Current situation and planning of sewage treatment

2022-09-23
  • Detail

Current situation and planning of urban sewage treatment in China (II)

current situation and planning of urban sewage treatment in China (II)

July 22, 2004

I. construction and development of urban sewage treatment facilities

China began to solve the purification problem of urban sewage in the 1970s. Some cities make use of the pits, ponds, depressions, waste rivers, marshes and other places in the suburbs to slightly repair or build dams with embankments to build stabilization ponds to purify urban sewage. According to the survey, 38 stabilization ponds of various types have been built throughout the country during this period, and the daily treatment of urban sewage is about 1.73 million m3. Among them, domestic sewage accounts for half, and the rest includes petroleum, chemical, papermaking, printing and dyeing and other industrial wastewater. At this stage, we began to pay attention to the introduction of foreign advanced technology and equipment, carry out technical exchanges with foreign countries, and gradually explore engineering technology and design suitable for China's national conditions, laying the foundation for future construction

In the 1980s, with the acceleration of urbanization and increasing attention to urban water pollution, the construction of urban drainage facilities developed rapidly. The state has timely adjusted policies to allow the use of preferential loans from international financial organizations, foreign governments and equipment suppliers under the conditions of loan repayment guaranteed by the urban government, thus promoting the construction of a large number of urban sewage treatment facilities. Tianjin Jizhuangzi sewage treatment plant, the first large-scale urban sewage treatment plant in China, broke ground in 1982 and was completed and put into operation on April 28, 1984, with a treatment capacity of 260000 m3/d. Driven by this successful experience, Beijing, Shanghai, Guangdong, Guangxi, Shaanxi, Shanxi, Hebei, Jiangsu, Zhejiang, Hubei, Hunan and other provinces and cities have built dozens of sewage treatment plants of different scales according to their specific conditions

during the Eighth Five Year Plan period, with the deepening of comprehensive urban environmental management and the strengthening of water pollution control in all river basins, the construction of urban sewage treatment facilities experienced a climax of development. By 1995, the length of drainage pipes in China's urban drainage system was about 110062km. According to the service area, the penetration rate of urban drainage pipes was 64.8%. Compared with 1990, urban drainage pipelines increased by 54373km, with an average annual increase of 10874km; There are 169 urban sewage treatment plants (including 116 secondary biochemical treatment plants), with an annual sewage treatment capacity of 1.749 billion m3 and a treatment rate of 8.69%. Compared with 1990, the number of urban sewage treatment plants increased by 89 (including Beijing Gaobeidian, the eastern suburbs of Tianjin, Shijiazhuang Qiaoxi, Guangzhou Da Tansha, Wuxi Lucun, Jinan and other large and medium-sized urban sewage treatment plants), with an average of 17 sewage treatment plants built every year

during the Ninth Five Year Plan period, China officially launched water pollution control in the "Three Rivers" (Huaihe River, Haihe River and Liaohe River), the "three lakes" (Taihu Lake, Chaohu Lake and Dianchi Lake) basins and the "Bohai Rim" region, and the state provided corresponding financial and technical support. From 1996 to 1999, 22 urban sewage treatment projects were completed and put into operation, with an investment of 5.958 billion yuan and a daily treatment scale of 3.717 million m3; There are 109 projects under construction, with a planned investment of 16.183 billion yuan and a daily treatment capacity of 8.32 million m3

according to statistics, by the end of 2000, 427 urban sewage treatment plants had been built nationwide, including 282 secondary treatment plants, with a secondary treatment rate of about 15%. In 2000, the total investment for the construction of urban sewage treatment projects was about 15billion yuan. However, the vast majority of small towns have not yet built sewage treatment facilities

