Phytoremediation: the state of rhizosphere ‘engineering’ for accelerated rhizodegradation of xenobiotic contaminants

Phytoremediation has emerged as the method of choice for cleaning up a broad range of environmental contaminants. One process through which plants render some xenobiotic organic contaminants innocuous in soil involves plant–microbe interactions in which root exudates stimulate entire microbial communities, or induce specific enzymes in competent individuals to cause enhanced rhizodegradation. For some contaminants these inherent processes can be slow; however, potentials exist for their improvement through rhizosphere manipulations. Although this requires a greater understanding than currently exists with respect to plant and microbe components and interactions involved in the biodegradation of xenobiotic contaminants, improved understanding is being achieved by advances in biochemical and molecular characterization, and visualization of rhizosphere phenomena. In combination with earlier knowledge of naturally‐occurring plant–microbe interactions such as the opine concept, this new knowledge considerably improves the opportunities for manipulating rhizosphere interactions to greatly accelerate rhizodegradation for routine practical implementation in the field. Copyright © 2007 Society of Chemical Industry     

Developing an inpatient practicum program for patients with serious and persistent mental illness.

Training psychology students to treat patients with serious and persistent mental illness (SPMI) can provide an excellent opportunity for psychologists to help an historically disenfranchised and ignored population. With proper training, psychologists can play an important role in the development, provision, and administration of services to people with SPMI. We outline some of the issues to be considered in developing such a training program for practicum students, discuss the clinical skills and systemic issues that need to be mastered at the graduate level, and delineate the process by which this can be achieved in an inpatient, acute-care setting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Removal of contaminants from recirculated white water by ultrafiltration and/or biological treatment

This study investigated the potential of ultrafiltration technology and/or biological treatment to remove contaminants such as total dissolved solids (TDS), chemical oxygen demand (COD), total organic carbon (TOC), and resin and fatty acids (RFAs) from recirculated white water. Batch ultrafiltration experiments indicated that TDS, soluble COD, and TOC removal efficiencies were affected by membrane molecular weight (molar mass) cut-off, but were independent of the operating temperature, in the 20 to 60°C range. Except for fatty acids, where average removals exceeded 90%, the separation efficiency of the process for all other parameters (TDS, soluble COD, TOC, and resin acids) was moderate, ranging from 10 to 41%. Biological treatment using a sequencing batch reactor (SBR) unit was very effective in removing RFAs, TOC, total and soluble COD. Furthermore, ultrafiltration of the biologically treated process water resulted in significant additional TDS, soluble COD, and TOC removal.     

氢基质生物膜反应器在饮用水处理中的研究进展

该文对氢基质生物膜反应器(MBf R)的作用机理、特性以及对饮用水中氧化性污染物的去除可行性进行了论述,并对国内外利用该技术去除饮用水中常见氧化性污染物(如:重金属离子:重铬酸盐、砷酸盐、硒酸盐等;无机阴离子:硝酸盐、溴酸盐、高氯酸盐;卤代有机化合物:对氯硝基苯、三氯乙烷、三氯乙烯、氯仿)的研究现状进行了总结。最后指出了MBf R研究中存在的问题以及在工程应用上的现状和发展前景。     

The Impact of PAHs Contamination on the Physicochemical Properties and Microbiological Activity of Industrial Soils

The aim of this article is the study of the potential relationships between PAHs contamination, physicochemical parameters, and microbial activity in industrial soils. The research was based on two series of measurements. The first was conducted in June 2013 and the second in November 2013. Samples used in study were collected from the area of fuel handling and a loading station, located in the Silesia region of Poland. All collected samples were characterized by the following analytical procedures: PAHs content analysis, the basic physical and chemical parameters determinations (pH, CEC, humic acids content, TC, TN, TP) and microbial activity analysis. The obtained results were also subjected to statistical analysis, based on the Pearson's correlation coefficient calculations.

Results collected during described above procedure show that: the PAHs content was highly positively correlated with C and N contents (p < 0.001) and moderately correlated with humic acids and P contents (p < 0.01). This phenomenon confirms the thesis that the increase of soil organic matter content promotes accumulation of hydrophobic organic compounds such as PAHs. Microbiological analysis shows that bacteria from the mesophilic group are most resistant to PAHs contamination. This information indicates that the organisms belonging to this group should be considered as potentially useful in the soil bioremediation processes.     

海水干湿交替作用下持载钢筋引气混凝土柱滞回性能

沿海地区的钢筋混凝土结构会同时受到使用荷载和氯离子侵蚀作用。通过实验室模拟沿海地区混凝土结构的工作状态,试验研究在海水干湿交替作用下承受不同比例持续偏心荷载钢筋引气混凝土柱的表面剥蚀、裂缝发展以及滞回性能,使用显微镜观测裂缝处混凝土并测定氯离子含量;分析海水干湿交替作用与持续荷载比例对柱承载力、刚度、延性的影响。结果表明,经过100次海水干湿交替作用后,钢筋混凝土柱的滞回曲线随着持续荷载比例的增加变得不对称;持载比例越大,正向加载时,柱子的屈服荷载、极限荷载、刚度和延性越小,反向加载时屈服荷载与极限荷载变化不大,刚度与延性均呈现先增大后降低的趋势。     

Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer

The effects of a dilute (ionic strength = 5 × 10⁻³ M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 μg/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only ∼3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.     

解读POPs公约

系统地介绍了持久性有机污染物的特点和对人们造成的危害、POPs公约的产生背景、首批POPs受控物质以及近年来新增的受控物质及正在审查的物质,并指出POPs公约的履行,将对整个涂料行业乃至经济社会产生巨大影响。