Combined toxicity of copper and cadmium to six rice genotypes （Oryza sativa L.）

Accumulation of copper (Cu) and cadmium (Cd) in six rice cultivars (94D-22, 94D-54, 94D-64, Gui630, YY-1 and KY1360) was evaluated through exposure to heavy metal contamination (100 mg/kg Cu, 1.0 mg/kg Cd, and 100 mg/kg Cu + 1.0 mg/kg Cd) in a greenhouse. The dry weight of shoot and root, concentrations of Cu and Cd in plant tissues and the Cu, Cd, P, Fe concentrations in the root surface iron plaques were analyzed eight weeks later after treatment. The results indicated that the plant biomass was mainly determined by rice genotypes, not Cu and Cd content in soil. Separated treatment with Cu/Cd increased each metal level in shoot, root and iron plaques. Soil Cu enhanced Cd accumulation in tissues. In contrast, Cu concentrations in shoot and root was unaffected by soil Cd. Compared to single metal contamination, combined treatment increased Cd content by 110.6%, 77.0% and 45.2% in shoot, and by 112.7%, 51.2% and 18.4% in root for Gui630, YY-1 and KY1360, respectively. The content level of Cu or Cd in root surface iron plaques was not affected by their soil content. Cu promoted Fe accumulation in iron plaques, while Cd has no effect on P and Fe accumulation in it. The translocation of Cu and Cd from iron plaques to root and shoot was also discussed. These results might be beneficial in selecting cultivars with low heavy metal accumulation and designing strategies for soil bioremediation.     

Concentrations and chemical forms of potentially toxic metals in road-deposited sediments from different zones of Hangzhou, China

The 25 road-deposited sediments were collected from five different land-use zones (industrial, residential, commercial, park, and countryside) in Hangzhou, China. The concentrations of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in these samples were determined using the ICP-AES after digestion with the mixture of HNO3-HF-HCl (aqua regia), and chemically fractionated using the modified BCR (the European Community Bureau of Reference) sequential extraction procedure. The highest metal concentration level was detected in the sample from industrial zone and commercial zone having heavy traffic. While the lowest metal level was noted in the street dust sample from residential zone, park, and countryside zone. The mobility sequence based on the sum of the BCR sequential extraction stages was: Zn (80.28%), Pb (78.68%), Cd (77.66%) ＞ Cu (73.34%) ＞ Mn (67.92%) ＞ Co (41.66%) ＞ Ni (30.36%) ＞ Cr (21.56%), Fe (20.86%). Correlation analysis and principal component analysis were applied to the data matrix to evaluate the analytical results and to identify the possible pollution sources of metals. Factor analysis showed that these areas were mainly contaminated by three sources, namely lithology, traffic, and industry.     

崇明东滩海三棱藨草生物硅分布及季节变化

利用Na2CO3连续提取法,分析了崇明东滩海三棱藨草(Scirpus mariqueter)体内生物硅(BSi)含量与分布特征.结果表明,BSi在海三棱藨草体内的分布存在明显的季节变化差异,在生物体中连续积累是BSi的一个主要特征.地上部分BSi含量变化范围为0.26% ~ 0.93%,地下部分为0.31% ~ 0.92%,果实中则为0.24% ~0.43%.地上部分含量明显高于其他部分,说明BSi主要沉积在蒸发强烈的叶片中,植株个体生长阶段是决定地上部分BSi含量的主要因素.统计分析显示,根际沉积物BSi和植物各器官BSi相关性均显著,说明海三棱藨草依从主动吸硅机制,从根际沉积物获取所需的Si.地上、地下部分BSi含量与有机氮(ON)、C/N、土壤温度、植株高度也存在明显的相关性.     

Partitioning of water soluble organic carbon in three sediment size fractions： Effect of the humic substances

Water soluble organic carbon (WSOC) in sediments plays an important role in transference and transformation of aquatic pollutants. This article investigated the inherent mechanisms of how sediemnt grain size affect the partitioning coeffcient (k) of WSOC. Influences of NaOH extracted humic substances were particularly focused on. Sediments were sampled from two cross-sections of the middle Yellow River and sieved into three size fractions (< 63 μm, 63-100 μm, and 100--300 μm). The total concentration of WSOC in sediments (CWSOC) and k were estimated using multiple water-sediment ratio experiments. Results show that CWSOC ranges from 0.012 to 0.022 mg/g, while k ranges from 0.8 to 3.9 L/kg. Correlations between the spectrum characteristics of NaOH extracted humic substances and k were analyzed. Strong positive correlations are determined between k and the aromaticity indicators of NaOH extracted humic substances in different sediment size fractions. Comparing with finer fractions (< 63 μm), k is higher in larger size fractions (63--100 and 100--300 μm) related to higher aromaticity degree of NaOH extracted humic substances mostly. While negative relationship between k and the area ratio of fourier transform infrared spectroscopy (FT-IR) at 3400 and 1430 cm-1 implied that the lowest k was related to the highest concentration of the acidic humic groups in particles < 63 μm. WSOC in finer fractions (< 63 μm) is likely to enter into pore water, which may further accelerate the transportation of aquatic contaminants from sediment to water.     

