This lecture shares characteristics of China's severe cold region sewage treatment plants. High emission standards in the region make it difficult to use traditional technology. Therefore, China's commonly used technology accord to China's national conditions. The scale of most urban Wastewater Treatment Plants (WWTP) is 10,000 to 100,000 tons/day. Large cities generally produce more than 200,000 tons of wastewater per day.The aeration tank for most urban WWTP are exposed. In recent years, they tend to be covered with glass or plastic film to retain warmth and collect odor. In winter, the influent temperature of WWTP is generally about 8 C, which meets the needs of psychrophilic bacteria metabolism. The higher the standard of living of urban residents, the higher the influent temperature will be. According to our research, a influent temperature lower than 5 C will seriously affect the biological activity. Methods for Severe Cold Regions are that a heat exchanger for inlet air of air blower must be used, a cover to keep warmth of aeration tank and collect odor to be treated should be used, and psychrophilic bacteria could be added in winter to increase the amount of important bacteria.
China's government put forward a national Energy-saving and Pollutant-decreasing strategy, however the water environmental problems still exist. Water resources in China are unevenly distributed. Although the central government has invested a lot of money, the pollution in the seven major river basins has not been effectively controlled. For economic development, China has become “the world's raw material processing plant”, which contributes to increasing money in China, but also to pollution. Chemical engineering, printing and dyeing, pharmaceutical wastewater, etc. are some of the main sources of pollution and ecological destruction. For severe cold regions of China, low temperature technology requirements and high technology requirements and standards are urgent problems to be solved. To address these issues it is extremely important to understand two questions: What kind of WWTP process can be used for cold regions in China? How can China's urban water resources and environment be improved?
At the end of this lecture students will:
- Understand China's Water Shortage situation and that the Pollution Status is serious.
- Understand that to address these issues it is important ask two questions: What kind of WWTP process can be used for cold regions in China? How can China's urban water resources and environment be improved?
- Using the status quo of seven cold urban water treatment plants, understand the summed up problems commonly encountered in sewage plants in cold regions and how to solve these problems.