湿法烟气脱硫系统的脱汞性能现场实验

分析湿法烟气脱硫系统的脱汞性能,对控制燃煤电厂的汞污染具有重要意义。利用安大略水法和吸附管法分别对某600 MW电厂湿法脱硫系统的进出口的烟气进行了采样,测量了烟气中各形态汞浓度,并分析了该系统对烟气总汞、气态氧化态汞的脱除效果以及对气态单质汞的影响。研究结果表明,安大略水法和吸附管法均能较为准确地测定湿法脱硫系统进出口烟气中的汞含量,测得入口和出口的氧化汞与平均值的相对误差的绝对值分别为3.5%和1.3%;入口和出口的单质汞与平均值相对误差的绝对值分别为16.6%和3.3%。其中吸附管法操作相对简单。通过湿法烟气脱硫系统后,烟气中氧化态汞的浓度可下降87.5%,其中约67.5%的氧化态汞被湿法脱硫系统脱除,约20%的氧化态汞在脱硫浆液的还原作用下被还原为单质汞,导致脱硫系统出口的单质汞浓度高于入口。     

Biological responses of wheat (Triticum aestivum) plants to the herbicide chlorotoluron in soils

Chlorotoluron is a phenylurea herbicide that is widely used for controlling grass weeds in the land of cereal, cotton and fruit production. However, extensive use of this herbicide may lead to its accumulation in ecosystems, thus inducing the toxicity to crops and vegetables. To assess chlorotoluron-induced toxicity in plants, we performed the experiment focusing on the metabolic adaptation of wheat plants (Triticum aestivum) to the chlorotoluron-induced oxidative stress. The wheat plants were cultured in the soils with chlorotoluron at concentrations of 0-25mg/kg. Chlorotoluron accumulation in plants was positively correlated with the external chlorotoluron concentrations, but negatively with the plant growth. Treatment with chlorotoluron induced the accumulation of O(2)(-) and H(2)O(2) in leaves and resulted in the peroxidation of plasma membrane lipids in the plant. We measured the endogenous proline level and found that it accumulated significantly in chlorotoluron-exposed roots and leaves. To understand the biochemical responses to the herbicide, activities of the antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were assayed. Analysis of SOD activity by non-denaturing polyacrylamide gel electrophoresis (PAGE) revealed that there were three isoforms in the roots and leaves, but the isoforms in the tissues showed different patterns. Also, using the native PAGE, 6 isoforms of root POD and 10 in leaves were detected. The total activity of POD in roots was significantly enhanced. Activities of APX in roots and leaves showed a similar pattern. The CAT activities were generally suppressed under the chlorotoluron exposure.     

Chemical Characteristics and Source Implications of Petroleum Hydrocarbon Contaminants in the Sediments near Major Drainage Outfalls along the Coastal of Laizhou Bay, Bohai Sea, China

The associated industrial and urban developments are located to a large extent along the Laizhou Bay, Bohai Sea coastal and raw sewage is often discharged into near shore waters with little treatment. To find out chemical characteristics and pollution source of the petroleum related contaminations in sediments near the major drainage outfalls located in the coastal, in this study, 10 surface sediment samples were collected during June. Sediment samples were extracted by organic solvents, separated by silica gel column chromatography and the concentrations and the profiles of n-alkane, biomarker and PAH in sediments were analyzed by gas chromatography-mass selective detector (GC-MSD). The use of several molecular markers and related indexes derived for n-alkane and PAHs has been proposed for assessing the relative contributions to the environment of hydrocarbon sources. As a result, n-alkanes reflect that the sea area of paper mill (Station ZZ08) is dominated by vascular plant. DY petroleum oil field and outer shore of the paper mill (Station ZZ02) have some degrees of petroleum related hydrocarbon contamination. Whereas the contamination of the sea area of TH River may be ascribed to different sources such as territorial non-point pollution source, domestic sewages, and stormwater runoff. Judged by their PAH ratios, the sediments near the paper mill (Station ZZ02) and the outer station of the oil field (Staion TH2) were pyrolytic. The estuary of Tiao River including the inner Station THX, TH10 and TH05 are petrogenic. The marine sediment near DY drainage outfall may have a mixture source of PAH both pyrolytic and petrogenic.     

