关键词: 乡镇河道, 苏南, 黑臭水体, 复合型湿地, 原位生态修复

Abstract: In recent years, the urbanization of southern Jiangsu province has developed rapidly, turning the towns and towns far away from the city into unplanned “urban suburbs”. At the same time as the rapid development of towns and villages, increasing sanitary sewage, industrial wastewater and initial rainwater which makes the water worse are the causes of black and odorous rivers. This project took the black and odorous river in the suburbs of a city in southern Jiangsu as an example. After a field investigation of the river, the river was divided into five parts according to biological phase, sediment, water quality and integrating the water landscape design concept of Jiangnan villages and towns. Each part adopted different physical-bio-ecological combination processes （desilting, interception, re-oxygenation, wetlands produce running water, ecoenhancement） for design and construction. Engineering test results showed that the remediation plan can have higher removal efficiency on pollutants including ammonia nitrogen （NH₃-N）, total nitrogen（TN）, total phosphorus（TP）, chemical oxygen demand （COD）, etc. in heavy polluted rivers. NH₃-N, TN, TP, COD can maintain its concentration at 1.5 mg/L, 2.0 mg/L, 0.3 mg/L, 34.7 mg/L, removal rates were 66.52%, 79.21%, 44.44%, 42.55% when 6 months after completion of the construction. At the same time, dissolved oxygen （DO）, transparency and redox potential in the river were stable at 5 mg/L, 60 cm, 500 MV. The quality of the river has reached the requirements of Class V of the Surface Water Environmental Quality Standards. After public comments, black and odorous rivers will be eliminated to create a natural, lively and beautiful ecological landscape of the town. According to the calculation, the total investment of the project is about 1.2 million, the annual operating cost is 61 000, and the emission reductions of NH₃-N, TN, TP and COD are up to 36.09 t/a, 92.28 t/a, 2.91 t/a, 310.86 t/a,respectively.

Key words: village rivers, south Jiangsu, black and smelly water, complex wetland, in situ ecological restoration