The interference of 2-chloro-5-oxo-3-hexene diacyl chloride (COHC) in the detection of strong mutagen MX

Laboratory experiments were conducted to examine the impact of cadmium (Cd) on survival of Diplostomum sp. cercariae. Freshly emerged cercariae were exposed to Cd solutions at concentrations ranging between 0.2 and 200 microg/l. The mortality patterns and mean survival times (MSTs) of the exposed parasites were determined by the Kaplan-Meier estimator and were compared (Log-Rank test) to corresponding patterns and estimators of the unexposed controls. Cd concentrations >20 microg/l caused statistically significant changes in the mortality pattern of Diplostomum sp. cercariae and reduced MST by at least five hours compared to the control group, where MST was 52 h. The results show that longevity of the free-living Diplostomum sp. cercariae can be reduced by direct exposure to heavy metals. Cd contamination of aquatic habitats thus potentially can have an impact on parasite populations and communities.     

气象灾害,气候和气候变化与中国的可持续发展

大气层是全球环境各组成部分中最活跃的一个部分。全球及区域气候变异以及各种时空尺度的气象灾害如暴雨、台风、干旱、洪涝等,对社会经济发展的影响是全方位、多层次的。人类活动可能导致的气候变化对社会经济发展有着广泛性、长远性和深刻性的影响。因此讨论可持续发展问题,须对提高社会防御气象灾害和适应、减缓气候变化的能力问题予以特别的注意。     

城市应急联动系统的研究

叙述了建设城市应急联动系统的必要性,分析了城市应急联动系统国内外发展现状,提出了系统的4种运作模式即集权模式、授权模式、代理模式、协同模式,强调了系统基础设施建设应包含的重要内容,设计了系统技术支撑体系和系统基本功能。最后得出应加快我国城市应急联动系统的统一协调和建设的结论。     

熔融碱法处理CFC-12的研究

采用熔融碱法处理CFC-12,考察了不同因素对于CFC-12转化率的影响。结果表明：当进口气体浓度300-2527 mg/m3时,在有水蒸汽,反应温度720℃,温度越高越有利于CFC-12的转化,NaOH用量60 g,气体流量25mL/min处理效果好,CFC-12的转化率达到90%。而且CFC-12的分解产物被NaOH吸收固化,实现了CFC-12的无害化处理。     

桂林盘龙洞滴水的物理化学指标变化研究及其意义

影响洞穴次生化学沉积物-石笋的形成因素,包括降水、气温、水温和滴水的性质(如pH值、电导率、Ca2+、HCO3-浓度和滴率等)。通过对桂林盘龙洞8个滴水点的2个水文年的监测表明,洞穴滴水主要来源于大气降水(或土壤水),受控于水-土-岩的相互作用。洞穴滴水对大气降水的响应较快,具有季节性的变化特征。洞穴滴水的物理、化学特性受降水、洞顶基岩厚度及渗入水的滞留时间、滴率的快、慢的影响。洞穴滴水的温度变化不大,大约为19.4~21.2℃。年平均pH值为7.85。洞穴滴水的电导率、Ca2+、HCO3-浓度与气温、水温和滴水速率表现为正相关关系。在夏半年,大气降水量大,土壤湿度大,土壤中PCO2分压高,溶解的CaCO3多,表层带下渗岩溶水的岩溶作用强,滴水的电导率、Ca2+、HCO3-浓度增大,滴水中的碳酸盐沉积多;而在冬半年或冬季,其降水量小或少,滴水的电导率、Ca2+、HCO3-浓度降低,指示溶解的CaCO3少,表层带下渗岩溶水的岩溶作用弱,水中Ca2+离子含量低,滴水沉积物的沉积量或生长量减少。从大气降水到土壤水再到洞穴滴水这些过程可以看出,洞穴滴水形成的岩溶次生化学碳酸盐沉积物-石笋,可记录岩溶环境变化的信息,已成为研究岩溶地区过去环境变化记录的重要载体。     

区域景观结构的生态风险评价方法与案例研究

大尺度区域高强度开发改变原有区域的生态系统与景观结构,引发的区域生态风险是难以避免的。如何从宏观上评价区域生态风险,其评价方法在不断实践发展,这成为当前环评研究的热点之一。在海南某一开发区的区域环评实践时,根据区域的特征,划分区域景观类型,提出景观结构的评价指标,建立评价模型,运用基于区域景观结构的生态风险评价方法,对开发区的生态风险进行动态的时空化分析、预测与评价。案例研究旨于提升区域生态风险评价方法的运用水平,丰富评价方式,完善技术手段,为区域生态风险评价实践服务。     

Numerical simulation of a horizontal sedimentation tank considering sludge recirculation

Most research conducted on the concentration distribution of sediment in the sedimentation tank does not consider the role of the suction dredge. To analyze concentration distribution more accurately, a suspended sediment transportation model was constructed and the velocity field in the sedimentation tank was determined based on the influence of the suction dredge. An application model was then used to analyze the concentration distribution in the sedimentation tank when the suction dredge was fixed, with results showing that distribution was in accordance with theoretical analysis. The simulated value of the outlet concentration was similar to the experimental value, and the trends of the isoconcentration distribution curves, as well as the vertical distribution curves of the five monitoring sections acquired through simulations, were almost the same as curves acquired through experimentation. The di erences between the simulated values and the experimental values were significant.     

石化企业中密闭采样存在的问题与对策

对石化企业在密闭采样器应用过程中存在的标准滞后、规格不一、器具过重等问题进行了分析,并提出了解决问题的对策建议。     

Speciation characterization and coagulation of poly-silica-ferric-chloride: The role of hydrolyzed Fe(Ⅲ) and silica interaction

The highly efficient inorganic polymer flocculants (IPFs) of the ferric-silica system is a new and promising coagulant. Interactions between ferric species and silica play a large part in the coagulation of suspensions. These effects are quite distinct from those associated with polymeric or colloid silica. However, although these species are key to coagulation efficiency, they have not been comprehensively discussed. A new type of coagulant, poly-silica-ferric-chloride (PFSC), was synthesized by co-polymerization and characterized by time complexation spectroscopy and photon correlation spectroscopy. Compared with traditional ferric salt, the results indicated that PFSC had a higher molecular weight, lesser positive charge, lower Feb and higher Fec. The higher the Si/Fe ratio, the higher the silica and lower the silicac found. The PFSC with appropriate polysilica acid not only obtained better coaguiation/fiocculation efficiency in turbidity removal, enhanced the flocculation index (FI) and provided less residual ferric, it also lowered water treatment costs compared to traditional ferric salt. Results showed that PFSC could remove colloid particles in water by charge neutralization and sweeping,adsorption bridging mechanism.     

石化装置苯泄漏检测及危害控制方法

石化装置苯泄漏的危害严重,已引起广泛关注。对石化装置苯泄漏的危害、苯泄漏的检测方法进行了评述,指出苯泄漏检测需要多种检测手段联合进行,同时应对泄漏危害加以控制。