化学需氧量测定方法的改进及研究进展

化学需氧量是综合评价水体污染程度的重要指标,是水质监测的重要水质参数。文章就国标方法的众多改进措施分类进行了探讨,包括消解方法的改进、氧化剂、替代催化剂和酸体系的研究、氯离子干扰的消除以及取样均匀性的改进,然后介绍了相关系数法、分光光度法、连续流动分析法、原子吸收法、电化学法、化学发光分析法、生物法、臭氧氧化法、光催化氧化法等COD测定替代技术,评价了各种方法的优缺点。最后指出,建立灵敏、准确、适应性强、低耗、无二次污染、性价比高COD监测分析方法是COD监测的发展趋势。     

Cost‐benefit analysis of soil remediation in Israeli industrial zones

Industrial zones are the main source of soil pollution in Israel. Due to the upcoming approval of the bill on soil contamination and remediation in Israel, it is important to assess the economic feasibility of soil remediation. This study examines the economic feasibility of an extensive remediation project of all contaminated industrial zones in Israel. The estimated economic benefits include both direct benefits, resulting from the increase in the land value of the contaminated site, and indirect benefits, arising from the increase in nearby property values. A cost‐benefit analysis showed a cost benefit ratio of 1:14. Nonetheless, the direct benefits were found to be lower than the costs. Thus, the question of funding requires collaboration between government and the private sector.     

哈希比色法与重铬酸盐法测定水中COD的对比分析

文章通过空白、标准样品、实际样品测定实验及色度影响实验,对两种COD测定方法进行比对,验证方法的准确度和精确度。结果表明:哈希比色法在测定色度小的水样时,多次测定均值与重铬酸盐法测定结果相差不大;测定色度较大水样时,可以利用色度与测定结果偏差的相关性进行结果修正。     

低压直流电电解剩余活性污泥

采用低压直流电电解剩余活性污泥,优化了支持电解质的种类、加入量及电压梯度等工艺条件,并考察了在最佳工艺条件下SS去除率、污泥中有机物的质量分数（以VSS/SS计）、污泥pH及污泥沉降性能随电解时间的变化情况。实验结果表明,低压直流电电解污泥的最佳工艺条件为：电压梯度7 V/cm;支持电解质Na₂SO₄加入量0.4.0 mmol/g（以每克干污泥计）。在最佳工艺条件下电解pH为5.8、SS=（7 850 ±200）mg/L、VSS=（6 150±150）mg/L、溶解性化学需氧量（SCOD）为（61.2 ±20）mg/L的污泥,电解60 min时污泥的SCOD最大,达393.3 mg/L,SS去除率达14.4%,VSS/SS为58.5%,污泥pH为3.1。电解后污泥中微生物的细胞结构已不完整,污泥絮体被严重破坏。电解时间越长,污泥的沉降速率越快。     

铅试金富集——原子吸收光谱法测定锡及锡合金废料的金含量

以火焰原子吸收光谱法测定锡及锡合金废料中的微量元素金。为消除测定过程中各种杂质干扰,采用铅试金法富集样品中的金,实现金与主体锡和其他杂质的分离,通过灰吹后得到金银合金,再以稀硝酸——王水溶解金银合金,在5％的盐酸介质中,以空气-乙炔火焰原子吸收光谱法测定锡及锡合金废料中的金含量。本方法相对标准偏差小于1．5％,加标回收率大于98．0％。     

Organic contamination of Italian and Tunisian culinary herbs and spices

Contaminants belonging to various classes, as polychlorobiphenyls, polycyclic aromatic hydrocarbons, organochlorine pesticides, organophosphorous pesticides, pyrethroid insecticides, fungicides, herbicides, synergists, carbamates, acaricides and insect growth regulators were simultaneously analysed by GC-MS/MS in 118 Italian and Tunisian culinary herbs and spices. The results obtained in Italian samples shown that laurel samples were the most contaminated with the presence of 15 residues on 140, whereas in rosemary (max value of 35?ng/g for cis-chlorfenyvinphos) and oregano (max value of 118.16?ng/g for ethion) some occasional residues can be observed, but always lower than the maximum residue levels; all the others samples shown no contamination. Among Tunisian samples, only rosemary contains a notably high content of pollutants exceeded the EU maximum residue limits (i.e., alachlor and phosalone with level of 359.2 and 43.3?ng/g, respectively), while oregano was determined to be free of contaminant residues. Considering the comparison among the different organic pollutants in Italian and Tunisian spices and herbs evaluated and the differences observed in this study a harmonization of regulation on contaminant residues in herbs and spices for human consumption should be needed, considering their increased use in diet and cooking.     

Effects of investment on energy intensity: evidence from China

This article explores the effects of investment upon energy intensity by applying a unique panel data of China’s 27 provinces between 2004 and 2013. In addition, it also particularly studies other factors, such as energy price, economic structure, and urbanization. The results, based on four econometric regression model results, suggest that in general, the indigenous investment on research and development is a more powerful tool to decrease China’s energy intensity regardless of region disparity. The foreign direct investment (FDI) has a prominent but not persistent effect on energy intensity. However, the outward direct investment has not shown its significant impact on energy intensity. At the level of an aggregate economy and China’s eastern region, the results demonstrate that FDI improves energy efficiency significantly. For the central and western provinces, FDI does not support the similar conclusion. Based on these analyses, we present the corresponding regional policies for policymakers.     

一种检测水体总氮的多技术协同氧化消解装置

在分析比较前人方法的基础上,研究开发了一套集臭氧、紫外、超声雾化、高压静放电等多技术协同的氧化消解装置,对含氮水样进行连续消解,将水中含氮物质中的N氧化为NO3-,从而测定水中的总氮。通过实验可以确定最佳消解条件,计算出总氮氧化的转化率,并进行精密度、准确度检验。本法具有无需添加化学氧化剂,总氮氧化率高和消解速度快,精密度、准确度高等特点。     

吡啶改性膨润土对直接耐晒翠蓝染料废水脱色性能研究

为了解决日益严重的水污染问题,用吡啶作改性剂,对膨润土进行有机改性,制得一种新型水处理剂,用于直接耐晒翠蓝染料废水的处理。研究了处理废水的最佳工艺条件。结果表明,投土量为10g／L,pH=3．5,搅拌速度为175r／min,搅拌时间25rain,离心时间为2min,吡啶改性土对直接耐晒翠蓝染料废水的脱色率可达80％。改性土对直接耐晒翠蓝的吸附过程可用准二级速率方程较好地描述。     

微絮凝直接过滤-超滤组合工艺深度处理印染废水

采用微絮凝直接过滤作为超滤的预处理工艺,对印染废水二级出水进行深度处理。考察了微絮凝直接过滤一超滤组合工艺处理效果和不同预处理方式砂滤、微絮凝、微絮凝直接过滤对超滤膜污染影响。实验结果表明,微絮凝直接过滤-超滤组合工艺对浊度、色度和COD平均去除率为99．2％、87％和56％;出水水质能满足《城市杂用水水质标准》（GB／T18920—2002）;与其他预处理方式相比,微絮凝直接过滤能大大地减轻超滤膜的负荷,延缓膜的污染,微絮凝直接过滤是一较优预处理工艺。由于采用变孔隙滤料,该系统具有用药量省的优点。