邻苯二甲酸酯在黄河沉积物上的吸附特性

文章利用反相高效液相色谱技术研究了黄河兰州段沉积物对水中邻苯二甲酸二甲酯(DMP)的吸附动力学,以及DMP、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸正二丙酯(DnPrP)和邻苯二甲酸二丁酯(DBP)在沉积物上共存的等温吸附行为,探讨了助溶剂甲醇、离子强度等对吸附的影响。结果表明,在一定的浓度范围内,DMP在沉积物上的吸附速率先快后慢;DMP、DEP在沉积物上的等温吸附行为符合线性方程,而DnPrP、DBP的吸附等温线以Freundlich方程拟合最佳;沉积物对DMP的吸附容量还随着离子强度和溶液中甲醇百分比含量的增大而降低。     

微波活化制备麻疯树果壳活性炭研究

实验采用微波法制备麻疯树果壳活性炭,以磷酸为活化剂,在800W固定微波功率下,辐照时间和活化剂的浓度是主要影响因素。最佳条件为辐照时间8min,磷酸浓度40%。最佳条件下制得的果壳炭碘值达704.4mg/g。测得该果壳炭比表面积为651.6m2/g,总孔容达0.49mL/g,孔结构以1～10nm孔径为主,达到商业活性炭的标准。表面官能团以含O官能团和含C官能团为主,其中C-C类和C-O类官能团含量较高。     

海水养殖区沉积物中溴氰菊酯检测方法研究

根据海水养殖区沉积物特点,研究建立了其中溴氰菊酯提取、浓缩、净化方法,对溴氰菊酯及其杂质进行分离,用配有电子捕获检测器(ECD)的气相色谱仪测定.该方法具有简便、快速、灵敏度高和费用低等特点.通过对不同养殖区中沉积物进行加标试验测定,方法回收率为79.1%～99.3%,精密度3.6～7.1%.     

福建近岸表层海水中阴离子表面活性剂和PCB的污染

用亚甲蓝分光光度法和GC-ECD法分别对福建近岸表层海水中的阴离子表面活性剂和PCBs进行了分析,初步探讨了表层海水中这两类污染物的来源.表层海水中阴离子表面活性剂浓度范围为0.04～1.987 mg/L,较高浓度值站点主要位于九龙江口、闽江口和湄洲湾海域.PCBs的浓度在3.9～367.1 ng/L之间,整体上近岸站点浓度值比离岸站点高,中北部浓度值比南部高.与其他地区的研究结果及海水水质标准进行比较,福建沿海表层海水中阴离子表面活性剂和PCB的污染都较为严重.     

二次富集气相色谱法测定环境中的痕量磷化氢

本文研究了富集柱类型、富集温度和色谱操作条件等因素对二次富集气相色谱法测定环境中痕量PH3的影响,并将其应用于青岛大气和东海陆架沉积物中PH3的测定,取得了较为满意的结果.该方法具有操作简单、灵敏度高、分析速度快、干扰少等优点,其检测限为0.02 pg、精密度2.0%、线性范围为0.56 pg～5.6 ng.用此方法测定了冬季东海大陆架表层沉积物中PH3含量为(0.51～23.10)×10-9,其分布明显受到人类活动的影响,研究结果还表明东海沉积物中的PH3是海洋中磷的潜在来源之一;青岛崂山大气中PH3日变化趋势说明大气中PH3明显受光照的影响.     

应对大型油罐特大火灾的研究——LASTFIRE项目组简介

简要介绍了LASTFIRE项目组的成立背景、组织结构、研究领域、研究目的、研究思路、研究进展等内容,总结了该项目组近几年的研究成果,指出我国的相关企业或研究机构应积极参与这种国际研究组织,实现研究国外资源共享,共同提高大型储罐的安全技术和管理水平。