便携式质谱联用仪快速定量测定水中7 种苯系物

针对地表水、地下水和饮用水中苯系物的快速定量测定建立方法,该方法适用于水体中苯、甲苯、乙苯、间/对-二甲苯、苯乙烯和邻-二甲苯等苯系物的快速定量结果测定,样品浓度在5~50μg/L的浓度范围内定量检测相对标准偏差低于10%。通过对标准样品测定,其回收率在96.16%~101.50%之间,在快速测定的同时,其定量测定数据具有很高的可靠性。     

顶空-毛细管气相色谱法测定水中三卤甲烷

采用项空-毛细管气相色谱法分析测定水中三卤甲烷(THM),样品在50℃静态顶空条件下平衡40 min,经HP-5毛细管色谱柱进行分离,采用气相色谱-电子捕获检测器分析,外标法定量三氯甲烷、一溴二氯甲烷、二溴一氯甲烷、三溴甲烷,对THM的回收率为96.0%~98.3%,相对标准偏差为1.2%~2.0%,检出限为0.008~0.07μg/L。所建立的方法简便、灵敏、准确,具有良好的精密度与准确度,可用于测定水中THM。     

顶空气相色谱法测定水中甲醛、乙醛和丙烯醛

建立了顶空气相色谱法同时测定水中甲醛、乙醛、丙烯醛的方法。目标化合物连续测定9次的相对标准偏差分别为0.01,1.89,3.54;检出限分别为0.03μg/L,5.68μg/L,10.3μg/L,实际水样加标回收率在98%~101%。方法简便,快速,灵敏度高,基体干扰小。适用于地表水、地下水和工业废水中甲醛、乙醛、丙烯醛的同时、快速测定。     

碰撞反应池ICP-MS同时测定地下水中十七种稀土元素

为了建立碰撞反应池ICP-MS同时测定地下水中十七种稀土元素分析检测方法,采取内标校正法,选用铑、铟、铼、铋为内标元素,结合优化的仪器条件和碰撞反应池技术,校正分析过程中的干扰和漂移。外标法定量,加标回收对方法进行质量控制。结果表明十七种稀土元素浓度在0.50~50.0μg/L范围内,具有良好的线性关系,标准曲线相关系数r≥0.999 6;方法检出限为0.001~0.036μg/L;在空白溶液和实际水样中分别添加高、中、低三个水平的稀土元素标准溶液测定方法回收率,加标回收率为85.7%~105%,实际水样的相对标准偏差为0.5%~3.5%。碰撞反应池ICP-MS具有灵敏度高、检出限低、干扰少、精密度好、准确度高、谱线相对简单、线性范围宽及多元素同时分析等优点,适用于地下水中稀土元素的测定。     

ICP-MS法测定地下水及地表水中的11种金属元素

优化ICP-MS的测定参数,选择合适的内标元素,测定了地下水及地表水中11种金属元素的含量。研究结果表明,此法测定水中11种金属元素的标准曲线相关系数(r)值均大于0.999,方法检出限为0.02~0.34μg/L,均低于国家现行标准,相对标准偏差(RSD)低于4%,对质控样的分析结果与标准值吻合,实际样品的加标回收率为95.0%~107.5%。该方法分析速度快、灵敏度高、检出限低,具有较好的精密度和准确度。     

阻抑光度法测定痕量乙醇的研究

文章研究了在稀硫酸介质中,乙醇阻抑高碘酸钾氧化中性红褪色反应的各种反应条件,建立了阻抑光度法测定痕量乙醇的新方法。讨论了体系酸度、试剂浓度、反应温度、反应时间、干扰离子等因素对反应体系的影响。选择530nm作为测定波长,确定了阻抑反应的最佳条件。在所选择的试验条件下,方法的线性范围为1.0~7.0μg/25mL,检测限为4×10~(-6)g/L。表观摩尔吸光系数ε=3.68×10~4L/mol·cm。对该方法进行了精密度测定,其相对标准偏差RSD5%。该方法用于水样中痕量乙醇含量的测定,并进行了加标回收试验,平均回收率为98.6%~98.7%。     

电位滴定法测定水中高锰酸盐指数

提出实验室用电位滴定测定水中高锰酸盐指数的方法。在国标法的基础上研究及优化了标定方法和实验方法,用电位滴定仪测定水中高锰酸盐指数,方法的检出限约为0.15mg/L,测定下限为0.60mg/L。实验证明,标准样品测量值均在推荐值范围内,对0.6mg/L,5.0mg/L,8.0mg/L浓度的NaC2O4标准溶液进行5次测定,得到的相对标准偏差分别为1.59%,0.97%,0.73%。在做低浓度的水样时,高锰酸钾溶液的浓度可以选择0.005mol/L。     

