四川省农村生活非点源污染负荷估算及评价研究

Estimation and Evaluation of Non-point Source Pollution Load in Rural Living of Sichuan Province

研究旨在明确现阶段四川省农村生活非点源污染状况,及对农村生活非点源污染控制提供依据。笔者依托输出系数模型,考虑农村生活垃圾、生活废水和人体粪尿污染物三方面,从污染物产生、输出到入河三阶段建立了农村生活非点源污染负荷估算模型。在模型支撑下,估算了2012年四川省各地级市(州)农村生活非点源污染物中TN(总氮)、TP(总磷)和COD(化学需氧量)的负荷量,并对TN、TP和COD的负荷总量、来源比例进行分析,同时结合地表水三级水质标准(GB 3838—2002),计算了农村生活非点源污染中TN、TP和COD的入河贡献率。结果显示四川省农村生活非点源产生负荷TN 421070 t,TP 91122 t,COD 2023186 t;输出负荷TN 120675 t,TP 26298 t,COD 419969 t;入河负荷TN 44499 t,TP 5780 t,COD 142049 t。各地市州中,南充、达州和成都产生、输出负荷最大;宜宾、南充和达州入河量最大。全省农村生活非点源污染TN、TP和COD的入河贡献率总体不大,仅遂宁、内江入河TN负荷对水体污染的贡献率超过地表水三级水质标准100%。随经济发展,四川省农村生活非点源污染部分区域较为严重,对其控制不容忽视。研究采用的方法可为其它区域的农村生活非点源污染负荷估算提供参考和借鉴。

In order to know the current pollution status of rural living non-point source pollution in 5ichuan Province, and provide the basis for the rural living non-point source pollution control, the author built estimate model of pollution load （household garbage, domestic sewage and human wastes） from 3 stages （generation, discharge and export） depended on the export coefficient model. Then the author estimated the total nitrogen （TN）, total phosphorus （TP） and chemical oxygen demanded （COD） loads of rural living non-point source pollution in 21 cities of Sichuan Province with the established estimation model, and the total amount of loads and the proportion pollution were analyzed. At last, the author combined with the third grade of surface water standard of China （GB 3838--2002）, calculated the into river contribution rates of TN, TP and COD,respectively. The results showed that the generation loads of TN, TP, and COD were 421070 t, 91122 t and 2023186 t, discharge loads were 120675 t, 26298 t and 419969 t and export loads were 44499 t, 5780 t and 142049 t, respectively. In Sichuan Province, Nanchong, Dazhou and Chengdu had the maximal generation and discharge loads, while Yibin, Nanchong and Dazhou had the maximal export load. In export progress, the contribution rates of TN, TP and COD into rivers were minor in Sichuan Province. However, the contribution rate of TN in Suining and Neijiang exceeded the third grade for 100%. The results showed that rural living non- point source pollution in some areas of Sichuan Province was very serious with the development of economy, and the control should be enhanced in the future. The method used in this study could offer reference to other areas for estimating the rural living non-point source pollutant load.