II. Current situation and development of urban sewage treatment technology

1. Current situation of process technology

more than 80% of the existing urban sewage treatment plants in China adopt activated sludge method, and the rest adopt primary treatment, enhanced primary treatment, stabilization pond method and land treatment method. The establishment and completion of the national scientific and technological research projects of the "Seventh Five Year Plan", "Eighth Five Year Plan" and "Ninth Five Year Plan" have made gratifying scientific research achievements in the new technologies of sewage treatment, sewage recycling and utilization, sludge treatment and other aspects. Our company will hold several activities of foreign tourism every year, and some research achievements have reached the international advanced level. At the same time, with the help of the construction of foreign loan urban sewage treatment projects, many new technologies, new processes and new equipment have been introduced into China. AB method, oxidation ditch method, a/o process, a/a/o process and SBR method have been applied in urban sewage treatment plants in China. Sewage treatment technology has developed from only focusing on the removal of organic matter in the past to having the function of phosphorus and nitrogen removal. Some advanced and efficient special sewage treatment equipment from abroad have also entered the sewage treatment industry market in China, such as grid machines, submersible pumps, desanding devices, sludge scrapers, aerators, blowers, sludge pumps, dehydrators, biogas generators, biogas boilers, sludge digestion and mixing systems and other large-scale equipment and devices

most of the urban sewage treatment plants built before the 1980s in China used the ordinary aeration activated sludge treatment process. Because this process mainly aimed at removing BOD and SS, the removal rate of nitrogen and phosphorus was very low. In order to meet the water environment and discharge requirements, some sewage treatment plants are being transformed to increase or strengthen the functions of nitrogen and phosphorus removal. AB method sewage treatment process has been applied in engineering practice in China since the early 1980s. Because of its strong impact load resistance and obvious buffering effect on pH changes and toxic substances, it is mainly used in urban sewage treatment plants with high sewage concentration and large changes in water quality and quantity, especially in urban sewage treatment plants with a high proportion of industrial sewage

at present, oxidation ditch process is one of the most widely used sewage treatment processes in China. Ober oxidation ditch process is widely used, which is designed by our country and the whole set of equipment is localized, and there have been successful examples. De oxidation ditch and three ditch oxidation ditch are also used in the treatment of medium and high concentration sewage in small and medium-sized cities. Most urban sewage treatment plants using Carrousel oxidation ditch process are foreign loan projects. Many types of SBR processes are applied in China, such as ICEAS process belonging to the second generation of SBR process, cast process belonging to the third generation, UNITANK process, etc

with the improvement of China's requirements for water environment quality, the revised national integrated wastewater discharge standard (GB8978-1996) is also becoming more and more stringent, especially the requirements for nitrogen and phosphorus in effluent. Therefore, the removal of nitrogen and phosphorus must be considered in the new urban sewage treatment plant. Therefore, the improved a/a/o process and the denitrifying biological phosphorus removal process of reflux sludge have been developed and have been applied in practical projects. Such as Tai'an sewage treatment plant, Qingdao Licun River sewage treatment plant, Tianjin BeiCang sewage treatment plant, Beijing Qinghe sewage treatment plant, etc

in terms of project scale, the successive completion and operation of a number of large sewage treatment plants marks a new stage in the development of China's sewage treatment industry. For example, Gaobeidian sewage treatment plant, the largest sewage treatment plant in China in the 20th century, has a treatment capacity of 1million m3/D; At present, Shanghai Zhuyuan sewage treatment plant, the largest urban sewage treatment plant in China, is under design, with a scale of 1.7 million m3/d. Table 1 lists some urban sewage treatment projects in China, which basically represents the current level of urban sewage treatment technology in China

Table 1 urban sewage treatment technology and some engineering projects in China

----------------------------------------------------------

serial number province or city project name project scale (10000 m3/d) application remarks

