热带地理 ›› 2021, Vol. 41 ›› Issue (1): 136-146.doi: 10.13284/j.cnki.rddl.003302

• 论文 • 上一篇    下一篇

高位虾池底质重金属富集特性及污染、生态风险评价

王子爱(), 唐少霞(), 傅雨萱, 郑苗, 吴丹, 陈珂珂, 戴文博   

  1. 海南师范大学 地理与环境科学学院,海南省热带海岛地表过程与环境变化重点实验室,海口 571158
  • 收稿日期:2020-05-21 修回日期:2020-09-04 出版日期:2021-01-05 发布日期:2021-02-19
  • 通讯作者: 唐少霞 E-mail:wangzai713@126.com;519635162@qq.com
  • 作者简介:王子爱(1995—),女,海南三亚人,硕士,主要研究方向为生态环境及资源开发利用,(E-mail)wangzai713@126.com
  • 基金资助:
    国家自然基金(41361108┫后续研究项目及海南省重点地理学科项目资助);研究生创新科研课题(Hsyx2018-20);海南省大学生创新创业训练项目(201711658022)

Evaluation of the Accumulation Characteristics, Pollution Status, and Ecological Risk of Heavy Metals in Sediments of Higher-Shrimp Ponds

Zi'ai Wang(), Shaoxia Tang(), Yuxuan Fu, Miao Zheng, Dan Wu, Keke Chen, Wenbo Dai   

  1. College of Geography and Environmental Science, Hainan Normal University, Key Laboratory of Earth Surface Processes and Environmental Change of Tropical Islands, Hainan Province, Haikou 571158, China
  • Received:2020-05-21 Revised:2020-09-04 Online:2021-01-05 Published:2021-02-19
  • Contact: Shaoxia Tang E-mail:wangzai713@126.com;519635162@qq.com

摘要:

为研究高位虾池养殖导致的环境影响,用电感耦合等离子体质谱仪ICP-MS(Agilent7700x型)对海口市东营镇3种类型养殖虾池及其外围沟渠底质中的Cr、Ni、Cu、Zn、As、Cd和Pb质量分数进行检测,用Vario TOC对底质中的TN(总氮)和TOC(有机碳)质量分数进行检测,并对所检测的数值采用单因子污染指数、地积累指数和综合潜在生态风险指数等方法进行分析及评价。结果表明:1)未清洗的虾池底质重金属质量分数呈现L1层向L4层明显递增的规律;2)虾池L1层底质中Cd呈现明显的累积(污染)现象,其质量分数是海南省土壤背景值5.47~35.18倍;3)地积累指数(Igeo)的评价表明,各样地底质中均有2种及以上重金属达到轻度—中等及以上污染程度;4)综合潜在生态风险指数(RI)结果表明,底质RI范围值为176.97~1 090.87,各样地综合潜在生态风险程度均达到中等及以上生态风险,其中Cd是主要的贡献因子;5)Pearson相关分析显示,虾池底质中的饵料残留物及对虾排泄物所含的Cr、Ni、Cu、As、Cd、TOC相互之间具有极显著相关性,相关系数高达0.9以上,表明农户所使用的饵料不同程度地含有以上重金属,同时有机碳是影响底质中重金属富集的重要因素。

关键词: 高位虾池, 底质, 重金属, 污染状况, 生态风险

Abstract:

To study the environmental impact caused by higher-place shrimp pond aquaculture, Inductively Coupled Plasma Mass Spectrometer (ICP-MS, Agilent 7700x) was used to detect the contents of Cr, Ni, Cu, Zn, As, Cd, and Pb in the sediments of three types of shrimp ponds (the bottom of the shrimp ponds was covered with sand, cement, and mulch, respectively) and their surrounding ditches in Dongying Town, Haikou City. The Vario TOC analyzer was used to detect the Total Nitrogen (TN) and Total Organic Carbon (TOC) contents in the sediments. The detected values were analyzed and evaluated using various parameters, such as the single factor pollution index, geo-accumulation index, and comprehensive potential ecological risk index, to reveal the spatial enrichment, pollution status, and ecological risk of heavy metal contents in the sediments of higher-place shrimp ponds and their surrounding ditches. The major results of this study were as follows: 1) The contents of heavy metals in the sediments of the unwashed shrimp pond increased significantly from the L1 layer to the L4 layer. 2) In the sediments of the surrounding ditches, the contents of all heavy metals (except for those of Ni and Cd, which were the highest in the L1 layer) were the highest in the L4 layer and were 1.29-15.51 times higher than those in the surface layer; 3) In the L1 layer of the sediment of the shrimp pond, Cd showed a significant accumulation (pollution); its content were 5.47-35.18 times higher than the soil background value in the Hainan Province . 4) The evaluation of Igeo indicated that there are two or more heavy metals in all types of sediments that reached a mild-medium pollution degree and above. The most serious pollutant in each sample pond was Cd, ranging from a level of 1.87 to 4.55; the highest level, 5, indicates strong-extremely severe pollution, while the lowest level, 2, indicates a medium pollution level. 5) The single-factor potential risk coefficient (Eri) of all heavy metals, except Cd, in the surface layer sediments of each sample pond was ≤40, which indicates a slight pollution degree. 6) The Comprehensive Potential Ecological Risk Index (RI) of the sediments was 176.97 to 1090.87, and the RIs of all plots showed moderate or higher ecological risks, for which Cd was the main contributing factor. The Cd pollution load sharing rate (the proportion of Cd in RI) in the seven sample plots exceeded 90%, mainly because the biological toxicity response coefficient (Ti=30) of Cd was the highest and the reference value (=0.05) was the lowest; this increased the RI values and the ecological risk index levels. 7) Pearson's correlation analysis showed that the Cr, Ni, Cu, As, Cd, and TOC contents in the bait residues and prawn excreta of shrimp pond bottoms had extremely significant correlations with each other, and the correlation coefficient was as high as 0.9 or more, indicating that the bait used contained the above heavy metals at varying concentrations and that organic carbon is an important factor that affects the enrichment of heavy metals in the substrate.

Key words: higher-place shrimp ponds, sediment, heavy metal, pollution status, ecological risk

中图分类号: 

  • X52