环境化学——文献学习

环境化学——文献学习

由于大气颗粒物来源不同，其组成成分也不同，因而可以根据颗粒物的组成推断它的来源。这样有助于解决污染源控制问题。有以下两种方法：1、富集因子法；2、化学元素平衡法。

富集因子法可推测污染物在某一地区富集的程度以及污染源收天然或人为污染的程度，但是它不给出各种污染源相对贡献的定量结果，只能做出定性判断。而化学元素平衡法是属于受体模型的一种。它不考虑颗粒物从排放量到受体传输过程中的化学变化和化学反应动力学，而是靠测定直接从受体处采集样品的化学组成来推测出他们的来源类型，并计算出不同来源类型所占的比例。

此法假定环境颗粒物中各种元素的组成是各污染源排放颗粒物元素组成的总和，即它们之间存在着线性组合的关系。根据质量平衡原理，其表达式为

ρi=∑ρjωij

式中：ρi——某采样点所得颗粒物中元素i的质量浓度

ρj——从污染源j产生的颗粒物总质量浓度

ωij——从污染源j排出的颗粒物中元素i的质量分数

本篇“中国东北部6个城市PM2.5的污染源研究”即采用化学元素平衡法进行分析，最后得出“在此6个城市中PM10的最大来源已经由从前的煤烟污染转为开放源的污染”的结论。虽然本文发表于2006年，在过去的6、7年中，我国城市经济与工业发展迅速，

当时的污染情况与现在的污染情况可能已经有所不同，但是对于空气质量检测的取样时间、取样地点、以及化学元素的选取以及如何采用化学元素法进行分析仍然对现在有着较大的借鉴作用。

Source apportionment of PM10 in six cities of northern China

Xiaohui Bi, Yinchang Feng, Jianhui Wu, Yuqiu Wang, Tan Zhu

Abstract

Ambient PM10 was sampled in six northern China cities (Urumqi, Yinchuan, Taiyuan, Anyang, Tianjin and Jinan) from December 1999 to July 2002, and analyzed for 16 chemical elements, two water-soluble ions, total carbon, and organic carbon. In addition, chemical source profiles consisting of the same particulate components were obtained from a number of naturally occurring geological sources (soil dust from exposed lands) and sources of atmospheric particulates resulting from human activities (resuspended dust, cement, coal combustion fly ash, vehicle exhaust, and secondary particles).Ambient and source data were used in a chemical mass balance (CMB) receptor model to determine the major source of PM10 in these six cities. Results of CMB modeling showed that the major source of ambient PM10 in all the cities was resuspended dust. Significant contributions from coal fly ash were also found in all six cities.

摘要：本文选取了6个城市周围环境的PM10数据，数据来源的时间范围为1999.11-2002.7，并对其分析了16种化学元素，两种水溶性离子，总碳和总有机碳。此

外，这些包含了相同颗粒物的化学源集合基本上均来自一系列的自然发生的地理源，然后大气颗粒物的来源基本上都是来自人为活动。这些周围环境中的原始数据被用于化学元素平衡法中以推测出这6个城市PM10的主要来源。化学元素平衡法的结果表明这六个城市中周围环境PM10的主要来源是再悬浮灰尘。煤烟灰尘也对着6个城市的PM10数据有着显著地影响

2. Experimental method

2.1. Area description

The six cities examined in this study, Urumqi(861370E, 421450N), Yinchuan (1051490E, 371290N),Taiyuan (1111300E, 371270N), Anyang (1131380E,351120N), Tianjin (1161430E, 381340N) and Jinan(1171000E, 361400N) all experience a continental monsoonal climate within a warm temperate zone, with similar characteristics of hot summer, cold winter, and windy spring. The locations of the cities are provided in Fig. 1. Higher than average annual precipitation levels(610 mm) were observed by the China Meteorological Administration in Anyang, Tianjin and Jinan—located in the eastern part of northern China. Higher relative humidity was also observed in these three cities. As traditionally agricultural areas, these three cities provide optimal conditions for growing crops in summer and fall. During these seasons, there is little exposed land. However, during the winter and spring seasons, the area of bare land rises dramatically. Human activities such as traffic and industry are significant and widespread as a result of the population (1.05_106 in Anyang, 5.33_106 in Tianjin, and 2.6_106 in Jinan) and booming economy of these three cities. Sophisticated urban environmental management

initiatives were implemented in these three cities as compared to western cities, and more capital was invested for environmental protection.

