Occurrence and congeners specific of poiychlorinated biphenyls in agricultural soils from Southern Jiangsu, China

A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls (PCBs) in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% ofΣPCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% ofΣPCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.     

GIS在环境监测数据管理分析中的应用

根据环境监测的特点和地理信息系统(GIS)所具备的功能,讨论了GIS与环境监测结合的必要性,按照环境监测的目的不同分环境质量监测、污染源监督监测和应急监测三个方面阐述GIS在环境监测数据管理分析中的具体应用,并利用现有的一些基于GIS的环境监测信息系统实例进行进一步说明GIS在环境监测数据管理分析中的应用,充分发挥了GIS空间信息表达处理及综合分析的优势,使得环境监测数据的管理分析更加快速、实时、有效.随着GIS技术的发展,GIS在环境监测数据管理分析中的应用也将获得源源不绝的驱动力.     

武汉市2001～2005年大气环境质量模糊综合评价

文章对武汉市2001～2005年东湖梨园等6个监测站所监测的二氧化硫(SO2)、二氧化氮(NO2)、可吸入颗粒物(PM10)结果的年变化趋势进行了分析,根据国家标准利用模糊综合评价模型对各区各年大气环境质量状况做出了合理的综合评价,并由模型中各污染因子的权重判断出可吸入颗粒物(PM10)武汉市大气质量的制约因子,二氧化氮(NO2)的权重逐步上升。根据分析数据初步分析了三种污染物的主要来源。     

石油类突发水污染事故应急处理技术研究进展

从事故原因、应急处理措施、处理结果等几方面总结了国内外发生的主要石油类突发水污染事故,综述了机械回收、原地焚烧、投加消油剂、生物修复等应对石油类水污染事故的主要应急处理技术.通过对比分析,得出它们的优缺点和适用场景.其中,机械回收中围栏法和吸附法应用研究较多;原地焚烧具有简单、快速与高效等特点;喷洒消油剂适应恶劣天气与大面积处理;而生物修复则具有成本低,无二次污染等优势.分析认为,复杂多变的事故场景决定了应急技术应是一个综合技术系统,通过构建油类突发水污染事故模拟平台,验证深化现有技术,强化现有单项技术的集成是未来的发展方向和重点.     

复合装药安全性优选BP神经网络模型

为在设计复合装药结构时得到复合装药的能量输出和安全性双优结构,利用BP人工神经网络理论,建立结构优选模型。利用不同的感度和能量输出试验数据,进行模型的训练,训练后对样本进行预测和优选。结果表明,该方法能够克服评估复合装药结构性能优劣的各因素之间的复杂关系,实现精确的非线性预测,得到安全性和能量输出双优的设计结构。     

粒子群优化的RBF瓦斯涌出量预测

瓦斯涌出量是煤矿瓦斯灾害的主要来源,它直接影响煤矿安全生产和经济技术指标。瓦斯涌出量的传统预测方法是将其影响因素线性化后提出的,具有一定的局限性。本文基于群体智能理论,提出了一种基于粒子群算法优化的RBF神经网络瓦斯涌出量预测模型。研究表明RBF神经网络预测精度与网络权值和RBF参数初始值有很大关系,因此本文采用粒子群算法优化RBF网络权值和其他参数,形成PSO-RBF预测模型。该模型通过计算种群粒子的适应度,确定全局最优值,寻找网络参数的最优值。实验结果表明PSO-RBF优于传统的RBF预测模型,训练速度和预测精度显著提高。     

DPX快速萃取程序升温大体积进样GC/MS法测定水中19种多溴联苯化合物

建立DPX快速吸附萃取、程序升温(PTV)大体积进样与气相色谱/质谱(GC/MS)联用,SIM模式同时测定水中19种多溴联苯(PBBs)单体的方法。该方法在PBBs质量浓度1~50μg/L范围内线性良好,19种PBBs单体检出限为0.147~0.230μg/L,相对标准偏差为6.61%~10.5%,加标回收率为61.5%~82.6%。     

Improve Compliance with Limited Resources by a Three-Group Inspection Regime

Frequent monitoring and relatively high fines are usually necessary to bring about improvements in environmental quality, but more challenging for many countries with limited human, material, and financial resources is to put them into practice. This paper developed a three-group model of a state-dependent enforcement in a repeated game to improve the policy implementation under limited inspection capacities. A certain number of firms are grouped (group 1, group 2, group 3) for different supervision intensity (e.g., the order of inspection probability corresponding to each group is p ₁?<?p ₂?<?p ₃) based on their environmental performance. The optimal policy parameters, such as inspection probability of each group and the probability that a firm found in compliance is moved to a better reputation group, were obtained as the basis for regulator’s policy making. Numerical simulations indicated that the three-group inspection regime can significantly increase compliance rate as compared with static enforcement with the same monitoring probability. Among the number of firms in each group under steady state conditions, group 2 had the most, group 1 was the second, and group 3 had the smallest. Analysis and prediction of a three-group reputation example provided a good experiment for the model. The results give a practical reference for the policy makers with inspection capacity constraints to achieve higher compliance rate.     

废气样品中甲烷的保存条件研究

气相色谱法检测废气中甲烷,样品保存容器可选择玻璃注射器、惰性气袋、真空瓶、苏码罐等,实验室对此做了比较研究。结果表明:玻璃注射器气密性较差,样品须在8 h内完成分析;真空瓶携带不方便,苏码罐价格昂贵,两者使用较少;使用玻璃注射器采集,然后注入惰性气袋保存的方法最佳,样品至少可稳定保存7d。     

环境污染物计算毒理学分析及环境行为模拟研究进展

根据国内外研究报道,系统地总结了计算毒理学和化合物环境行为模拟在环境科学领域的研究进展,包括二者的概念、理论、研究方法以及在环境研究中的应用;分析了计算毒理学和化合物环境行为模拟在发展中所面临的挑战,并提出对策;展望了计算毒理学和化合物环境行为模拟在环境研究中的发展前景。