西安市路面沉积物污染机制研究

发布时间：2018-01-03 15:40

本文关键词：西安市路面沉积物污染机制研究　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：为研究西安市路面沉积物污染特性及其可能产生的生态风险,为西安市路面沉积物污染治理提供科学依据,在西安市典型工业区、商业区、居民文教区及旅游区各选择三条车流量分别为10000pcu/d、10000-30000 pcu/d和30000pcu/d的12条城市道路设置路面沉积物取样样地,从2013年10月开始,在秋、冬、春、夏四季的代表月份(10、1、5、8)在各采样地选取固定采样点,连续采样6日,用以研究西安市路面沉积物污染负荷的时空分异特征。在2014年8月底9月初,在3场降雨之间,在旅游区三个采样地,采集9天共27个样品,用以研究路面沉积物累积规律以及车流量和径流冲刷对路面沉积物累积效果的影响。测定各样品的COD、淋溶COD、NH4+-N、NO3--N、NO2--N、Pb、Zn、Cu、Ni、Cr、Cd、V、Ba等污染指标的含量,研究西安市路面沉积物污染负荷,探讨车流量及径流冲刷对路面沉积物污染累积的影响,并应用潜在生态危害指数法评价其生态风险,利用美国EPA颁布的健康风险评价方法评价其对西安市居民的健康风险。研究结果表明:(1)西安市路面沉积物中COD、NH4+-N、NO2--N的质量浓度在不同车流量下有显著差异,表现为:大车流量中等车流量小车流量,而各车流量道路的路面沉积物中淋溶COD与NO3--N的质量浓度无显著差异。NH4+-N、NO3--N和NO2--N浓度均表现为冬季春季夏季秋季。(2)沉积物中Ba、V、Cr、Cu、Ni、Zn的质量浓度在不同功能区有显著差异,Cd、Pb的质量浓度无显著差异。Ba、Pb、Zn和Cd均为工业区商业区居民文教区旅游区,Cu和Cr均在居民文教区表现较高,V和Ni与其他重金属相比,较为接近或略高于陕西省土壤背景值。路面沉积物中重金属元素表现出了夏秋季节较低而冬春季节较高的分布特征。(3)西安市路面沉积物对人群健康的影响不容忽视。各重金属多暴露途径对儿童产生的非致癌总风险值HI为1.19,大于临界值,表明存在明显的非致癌健康风险。对成人的影响小于儿童,成人非致癌总风险值为0.196。3种暴露途径中,非致癌风险值均为手-口接触摄入皮肤吸收呼吸吸入,非致癌风险排序PbBaVCdNiCrCuZn,表现出较大的危害,Pb、Ba、V对儿童的非致癌健康风险分别为0.231、0.481和0.148,其可能对儿童健康造成不良影响;Pb、Ba、V比其他重金属的非致癌风险高出1-2个数量级,是西安市路面沉积物导致人体非致癌健康风险的最主要污染物。Cr、Cd、Ni三种重金属总致癌风险为4.25×10-7,单种重金属的致癌风险及三种重金属总致癌风险均低于10-6-10-4,低于致癌风险量级水平。(4)西安市路面沉积物重金属生态危害处于中等水平,Cu、Pb、Cd、Ba、Zn、Cr、Ni和V的生态危害指数RI已达到了1359,多种重金属的潜在危害指数达到生态危害IV级水平,应引起足够重视;不同重金属单项生态风险系数和污染指数的排序分别为:CdPbCuCrNi=BaZnV,CdPbZnCuBaCrNiV。(5)车流量10000pcu/d(旅小)时,路面沉积物累积量范围在4.36~16.88g;车流量在10000-30000 pcu/d之间(旅中)时,沉积物累积量范围在4.86~20.58g;车流量30000pcu/d(旅大)时,沉积物累积量范围在7.84~32.31g;大体上来看,随着车流量的增加,路面沉积物的累积量呈现出上升趋势,即旅小旅中旅大。路面沉积物在降雨的径流冲刷下累积量有明显的损失,旅小、旅中和旅大三个采样地的路面沉积物量的去除率非别为60%、53%和48%。
[Abstract]:For the ecological risk of Xi'an City Road sediment pollution characteristics and possible, provide scientific basis for the Xi'an City Road sediment pollution in typical area of commercial, industrial zone, Xi'an City, residential and educational area and tourism area the three cars were 10000pcu/d, pcu/d and 10000-30000 12 city roads 30000pcu/d road sediments take everything, from the beginning of October 2013, in autumn, winter, spring and summer seasons, representing the month (10,1,5,8) in each sampling to select fixed sampling points, continuous sampling 6, is used to study the temporal and spatial characteristic of Xi'an city road surface sediment pollution load. At the end of August 2014 and early September, between the 3 rainfall and in the tourist area of three sampling, a total of 27 samples were collected for 9 days, in order to study the effects of sediment accumulation and road traffic flow and runoff cumulative effect on the road surface sediments. Each sample was determined COD, NH4+-N, NO3--N, COD leaching, NO2--N, Pb, Zn, Cu, Ni, Cr, Cd, V, Ba content of the pollution index, Xi'an City Road sediment pollution load, to explore the traffic flow and runoff scouring effect on road sediment pollution accumulation, and the application of the method of potential ecological risk index evaluation ecological risk, health risk assessment method using the United States EPA issued a healthy risk assessment of Xi'an city residents. The results show that: (1) Xi'an City