基于改进模糊层次分析法的贡湖水源地水质安全风险评估

发布时间：2018-05-26 20:43

本文选题：贡湖 + 饮用水源地　；参考：《江南大学》2017年硕士论文

【摘要】：近年来太湖流域环境污染问题越来越多的受到人们的关注,其中贡湖湾作为无锡和苏州重要的饮用水水源地,其水质安全问题更是关系着流域周边的居民的健康生活。本研究通过2015年12月至2016年11月进行为期一年的采样监测,调查分析贡湖湾水源地11个重点区域水质情况,筛选出湖湾的水质等级、富营养状态、溶解态重金属健康风险评价、微囊藻毒素风险评价、抗生素风险评价作为风险指标,通过改进改进层次分析法的模糊综合评价模型(Analytic hierarchy process and fuzzy comprehensive evaluation,AHP-FCE),对各风险指标赋予权重,最终加权求和得到贡湖湾各水域水质安全风险综合评值,对贡湖湾水质安全问题做出科学评价,以期为后续水域的管理决策提供科学的依据。(1)通过单因子-主成分分析法评价水质等级,结果显示贡湖湾主要污染物为总氮、总磷、chla(chlorophyll a)以及TOC(Total organic carbon);贡湖湾监测期间水质状况达到Ⅲ类及以上仅为50%,在蓝藻爆发的月份水质依然处于劣V类水质。综合营养指数(Comprehensive trophic level index,TLI)评价贡湖营养水平显示,在监测期间贡湖湾水域均处于中营养以上,且北部75%时段、南部全部时段处于富营养状态,在蓝藻爆发的5月份甚至达到了重度富营养状态,这说明当前贡湖湾富营养化问题依然严重,不容忽视。(2)监测期间丰水期表层水检出的5种重金属Zn检出浓度为各点最高;枯水期贡湖湾仅在1号(南泉取水口)、7号(望虞河口)有极少量检出。通过健康风险模型评估显示,枯水期状况良好,处于极低可忽略水平;丰水期检出各元素中As风险值最高,存在一定风险,在5号点(小溪港)的总风险值最大,处于较低风险等级,整体北部总风险值明显高于南部湖湾。表层沉积物参照土壤元素背景值计算重金属污染超标区域比率:Mn为33.3%、Zn为66.7%、Cu为33.3%、As为22.2%、Pb为11.1%;通过潜在生态风险指数法RI(Potential ecological risk index)评估,单因子Eir均低于40,属于比较轻微的;累积生态危害指数RI值均处于轻微生态危害。(3)通过风险指数(Hazard index,HI)对微囊藻毒素风险状况评价,监测期间MCs(Microcystin)风险最高为0.15左右,处于可能有风险的程度。整体上贡湖湾抗生素污染情况有一定好转,丰水期仅1号点检出19.9 ng/L诺氟沙星(Norfloxacin,NOR),6号(锡东取水口)检出2.3 ng/L氧氟沙星(Ofloxacin,OFL);枯水期在1号点总浓度最高,整体上北区的抗生素浓度水平高于南区。风险熵值(Risk Quotients,RQs)评价显示丰水期风险熵值整体水域处于较低风险;枯水期中高风险有3种,抗生素累积RQs评估,磺胺甲恶唑(Sulfamethoxazole,SMZ)在各点占主要组成,90.9%区域处于中高风险;综合来看,贡湖湾抗生素枯水期仍存在较高风险。(4)通过改进的层次分析法的模糊综合评价模型(AHP-FCE)来对贡湖湾水域水质安全风险开展综合评价,确定五部分指标权重W=[0.053,0.413,0.158,0.345,0.031];安全风险综合评价54.5%区域属于良好偏中等范围,其余评分在40以上,属中等较好;北部湖湾(40.02)处于中等中较好水平,南部湖湾(39.85)处于良好偏中等;贡湖湾整体上综合评值为39.99,处于良好,近中等水平。
[Abstract]:In recent years, more and more attention has been paid to the environmental pollution problem in the Taihu River Basin. As an important drinking water source in Wuxi and Suzhou, the water quality safety problem of the Gong lake bay is related to the healthy life of the residents around the river basin. This study carried out a year of sampling and monitoring from December 2015 to November 2016. The water quality of 11 key areas in the water source area of the lake bay is analyzed. The water quality level, the eutrophic state, the health risk of dissolved heavy metals, the risk assessment of microcystin, the risk evaluation of the antibiotic as the risk index are selected, and the Analytic hierarchy process and fuzz model is improved by improving the evaluation model of the analytic hierarchy process (process and fuzz). Y comprehensive evaluation, AHP-FCE), giving weight to each risk index, and finally weighting and obtaining the comprehensive evaluation of the water quality safety risk in the waters of the Gong Lake Bay, making a scientific evaluation on the water quality safety problem in the tribute Lake Bay, in order to provide scientific basis for the management decision of the following waters. (1) evaluation of water quality by the single factor principal component analysis method. The results show that the main pollutants in the Gong Lake Bay are total nitrogen, total phosphorus, Chla (chlorophyll a) and TOC (Total organic carbon). The water quality of the Gong Lake Bay monitoring period is only 50%. The water quality in the month of cyanobacteria is still