Taiyuan is located in the middle of northern China, and has a lower annual average precipitation (395 mm) and relative humidity than the three eastern cities mentioned above (Anyang, Tianjin and Jinan). Exposed land is common in Taiyuan during winter and spring, and scarce in summer and fall. The rapidly developing economy of Taiyuan is largely propelled by massive coal consumption; in addition to using coal as an energy source, it is also used as raw material by a number of industries. There are a large number of coal traversing the city and surrounding vicinity of Taiyuan almost every day and plenty of road dust is created.

Urumqi and Yinchuan have lower than average annual precipitation (252 mm) and relative humidity. The proximity of these two cities to the desert limits their feasibility for growing crops. With relatively lower populations and underdeveloped economies, Urumqi and Yinchuan exhibit less significant anthropogenic impacts as compared to the eastern cities.

2．实验方法

2．1 选取地点的描述

本实验选取的六个城市：乌鲁木齐（86°37’E，42°45’N），银川，太原，安阳，天津，济南均为大陆季风气候并处于暖温带，有着相似的气候，夏季炎热，冬季寒冷，春天的风都比较大。

安阳、天津和济南有着高于全国平均水平的降雨量（610mm，由中国气象局提供的观测数据）它们都坐落于中国北部的偏东地区。这三个城市同时也被观测到了相对较高的湿度。作为传统的农业耕种区域，这三个城市为在夏季和秋季种植谷物提供了理想的环境。在这几个季节，这里很少有裸露的土地。但是，在冬春两季，荒地的数量将会快速上升。人类活动（例如交通运输业和工业）分布广泛并且有着非常重要的地位，这都归结于人口和经济的快速增长。这三个城市相比于西部的城市来说有着复杂的城市环境管理初始状况，同时更多的资本也被投入到了环境保护之中来。

太原坐落在中国的北部的中央，有着低于平均水平的降水量和低于其他三个城市的相对湿度。荒地在太原的冬、春两季非常常见，同时会在夏、秋两季消失。巨大的煤炭储量大大促进了太原经济的快速增长。除了利用煤炭提供能源以外，太原同时利用煤炭作为许多工业的原材料。几乎每一天，在太原及其周边地区都有着大量的煤炭的运输，与此同时，大量的道路灰尘也就产生了。

乌鲁木齐和银川有着低于全国平均水平的降雨量（252mm）和相对湿度。两个城市由于都距离沙漠比较近，因此这限制了他们的谷物的种植。乌鲁木齐和银川人口较少并且经济也不发达，所以人类活动的影响对于这两个城市相较于东部城市弱一些。

2.2. Ambient samples

Ambient and source samples were collected in the six cities as follows: December 1999 to September 2000 (Jinan), December 2000 to October 2001 (Tianjin), April 2001 to December 2001 (Anyang), April 2001 to January 2002 (Taiyuan), January 2002 to October 2002 (Yinchuan), and January 2002 to July 2002 (Urumqi).

