基于稳定同位素模型解析农业污染河流氮源

采用水质监测技术和稳定氮同位素示踪技术对社渎港中游地区进行氮污染特征和污染源解析。在定性描述的基础上结合稳定同位素模型(SIAR),对各硝酸盐污染源的贡献率进行定量计算并进行了后验概率分布检验。结果表明:(1)在枯水期TN较高,平均为5.34mg/L,农业生产集中区TN污染最严重。(2)硝酸盐污染主要来源包括生活污水和粪肥、化学肥料及土壤氮。其中,生活污水和粪肥对硝酸盐的贡献率最高,平均为45%;化学肥料次之,贡献率平均为31%;土壤氮的贡献率平均为24%。

Analysis of nitrogen sources in agricultural polluted rivers based on stable isotope model

The nitrogen pollution characteristics and pollution sources was investigated by using water quality monitoring technique and stable nitrogen isotope tracer technique in midstream areas of the Shedu River basin.Stable isotopes and a Bayesian model(stable isotope analysis in R)were applied to identify nitrate sources and estimate the proportional contributions of multiple nitrate sources.And the posterior probability distribution was tested.It was showed that:(1)the TN was high in the drought water period,with an average mass concentration of 5.35 mg/L.The concentration in agricultural production area was the most serious.(2)The main sources of nitrate pollution were follows:manure and sewage from human and animal,soil nitrogen and fertilizer.Among them,manure and sewage had the highest contribution rate to nitrate pollution,with an average distribution range of 45%.The contribution rate of fertilizer was next,with an average distribution range of 31%.The average contribution rate of soil nitrogen was 24%.