燃煤电厂飞灰吸附非多环芳烃类有机污染物的检出及意义

电厂燃煤过程中可以产生大量的SOX、NOX 及多环芳烃类 (PAHS)污染物。本文通过贵阳电厂飞灰吸附有机烃类污染物的实验研究 ,首次发现并检出了大量非PAHS 类有机污染物 ,其中包括有机酸类化合物以及非有机酸类化合物 ,从而证明燃煤过程是上述非PAHS 类有机污染物形成和排放 ,尤其是酸雨前体物质之一———有机酸生成排放的一个重要途径 ,丰富了关于煤粉燃烧过程中有机污染物生成排放的理论研究体系。     

Photolysis of a mixture of anthracene and benzo[a]pyrene at ultra-trace levels in natural water with disinfection purposes

The photodegradation of anthracene(AN) and benzo[a]pyrene(BaP),two priority polycyclic aromatic hydrocarbons(PAHs),was examined at ultra-trace levels in surface water to elucidate their behaviour under several irradiance values and types of radiation.The emitting flux and the spectrum of the lamps were found to develop a crucial role in AN and BaP degradation since removal efficiencies of the target contaminants higher than 99%were found after 15 min of irradiation under an ultraviolet C(UVC) irradiance of 0.63 mW/cm~2,corresponding to a fluence of 560.25 mJ/cm~2.On the other hand,although ultraviolet A(UVA) lamps exhibited a higher irradiance compared to that of UVC lamps,they were not efficient for degrading the target PAHs.The removal kinetic studies corroborated these findings,being the AN elimination rate in surface water higher than that in deionized water at optimal operating conditions.Disinfection potential was also measured.A rapid microbial load inactivation,in terms of total coliforms naturally contained in the water matrix studied,was evidenced within 15 min of treatment for the fluence referred.However,after 24 hr in the dark,a regrowth was observed.Additionally,photolysis products more toxic than the parent compounds were found,which were not removed even by extending the treatment time.In this regard,it can be concluded that the individual action of UVC light for removing AN and BaP with disinfection purposes is not an efficient treatment;therefore,the use of radiation in combination with other kinds of treatments is required.     

石油污染对土壤水分特性的影响

陕北是石油工业的发祥地,在石油大规模开采运输过程中,不可避免会造成石油的泄露倾洒,从而对土壤和地下水造成一定程度的污染。为了探讨陕北地区石油污染对土壤水分特性的影响,以3种不同土质土壤(塿土、黄绵土和风沙土)为研究对象,开展了3种土壤在4个不同污染梯度(0.5%、1%、2%和4%)下的土壤润湿性试验和饱和导水率实验,同时以清洁土壤作为对照。结果表明:当土壤受石油污染时,会引起其润湿性发生变化,产生一定程度的斥水性,该变化在风沙土上表现尤为明显;石油污染使3种土壤的饱和导水率均随着污染浓度的增大而呈现下降趋势,饱和导水率虽有降低,但是对于同一土质的土壤来说,均在一个数量级内。     

A methodology for enhancing the reliability of expert system applications in probabilistic risk assessment

In highly complex industries, capturing and employing expert systems is significantly important to an organization's success considering the advantages of knowledge-based systems. The two most important issues within the expert system applications in risk and reliability analysis are the acquisition of domain experts' professional knowledge and the reasoning and representation of the knowledge that might be expressed. The first issue can be correctly handled by employing a heterogeneous group of experts during the expert knowledge acquisition processes. The members of an expert panel regularly represent different experiences and knowledge. Subsequently, this diversity produces various sorts of information which may be known or unknown, accurate or inaccurate, and complete or incomplete based on its cross-functional and multidisciplinary nature. The second issue, as a promising tool for knowledge reasoning, still suffers from lack of deficiencies such as weight and certainty factor, and are insufficient to accurately represent complex rule-based expert systems. The outputs in current expert system applications in probabilistic risk assessment could not accurately represent the increasingly complex knowledge-based systems. The reason is the lack of certainty and self-assurance of experts when they are expressing their opinions. In this paper, a novel methodology is presented based on the concept of Z-numbers to overcome this issue. A case study in a high-tech process industry is provided in detail to demonstrate the application and feasibility of the proposed methodology.     

