Organic ligands unexpectedly increase the toxicity of chromium(III) for luminescent bacteria

Environmental Chemistry Letters - Organic ligands are commonly believed to decrease the toxicity of metal ions, but there is few experimental evidence, especially for chromium (Cr(III)), which...     

蒙脱石-OR-SH复合体修复剂对重金属污染土壤中Cd的钝化效果

利用溶剂分散法成功地将功能基团—SH嫁接到蒙脱石上,得到蒙脱石-OR-SH复合体材料,该复合体材料对Cd的饱和吸附容量可达37.82 mg·g-1(0.1 mol·L-1KNO3体系)和69.13 mg·g-1(不考虑离子浓度影响).通过小白菜盆栽和大田试验探讨了该复合体材料对Cd污染土壤的钝化效果.结果表明,在Cd污染土壤上施加蒙脱石-OR-SH复合体材料后,土壤中可交换态Cd形态占比分别低了64.51%(原土)和80.37%(3 mg·kg-1Cd含量的成化土),铁锰氧化结合态Cd形态占比分别提升了176.66%(原土)和418.31%(3 mg·kg-1Cd含量的成化土),降低了毒性元素Cd在土壤中的活性和可移动性,有效地固定了土壤中的Cd,小白菜中镉含量比对照分别降低了57.14%(原土)和60.64%(3 mg·kg-1Cd含量的成化土),同时能促进小白菜的生长.     

Beijing environmental sustainable development from 1983 to 2003

Ever since the Earth Summit was launched at Rio de Janeiro, research has been done on the problems of developing indices for the health of the environment and for its sustainable development. However, this research has concentrated more on national and regional levels than on local levels, more on spatial comparisons than on time series analysis, more on short-term than on long-time analysis, more on qualitative than on quantitative analysis. In contrast, therefore, this paper presents an indicator system procedure for measuring Beijing (the capital of China) environmental sustainability based on the Pressure-State-Response (PSR) philosophy, evaluates the trend of Beijing environmental sustainability index (BESI) quantitatively for 21 years, from 1983 to 2003, and suggests three great opportunities in the near future that are expected to provide some dependable information to policy makers. The results suggest that Beijing is still far from environmental sustainable development. The total trend was better in the 1980s than in the 1990s, and has improved slightly since 2000.     

环境中有机紫外防晒剂残留及其生态毒性研究进展

有机紫外防晒剂被广泛添加在个人护理品中,随着日常使用源源不断地进入环境中,成为一类新兴污染物。环境介质中有机紫外防晒剂的检测及其生态毒理是目前的研究热点。概述了个人护理品中常用的有机紫外防晒剂,总结了有机紫外防晒剂在各类地表水、沉积物和生物体等不同介质中的浓度水平,详细分析了有机紫外防晒剂对鱼类的内分泌干扰效应和对水生无脊椎动物的急性毒性,为今后深入研究和科学评价这类新兴污染物提供重要参考。     

Land resource degradation in China: Analysis of status,trends and strategy

Land degradation threatens environmental well-being and is a growing global issue. China is among the most affected countries in the world in terms of the extent, intensity and economic impact of land degradation. Sustainable and successful intervention requires clear definition and quantification of land degradation. Based on land resource variation survey data from 1991 to 2002, this paper identified, defined and classified land resource degradation, and analyzed dynamic changes in the degradation and rehabilitation process. Through the establishment of a land resource degradation index, the status and trend of degradation in China was explored to enable the design and planning of interventions for mitigation and establishment of sustainable land use and management practices. Results showed that: (1) The total land degradation index (A) fluctuated upwards from 1991 to 2002, although some parts improved. (2) Sand and rock desertification, deforestation and wetland loss reduced slightly, whereas secondary salinification, non-agricultural land occupation and natural grassland further deteriorated. (3) 66.27% of degradation was in natural grassland and non-agricultural land; while 57.5% of rehabilitation focused on sandy desertification and forests. (4) Non-agricultural land occupation and wetland shrinkage are primary causes of land resource deterioration in China. (5) Grassland, cultivated land and forest land accounted for 83.9% of degradation. (6) All the degradation processes are interrelated. These results provide useful information to combat future land resource degradation in China.     

