引用本文: | 廖润华,吴小刚,王兆德,王宝莹,柯凡,韩超,周强,任静华.太湖流域滆湖围网拆除后沉积物营养盐和重金属空间分布特征及评价.湖泊科学,2021,33(5):1436-1447. DOI:10.18307/2021.0511 |
| Liao Runhua,Wu Xiaogang,Wang Zhaode,Wang Baoying,Ke Fan,Han Chao,Zhou Qiang,Ren Jinghua.Spatial distribution and pollution assessment on the main nutrients and heavy metals in sediments of Lake Gehu, Taihu Basin after removing the aquaculture net*. J. Lake Sci.2021,33(5):1436-1447. DOI:10.18307/2021.0511 |
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太湖流域滆湖围网拆除后沉积物营养盐和重金属空间分布特征及评价 |
廖润华1, 吴小刚1,2, 王兆德2, 王宝莹2, 柯凡2, 韩超2, 周强3, 任静华3
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1.景德镇陶瓷大学材料科学与工程学院, 景德镇 333403;2.中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室, 南京 210008;3.自然资源部国土(耕地)生态监测与修复工程技术创新中心, 江苏省地质调查研究院, 南京 210018
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摘要: |
为评估滆湖围网拆除工程实施效果,采用高密度网格化布点方法,系统分析滆湖沉积物营养盐和重金属的空间分布和污染特征;并基于有机氮评价方法、综合污染指数评价方法、重金属地质累积指数法和重金属潜在生态风险评价方法进行污染风险评价.结果表明,滆湖沉积物总氮(TN)、总磷(TP)和总有机碳(TOC)的平均含量分别为(3709±1004)mg/kg、(1127±650)mg/kg和(78.39±23.88)mg/g,三者空间分布特征较为一致;营养盐综合污染指数评价表明,全湖整体为重度污染,其中全湖TN均处于重度污染状态,TP绝大部分区域也处于重度污染状态.沉积物重金属Zn、Cr、As、Pb、Ni、Cu、Cd的平均含量分别为(170.62±47.25)、(105.18±34.91)、(68.55±10.86)、(52.43±14.73)、(44.04±11.93)、(42.57±12.43)、(1.55±1.06)mg/kg,整体上呈现出由南向北、自西向东逐渐增加的趋势,重金属含量最高值在湖区东北角;地积累指数法和潜在生态风险指数法评价结果均表明Cd和As是主要的生态风险贡献因子,其中Cr和Ni的污染程度表现为清洁,Cr、Ni、Cu、Zn和Pb的单项潜在生态风险等级表现为轻微风险.与围网拆除前比,湖中区西南部沉积物营养盐含量无显著变化,湖南区南部沉积物营养盐状况明显改善,但其余各区域沉积物营养盐状况均有不同程度的恶化;湖区沉积物中重金属元素平均含量均有极大程度的降低,降幅在29.50%~80.45%之间,表明在外源污染输入得到一定控制时,围网拆除在控氮、控磷效果及改善重金属污染状况方面有着积极作用. |
关键词: 滆湖 养殖围网 沉积物 营养盐 重金属 污染评价 |
DOI:10.18307/2021.0511 |
分类号: |
基金项目:江苏省优秀青年基金项目(BK20180109)、国家自然科学基金项目(41773087)、国家水体污染控制与治理科技重大专项(2017ZX07603002)、江西省自然科学基金项目(20202BABL203037)、江西省教育厅项目(GJJ201311)和景德镇市科技计划项目(20192GYZD008-33)联合资助. |
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Spatial distribution and pollution assessment on the main nutrients and heavy metals in sediments of Lake Gehu, Taihu Basin after removing the aquaculture net* |
Liao Runhua1, Wu Xiaogang1,2, Wang Zhaode2, Wang Baoying2, Ke Fan2, Han Chao2, Zhou Qiang3, Ren Jinghua3
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1.School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, P. R. China;2.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;3.Geological Survey of Jiangsu Province, Technical Innovation Center of Ecological Monitoring & Restoration Project on Land(Arable), Ministry of Natural Resource, Nanjing 210018, P. R. China
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Abstract: |
In this study, the spatial distribution characteristics of the main nutrients and heavy metals in sediments of Lake Gehu after completely removing the aquaculture net were investigated using high-density sampling methods, and their potential ecological risks were assessed based on organic nitrogen index, integrated pollution index, geo-accumulation index (Igeo) and potential ecological risk index. Results showed that the average contents of TN, TP and TOC were (3709±1004) mg/kg, (1127±650) mg/kg and (78.39±23.88) mg/g, respectively. The spatial distribution characteristics of TN, TP and TOC were relatively consistent, generally, those of the middle and upper part of the lake was higher than those of the southern part except the northern. Integrated pollution index showed that the whole lake was heavily polluted, meanwhile, the lake-was severely TN-polluted and slightly TP-polluted in most areas. The average contents of heavy metals Zn, Cr, As, Pb, Ni, Cu and Cd were (170.62±47.25), (105.18±34.91), (68.55±10.86), (52.43±14.73), (44.04±11.93), (42.57±12.43) and (1.55±1.06) mg/kg, respectively. Generally, the heavy metal contents increased from south to north, from west to east, and reached the highest level in the northeast corner. Igeo and the potential ecological risk assessment indicated that Cd and As were the most polluted elements and led to high potential ecological risk. According to the result of Igeo, Cr and Ni were not polluted, while Cr, Ni, Cu, Zn and Pb were at a slight potential ecological risk. Since the aquaculture net was being demolished, there was no significant change in the nutrient content in the southwestern part of the lake, and the nutrient status in the southern end of the Gehu Lake area was significantly improved, but the nutrient status in the rest of the area had deteriorated to varying degrees; the heavy metal content has a great reduction, ranging from 29.50% to 80.45%, indicating that when the input of external pollution is controlled to a certain extent, the removal of the fence has a positive effect on the effect of controlling nitrogen and phosphorus and improving the pollution of heavy metals. |
Key words: Lake Gehu aquaculture net sediments nutrient heavy metal risk assessment |
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