Environmental Engineering Reference
In-Depth Information
In 2009 and 2010, there were no sections of the main portions of the Liaohe or
Huaihe rivers with a chemical oxygen demand of Level V, the worst rating, and the
water quality of the Haihe River improved. The level of eutrophication in the Taihu
River went from moderate to light, and the number of Level V rivers flowing into
lakes decreased from eight to one. Furthermore, the eutrophication level of Lake
Chaohu improved markedly, preventing the huge outbreaks of cyanophyta, and the
water quality in Lake Dianchi also improved.
6.4.3.3 The Urban Sewage Treatment and Recycling Construction
Project
During the 11th Five-Year Plan, China's daily urban sewage disposal capacity
increased by 65 million tons, and the urban water waste disposal rate improved
from 51.95 % to 75.25 %. As of the end of 2010, 2,832 water disposal plants had
been built in urban areas and counties nationwide, raising the wastewater disposal
capacity to 125 million cubic meters per day.
Of the 654 urban cities, 607 have built water waste disposal plants, accounting
for 92.8 % of all cities. In 2010, 337 new water waste disposal plants were built in
cities, increasing the disposal capacity to 13.8 million cubic meters per day. Nearly
1,700 disposal plants have been built in total, allowing for a capacity of 167 million
cubic meters per day, and 36 major cities built 338 disposal plants capable of
treating a combined level of 44.28 million cubic meters per day.
By the end of 2010, there were more than 1,000 disposal plants at the county
level covering 63.2 % of counties across the nation, double the number in operation
at the end of the previous year. Disposal capacity reached 20.66 million cubic
meters per day, accounting for one-sixth of the country's total capacity. By the end
of 2010, 16 provinces and municipalities directly under the central government
realized the goal of having at least one disposal plant per county. These include
many of the more-developed regions, such as Beijing, Shanghai, Zhejiang, Henan,
Shandong, Jiangsu, Anhui and Tianjin [
10
].
It should be noted that pollution of surface water remains relatively heavy. Seven
of the great rivers are mildly polluted, and rivers in the regions of Zhejiang and
Fujian and northwestern region are also. Water quality in the southwestern region is
better, however.
Based on a 2009 sampling of 204 river and 409 surface water quality monitoring
sections throughout the country, those sections with water quality graded between
Level I and Level III accounted for 59.9 %; sections graded between Level IV and
Level V accounted for 23.7 %; and 16.4 % were given the poorest ranking.
The major pollution indicators are potassium permanganate index, bods and
ammonia nitrogen. In addition, the level of eutrophication in lakes and reservoirs is
serious. Of the 26 key state-controlled lakes and reservoirs surveyed in 2010, one had a
water quality of Level II, accounting for 1.8 %; five were graded Level III, accounting
for 19.2 %; four met Level IV standards, accounting for 15.4 %; six met the Level V
standard, accounting for 23.1 %; and ten met were ranked at the worst level, account-
ing for 38.5 %. The major pollution indicators are nitrogen and phosphorus. One, or
3.8 % of the total, had severe eutrophication; two had moderate eutrophication,
