山地城市小流域污染状况和对策研究——以重庆市巴南区花溪河为例

Study on Pollution Status and Countermeasures of Small Watersheds in Mountainous Cities——Taking Huaxi River in Banan District of Chongqing as an Example

城市的快速发展带来城区面积扩大,与之相对的是基础设施建设滞后与污染加剧的城市水体。重庆市是典型的山地城市,城区河流众多,花溪河也是其中较大河流之一。以花溪河为研究对象,通过现场调查和水质分析,制定山地城市小流域的污染治理对策。结果显示,花溪河流域COD为8~74 mg/L,氨氮为0.069~4.890 mg/L,TP为0.04~0.70 mg/L。南彭水库饮用水源地出水污染较轻,随后流经乡镇后COD、氨氮到达峰值,表征生活污水直接排放,TP沿流域持续增加至入河口,表明面源污染与生活污水同时增加,加剧了入江河流的TP浓度。调查发现流域内“小散乱”工业企业多至1500余家,污水管网建设管理不善,多处出现管网破裂,流域污水处理能力不能满足人口日常排污需求。针对以上问题,应当制定出台流域发展和水体达标规划,明确流域资源环境承载底线,建立科学性、系统性的治理体系和治污路径,推动“当前治标”和“长久治本”双管齐下,同时,深化上下游联防联控机制,鼓励建立流域生态补偿机制。

Highly development of city drove the expansion of urban area with lagged infrastructure construction and heavily polluted city waterbody.As a typical mountainous city,Chongqing gets lots of river which get across the whole city and Huaxi River is one of them.In this research,it was studied through local survey,water quality monitor to make strategies for mountain cities water pollution control.The results showed,in the watershed of Huaxi River,COD varied from 8~74 mg/L,NH 3-N varied from 0.069~4.890 mg/L,TP varied 0.04~0.70 mg/L.The water came from Nanpeng Reservoir was clean,and then the COD,NH 3-N got increased to the highest concentration after it got across to the gathered towns which means the water quality was affected by the sewage water.The TP increased along the river which indicated the non-pointed pollution might dominate the water quality deterioration.The survey results also indicated that there were more than 1500 industries in the watershed with water sewage pipes broken and lost.At the same time,the capacity of water treatment could not match the daily sewage discharge in the whole region.At last,based on the above problems,suggestions of policies were put forward as follows:first,river basin planning should be scientific formulated.Then,the environmental carrying capacities of watershed also need to be defined and the path of pollution control would be more scientific and systematic for whole region.At the same time,the alliance of up-downstream and watershed ecological compensation policy are of vital importance for river remediation.