Yang Baoshan, Wang Hui, Jiang Yingkui, Dong Fang, He Xinhua, Lai Xiaoshuang
School of Water Conservancy and Environment, University of Jinan Jinan 250022 China
Key Laboratory of Water Resources and Environmental Engineering in Universities of Shandong Jinan 250022 China.
RSC Adv. 2018 Jun 26;8(41):23199-23205. doi: 10.1039/c8ra04364g. eCollection 2018 Jun 21.
Identifying the anthropogenic and natural sources of nitrate emissions contributing to surface water continues to be an enormous challenge. It is necessary to control the water quality in the watershed impacted by human disturbance. In this study, water chemical parameters including nitrate (NO ) concentrations, δN-NO , δO-NO , and δO-HO were analyzed to investigate the contamination and sources of NO in two watershed rivers (Jinyun, JYN and Jinyang, JYA), Jinan, Shandong, China. Results indicated NO concentrations in the JYN were significantly higher than those in the JYA ( < 0.05), probably because of high N input of the extensive farmlands or orchards in the drainage basin. δN-NO and δO-NO , associated with Cl, indicated that nitrate-nitrogen (NO -N) was not derived from atmospheric deposition but came principally from manure/sewage and soil organic matter in these two watersheds. The microbial nitrification took place in the nitrate of manure/sewage and soil nitrate. The combination of NO concentration and nitrogen and oxygen isotope suggested that NO had undergone microbial denitrification after entering the rivers. Furthermore, NO concentrations had significant temporal and spatial variation highlighting differential sources and fates. These results expand our understanding of mechanisms driving NO retention and transport and provide strategies in managing NO contamination in different land use watersheds around the world.
确定导致地表水硝酸盐排放的人为和自然来源仍然是一项巨大的挑战。有必要控制受人类干扰影响的流域内的水质。在本研究中，分析了包括硝酸盐（NO₃⁻）浓度、δ¹⁵N-NO₃⁻、δ¹⁸O-NO₃⁻和δ¹⁸O-H₂O在内的水化学参数，以调查中国山东济南两条流域河流（缙云，JYN和晋阳，JYA）中NO₃⁻的污染情况和来源。结果表明，JYN中的NO₃⁻浓度显著高于JYA中的浓度（P < 0.05），这可能是由于流域内广泛的农田或果园的氮输入量较高。与Cl相关的δ¹⁵N-NO₃⁻和δ¹⁸O-NO₃⁻表明，硝态氮（NO₃-N）并非来自大气沉降，而是主要来自这两个流域的粪便/污水和土壤有机质。微生物硝化作用发生在粪便/污水的硝酸盐和土壤硝酸盐中。NO₃⁻浓度与氮、氧同位素的结合表明，NO₃⁻进入河流后发生了微生物反硝化作用。此外，NO₃⁻浓度具有显著的时空变化，突出了不同的来源和归宿。这些结果扩展了我们对驱动NO₃⁻滞留和运输机制的理解，并为管理世界各地不同土地利用流域的NO₃⁻污染提供了策略。
