Xu Mei-Juan, Yang Jia, Ren Xiao-Jing, Zhao Hong-Yan, Gao Fu-Yan, Jiang Yue-Jun
College of Mechanical and Energy Engineering, NingboTech University, Zhejiang University, Ningbo 315100, China.
Ninghai Society of Environmental Science and Technology, Ninghai 315600, China.
Huan Jing Ke Xue. 2023 Mar 8;44(3):1407-1415. doi: 10.13227/j.hjkx.202202195.
A total of 120 surface water samples were collected from industrial and commercial districts of Ningbo, China in the wet and dry seasons. The concentrations of six heavy metals (Cd, Cr, Ni, Pb, Zn, and Fe) in the samples were measured, the temporal-spatial distribution characteristics of the six heavy metals were analyzed, and Pearson correlation coefficients of the six heavy metals were calculated. Combined with the temporal-spatial distribution characteristics and Pearson correlation coefficients of the six heavy metals, the main pollution sources of the two districts were analyzed, respectively. The risk of heavy metals in surface water to the exposed population was evaluated by calculating the health risk index and carcinogenic risk index. The results showed that the pollution characteristics of heavy metals in the surface water of Ningbo industrial district and commercial district differed greatly in different seasons. In the industrial district, the orders of the average concentration of heavy metals in the wet season and dry season were Fe>Zn>Ni>Pb>Cr>Cd and Fe>Zn>Cr>Ni>Pb>Cd, respectively. The concentrations of Cr, Cd, and Pb in the wet and dry seasons exceeded the class Ⅳ recommended values, following the degrees of Cr>Cd>>Pb and Pb>Cr=Cd, respectively. Sewage containing heavy metals was one of the major pollution sources. In the commercial district, the average concentrations of heavy metals in the wet season and dry season were in the order of Fe>Pb>Ni>Zn>Cd>Cr and Fe>Pb>Ni>Zn>Cr=Cd, respectively. The concentrations of Cd and Pb in the wet season exceeded the corresponding levels (class Ⅳ), and the degree followed Cd>Pb. Only Pb exceeded the standard in the dry season, with the exceeding standard rate of 60%. Road pollution containing heavy metals was the major pollution source, and heavy metals entered surface water mostly with surface runoff and precipitation. The carcinogenic risk posed by heavy metals in the surface water of the Ningbo industrial district and commercial district was very high, and the carcinogenic risk in the commercial district was much higher than that in the industrial district. The main carcinogen was Cr. Compared to the research results of the research group in 2015, the pollution degree of heavy metals has been greatly reduced. In the future, we still need to give adequate attention to the prevention and control of heavy metal pollution in surface water in Ningbo.
在中国宁波的工商业区，于湿季和干季共采集了120份地表水样本。测定了样本中六种重金属（镉、铬、镍、铅、锌和铁）的浓度，分析了这六种重金属的时空分布特征，并计算了六种重金属的皮尔逊相关系数。结合六种重金属的时空分布特征和皮尔逊相关系数，分别分析了两个区域的主要污染源。通过计算健康风险指数和致癌风险指数，评估了地表水中重金属对暴露人群的风险。结果表明，宁波工业区和商业区地表水中重金属的污染特征在不同季节差异很大。在工业区，湿季和干季重金属平均浓度顺序分别为铁>锌>镍>铅>铬>镉和铁>锌>铬>镍>铅>镉。湿季和干季铬、镉和铅的浓度均超过Ⅳ类推荐值，超标程度分别为铬>镉>>铅和铅>铬=镉。含重金属污水是主要污染源之一。在商业区，湿季和干季重金属平均浓度顺序分别为铁>铅>镍>锌>镉>铬和铁>铅>镍>锌>铬=镉。湿季镉和铅的浓度超过相应标准（Ⅳ类），超标程度为镉>铅。干季只有铅超标，超标率为60%。含重金属的道路污染是主要污染源，重金属大多随地表径流和降水进入地表水。宁波工业区和商业区地表水中重金属造成的致癌风险非常高，商业区的致癌风险远高于工业区。主要致癌物是铬。与该研究团队2015年的研究结果相比，重金属污染程度已大幅降低。未来，仍需对宁波地表水中重金属污染的防治给予充分关注。
