City hazardous gas monitoring network

In our today's societies, many dangerous chemicals are produced and transported. Due to the vast use of chemicals, more chemical accidents are taking place with huge losses. In this study a city hazardous gas monitoring network was designed to detect the dispersion of toxic and combustible gases in the primary stages. The network could cover hazardous chemical facilities, important hazardous chemical routes, warehouses and special locations which may be the targets of terrorist attacks. The network is consisted of several local networks and a central control panel complex. Each local network has a local control panel in the center and many detectors and sounders around it at distances less than 3000 m that communicate with the local control panels wirelessly. In each location there are two types of gas detectors, toxic and combustible, and a sounder which are equipped with a wireless, radio frequency modem allowing the units to communicate readings and other information on a real-time basis with a remotely located local control panel. High sensitive Photo Ionization Detectors, PIDs, are used to provide fast and low-level on-site screening for chemicals contamination. Combustible gas detectors are the second choice to sense the combustible gas and verify the readings of PIDs in this regard. The central panel consists of several connected control panels work uniquely helping a computer set and the appropriate software and communicate with local control panels via telephone lines. All of the network components are shown on the monitor of central panel with special symbols by geographical information system program. The system is fully addressable so that the high level detection of a detector produces a blinking color double-circle around its symbol in GIS plan. In case of high level gas detection, a team of experts who are fully equipped with different portable detectors depart to the site to test the field to identify the chemicals. All readings of detectors are saved in a data bank and then analyzed to find any chemicals spills and leakages. The network was simulated by a special program so that the components of local networks and the central panel are shown in separate windows. By clicking on one detector on environmental window the formerly designed responses will be activated in central panel window.     

The indirect involvement of buses in traffic accident processes

The involvement of buses in accidents usually is assessed implicitly on the basis of the direct involvement of the bus in the collision or in injury production. This paper deals with the scope and forms of indirect involvement of buses (as a sight obstruction, for example). Accidents were selected by identifying the presence of the term ‘bus’ or synonyms in the text parts of complete police reports (testimonies, statements by the persons involved, etc.) available in electronic form, then analysed in detail. Direct or indirect involvement of a bus is found in 3.6% of traffic injury accidents reported by the police in the community studied (direct involvement: 1.4%; indirect involvement: 2.2%). The different forms of indirect involvement are then described, and some possibilities of preventive measures are discussed.     

Status and fuzzy comprehensive assessment of combined heavy metal and organo-chlorine pesticide pollution in the Taihu Lake region of China

The status of combined heavy metal and organo-chlorine pesticide (OCPs; i.e. HCH and DDT) pollution was investigated and the soil environmental quality of the Taihu Lake watershed, one of the most developed regions in China, was evaluated using a fuzzy comprehensive assessment. Statistical analyses showed the presence of combined pollution in the soil. At many sampling sites, heavy metal concentrations were above corresponding background values, indicating the effects of extraneous pollutants. It has been over 20 years since China banned the use of OCPs, but they can still be found in soil samples of this region. HCH levels at all investigated sites were below the Chinese Environmental Quality Standard for Soils. Fuzzy comprehensive assessment showed that the overall soil quality in this region could be categorized as class I. Nevertheless, the high coefficients of variation for levels of DDT, Cd and Hg indicated the existence of some point-source pollution. Continuous monitoring and further studies of the region are recommended to prevent pollution of farmland from these sources.     

石家庄市冬季大气中VOCs污染特征分析

为弄清石家庄市冬季大气中VOCs的污染特征,采用美国环保局TO-15方法对石家庄市冬季大气中VOCs组成进行了定性和定量分析。在此基础上,进行了VOCs的月度变化分析、春节期间的变化分析,并进行了VOCs与空气质量指数AQI、PM2.5等之间的相关性分析;根据VOCs组成及变化情况和相关性,分析了其可能的来源。结果表明,石家庄市冬季大气中VOCs的质量浓度为145.7~1 410.7μg/m3,VOCs组分主要有丙酮、二氯甲烷、苯、乙酸乙酯、甲苯、1,2-二氯丙烷、三氯甲烷。春节期间,大气中VOCs的浓度有大幅的下降,比日常均值下降了40.9%。AQI较高时,大气中VOCs浓度有所升高。石家庄市冬季大气中丙酮、二氯甲烷、乙酸乙酯等主要来源于医药化工生产活动,苯、甲苯主要来源于煤燃烧。     