微波消解-原子荧光光谱法同时测定土壤中痕量砷和汞

建立了微波消解—原子荧光光谱法同时测定土壤中痕量砷和汞的方法。通过对消解体系以及灯电流、载气流量、屏蔽气流量等仪器参数进行优化,确定了最佳实验条件。在优化的实验条件下,采用原子荧光光谱法同时测定砷和汞的检出限分别为0.02μg/L和0.01μg/L,线性范围分别为0～40μg/L和0～4μg/L,两元素的加标回收率在92%～102%之间,相对标准偏差砷为0.9%～3.1%,汞为1.5%～3.4%,完全适用于土壤环境样品的检测。     

Cd(Ⅱ)印迹吸附剂去除水中重金属Cd(Ⅱ)的研究

重金属污染问题已经成为近年来危害最大的水污染问题之一。Cd是一种有毒的重金属元素,造成的环境污染受到广泛关注。合成了一种Cd(II)印迹吸附剂来去除水样中的Cd(II),并采用电感耦合等离子体质谱测定水中Cd(II)浓度。研究了水体p H值、洗脱条件、吸附时间以及循环使用次数等影响因素。方法的检出限为0.026μg/L,相对标准偏差为1.46%。为确认实验的准确度,分析了一个已知准确浓度的国家标准样品(GSB07-1185-2000 201422),测定值与标准值基本吻合。地表水样中Cd(II)的加标回收率为98%~101.2%,说明运用Cd(II)印迹吸附剂对水中Cd(II)的去除效果较好,建立的方法准确可靠。     

真空采血管顶空气相色谱法检测水中三氯甲烷、四氯化碳

采用真空采血管顶空填充柱气相色谱法测定水中三氯甲烷和四氯化碳,结果表明,三氯甲烷在10.0～50.0μg/L,四氯化碳在0.5～4.0μg/L浓度范围内呈良好线性关系,其r值分别为0.9994和0.9998;三氯甲烷和四氯化碳RSD分别在1.64%~2.27%和1.45%~2.40%之间;加标回收率分别在97.0%~103.5%和94.0%~103.2%之间。该方法操作简单,具有较好的灵敏度和准确度,适用于水中三氯甲烷和四氯化碳的检测。     

Projected Changes in Discharge in an Agricultural Watershed in Iowa

Our improved capability to adapt to the future changes in discharge is linked to our capability to predict the magnitude or at least the direction of these changes. For the agricultural United States Midwest, too much or too little water has severe socioeconomic impacts. Here, we focus on the Raccoon River at Van Meter, Iowa, and use a statistical approach to examine projected changes in discharge. We build on statistical models using rainfall and harvested corn and soybean acreage to explain the observed discharge variability. We then use projections of these two predictors to examine the projected discharge response. Results are based on seven global climate models part of the Coupled Model Intercomparison Project Phase 5 and two representative concentration pathways (RCPs 4.5 and 8.5). There is not a strong signal of change in the discharge projections under the RCP 4.5. However, the results for the RCP 8.5 point to a stronger changing signal related to larger projected increases in rainfall, resulting in increased trends, in particular, in the upper part of the discharge distribution (i.e., 60th percentile and above). Examination of two hypothetical agricultural scenarios indicates that these increasing trends could be alleviated by decreasing the extent of the agricultural production. We also discuss how the methodology presented in this study represents a viable approach to move forward with the concept of return period for engineering design and management in a nonstationary world.     

Investment in human capital in Africa

Summary The author analyses the problems currently faced by the African continent, recognises six factors which he believes are important in influencing the analysis, and argues that the only secure, renewable asset any country or continent has, is its people. He maintains that people development, rather than the classical economic forms of encouraging development, offers Africa a viable way forward. He then identifies a number of specific issues within such a strategy of investment in human capital.Brian Walker is the President of the International Institute for Environment and Development (IIED), and this address was given at the inaugural meeting of the International Year of Shelter for the Homeless, in London, on 18th April, 1985. A second, earlier, associated address was published inThe Environmentalist 5(3) 167–170.     

