三氯氢硅建设项目污染源分析与控制

三氯氢硅是制备多晶硅的重要原料,三氯氢硅极易挥发,在空气中易燃,并能与空气形成爆炸混合物,其化学性质很不稳定,遇水或水蒸气发生剧烈的放热反应,形成有毒的腐蚀性氯化氢烟雾;通过对三氯氢硅建设项目工艺流程及产污环节分析,探讨了该类项目生产过程废气、废水、噪声、固体废物等污染物的种类、成分及产生量,在此基础上提出了相应的污染控制措施,对该类项目环境影响评价工作有一定的指导作用。     

环境信访源的特点与妥善处理机制初探

本文对常见和罕见的环境信访源的特点进行了分析,并对妥善处理的长效机制进行了探讨。     

基于“公地悲剧”和“反公地悲剧”解析气候变暖和低碳技术壁垒

化石燃料的大量使用所排放的温室气体使得全球气候日益变暖,低碳经济的提出成为了目前全球应对气候变暖的主要策略,而发展中国家在进行低碳技术引进时常常面临来自发达国家的知识产权贸易壁垒。本文从"公地悲剧"角度解析气候变暖的经济学根源,从"反公地悲剧"角度揭示低碳技术转让过程中发达国家以知识产权为借口制造技术壁垒的经济学缘由。     

环境管理过程中对锅炉型号的识别

通过对锅炉型号的简要介绍,提高对锅炉的认识,增强在污染源动态更新调查表的填报过程中锅炉技术指标的填报能力是十分必要的。     

Improvement of welding heat source models for TIG-MIG hybrid welding process

Tungsten inert gas-metal inert gas (TIG-MIG) hybrid welding process is an effective way to improve welding productivity and quality due to advantages of the two processes. Mathematical analysis is crucial to fundamentally understand this synergetic welding process. In this study, based on experimental visualization of arc behaviors, some assumptions are proposed to deduce adaptive plane and volumetric heat source models separately for each involved welding method first. The influence of torch angles on distribution of temperature and geometry of weld bead are calculated and compared with experimental results. It shows that this developed algorithm of heat source can be employed to accurately predict welding process whether the electrode gun is slanted backward or forward to the direction of welding. Then TIG-MIG hybrid welding process is simulated and analyzed without considering the attractive or repulsive force of two arcs. The characteristic of TIG-MIG welding process is discussed compared to single MIG. It lays the foundation for the further research on the interaction of the two arcs during TIG-MIG hybrid welding.     

我国24个典型饮用水源地中14种酚类化合物浓度分布特征

研究了14种酚类化合物在我国五大流域(黄河、海河、辽河、长江、淮河)24个典型饮用水源地水源水中的浓度水平.结果显示:14种酚类化合物在我国饮用水源地中的浓度在nd～213 ng·L-1范围内,浓度均值在2.44～31.2 ng·L-1范围内,浓度中位数在nd～40.0 ng·L-1范围内.14种酚类化合物中,硝基苯酚类化合物浓度最高,浓度中位数为37.9 ng·L-1,浓度平均值为27.4 ng·L-1.其次为苯酚、五氯酚、二氯苯酚(2,4-二氯苯酚和2,6-二氯苯酚)和三氯苯酚(2,4,6-三氯苯酚和2,4,5-三氯苯酚);四氯苯酚(2,3,5,6-四氯苯酚、2,3,4,6-四氯苯酚、2,3,4,5-四氯苯酚)和烷基苯酚(邻甲基苯酚、间甲基苯酚和对甲基苯酚)浓度较低.通过商值法对14种酚类化合物进行生态风险评价后发现,14种酚类化合物的风险商均远小于1,表明其对我国饮用水源地的生态风险较低.对8种已报道健康参考剂量或致癌斜率因子的酚类化合物进行健康风险评价,结果显示,7种酚类化合物的最大非致癌风险在10-6到10-4范围内,2,4,6-三氯酚和五氯酚的致癌风险在10-6量级以下,表明其健康危害较弱.     

