氯代烃在铜电极上的电还原特性和pH值的影响

采用循环伏安法,对氯代烃类化合物在铜电极表面上的电还原特性进行了研究,结果表明,氯代烷烃类化合物能在铜电极表面被直接还原,氯代芳烃不易在铜电极上被直接还原．碱性条件有利于中间体碳负离子的形成;在酸性条件下,碳负离子与氢离子之间反应的几率增大,导致通过溶液的电流值增加．pH值对不同氯代烃在铜电极上的电还原特性有不同程度的影响,这主要取决于碳链(或苯环)上其它取代基的性质、结构、数量和它与氯在苯环上的相对位置．     

多环芳烃在渤海海峡柱状沉积物中的分布

在渤海海峡(S44和T4站位)柱状沉积物中运用气相色谱法定量地检出13种多环芳烃化合物,并对其含量分布及来源进行了分析.多环芳烃浓度总和为60.3ng/g～2076.5ng/g,尚不属严重污染状况,但是苯并芘等强致癌性化合物均有不同程度检出.利用多环芳烃的一些参数(菲/蒽、荧蒽/芘、2～3环化合物总量和4环以上化合物总量等比值及不同分子量的相对浓度)估测了该区的多环芳烃的来源,S44站位的多环芳烃主要来源于化石燃料的不完全燃烧过程;而在T4显示的是石油源和不完全燃烧源的混合特征,这应与研究海区的石油开发或航运等事件有关.同时研究表明多环芳烃在柱样中的分布可提示人文活动强度的影响.     

Air pollutant emissions from the asphalt industry in Beijing, China

Improving our understanding of air pollutant emissions from the asphalt industry is critical for the development and implementation of pollution control policies. In this study, the spatial distribution of potential maximum emissions of volatile organic compounds (VOCs) in the complete life cycle of asphalt mixtures, as well as the particulate matter (PM), asphalt fume, nonmethane hydrocarbons (NMHCs), VOCs, and benzoapyrene (BaP) emissions from typical processes (e.g., asphalt and concrete mixing stations, asphalt heating boilers, and asphalt storage tanks) in asphalt mixing plants, were determined in Beijing in 2017. The results indicated that the potential maximum emissions of VOCs in the complete life cycle of asphalt mixtures were 18,001 ton, with a large contribution from the districts of Daxing, Changping, and Tongzhou. The total emissions of PM, asphalt fume, NMHC, VOCs, and BaP from asphalt mixing plants were 3.1, 12.6, 3.1, 23.5, and 1.9 × 10^?3 ton, respectively. The emissions of PM from asphalt and concrete mixing stations contributed the most to the total emissions. The asphalt storage tank was the dominant emission source of VOCs, accounting for 96.1% of the total VOCs emissions in asphalt mixing plants, followed by asphalt heating boilers. The districts of Daxing, Changping, and Shunyi were the dominant regions for the emissions of PM, asphalt fume, NMHC, and BaP, while the districts of Shunyi, Tongzhou, and Changping contributed the most emissions of VOCs.     

近岸海洋沾污沉积物中石油烃类化合物释放过程的实验室研究 Ⅰ.实验室动态模拟研究

通过实验室动态模拟实验，研究了在不同固／液比例、溶出温度、搅拌强度、沉积物的粒度等条件下，近岸海洋沾污沉积物中石油烃类化合物的释放过程。研究结果表明，石油烃类化合物的溶出浓度与参与溶出过程的固／液相比例成正比：当固液相比例为１／８时，可在３０ｍｉｎ之内确定溶出／吸附过程的动态平衡点。沉积物中石油烃类物质向海水中的释放，在１０ｍｉｎ之内，可基本达到最大初始浓度；未经处理的新鲜沉积物样品较烘干研磨样品，更利于油类的释放。溶出温度的升高及剧烈的反应条件，有利于沉积物中石油烃类物质向海水中的释放。沉积物的组成颗粒愈细，释放的初始浓度愈高。     

野生观赏植物长药八宝对石油烃污染土壤的修复研究

植物修复作为一项绿色修复技术,是石油烃污染土壤有效而可行的修复方法之一.野生观赏植物应用于植物修复,不仅能展现野生植物的良好耐性,在治理污染的同时美化环境,还能发挥观赏植物的特性,避免将污染带入食物链.本研究通过温室盆栽试验探讨了野生观赏植物长药八宝(Hylotelephium spectabile(Boreau)H.Ohba)对大港油田石油烃污染土壤的修复潜力.结果表明:长药八宝对石油烃污染的盐碱土具备良好的耐性,虽然长药八宝的地上部生物量相对于对照组有所降低,但与修复活动更为相关的根部生物量并未受到明显抑制,长药八宝也未表现出明显的毒害症状;长药八宝对石油烃污染土壤的修复效果比较显著,当土壤石油烃浓度为11874 mg·kg-1、20075 mg·kg-1和38986mg·kg-1时,其降解率分别为47.99%、24.49%和22.98%,明显高于空白对照组的降解率(仅为32.37%、21.57%和17.64%)(p0.01);通过最大或然数法(most probable number,MPN)观测到11874mg·kg-1、20075 mg·kg-1和38986 mg·kg-1浓度的石油烃污染胁迫下,烷烃和芳烃降解菌的数量都要高于空白对照组,这在一定程度上促进了根际微生物对石油烃的降解.总之,长药八宝对一定浓度的石油烃污染盐碱土具备良好的耐性,对土壤中石油烃污染物具备较高的降解率,具备修复总石油烃浓度在40000mg·kg-1以下的石油烃污染盐碱土的能力.     

