淳安县主城区街道灰尘污染特征及风险分析

发布时间：2018-04-01 11:11

本文选题：小城镇　切入点：街道灰尘　出处：《浙江大学》2015年硕士论文

【摘要】：城市街道灰尘是城市生态系统的重要组成部分,也是地壳层水、气、固三相介质中循环流动的重要环节。城市街道灰尘由于附着了包括重金属、有机污染物、N/P营养物质等多种污染物,对区域环境质量以及人群健康等都有着一定的影响。论文以淳安县主城区街道灰尘为研究对象,通过调查分析不同功能区典型街道的地表灰尘粒径组成、主要污染物质赋存含量及污染来源,并对街道灰尘污染物的环境风险与健康风险进行评价。论文主要结论如下：对淳安县商贸区、交通区和综合区分别设置采样点,采集相应的灰尘进行粒径分布特征分析,结果表明淳安县主城区街道灰尘分布呈单峰趋势,主要以150～360μm粒径颗粒为主,占总颗粒物的33.86%；其后依次为360μm和65～150μm粒径颗粒,分别占总颗粒物的26.57%和25.53%；比重最小的是65μm粒径颗粒,占总颗粒物的14.03%。各功能区街道灰尘粒径分布差异性并不明显。对淳安县主城区街道灰尘样品中总磷、氨氮进行测试分析,结果表明,主城区街道灰尘中总磷、氨氮的含量分别为588.29μg/g、13.67μg/g。不同营养物质在不同功能区街道灰尘赋存量有较大差异,总体上位于交通区的环湖北路街尘营养物质含量最小,位于商贸区的新安大街和新安北路监测点氨氮含量相对较高,位于综合区的南山大街总磷含量较高。街道灰尘对营养物质的富集能力随街尘粒径增大逐渐变小,总磷和氨氮贡献率主要来源于中粒径颗粒。相对春、冬两季而言,淳安县主城区街道灰尘中营养物质在夏季含量相对较高。淳安县主城区街道灰尘样品中重金属含量测试结果表明,淳安县主城区街道灰尘Ni、Pb、Cd、Cu、Zn、Cr六类重金属的平均含量分别是84.77、233.55、4.61、142.11、293.19和815.46mg/kg,相较已有研究中关于浙江省平均值,Pb、Ni、Cr元素平均浓度分别超出全省平均浓度的25.3%、46%和238%, Cu、Zn元素平均浓度分别低于全省平均浓度13.6%和56%；各类重金属元素在不同功能区分布有所差异,其中Pb、Zn、Ni、Cr在交通区检出浓度最高,其次为商贸区和综合区,Cu、Cd在商贸区检出浓度更高,其次为交通区和综合区；除了Pb以外,街道灰尘对大多数重金属的富集能力均随街尘粒径增大逐渐变小；在季节分布上,除Cd外,大部分重金属含量均在夏季出现峰值。以土壤环境质量二级标准来评价淳安县主城区街道灰尘重金属污染状况,Cr元素已达到轻污染水平临界值,其余四类重金属元素均处于无污染程度。以浙江省浙北杭嘉湖平原土壤环境背景值为基准分析淳安县主城区街道灰尘重金属环境风险。按照地质累积指数方法进行评价,淳安县主城区街道灰尘中Pb和Cr元素的地质累积程度相对较高,其中Pb在商贸区(新安大街)、交通区和综合区均达到中度污染到强度污染范围,Cr在各功能区均达到中度污染到强度污染范围；其次为Cu,在各功能区均达到中度污染范围；Ni除了在交通区达到中度污染范围外,在其他各功能区为无污染到中度污染范围；Cd和Zn在该区域灰尘中没有累积。按照生态危害指数方法进行评价,淳安县主城区街道灰尘中Cd元素已达到强度生态危害水平,其余各元素尚在轻度生态危害水平。各功能区中,商贸区(新安大街)和交通区的多个重金属潜在生态危害累计值已达到中度生态危害水平,商贸区(新安北路)和综合区尚在轻度生态危害水平。
[Abstract]:Urban street dust is an important part of urban ecological system , and it is an important link in the circulation flow of water , gas and solid three - phase medium in the crust .
followed by 360 . m u.m and 65 - 150 . m u.m particle diameter particles in turn , accounting for 26.57 % and 25.53 % of the total particulate matter , respectively ;
The content of total phosphorus and ammonia nitrogen in the streets and dust in the main urban area of Chun ' an county is relatively high . The results show that the content of total phosphorus and ammonia nitrogen in the street dust in the main urban area of Chun ' an county is relatively high . The results show that the average content of total phosphorus and ammonia nitrogen in the street dust in the main urban area of Chun ' an county is relatively high . The average concentration of total phosphorus and ammonia nitrogen in the main urban streets of Chun ' an county is higher than that of the average concentration in the whole province .
The concentration of Pb , Zn , Ni and Cr in the traffic area is the highest , and the concentration of Pb , Zn , Ni and Cr in the traffic area is the highest , followed by the higher concentration of Cu and Cd in the commercial area , followed by the traffic area and the complex area ;
In addition to the Pb , the enrichment ability of the street dust to most heavy metals decreased gradually with the increase of the diameter of the street dust ;
In the seasonal distribution , most of the heavy metal contents in the main urban streets of Chun ' an county are higher than that of Cd except Cd , and the pollution of heavy metals in the streets and dust in the main urban area of Chun ' an county is evaluated by using the second - level standard of soil environment quality .
secondly , Cu is adopted , and a moderate pollution range is achieved in each functional area ;
In addition to the moderate pollution range in the traffic area , Ni has no pollution to the moderate pollution range in the other functional zones ;
Cd and Zn do not accumulate in the dust of this area . According to the ecological hazard index method , the Cd element in the street dust in the main urban area of Chun ' an county has reached the level of intensity ecological damage , and the remaining elements are still in the light ecological hazard level . In each function area , the accumulated value of the potential ecological harm of the heavy metals in the commercial area ( Xinan Avenue ) and the traffic area has reached the moderate ecological hazard level , and the trade area ( Xin ' an North Road ) and the comprehensive area are still in the light ecological hazard level .

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X513

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