I General exposure method

1 Beijing Gaobeidian sewage treatment plant 100 has been in operation

2 Tianjin Jizhuangzi sewage treatment project 26 has been in operation

3 Tianjin eastern suburb sewage treatment plant 40 has been in operation

4 Shandong Jinan sewage treatment plant 22 has been in operation

5 Hebei Shijiazhuang Qiaoxi sewage treatment plant 16 has been in operation

6 Shaanxi Xi'an Sewage treatment plant 12 has been in operation

7 Jiangsu Wuxi Lucun sewage treatment plant (phase I) 10 running

8 Chongqing Tangjiaqiao sewage treatment plant 6 running

9 Hubei Wuhan water purification plant 5 running

II Oxidation ditch process

1 Shandong Laixi sewage treatment plant project 4 has been in operation Orbal

2 Beijing Daxing Huangcun sewage treatment plant 8 has been in operation Orbal

3 Hebei Langfang sewage treatment plant 8 has been in operation Orbal

4 Zhejiang Wenzhou Central District sewage treatment plant 10 has been in operation Orbal

5 Guangdong Zhongshan sewage treatment company 10 has been in operation carrouse

6 Beijing Shunyi sewage treatment plant 8 has been in operation carrouse

7 Anhui Huainan sewage treatment plant 10 carrouse

8 Hebei Handan East sewage treatment plant 10 has been in operation three ditch type

9 Shandong Zaozhuang sewage treatment plant 7 has been in operation three ditch type

10 Jiangsu Suzhou New Area Sewage treatment plant 4 has been in operation three ditch type

11 Anhui Hefei wangxiaozhi sewage treatment plant (phase I) 15 single ditch

12 construction drawing of Shangqiu sewage treatment plant in Henan 8 single ditch

13 Beishiqiao sewage purification center in Xi'an, Shaanxi 15 de type

III AB process

1 Shandong Qingdao Haibohe sewage treatment plant 8 has been in operation

2 Shandong Zibo sewage treatment plant 14 has been in operation

3 Guangdong Shenzhen Luofang sewage treatment plant 10 has been in operation

4 Guangdong Guangzhou Liede Sewage Treatment Plant 22 has been in operation

IV A/o phosphorus removal or nitrogen removal process

1 Zhejiang Hangzhou Sibao Sewage treatment expansion project 60 has been in operation a/o

2 Zhejiang Hangzhou Qige sewage treatment project 40 has been in operation a/o

3 Hebei Baoding yindingzhuang sewage treatment plant 8 has been in operation a/o

4 Hebei Baoding Lugang Sewage Treatment Plant 8 has been in operation a/o

5 Tianjin Jizhuangzi sewage treatment plant expansion project 26 construction drawing a/o

6 Shandong Qingdao Licun River sewage treatment plant 8 has been in operation Operation improvement a/o

7 preliminary design improvement of Tianjin BeiCang sewage treatment plant a/o

v A/a/o or improved a/a/o phosphorus and nitrogen removal process

1 Guangdong Guangzhou Datansha sewage treatment project 15 has been in operation a/a/o

2 Guangxi Guilin fourth sewage treatment plant 10 has been in operation a/a/o

3 Jiangsu Wuxi Lucun sewage treatment plant (phase II) 10 running a/a/o

4 Kunming second sewage treatment plant 10 running a/a/o

5 Tai'an sewage treatment plant 5 running a+a/a/o

6 Tuandao sewage treatment plant 10 running improved a/a/o

VI SBR process

1 Kunming No. 3 sewage treatment plant in Yunnan 15 has been in operation ICEAS

2 Jinhua sewage treatment plant in Zhejiang 8 has been in operation cast

3 Zunyi sewage treatment plant in Guizhou 8 has been in operation SBR

4 Yangzhou sewage treatment plant in Jiangsu 10 is under construction cast

5 Nanjing Development Zone sewage treatment plant in Jiangsu 4 is under construction cast

6 Wuzhou sewage treatment plant in Guangxi 10 is initially set up UNITANK

7 Primary and enhanced primary treatment process

1 Hainan Haikou sewage treatment plant 30 has run section a + sea discharge

2 Zhejiang Hangzhou Sibao Sewage Treatment Plant Project (phase I) 40 grade I + river drainage has been operated

3 Shandong Weihai sewage drainage project 8 grade I + sea drainage has been operated

4 Jiangsu Nanjing Qinhuai River sewage treatment project 54 grade I + river drainage has been operated

5 Shanghai Zhuyuan sewage treatment project 170 feasibility study enhanced grade I + river drainage

VIII Other

1 Guangdong Huadu Xinhua water purification plant 4 has run oxidation pond

2 Hebei Qinhuangdao sewage treatment plant project 4 has run jet aeration

2 development trend

at present, among the processes used in the urban sewage treatment plant where Alcoa and Danieli group of Italy signed a cooperation agreement in October 2015, various types of activated sludge process are still the mainstream, Accounting for 90%

Copyright © 2011 JIN SHI