典型涉污企业周边土壤重金属污染特征及潜在生态风险评价

分析和评价典型涉污企业周边土壤环境质量,对于加强企业用地环境风险管控,实施土壤重金属污染精准防控,进一步保障农产品质量安全具有重要意义。以18类典型涉污企业周边土壤为研究对象,对475家企业周边的2 017个监测样点进行土壤重金属Cd、As、Pb、Hg、Cr、Cu、Zn和Ni元素含量测定,并采用主成分分析法、Hakanson 潜在生态风险指数法进行分析及评价。结果表明:典型涉污企业周边土壤重金属污染以Cd、Pb和As元素为主,各元素含量超过土壤污染风险筛选值的样品比例为9.82%~31.0%,超过土壤污染风险管控值的样品比例为4.46%~13.1%,其次是Zn、Cu、Hg和Ni,Cr无明显污染;主要污染元素Cd、Pb、As、Zn和Cu来自相同污染源且主要分布在有色金属矿采选业(B9)、黑色金属冶炼和压延加工业(C31)、有色金属冶炼和压延加工业(C32)、生态保护和环境治理业(N77)等行业企业周边;黑色金属冶炼和压延加工业(C31)、有色金属矿采选业(B9)、有色金属冶炼和压延加工业(C32)等行业企业周边土壤重金属潜在生态风险等级较高,中等风险及以上比例分别为76.0%、53.0%和54.1%。可见,典型涉污企业周边土壤重金属存在一定程度的污染,尤其是有色金属矿采选业(B9)等采矿业以及黑色金属冶炼和压延加工(C31)等制造业等,污染程度高,潜在生态风险大,需要加强监测和管控。     

2016—2017年武汉市城区大气PM2.5污染特征及来源解析

利用2016年1月至2017年9月湖北省环境监测中心站大气复合污染自动监测站的在线监测数据,对武汉市城区PM_2.5的污染特征及主要来源进行解析。结果表明,武汉市城区PM_2.5质量浓度呈现出明显的季节差异,季节变化规律为冬季>春季>秋季>夏季。水溶性离子的主要成分SO₄^2-、NO₃^-和NH₄⁺占总离子质量浓度的82.0%。PM_2.5中阴离子相对阳离子较为亏损,颗粒整体呈碱性。夏季气态污染物的氧化程度较高且SO₂较NO₂氧化程度高。后向轨迹分析结果表明,区域传输是武汉市PM_2.5的一个重要来源,在4个典型重污染阶段,武汉市分别受到局地、东北、西北及西南方向气团传输的影响。PMF模型解析出武汉市PM_2.5五大主要来源及平均贡献率：扬尘22.0%、机动车排放27.7%、二次气溶胶21.6%、重油燃烧14.9%和生物质燃烧13.8%。     

污染源监督性监测数据元的构建研究

系统梳理了污染源监督性监测数据元的研究现状,提出了污染源监督性监测数据元的构建过程和体系指标,为制定污染源监督性监测数据元技术标准提供技术支持。通过污染源监督性监测数据元的构建,建立监测数据共享和应用的长效机制,实现污染源监督性监测信息的规范管理、交换与共享,为各级环保部门加强对污染源的监管和政府决策提供强有力的技术支持。     

长湖流域水质时空分布特征及影响因子

利用2009—2014年长湖5个水质监测点数据,采用时间序列法分析了长湖水质的时间变化规律,采用相关性分析法,分析了流域水污染的影响因子。结果表明:在时间上,长湖水污染物质量浓度季节变化明显,COD、TN、NH3-N均为7、9月较低,1、3月较高,丰水期水质好于枯水期。入湖地区TP质量浓度7月达最高值,且7月份入湖地区的桥河口、关沮口的NH3-N、TN含量稍高于5月。空间上,西北部入湖地区水质劣于湖心及东南部出湖地区。工业、生活等点源污水,以耕地为主的农业非点源以及天然降水量和径流量是影响水质的主要因素,入湖排污量、降水量和径流量与长湖水质呈显著相关关系(P0.05)。     

环保投资增长规律及其理论证明

本文从国内外环保投资的实践入手,分析和总结出环保投资长期增长规律,并依据环境--经济--社会的技术经济关系,建立起“污染平衡方程式”,从理论上对该规律进行了证明。     

南京市郊区雾天大气污染及雾水中Hg的特征

根据南京市郊区雾的外场实验观测资料及采集的雾水样品分析,探讨南京市郊区雾水中Hg和雾天大气污染特征.郊区出现雾天时,不利于大气污染物的扩散,造成PM10,CO和总烃浓度先增加后降低,污染物浓度的变化与雾的生消基本同步;雾消散后SO2,PM10和NOx的浓度比雾前高2.5-10倍.雾水中汞浓度在2.956-7.205 μg·l-1范围内,平均为5.471 μg·l-1,浓度高值出现在雾的维持阶段;对Hg与大气污染物之间的关系作相关分析,其中汞与大气中CO的相关系数为0.939,说明其具有同源性.