废水处理系统中胞外水解酶的作用特性研究

从pH、温度、底物浓度和抑制剂等四方面的作用条件,对厌氧-缺氧-好氧废水生物处理系统中β-葡萄糖苷酶、碱性磷酸酶、亮氨酸氨基肽酶和脂肪酶的作用特性进行研究.试验结果表明,4种酶在60℃有最高酶活;偏碱性条件(pH=8～9)有利于酶促反应的进行;酶活随底物浓度的增加而增大;抑制剂PMSF对各酶抑制效果不尽相同,对葡萄糖、蛋白质和磷酸水解酶的抑制率分别为72.7%、26.1%和26.8%,而对脂肪酶的抑制率高达85.2%;最适作用条件下的各待测酶的活性可达日常作用条件的1.5～8倍;酶的活性与COD、氨氮、总氮和总磷等生化因子有较好的相关性.由此得出控制相关作用条件可最大限度地发挥酶的作用性能,提高废水处理效率.     

自然灾害风险评估国际计划述评Ⅱ——评估方法

自然灾害风险评估是综合灾害风险管理的关键途径,而评估方法又是灾害风险评估的关键.总结了近年来3个重要的自然灾害风险评估国际计划:灾害风险指标计划(DRI)、多发展指标计划(Hotspots)和美洲计划的(American Programme)分析单元、灾种选择和数据源.评述了3个国际计划采用的数据处理方法、模型和评估方法:计算DRI的指标需计算3个数值--物质暴露、相对脆弱性和社会-经济脆弱性指标;Hotspots首次利用栅格单元和地区/财富等级来计算死亡风险和经济损失风险;美洲计划分别建立了4个独立指标的计算模型,并应用到城市级别.通过比较3个国际计划的风险评估方法的优点与不足,提出了今后灾害风险评估的重点和关键应是风险的时空分布、动态风险评估和案例研究.     

基于PPGIS的社会化震害信息获取模型研究

从充分利用社会化信息资源的角度,针对目前地震应急反应中灾情信息收集慢、费用大等问题,研究提出基于PPGIS的社会化震害信息实时获取模型.以实现快速验证和修正基于灾害经验给出的地震影响和灾情评估结果,为地震的应急指挥决策提供更可靠的基础信息.     

嘉陵江上游暴雨洪水特性分析

介绍了流域气候和地理特征,分析了流域降水、径流特性和泥沙特点;通过对历年暴雨洪水资料的统计,分析了流域内暴雨洪水形成的规律;对干流段灾害性洪水的重现期及大洪水发生的周期和季节规律进行了分析,并提出了防洪减灾对策.     

高含硫天然气井测试施工安全对策分析

本文阐述了作者在罗家寨等高含硫气田多口井的完井放喷测试施工中加强安全管理的具体做法,即施工现场安全组织、入场施工安全控制以及安全培训与演练,尤其是对放喷测试施工中危险点（源）的辨识及正确采取削减措施。     

基础工程施工中的事故隐患与整改

基础施工是基础设施建设中的首要环节,是整个工程建设赖以进行的基础工作,因而国家颁布了一系列标准与规程,用以确保施工质量与安全。本文就基础工程施工中事故隐患的整改谈谈个人看法。     

美国《有毒物质控制法》的修订进展和启示

回顾了美国《有毒物质控制法》(TSCA)的诞生、作用、修订的缘由、修订的过程和进展。从运用定量构效关系(QSAR)技术、完善生物测试技术、增加我国化学品管理领域的风险评估、推广绿色化学概念和规范信息管理与公开等5个方面阐述了TSCA的修订给我国化学品管理工作带来的启示。