重庆市典型建筑工地扬尘排放特征研究

发布时间：2018-11-18 22:11

【摘要】：随着社会和经济的快速发展,近年来,“京津冀”、“长三角”、“珠三角”以及成渝城市群,均爆发过比较严重的雾霾天气。空气污染已成为我国城市最为突出的环境问题之一。随着城市化进程的深入推进,大量的建筑工地产生的扬尘己成为大气颗粒物的重要来源,重庆市也不例外;但有关重庆市建筑扬尘排放特征的相关研究较少,针对其排放因子的研究更为少见,因此,本研究针对重庆市典型建筑施工工地,即两江新区礼嘉的重庆市环保产业园建筑工地,在土方开挖、地基建设、一般建设及土方回填等三个不同施工阶段,系统开展其扬尘排放特征和污染水平的研究,以期能为政府相关管理部门制定建筑扬尘控制对策提供科学依据和技术支撑。首先,对各施工阶段的扬尘浓度和气象参数进行了连续监测,对建筑扬尘浓度随时间的演变进行了分析,并对影响建筑扬尘浓度的因素进行了讨论。其次,采用通量计算方法建立了不同施工阶段的初始排放因子;利用模型校正的方法得到了不同施工阶段的扬尘排放因子。再次,同步采集了不同施工阶段的PM_(10)和PM_(2.5)滤膜样品,并对其进行了元素组分分析、水溶性离子组分及有机碳/元素碳(OC/EC)组分测试分析,获得了相应的化学组分特征,并对PM_(10)和PM_(2.5)化学组分进行了对比分析。研究表明:(1)地基开挖阶段,建筑扬尘净浓度排放主要集中在中午12时至半夜4时;地基建设阶段,建筑扬尘净浓度排放主要集中在早上8时至晚上23时;一般建设及土方回填阶段扬尘净浓度排放主要集中早上8时至下午18时。建筑扬尘净浓度受气象条件的影响明显,其净浓度与风速、相对湿度呈显著正相关,与温度呈弱相关。(2)不同施工阶段建筑扬尘排放因子为土方开挖阶段为0.25 g/(m2.h),地基建设阶段为0.09 g/(m2.h),一般建设及土方回填阶段为0.07 g/(m2.h)。(3)一般建设及土方回填阶段,元素组分以Si、S、Ca、Fe、Zn等净含量较高;水溶性离子组分以Ca2+、Na+、SO42-、NO3-净含量较高,其中,地基建设阶段NO3-净含量最高;地基开挖阶段SO42-净含量最高;一般建设与土方回填阶段Ca2+净含量最高;各施工阶段建筑扬尘碳组分净含量OC均高于EC。(4)在地基开挖阶段,PM_(2.5)/PM_(10)的平均比值为0.496;在地基建设阶段,PM_(2.5)/PM_(10)的平均比值为0.595;在一般建设阶段及土方回填阶段,PM_(2.5)/PM_(10)的比值为0.661。
[Abstract]:With the rapid development of society and economy, in recent years, "Beijing-Tianjin-Hebei", "Yangtze River Delta", "Pearl River Delta" and Chengdu-Chongqing urban agglomeration have all experienced severe haze weather. Air pollution has become one of the most prominent environmental problems in Chinese cities. With the further development of urbanization, the dust produced by a large number of construction sites has become an important source of atmospheric particulate matter, Chongqing is no exception; However, there are few studies on the characteristics of dust emission from buildings in Chongqing, especially on the emission factors. Therefore, this study is aimed at typical construction sites in Chongqing. That is, at the construction site of Chongqing Environmental Protection Industrial Park in Lijia, Lijiang New District, three different construction stages, namely, earthwork excavation, foundation construction, general construction and earthwork backfilling, were systematically carried out to study the characteristics of dust emission and pollution levels. In order to provide scientific basis and technical support for the relevant government management departments to formulate the countermeasures of building dust control. Firstly, the dust concentration and meteorological parameters of each construction stage are continuously monitored, the evolution of building dust concentration with time is analyzed, and the factors influencing the building dust concentration are discussed. Secondly, the initial emission factors of different construction stages are established by using flux calculation method, and the dust emission factors of different construction stages are obtained by using model correction method. Thirdly, the samples of PM_ (10) and PM_ (2.5) filter membranes in different construction stages were simultaneously collected, and their elemental components, water-soluble ion components and organic carbon / elemental carbon (OC/EC) components were analyzed. The chemical components of PM_ (10) and PM_ (2.5) were compared and analyzed. The results show that: (1) in the excavation stage of the foundation, the net concentration of building dust is mainly discharged from 12:00 to 4 midnight, and in the stage of foundation construction, the emission of building dust concentration is mainly from 8 am to 23:00; General construction and earthwork backfill stage dust concentration emission mainly concentrated from 8 am to 18:00. The net concentration of building dust was obviously affected by meteorological conditions, and its net concentration was positively correlated with wind speed and relative humidity. (2) the emission factor of building dust in different construction stage is 0.25 g / (m ~ 2 路h) in excavation stage and 0.09 g / (m ~ 2 路h) in foundation construction stage. The average construction and earthwork backfill stage is 0.07 g / (m ~ 2 路h). (_ 3), and the net content of elements such as Si,S,Ca,Fe,Zn is higher. The net content of Ca2, Na, SO42-,NO3- is higher in the water soluble ions, among which, the net content of NO3- is the highest in the foundation construction stage, the highest in the foundation excavation stage, the highest in the general construction and earthwork backfill stage. The net content of carbon component of building dust in each construction stage is higher than that of EC. (4) in the excavation stage of foundation, the average ratio of PM_ (2.5) / PM_ (10) is 0.496; The average ratio of PM_ (2.5) / PM_ (10) is 0.595in foundation construction stage, and the ratio of PM_ (2.5) / PM_ (10) is 0.661in general construction stage and earthwork backfill stage.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X799.1

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