基于氮氧同位素示踪的滨州市水体硝酸盐污染来源解析

利用硝酸盐氮氧双同位素技术和同位素混合模型，对滨州市水体硝酸盐的氮氧同位素组成进行分析，在此基础上进行硝酸盐污染溯源，确定各污染源的贡献率．结果表明:研究区地表水和地下水硝酸盐质量浓度分别为0~168.07、0~336.04 mg·L?1，超标率分别为8.70%和27.78%；从河流上游到下游，地表水硝酸盐污染有加重的趋势，地下水硝酸盐污染空间变异性较大．地表水和地下水δ（15N-NO₃）范围分别为4.02‰~10.10‰、9.07‰~18.75‰，δ（18O-NO₃）范围分别为2.24‰~6.14‰、4.93‰~10.64‰；有机肥和污水是本地地表水和地下水硝酸盐污染的主要来源，其平均贡献率分别为45%和81%，其次为含氮化肥，分别占26%和17%。通过定量分析地表水及地下水硝酸盐污染来源，可以为本地区制定防治水体污染措施提供科学依据． 

Analysis of surface water and groundwater nitrate sources in Binzhou City in the Yellow River Delta using isotopes of nitrogen and oxygen

The Yellow River Delta area is well developed in both agriculture and industry, but with frequent nitrate pollution in surface water and groundwater．δ(15N) and δ(18O) isotopic tracing of nitrate was used in the present study to identify major pollution sources in Binzhou City．Nitrate concentrations in surface water and groundwater was found to range from 0 to 168.07 and 0 to 336.04 mg·L?1, with a over-standard rate of 8.70% and 27.78%, respectively．Surface water nitrate pollution became more serious down the river, nitrate concentrations in groundwater fluctuated greatly as well．δ(15N-NO₃) was found to range in surface water and groundwater from 4.02‰-10.10‰ and 9.07‰-18.75‰, δ(18O-NO₃) from 2.24‰-6.14‰ and 4.93‰-10.64‰, respectively．Manure and septic waste were found to be the major sources of nitrate pollution both in surface water and groundwater, with a contribution rate of 45% and 81%, respectively．Artificial N fertilizer was the second largest source of nitrate pollution in surface water and groundwater, with a contribution rate of 26% and 17%, respectively．These data will be helpful when making policies to prevent nitrate pollution in surface water and groundwater in the Yellow River Delta．