Effects of typical karst tourist town on the Lijiang River water: from heavy metals to N-nitrosamines

作     者：Yuanyu Shan Yuru Su Xinli Xing Bingquan Zhu Honghu Zeng Yuan Zhang Junyu Li Xiaoyu Yan Wenwen Chen Benjian Li 

作者机构：College of Environmental Science and Engineering， Guilin University of Technology School of Environmental Studies， China University of Geosciences State Key Laboratory of Biogeology and Environmental Geology， China University of Geosciences College of arts， Guilin University of Technology College of arts and communication， China University of Geosciences430070 China 

出 版 物：《Journal of Earth Science》 (地球科学学刊)

年 卷 期：2024年

核心收录：

学科分类：08[工学] 0815[工学-水利工程] 

基　　金：supported by the National Natural Science Foundation of China (No. 52360001 and 42067048 and 41807387) the Guangxi Foundation for the Program of Science and Technology Research (No. 2021GXNSFBA220066) 

摘      要：N-nitrosamines are nitrogenous organic pollutants with high carcinogenicity to human. Heavy metal pollution in aquatic system is currently a major environmental problem. Tourism in typical karst areas may influence the environment through wastewater discharge. However， it remains unclear whether these activities would cause water pollution. To evaluate the impact of tourism activities in typical tourist towns， this study investigated the occurrence and sources of 18 N-nitrosamines， eight heavy metals （HMs）， and dissolved inorganic nitrogen （DIN） in the Lijiang River and its tributaries. Seven N-nitrosamines were detected as the dominant compounds in N-nitroso-N-ethylaniline （NEA， average of 24.8 ng/L） and N-nitroso-l-proline （NPRO， 20.4 ng/L）， while especially low concentrations of HMs （Mn， Cu， As， Ni， Cr， Co， Pb， and Cd） and DIN (NH4+-N， NO2--N， and NO3--N) were observed. The most important influencing factors were seasonal factors， followed by land-use type and mainstem and tributary factors. Principal component analysis revealed that in the city with developed tourism and relatively less heavy industry， aquaculture and agricultural wastewater were identified as the primary sources of N-nitrosamines. Meanwhile， domestic sewage and agricultural wastewater were found to be the main sources of HMs and DIN， respectively. The ecological risk assessments for all pollutants are relatively low （ 1）. Therefore， N-nitrosamines， HMs， and DIN pollution caused by tourist activities pose a negligible risk to the Lijiang River.