Pesticides in rain in four agricultural watersheds in the United States

Rainfall samples were collected during the 2003 and 2004 growing seasons at four agricultural locales across the USA in Maryland, Indiana, Nebraska, and California. The samples were analyzed for 21 insecticides, 18 herbicides, three fungicides, and 40 pesticide degradates. Data from all sites combined show that 7 of the 10 most frequently detected pesticides were herbicides, with atrazine (70%) and metolachlor (83%) detected at every site. Dacthal, acetochlor, simazine, alachlor, and pendimethalin were detected in more than 50% of the samples. Chlorpyrifos, carbaryl, and diazinon were the only insecticides among the 10 most frequently detected compounds. Of the remaining pesticide parent compounds, 18 were detected in fewer than 30% of the samples, and 13 were not detected. The most frequently detected degradates were deethylatrazine; the oxygen analogs (OAs) of the organophosphorus insecticides chlorpyrifos, diazinon, and malathion; and 1-napthol (degradate of carbaryl). Deethylatrazine was detected in nearly 70% of the samples collected in Maryland, Indiana, and Nebraska but was detected only once in California. The OAs of chlorpyrifos and diazinon were detected primarily in California. Degradates of the acetanilide herbicides were rarely detected in rain, indicating that they are not formed in the atmosphere or readily volatilized from soils. Herbicides accounted for 91 to 98% of the total pesticide mass deposited by rain except in California, where insecticides accounted for 61% in 2004. The mass of pesticides deposited by rainfall was estimated to be less than 2% of the total applied in these agricultural areas.     

Environmental assessment in countries in transition: evolution in a changing context

Over the last fifteen years, Environmental Assessment systems of transitional societies of Central and Eastern Europe and Central Asia have undergone dramatic change from appraisals integrated into centrally planned economies to formal procedures aimed to ensure interdisciplinary analysis of environmental impacts and linked to publicly accountable decision-making. In most Central European nations, EA systems have been radically reformed to approximate the procedures used in developed countries, particularly in the European Union. In contrast, EA in most of the former Soviet republics has been reformed more gradually and is still based on the so-called State Environmental Review procedure inherited from the USSR and substantially different from 'Western' EA. About one-third of the transitional countries (in the Balkans, the Caucasus and Central Asia) have, so far, failed to establish functioning EA systems. Throughout the region, there has been a gap between EA legislation and practice, especially concerning interdisciplinary analysis of environmental impacts, public participation, and utilisation of EA findings in decision-making. A key driving force in the reform of EA systems has been the change in their societal context, the so-called 'process of transition'. Three main policy agendas--environmental protection, reforms of decision-making, and conforming to international requirements--along with the institutional context of EA regulations and practice have influenced both the change of EA systems over time and the regional variations in the patterns of their evolution. This study suggests that an effective reform of an EA system should be context-sensitive, or be 'in gear' with the political and economic transition. Future EA research should consider their changing societal contexts and focused on practical effects of applying EA procedures.     

Community-company relations in gold mining in Ghana

As a result of Structural Adjustment Programme from the 1980s, many developing countries have experienced an increase in resource extraction activities by international and transnational corporations. The work reported here examines the perceived impacts of gold mining at the community level in the Wassa West District of Ghana, Africa and discusses those perceived impacts in the context of globalization processes and growing multinational corporate interest in Corporate Social Responsibility (CSR). Interview data compared community members' perceptions with those of company representatives in three communities. The results indicate that communities held companies responsible for a series of economic, social, and environmental changes. While recognizing some of the benefits brought by the mines, communities felt that the companies did not live up to their responsibility to support local development. Companies responded by denying, dismissing concerns, or shifting blame. Findings from this work show that lack of engagement and action by government agencies at all levels resulted in companies acting in a surrogate governmental capacity. In such situations, managing expectations is key to community-company relations.     

电催化氧化处理难降解废水技术研究进展

电催化氧化处理难降解废水技术已得到了广泛关注.本文从电极材料与应用,电极结构及反应器形状,以及与其它处理方法联用等综述了最新研究进展,并在此基础上总结出了电催化氧化技术今后的发展方向.     

Water management problems in economies in transition

Ambitious programmes of reform in Central and Eastern Europe (CEE) are threatened by a serious deterioration of the environment. Large-scale damage of the natural environment in many forms, including water pollution has created development barriers which adversely affect the living conditions of current and future generations. Despite similar patterns of environmental policy in the CEE countries compared with their Western counterparts, neither environmental legislation nor economic incentives have produced any significant improvement in water quality over the last 10–20 years. For that very reason in the transition period, it is necessary to identify existing deficiencies in the system and to build up a mixed system of new institutions of water management, more realistic legislation with a strong enforcement system, and market based incentives for water conservation and protection against pollution.     

我国城市生态评价研究进展

城市建设带来了越来越多的生态环境问题，生态城市建设是解决这些问题的良好途径。生态城市的建设要有一定的评价体系作为支撑，本文综述了国内基于AHP方法建立的应用较为广泛的城市生态评价体系和方法，并对国内城市生态评价的现状做了分析。     

Private participation in isolated grids in Mozambique

This article presents a case study from Mozambique of the electrification of two selected towns under a World Bank financed project. Low-cost electricity services were extended to the two isolated areas after an enabling framework had been created for private sector participation. The World Bank project also demonstrates that the private sector can be attracted to participate in rural electrification schemes even in a poor country. The example shown in this article is one of the few of its kind in SubSaharan Africa.