The calculation of equivalence factor for ecological footprints in China: a methodological note

The Ecological Footprint (EF), a physical indicator to measure the extent of humanity’s use of natural resources, has gained much attention since it was first used by Wackernagel and Rees in 1996. In order to appraise land area types with different levels of productivity, they introduced the concept of an equivalence factor. This relates to the average primary biomass productivities of different types of land (i.e. arable land, pasture, forest, water/fishery, built-up land and fossil energy land) to the regional average primary biomass productivity of all land types in a given year. Hence, the equivalence factor is an important parameter in the EF model and it directly affects the reliability of all results. Thus, this article calculates equivalence factors on the national and provincial levels in China based on Net Primary Production (NPP) from MODIS 1 km data in 2008. Firstly, based on the Light Utility Efficiency and CASA model, the NPP of different biologically productive lands of China and of different provinces was calculated. Secondly, China’s equivalence factor for 6 land area types was calculated based on NPP: arable land and built-up land has an equivalence factor of 1.71, forest and fossil energy land has a factor of 1.41, pasture has a factor of 0.44 and water/fishery 0.35; Finally, the equivalence factor of 6 land area types in different provinces was also calculated. The NPP of each ecosystem type varies along with the equivalence factor in different provinces. However, the ranking of the equivalence factors in different provinces remain the same, with that of arable land being the largest, and the water/fishery being the smallest.     

外源褪黑素对As~(3+)胁迫下水稻种子萌发的影响

本文研究了添加外源褪黑素对As~(3+)胁迫下水稻种子萌发及生理指标的影响。结果表明:添加外源褪黑素能促进As~(3+)胁迫下水稻种子的萌发,提高水稻的发芽势和发芽率,促进水稻幼苗的生长。当As~(3+)浓度为100μmol·L~(-1)时,添加100μmol·L~(-1)褪黑素能使水稻种子发芽率和总根长比对照分别提高57.1%和50.0%。添加褪黑素能显著提高As~(3+)胁迫下水稻幼苗中抗氧化酶系统过氧化氢酶(CAT)、过氧化物酶(POD)活性和超氧化物歧化酶(SOD)的活性,并降低水稻幼芽中丙二醛(MDA)的含量。当As~(3+)浓度为100μmol·L~(-1)时,添加50μmol·L~(-1)和100μmol·L~(-1)褪黑素导致水稻幼芽中POD活性比对照处理分别提高57.5%和114.8%,CAT活性提高29.4%和53.8%,SOD活性提高31.5%和56.0%,丙二醛含量比对照处理降低16.5%和31.9%。添加褪黑素也能显著提高As~(3+)胁迫下水稻的根系活力,当As~(3+)浓度为100μmol·L~(-1)时,50、100μmol·L~(-1)褪黑素处理后根系活力比对照分别提高42.4%和124.1%。这说明添加外源褪黑素可缓解As~(3+)胁迫对水稻的脂质过氧化损害,有效降低As对水稻内膜的破坏,显著缓解As污染对水稻的毒害作用。     

提高异丙醇废水可生化性的试验研究

感光材料行业排出的异丙醇废水,BOD5／COD为0．40左右,经水解酸化处理后BOD5／COD提高至0．05左右,证实了水解酸化处理具有提高异丙酸废水可生化性的功能。在进水COD为2000－3000mg／L条件下,用水解酸化－好氧生化工艺处理,COD总去除率可达90％左右,BOD5总去除率可达95％左右,均明显优于平等对照组传统活性污泥法的处理效果。     

降水中汞及其它元素来源的识别分析

在北京市不同地点采集４６ 个降水样品,测定了其中汞和其它元素的含量,通过主成分因子分析进行来源识别分析． 结果表明,降水中元素主要来源于燃煤、扬尘、燃油和特殊污染源．降水中汞（Ｈｇ）可能主要是土壤中汞挥发到大气中,经氧化后随降水降到地面．     

疏水改性ZSM-5的优化制备及其在高湿度下的VOCs吸附性能研究

针对分子筛在高湿度条件下VOCs吸附容量急剧下降的问题,通过优化液相沉积法合成了疏水改性的ZSM-5分子筛.实验选用更加经济环保的乙醇替代甲苯作为改性溶剂,并对两种溶剂的改性效果进行比较,优选出最佳改性条件制备疏水改性ZSM-5,考察了该吸附剂对模拟高湿度有机废气的吸附性能,并采用了 SEM、XRD、FTIR、氮气吸脱...