氧含量对甲烷及丙烯爆炸特性的影响

为了进一步研究烷烃类气体在与氧气接触时的爆炸特性规律,对烃类气体爆炸理论、爆炸特性参数做了理论分析和计算,并以甲烷和丙烯为例,通过对其爆炸极限、爆炸压力、爆炸压力上升速率、爆炸指数的测试,探讨了氧含量对烃类气体爆炸特性的影响。测试结果表明:氧含量的增加能提升其最大爆炸压力,当氧含量达到一定值时,理论计算值已不适用;提高甲烷爆炸极限的宽度,对其爆炸上限影响十分显著,但对爆炸下限的影响并不明显;对爆炸压力上升速率也有巨大的促进作用,当氧含量提高时,爆炸压力上升速率可能提升数十倍;并测得了丙烯在80℃,表压0.14MPa条件下的极限氧含量值(LOC)。总之,氧含量的增加对烃类气体爆炸特性的促进作用是十分显著的。     

加油站油气回收效果检测及分析

对某地区4个加油站的油气回收改造效果进行了抽样检测。重点对一次油气回收中的回气量、回气浓度、回气压力和卸油速度以及二次油气回收中的密闭性、液阻和气液比等指标进行了测试,分析了存在的问题,并提出了相应的改造措施和建议。     

Hepatoprotective and antioxidant effects of dietary Glycyrrhiza polysaccharide against TCDD-induced hepatic injury and RT-PCR quantification of AHR2, ARNT2, CYP1A mRNA in Jian Carp (Cyprinus carpio var. Jian)

To evaluate the protective effects of Glycyrrhiza polysaccharide (GPS) against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced hepatotoxicity in Jian carp, the fish were fed diets containing GPS at doses of 0.1, 0.5 and 1.0 g/kg for 60 days before an intraperitoneal injection of 0.6 μg/kg TCDD at a volume of 0.05 mL/10 g body weight. At 72 hr post-injection, blood and liver samples were taken for biochemical analysis and the fish liver samples were used for the preparation of pathological slices. The results showed that increases in alanine aminotransferase (GPT), aspartate aminotransferase (GOT), lactate dehydrogenase (LDH), and alkaline phosphatase (AKP) in serum induced by TCDD were significantly inhibited by pre-treatment with 1.0 g/kg GPS. Following the 1.0 g/kg GPS pre-treatment, total protein (TP), albumin (Alb), catalase (CAT), glutathione peroxidase (GPx), total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activities in liver tissue increased significantly, malondialdehyde (MDA) formation (P < 0.05 or P < 0.01) was significantly inhibited, and the expression of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor 2 (AHR2) and aryl hydrocarbon receptor nuclear translocator 2 (ARNT2) mRNA (P < 0.05) was significantly enhanced. Histological observations on fish liver were obtained by preparing paraffin tissue sections via HE staining, and the results showed that histological changes were obviously reduced by 0.5 and 1.0 g/kg GPS. GPS significantly reduced liver tissue damage caused by TCDD. Overall, these results proved the hepatoprotective effect of GPS in protecting against fish liver injury induced by TCDD, and supported the use of GPS (1.0 g/kg) as a hepatoprotective and antioxidant agent in fish.     

溢油污染潮间带大型底栖动物体内总石油烃含量及风险动态

以溢油污染潮间带大型底栖动物无齿螳臂相手蟹为对象,研究其体内TPH含量分布及动态变化,并开展健康风险评估,判断污染区域生态系统修复与恢复措施的有效性,从而为类似溢油事故的处理处置提供参考.分别在采取应急处置后、应急处置1 a后和二次修复1 a后采集了沉积物和相关生物体样品,采用紫外分光光度法和荧光分光光度法测得TPH含量.结果表明,二次修复1 a后生物体内脏和肌肉组织中TPH含量较应急处置1 a后呈显著下降趋势(p0.05),分别下降了64.28%~83.81%和27.44%~48.02%,生物体内脏组织中TPH含量明显高于肌肉组织,且二者呈现显著正相关关系(p0.01).二次修复1 a后生物体内脏和肌肉组织中TPH含量与应急处置后沉积物中TPH含量呈明显的线性关系(y=0.001x+4.3831,R2=0.9089;y=0.0004x+1.7744,R2=0.8705),表明溢油事故造成的沉积物污染是影响生物体内TPH累积的一个重要因素.同时,人体健康风险评估结果显示,应急处置1 a后和二次修复1 a后生物体体内的TPH暴露风险指数均处于可接受水平,采取二次修复后,暴露风险指数有明显下降趋势,较应急处置后下降了62.81%~82.31%.研究结果表明应急和修复措施均取得了一定效果,可为今后类似事故处理处置提供参考.     

烃类及其衍生物闪点、沸点的定量构效关系

基于定量结构一性质相关性（QSPR）原理,研究了烃类及其衍生物闪点、沸点与其分子结构间的内在定量关系。应用CODESSA软件计算384种烃类及其衍生物的分子结构描述符,建立了闪点和沸点的QSPR模型。用最佳多元线性回归（B．MLR）方法筛选得到的分子描述符建立了线性回归模型。用B-MLR方法所选择的5个描述符作为支持向量机（SVM）的输入建立了非线性模型。所有的化合物被分为训练集和测试集,对每个模型的训练集和测试集的复相关系数、交互验证系数、均方根误差等进行了计算,并用测试集对模型的预测能力进行检验,预测结果表明：预测值与实验值均符合良好,所建立的闪点模型稳健,泛化能力强,预测误差小,预测的效果令人满意,但沸点的模型预测效果有待加强。相比烃类物质的模型,加了衍生物的模型性能均有所下降。