南昌市移动源排放清单研究

根据收集的南昌市移动源活动水平数据,采用合适的估算方法、排放因子和GIS技术,建立了南昌市2007—2014年移动源排放清单,并对2014年移动源清单进行了空间化处理与分析,空间分辨率为1 km×1 km.结果表明,2007—2014年南昌市移动源共向大气排放CO、HC、NO_x、PM_(2.5)、PM_(10)、SO_2分别为18.26×10~4、5.07×10~4、18.46×10~4、0.99×10~4、1.08×10~4、3.31×10~4t.其中,2014年移动源向大气中排放的这6种污染物总量分别为2.14×10~4、0.76×10~4、1.97×10~4、0.08×10~4、0.09×10~4、0.55×10~4t.道路移动源中,汽油小型客车是CO、HC和SO_2最大的贡献源,排放量分别占机动车排放总量的55.1%、78.5%和56.1%;柴油重型货车是NO_x、PM_(2.5)和PM_(10)排放贡献率最大的车型,分别占43.2%、40%和40%.非道路移动源中,小型拖拉机对CO、HC、NO_x、PM_(2.5)和PM_(10)的贡献率均较大,分别占非道路移动源排放总量的29.9%、26.9%、23.4%、29.5%和29.8%;SO_2排放主要来源于船舶,占非道路移动源SO_2排放总量的45.1%.高污染排放集中的区域,主要是青山湖区、西湖区和东湖区.     

瑞平塘河氟化物污染状况调查及溯源研究

以2016—2020年地表水常规监测结果为依据,发现瑞平塘河自2017年起出现氟化物质量浓度升高现象,2020年其中1个断面氟化物质量浓度平均值达到1.25 mg/L,比2016年高出145%。为此于2021年3—6月,对瑞平塘河流域的氟化物污染状况进行实地调查并开展溯源研究。研究结果显示,2021年氟化物质量浓度超过1.0 mg/L的点位占59.34%,其中超过1.5 mg/L的点位占42.86%,表明大部分河道氟化物质量浓度已经超过水体功能区要求,对生态环境安全构成较大潜在风险。溯源调查结果表明,排除了农业源及矿山源污染的可能,乳胶制品企业排放的废水为瑞平塘河氟化物的污染来源。针对目前该行业的排放标准和环境影响评价均未提及氟化物污染,企业废水处理设施也无除氟工艺单元,缺乏有效的污染防治措施与监管要求等问题。提出,应及时组织开展该区域乳胶制品行业整治提升,增加氟化物处理工艺单元,提升出水水质,确定氟化物排放浓度限值,并对该行业排放标准做进一步研究和完善等建议。     

Estimation of Land Use Specific Runoff and Pollutant Concentration for Tapi River Basin in India

Non-point source (NPS) pollution is the result of various land use practices such as agriculture, sites of construction and waste disposal, urban development and so on. The control of NPS pollution is possible by regular monitoring and assessment on watershed basis to educate people for implementing well-known structural and non-structural measures. Recent trend is to use GIS based modelling tool for assessment of rainfall-runoff and non-point loading. The approach requires generation and analysis of basin wide data on various features of land and estimates of Event Mean Concentrations (EMCs) of pollutants in the runoff. In the present paper, basin wide data in different districts of Tapi basin has been analysed for land use distribution; fertilizer application; low, medium and high-density habitation; and annual rainfall. Coefficients of runoff have been estimated considering pervious and impervious area for different land use types, and compared with the reported values for Indian conditions. The estimated mean annual runoff flow indicated that two districts Jalgaon and Dhule contribute maximum runoff to the Tapi River. Estimates of EMCs for BOD and nutrients (N and P) in the runoff from various districts are useful in GIS-based modelling study for NPS pollution assessment.