重污染河道疏浚对菹草水生态环境的影响  

Impacts of dredging of seriously polluted rivers on water ecological environment of Potamogeton crispus

作　　者：沈乐[1] 

机构地区：[1]江苏省水文水资源勘测局南京分局,江苏南京210008

出　　处：《水资源保护》2012年第3期32-37,共6页Water Resources Protection

基　　金：国家"十五"重大科技专项(2003AA601070)

摘　　要：通过采集苏州有机重污染河道南园河疏浚段、未疏浚段底泥和水质较好的内城河底泥进行菹草种植试验,分析各种底泥栽种菹草后上覆水体营养盐质量浓度的变化、菹草生长特点、浮游藻类和底栖附泥藻类的繁殖情况,研究疏浚对菹草水生态环境的影响。结果表明:重污染河道疏浚可以降低底泥中的营养盐浓度,有利于恢复菹草生境和改善水生态环境;河道疏浚后底泥TN、TP、有机质质量比分别降为1.50 g/kg、1.00 g/kg、27.00 g/kg左右时,浮游藻类和底栖附泥藻类的繁殖受到抑制,菹草生物量增加,上覆水体的营养盐质量浓度降低;经过一段时期的泥-水界面反应,疏浚后的底泥含水率得以提高,底栖附泥藻类数量及生物量将会增加,将恢复菹草、浮游藻类和底栖附泥藻类共存并相互制约的生物多样化的水生态环境。Potamogeton crips planting experiments were non-dredged conducted through collection of deposits in dredged reaches and reaches of the Nanyuan River, which is a heavily polluted river, and in the Inland River, which has high- quality water, in Suzhou City. The impacts of river dredging on the water ecological environment of Potamogeton cripus were studied through analysis of the change of nutrient concentration in the overlying water, the characteristics of growth of Potamogeton cripus, and propagation of planktonic algae and benthic epipelic algae, after planting of Potamogeton cripus in various kinds of deposits. The results show that dredging of seriously polluted rivers can contribute to reducing the nutrient concentration in the deposits, restoring the habitat of Potamogeton cripus, and improving the water ecological environment. After dredging, the propagation of planktonic algae and benthic epipelic algae was restrained, the hiomass of Potamogeton cripus increased, and the nutrient concentration in the overlying water decreased, when the concentrations of TN, TP, and organic matter in the deposits decreased to 1.50 g·kg^-1, 1.00 g·kg^-1, and 27.00 g·kg^-1, respectively. After a period of sediment-water reaction, the water content in the deposits, and the species and biomass of benthic epipelic algae increased, which would help restore the bio-diversified water ecological environment where Potamogeton crinus, planktonic algae, and benthic eoioelic algae co-exist and restrain each other.

关 键 词：疏浚 重污染 菹草 浮游藻类 底栖附泥藻类 

分 类 号：X52[环境科学与工程—环境工程] X17