汉江中下游流域污染负荷及水环境容量研究

通过调查和分析汉江中下游流域各污染源,以化学需氧量(COD)和氨氮(NH_3-N)为污染负荷指标,分析了流域污染负荷现状,确定了主要污染源。在此基础上,选择COD和NH_3-N作为计算因子,利用一维水质模型测算汉江中下游流域干流及主要支流的水环境容量。结果表明:江汉污染源主要为中心城镇生活污染源、规模化畜禽养殖污染源和工业污染源; 2015年排入汉江中下游干流河道的污染负荷量为340 572. 15 t,以COD为主;潜江段以规模畜禽养殖污染源为主,其他均以城镇生活污染源为主。根据模型计算结果可推知,汉江中下游干流河道COD的水环境容量目前尚较富足,但NH_3-N的水环境容量已接近负荷阈值;汉江中下游支流唐白河、竹皮河和天门河的COD和NH_3-N水环境容量均较小。

Research on pollution load and water environmental capacity in middle and lower reaches of Hanjiang River

Based on the investigation and analysis of various pollution sources, pollution status quo in the middle and lower reaches of the Hangjiang River was analyzed with COD and NH3-N as index of pollution load, and main pollution sources were found. Choosing COD and NH3-N as main indicators, water environmental capacity was computed by one dimensional water quality model. Results indicated that the main pollution sources of the middle and lower reaches of the Hanjiang River were urban domestic sewage, scale livestock culturing and industry discharge; the pollution load discharged into the middle and lower reaches of the Hanjiang River was 340 572.15 t in 2015, most of which was COD; scale livestock culturing was the main pollution source to Qianjiang reach, and urban sewage for other reaches. According to the calculation result of the one-dimensional water quality model, the middle and lower reaches of the Hanjiang River have ample water environmental capacity of COD, but do not have enough residual water environmental capacity of NH3-N; the tributaries such as the Tangbai River, the Zhupi River and the Tianmen River both have low COD and NH3-N water environmental capacity.