Road sediments COD, NH4+-N, NO2--N concentrations were significantly different in different traffic flow shows: the traffic flow medium traffic flow and the quality of the car. The concentration of COD and NO3--N leaching road sediment the traffic flow in no significant difference in.NH4+-N, NO3--N and NO2--N concentration were in winter spring and summer autumn. (2) in the sediments of Ba, V, Cr, Cu, Ni, Zn concentration in different functional areas have significant difference ISO, Cd, Pb concentration had no significant difference in.Ba, Pb, Zn and Cd are industrial residential commercial district cultural district tourism area, Cu and Cr are in the cultural district residents showed higher V and Ni compared with other heavy metals, is close to or slightly higher than the background values of soils in Shaanxi province. Heavy metals in road sediments show the distribution features of summer and autumn winter season is lower and higher. (3) Xi'an City Road sediment influence on people's health can not be ignored. The heavy metal exposure total non carcinogenic risk value of HI is 1.19 of children, is greater than the critical value, that in the non carcinogenic health risk effects obviously. The adult children less than adults, non carcinogenic risk value for 0.196.3 exposure, non carcinogenic risk value is hand mouth intake contact skin absorption inhalation, non carcinogenic risk ranking PbBaVCdNiCrCuZn, showed a greater harm, Pb, Ba, V The children of non carcinogenic health risk were 0.231,0.481 and 0.148, which may have adverse effects on the health of children; Pb, Ba, V risk is 1-2 orders of magnitude higher than other heavy metals non carcinogenic, Xi'an city is the most non road sediment causes the body's major pollutants.Cr, carcinogenic risk of Cd, Ni three kinds of heavy metals the total cancer risk is 4.25 * 10-7, single heavy metals and three kinds of heavy metals in the carcinogenic risk of total cancer risk was lower than 10-6-10-4, less than the magnitude of the carcinogenic risk level. (4) Xi'an city road ecological risk of heavy metals in the sediments in the middle level, Cu, Pb, Cd, Ba, Zn, Cr, Ni and V ecological risk index RI has reached 1359, the potential hazard index of heavy metals to achieve ecological hazard level IV, should pay more attention; different single heavy metal pollution index and ecological risk ranking were: CdPbCuCrNi= BaZnV, CdPbZnCuBaCrNiV. (5) traffic The amount of 10000pcu/d (travel small), road sediment accumulation in the range of 4.36~16.88g; traffic in 10000-30000 pcu/d (travel), the sediment accumulation in the range of 4.86~20.58g; 30000pcu/d (LD) traffic flow, sediment accumulation in the range of 7.84~32.31g; a large body, with the increase in traffic flow, accumulation the surface sediments showed a rising trend, namely small brigade. Brigade brigade road sediments in runoff under rainfall accumulation has obvious loss, small and large brigade brigade brigade, a sample road sediment removal rate 53% and 48%. = 60%.

【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X734

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