in the inferior V water quality. The comprehensive nutrition index (Comprehensive trophic level index) is used to evaluate the tribute lake. The nutrition level showed that during the monitoring period, the waters of Gong Hu bay were in the middle nutrition above, and the northern 75% period was in the eutrophic state in the southern part of the period. In May, it even reached the severe eutrophication state in the outbreak of cyanobacteria. This indicates that the current eutrophication problem in Gong Hu Bay is still serious and can not be ignored. (2) surface water inspection during the flood season during the monitoring period. The highest detection concentration of the 5 kinds of heavy metals Zn was the highest, while the Gong Lake Bay was only in No. 1 (the South Spring water intake), and the 7 (Wangyu estuary) was detected very small. The total risk value is the lowest, the total risk value of the whole north is obviously higher than that of the southern Lake Bay. The surface sediments refer to the background value of soil elements to calculate the ratio of heavy metal pollution over the standard area: Mn is 33.3%, Zn is 66.7%, Cu is 33.3%, As is 22.2%, Pb is 11.1%, RI (Potential ecological RI) through the potential ecological risk index method RI (Potential ecological RI). Sk index) assessment, the single factor Eir is less than 40, is relatively mild; the cumulative ecological hazard index RI values are in minor ecological hazards. (3) the risk index (Hazard index, HI) for the risk assessment of microcystins, the maximum risk of MCs (Microcystin) is about 0.15, at a possible risk. On the whole of the tribute Lake Bay The situation of antibiotic pollution was improved, 19.9 ng/L norfloxacin (Norfloxacin, NOR) was detected only at No. 1, and 2.3 ng/L ofloxacin (Ofloxacin, OFL) was detected (Ofloxacin, OFL) in No. 6 (Xi Dong water intake). The total concentration of the No. 1 point in the dry season was higher than that in the southern region. The risk entropy (Risk Quotients, RQs) evaluation showed that the abundance of the risk entropy (Risk Quotients, RQs) showed abundant. The risk entropy in the whole water period is at a low risk, and there are 3 high risks in the low water period, the cumulative RQs assessment of antibiotics, the main composition of the sulfa methoxazole (Sulfamethoxazole, SMZ) in each point, and the middle and high risk in the 90.9% region. In a comprehensive view, the high risk still exists in the period of antibiotic dry water in the Gong lake bay. (4) the fuzziness of the improved analytic hierarchy process (AHP) is adopted. The comprehensive evaluation model (AHP-FCE) is used to evaluate the safety risk of the water quality in the waters of the Gong Lake Bay, and determine the weight of the five part of the index W=[0.053,0.413,0.158,0.345,0.031]; the comprehensive evaluation of the safety risk is in a good medium range, the other score is above 40, and the northern Lake Bay (40.02) is in the middle and middle level. The whole lake (39.85) is in a good middle class; the overall evaluation of Gong Hu Bay is 39.99, at a good, near middle level.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X824

【参考文献】