Ambient PM10 samples were collected in three weeks (a winter week, a spring week, and a summer or fall week), in each city of different years mentioned above, that represent different seasons (winter, spring, and summer or fall, respectively) at sites that represent different functional areas, such as city downtown areas, industrial areas, educational or residential areas, and heavy traffic areas. All the sites were established with the criterion of Environmental Monitoring Station of China. The establishment of the functional areas complies with Principle and technical methods for regionalizing ambient air quality function of China, 1996S. Samples were collected for 20 h everyday from 8:00 AM to 4:00 AM of the next day during the sampling period using medium-volume PM10 samplers (Wuhan Tianhong Intelligence Instrumentation Facility, TH-150 Medium Volume Sampler). Two samplers were used in parallel to collect airborne particles on quartz-fiber filters (90 mmdiameter, type 2500QAT-UP, Pall Life Sciences, USA) for subsequent ionic/carbon component analysis, and on polypropylene-fiber filters (90 mm-diameter, Beijing Synthetic Fiber Research Institute, China) for elemental analysis. Gravimetric values of PM10 are determined based on quartz filters. Loaded and unloaded filters were conditioned for 48 h in darkened desiccators before gravimetric determination. The filter was airproofed in a tinfoil pouch after sampling. A total of 666 available ambient samples were collected in the six cities and 164 invalid ambient samples were rejected due to the rain, sampler’s malfunction, filter’s fracture, or other unexpected accidents. Further details about sampling of ambient PM10 have been previously described (Feng et al., 2005; Watson and Chow, 1993).

2.2环境采样

这些环境采样的样本以如下方式在6个城市进行采集：1999.11-2000.9（济南），2000.11-2001.10（天津），2001.4-2001.11（安阳），2001.4-2002.1（太原），2002.1-2002.10（银川），2002.1-2002.7（乌鲁木齐）。

环境中PM10的样本需要三周的时间（冬天一周，春天一周，夏天或秋天一周），在每个城市的上述不同年份，代表（分别为冬，春，夏季或下降， ）不同的季节在代表不同的功能区域，如城市中心区，工业区，教育或居住区，以及交通繁忙的网站。所有的网站都建立了与中国环境监测总站的标准。该功能区的设立符合原理和技术方法的中国区域化， 1996S的环境空气质量功能。收集样本进行日常20小时，从早上8点到4点，第二天的过程中使用中等音量可吸入颗粒物采样器（武汉天虹智能仪表设备， TH- 150中流量采样）的采样周期。两个采样器并联使用，以收集石英纤维过滤空气中的颗粒（ 90 mmdiameter ，类型2500QAT -UP ，颇尔生命科学，美国）进行后续离子/碳成分分析，和聚丙烯纤维过滤器（90毫米直径，北京合成纤维研究所，中国）进行元素分析。基于石英滤波器确定可吸入颗粒物的重力值。加载和卸载过滤器被调节为重量法测定之前变暗干燥器48小时。该过滤器是airproofed在采样后锡箔袋。共有666提供环境样品收集在六个城市和164无效的环境样品被拒绝由于下雨，采样器的故障，过滤器的骨折或其他意外事故的发生。关于环境可吸入颗粒物的采样进一步详情已如前所述。

2.3. Source sampling

Before source sampling, the investigation of PM10 sources based on the in situ investigation and the air pollution emission inventory from the official reports was implemented in the six cities and major sources were identified, including resuspended dust (RD), soil dust, cement dust, vehicle exhaust dust, coal combustion fly ash and secondary ionic particles. Samples of particulate sources

including RD, soil dust, cement dust, vehicle exhaust dust, and coal combustion fly ash were collected in the six cities and chemical components of 765 source samples were analyzed. RD refers to dust that is continually raised into the surrounding atmosphere by natural forces or human activities, after being initially deposited in urban areas. The resuspended dust was collected on windowsills positioned at heights of 5 m–15m in residential areas. Soil dust was collected from bare croplands, hilly country, dry riverbeds in the

vicinity of the six cities, or exposed land within urban areas. Cement dust was collected from roofs of residential buildings around the building site, or from production lines of nearby cement factories. Coal combustion fly ash was collected from particulate pollution control devices (electrostatic precipitators, fabric filters or wet scrubbers). The collected source samples were dried in a dark room with ventilation devices and sieved through 150 mesh sieves. The sieved material was then suspended in a chamber and sampled through sizeselective inlets onto filters to obtain the PM10 samples used for analyses (Chow et al., 1994). Vehicle exhaust samples were collected at underground parking lots and car tunnels by mediumvolume PM10 samplers and totally 12 samples were collected. Further details about the source sampling have been previously described (Feng et al., 2005) and the similar sampling procedures of sources were mentioned elsewhere (Zhu et al., 1995a,b,1996; Chow and Watson, 1989, 1994; Zhao et al., 2006). According to the main form of the secondary ions in North China, the chemical profiles of SO4 2_ and NO3 _ were established according to the composition of pure (NH4)2SO4 and NH4NO3.