辽东湾海域生物体内石油烃污染状况

根据2013年8月对辽东湾海域拖网采集的127个生物体样品石油烃含量测试结果,结合历史调查数据,分析该海区生物体内石油烃含量水平、分布特征和变化趋势,评估生物体石油烃污染程度.结果表明:调查海区生物体内石油烃含量为2.76~41.81 mg·kg-1,平均为12.19mg·kg-1;整体石油烃含量具有软体腹足纲甲壳动物蟹类软体头足甲壳动物虾类鱼类,内脏组织高于肌肉组织的特点;生物体内石油烃含量与沉积物中石油烃含量存在显著相关性,与水体石油烃含量不存在明显相关性;年际变化趋势分析显示2012年软体类和甲壳类生物体石油烃含量高于2007年和2013年,表明调查海域2012年以前存在明显的石油烃输入;与国内其他海域相比,调查海域生物体石油烃含量较高.     

Polycyclic aromatic hydrocarbon concentrations, compositions, sources, and associated carcinogenic risks to humans in farmland soils and riverine sediments from Guiyu, China

The concentrations of 16 priority polycyclic aromatic hydrocarbons(PAHs) were measured in 23 farmland soil samples and 10 riverine sediment samples from Guiyu, China, and the carcinogenic risks associated with PAHs in the samples were evaluated. Guiyu is the largest electronic waste(EW) dismantling area globally, and has been well known for the primitive and crude manner in which EWs are disposed, such as by open burning and roasting. The total PAH concentrations were 56–567 ng/g in the soils and 181–3034 ng/g in the sediments.The Shanglian and Huamei districts were found to be more contaminated with PAHs than the north of Guiyu. The soils were relatively weakly contaminated but the sediments were more contaminated, and sediments in some river sections might cause carcinogenic risks to the groundwater system. The PAHs in the soils were derived from combustion sources,but the PAHs in the sediments were derived from both combustion and petroleum sources.     

鲤体内芳香烃受体的分离纯化及其与葸的相互作用

从暴露于污染物蒽的鲤肝脏中提取出芳香烃受体,并采用紫外可见分光光度计进行最大吸收波长扫描,再通过离子交换层析法分离纯化鲤体内的芳香烃受体,并采用聚丙烯酰胺凝胶电泳对受体进行鉴定,最后通过傅里叶变换红外光谱探讨芳香烃受体与蒽结合后的结构变化.结果表明,提取的芳香烃受体在280 nm处有特征吸收峰,测得质量浓度为27.3 mg/mL.通过离子交换层析法纯化了单一组分的受体蛋白质,其相对分子质量约为110 kD.测定了芳香烃受体的红外光谱,与蒽结合后其在一定波段的谱峰发生了明显位移,表明污染物配体蒽能与芳香烃受体结合,并对其蛋白二级结构产生明显影响.     

长江流域沉积物中黑碳分布及其与多环芳烃的相关性研究

本文采用CTO-375法测定了长江流域主流及直流20个表层沉积物中黑碳的含量,探讨了沉积物中黑碳与粒度、总有机碳以及多环芳烃之间的关系。结果表明,长江流域沉积物中黑碳的含量范围在0.22~1.89mg/g之间,与粘土、粉砂及砂含量之间的相关性并不明显,说明粒度组成并不是控制BC分布的主要因素。BC与TOC之间的显著正相关性,表明BC与TOC有相似的来源,如人类活动、土壤流失。沉积物中BC与PAHs有较好的相关性,表明二者之间有相似的来源,同时也表明PAHs在研究区域沉积物中吸附主要由BC控制,这为研究多环芳烃在长江流域的环境归趋与影响因素等提供了新的信息。     

滇池沉积物中多环芳烃赋存状态及其再分配的初步研究

利用索氏抽提、Tenax部分萃取和沉积物的粒度和密度分离等方法对滇池沉积物中多环芳烃(PAHs)的赋存状态及其再分配进行了研究。研究结果表明:滇池沉积物中PAHs主要存在于小粒度和低密度的组分中;尽管PAHs在粒度分布上存在一定的差异,但沉积物中碳质吸附剂的组成和含量才是决定PAHs在沉积物中赋存状态的主要因素;由于PAHs与沉积物中不同吸附剂相互作用的差异,随着时间的推移,沉积物中的PAHs存在一个再分配过程,吸附在无定形有机质和无机矿物等弱吸附剂上的PAHs逐渐向黑炭、焦炭等碳质吸附剂上转移,导致沉积物中的PAHs慢慢被锁定,因而其生物有效性也逐渐下降。