment Capacity and Improving the Centralized Collection and Treatment Rate of Sewage in an All-round Way, demanding "to study and formulate the discharge standards of sewage treatment plants with differentiated control in our province and promote a new round.
In October p>219, Jiangsu Provincial Department of Ecology and Environment entrusted Nanjing University to compile the Pollutant Discharge Standard for Urban Sewage Treatment Plants. During the compilation of the Standard, Nanjing University conducted field research and sampling on 6 urban sewage treatment plants, and systematically analyzed more than 1, online monitoring data of more than 37 urban sewage treatment plants. Xu Ke, a professor at the School of Environment, Nanjing University, said that according to the emission limits of the Standard, the average compliance rate of major pollutants in urban sewage treatment plants in our province is between 7% and 96%. The urban sewage treatment plant has a mature pollutant treatment process, and the standard discharge can be realized through process optimization or engineering transformation. The promulgation and implementation of the Standard will further reduce the total discharge of pollutants. According to estimates, the chemical oxygen demand (COD) of drainage pollutants can be reduced by about 13,3 tons, ammonia nitrogen by about 4,7 tons, total nitrogen by about 12,8 tons and total phosphorus by about ,27 tons every year. About 172 tons of ammonia and 35 tons of hydrogen sulfide were reduced.
zoning and grading management to prevent the risk of toxic and harmful pollutants
From the perspective of pollutant types, the Standard mainly tightens the control of water pollutants and air pollutants.
in terms of water pollutants, it is firstly divided into key protected areas and general protected areas. Among them, the Yangtze River, the South-to-North Water Diversion Project and the Grand Canal, which have been included in the national major strategies, will be included in the first-and second-class protected areas in Taihu Lake Basin, the waters of the main stream of the Yangtze River, the main line of the South-to-North Water Diversion Project, the southern part of the Beijing-Hangzhou Grand Canal, and the coastline boundary of the above waters within 1 km of the land, and more stringent emission limits will be implemented. For example, for newly-built urban sewage treatment plants with sewage outlets located in key protected areas and with a total design scale of 5, tons/day or above, and sewage outlets located in general areas with a total design scale of 1, tons/day or above, the most stringent emission limits will be implemented in the Yangtze River Delta region.
Secondly, the Standard subdivides four levels of water pollutant discharge limits from three latitudes, namely, the area where the sewage outlet of the urban sewage treatment plant enters the river, the construction scale, the newly-built and the existing ones, and implements four standard levels of A, B, C and D respectively. For example, Gu Aiwu, deputy director of the Water Department of Jiangsu Provincial Department of Ecology and Environment, said that the new Standard requires the existing urban sewage treatment plants with a total design scale of less than 3, tons per day to implement the D standard. At present, the sewage treatment plants that meet this condition are basically township sewage treatment plants, and the investigation found that the current primary task is to speed up the improvement of sewage pipe network and enhance the centralized collection capacity of sewage. Therefore, for this kind of sewage treatment plants, the discharge limits of major pollutants are implemented according to the national first-class A standard, and the discharge limits are no longer tightened.
In addition to the national standard control items, the Standard has added risk control indicators reflecting comprehensive biological toxicity (acute toxicity of zebra fish eggs), tightened emission limits of eight characteristic pollutants such as volatile phenol, sulfide, total hydrogen cyanide, organophosphorus pesticide, malathion, dimethoate, parathion and methyl parathion, and added fluoride as characteristic pollutant control indicators according to the characteristics of Jiangsu's industrial structure.
in terms of air pollutants, in order to prevent the influence of odor, the emission concentration limits of hydrogen sulfide and ammonia, two major malodorous pollutants, at the factory boundary should be properly tightened.
"At present, the monitoring standard in national standards is judged as daily average, and there are practical difficulties such as different discharge fluctuation laws of sewage treatment processes and the need for multiple sampling in a long time for law enforcement monitoring." Gu Aiwu said that the "Standard" has added emission limits for one-time monitoring of four conventional pollutants, namely chemical oxygen demand, ammonia nitrogen, total nitrogen and total phosphorus, which is conducive to promoting pollutant discharge units to strengthen their own emission monitoring and fluctuation law research, and improve the refined management of the environment.
upgrading of existing urban sewage treatment plants within three years
The newly-built urban sewage treatment plants will be implemented from the date of implementation (March 28th, 223), and the existing urban sewage treatment plants will be implemented three years later from the date of implementation (March 28th, 226). During the transition period, the existing urban sewage treatment plants will still implement national standards and local standards of Taihu Province respectively.
"Since p>“28, the urban sewage treatment plants in Taihu Basin in our province have been upgraded twice, which has provided mature experience for upgrading the urban sewage treatment plants in our province." Wang Huacheng, deputy director of the Urban Construction Department of the Housing and Urban-Rural Development Department of Jiangsu Province, said that the bidding plan for urban sewage treatment plants will be scientifically formulated, and the "one factory and one policy" will be formulated, giving priority to non-engineering control measures; Coordinate the promotion of bid upgrading, improve the stability of inlet water quality of urban sewage treatment plants, and ensure the normal operation of sewage treatment plants; Improve policy safeguard measures, guide all localities to further improve the sewage treatment fee system, rationally adjust the collection standards of urban sewage treatment fees, guide all localities to establish a multi-input mechanism for sewage treatment facilities, strengthen financial guarantee, and strengthen technical research on upgrading and upgrading.
Huang Wei said that risk management and control will be strengthened, and the classified collection and quality treatment of industrial wastewater and domestic sewage will be accelerated together with the housing and construction departments to prevent heavy metals and toxic and harmful pollutants from affecting the stable operation of urban sewage treatment plants; In accordance with the requirements of laws and regulations, guide enterprises to apply for or change the relevant information of pollutant discharge permits according to the new emission standards, supervise and urge the implementation of self-monitoring and emission standards, and strengthen environmental law enforcement supervision; Increase financial support, hold a special golden ring dialogue, make good use of environmental and economic policies such as "environmental loan" and "environmental burden", and guide financial capital to help sewage treatment plants upgrade and transform.