2.3源取样

源取样前，的基础上，在现场调查，并从官方报道的空气污染排放清单中的六个城市和主要来源的实施可吸入颗粒物的来源进行调查鉴定，包括悬浮的灰尘，土壤尘，水泥尘，机动车尾气尘，燃煤飞灰和二次离子粒子。颗粒物的来源包括RD ，土壤尘，水泥粉尘，汽车尾气尘，煤燃烧飞灰样品收集在六个城市和765源样品进行了分析化学成分。 RD是指粉尘不断提高到周围大气中自然力量或人类活动，经过最初被存放在城市地区。再悬浮的灰尘被收集在窗台放置在5米-15米的居民区高度。土壤尘是从裸农田，丘陵地带，干涸的河床中采集的附近的六个城市中，或在市区裸露的土地。水泥粉尘收集来自各地的建筑工地住宅楼的屋顶，或从附近水泥厂生产线。煤燃烧飞灰从颗粒物污染控制设备（静电除尘器，袋式除尘器或湿法除尘器）收集。所收集的源样品干燥在一个黑暗的房间，通风设备，并通过150目筛过筛。然后将过筛的物质悬浮在腔室中，并通过sizeselective入口采样到的过滤器，得到用于分析（ Chow等人，1994 ）的可吸入颗粒物样品。汽车尾气样品收集在地下停车场及汽车隧道由mediumvolume可吸入颗粒物采样器和共采集12个样品。关于源采样的进一步详情以前已经描述和源的类似抽样程序在其他地方提到的。据中国北方的二次离子的主要形式， SO4 2_的化学特性和NO3 _是按照纯（ NH4）2SO4和NH4NO3的组成建立。

2.4. Sample analysis

2.4样品分析

Inductively coupled plasma (ICP) analysis was employed to determine concentrations of Na, Mg,Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb in samples collected on polypropylene-fiber filters and from dust samples.

Water-soluble ions (SO4 2_, NO3 _) collected with quartz-fiber filters and from dust samples were determined using ion chromatography (DX-100, Dionex Ltd., USA) after sample extraction with deionized water. Total carbon (TC) and organic carbon (OC) were measured using an Element Analyzer (Elementar Analysensysteme GmbH VarioE1, Germany).Blanks (including filters) and duplicate sample analyses were performed for approximately 10% of all the samples. Certified reference materials (CRM) were used to ensure accuracy and precision (National Research Center of CRM, China). The same protocols and methods were used for analysis of source and ambient samples.

电感耦合等离子体（ICP）分析来测定钠，镁的浓度铝，硅，钾，钙，钛，钒，铬，锰，铁，钴，镍，铜，锌，铅中收集的聚丙烯纤维样品过滤器和灰尘样品。水溶性离子（SO 42_，NO3_）用石英纤维过滤器和灰尘收集样品是用离子色谱法（DX-100，戴安公司，美国）的样品萃取用离子交换水后确定。被执行用于所有样品的约10％的总碳（TC）和有机碳（OC）的使用元素分析仪（Elementar公司Analysensysteme联系VarioE1，德国）。空白（包括过滤器）进行测定，并重复样品的分析。证标准物质（CRM）被用来确保准确度和精密度（国家研究中心的CRM，中国）。相同的协议和方法被用于源和环境样品的分析。SO42_和NO3的化学访问_是按照纯（NH 4）2 SO 4和NH 4 NO 3的组成确定。

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