Yield and arsenate uptake of arbuscular mycorrhizal tomato colonized by Glomus mosseae BEG167 in As spiked soil under glasshouse conditions

A glasshouse pot experiment was conducted to study the effect of arbuscular mycorrhizal (AM) colonization by Glomus mosseae BEG167 on the yield and arsenate uptake of tomato plants in soil experimentally contaminated with five As levels (0, 25, 50, 75 and 150 mg kg(-1)). Mycorrhizal colonization (50-70% of root length) was little affected by As application and declined only in soil amended with 150 mg As kg(-1). Mycorrhizal colonization increased plant biomass at As application rates of 25, 50 and 75 mg kg(-1). Shoot As concentration increased with increasing As addition up to 50 mg kg(-1) but decreased with mycorrhizal colonization at As addition rates of 75 and 150 mg kg(-1). Shoot As uptake increased with mycorrhizal colonization at most As addition levels studied, but tended to decrease with addition of 150 mg As kg(-1). Total P uptake by mycorrhizal plants was elevated at As rates of 25, 50 and 75 mg kg(-1), and more P was allocated to the roots of mycorrhizal plants. Mycorrhizal plants had higher shoot and root P/As ratios at higher As application rates than did non-mycorrhizal controls. The soil of inoculated treatments had higher available As than uninoculated controls, and higher pH values at As addition levels of 25, 50 and 75 mg kg(-1). Mycorrhizal colonization may have increased plant resistance to potential As toxicity at the highest level of As contamination studied. Mycorrhizal tomato plants may have potential for phytoextraction of As from moderately contaminated soils or phytostabilization of more highly polluted sites.     

Residues and source identification of persistent organic pollutants in farmland soils irrigated by effluents from biological treatment plants

Sewage and industrial effluents from biological treatment plant have been widely used for agricultural irrigation in north part of China. However, effluents after biological treatment still contain heavy metals and persistent organic contaminants. The persistent organic contaminants accumulated in soil may transfer through the food chains and cause adverse health effects on human or biological effects on soil fauna and flora after long-term application. In present study, field surveys were carried out in the farmlands irrigated by effluents from biological treatment plants that receive sewage wastewater and industrial discharges. Residues of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in the soils irrigated using both ground water and effluents were compared. The origins of PAHs in the soils were discussed. The results showed that wastewater irrigation could cause accumulation of PAHs in soils close to the pollution discharge. Significantly higher concentrations of PAHs were observed in the sampling sites close to the entrance of main channel in contrast to those along branches and the reference sites. There was no significant relationship between the accumulation of persistent organic pollutants and organic matter content in soil (TOC). Soil contamination of these persistent organic pollutants as affected by effluent irrigation was characterized by the dominant accumulation of high-molecular-weight PAHs (HMW-PAHs). In the case study, concentration of benzo[a]pyrane (BaP, 45.6 ng/g), indeno[1,2,3-cd]pyrene (IcP, 86.3 ng/g), benzo[g,h,i]perlene (BgP, 66.9 ng/g) could exceed the limits of the soil quality standard for biodegraded soils. In identification of the sources, the IcP/BgP values of PAHs in soils were more close to that in air particulates from coal/coke source (1.09+/-0.03 ng/g) [Dickhut RM, Canuel EA, Gustafson KE, Liu K, Arzayus KM, Walkers E, et al. Automotive sources of carcinogenic polycyclic aromatic hydrocarbons associated with particulate matter in the chesapeake bay region. Environ Sci Technol 2000;34:4635-40]. Therefore, both of the PAHs residues in effluents and emission from a nearby coal/coke plant were responsible. Also in this case study, low levels of the OCPs were observed and were not of significant concern in this wastewater irrigation area. Among the different OCPs analyzed, DDTs (mean 8.41 ng/g) and HCHs (mean 2.91 ng/g) were the major components. From the ratios of DDT/DDTs and beta-HCH/HCHs, it indicated that OCPs residues should be from historical usage.     

Analysis of the Energy Embodied in Foreign Goods Trade of China

In recent years, scientists have been increasingly interested in the energy embodied in traded goods among countries. In this article, the direct energy intensities in various economic sectors of China were calculated with the data of energy consumption and output value of each sector, and the input-output table was used to estimate the external energy consumption. The total energy intensity of all sectors was then obtained. From the data of international trade, the energy embodied in goods trade of China was estimated for the period of 1994-2001. During this period, the average energy intensity of imported goods was always higher than that of exported ones. As a country with a surplus in international goods trade, China actually imported net embodied energy in the past few years. The net embodied energy imported was at the same magnitude of the imported energy in the form of fossil fuels.     

Acid-assisted hydrothermal synthesis of nanocrystalline TiO2 from titanate nanotubes: Influence of acids on the photodegradation of gaseous toluene

In order to efficiently remove volatile organic compounds (VOCs) from indoor air, onedimensional titanate nanotubes (TiNTs) were hydrothermally treated to prepare TiO₂ nanocrystals with different crystalline phases, shapes and sizes. The influences of various acids such as CH₃COOH, HNO₃, HCl, HF and H₂SO₄ used in the treatment were separately compared to optimize the performance of the TiO₂ nanocrystals. Comparedwith the strong and corrosive inorganic acids, CH₃COOH was not only safer andmore environmentally friendly, but also more efficient in promoting the photocatalytic activity of the obtained TiO₂. Itwasobserved that the anatase TiO₂ synthesized in 15 mol/L CH₃COOH solution exhibited the highest photodegradation rate of gaseous toluene (94%), exceeding that of P25 (44%) by a factor ofmore than two. The improved photocatalytic activity was attributed to the small crystallite size and surface modification by CH₃COOH. The influence of relative humidity (20%-80%) on the performance of TiO₂ nanocrystals was also studied. The anatase TiO₂ synthesized in 15 mol/L CH₃COOH solution was more tolerant tomoisture than the other TiO₂ nanocrystals and P25.     

Diversity and biogenesis contribution of sulfate-reducing bacteria in arsenic-contaminated soils from realgar deposits

Environmental Science and Pollution Research - Microbial sulfate reduction, a vital mechanism for microorganisms living in anaerobic, sulfate-rich environments, is an essential aspect of the sulfur...     

Preparation of in-situ nitrogen-doped lignin-based porous carbon and its efficient adsorption of chloramphenicol in water

Porous carbon is an excellent absorbent for pollutants in water. Here, we report a breakthrough in performance of porous carbon based on lignin prepared using sodium lignosulfonate (SLS), potassium carbonate and melamine as precursor, activator and nitrogen source, respectively. A series of characterization tests confirmed that in-situ nitrogen doping greatly enhanced porous structure, resulting in a specific surface area of 2567.9 m² g^?1 and total pore volume of 1.499 cm³ g^?1, which is nearly twice that of non-nitrogen-doped porous carbon. Moreover, adsorption experiments revealed that at 303 K, the saturated adsorption capacity of chloramphenicol was as high as 713.7 mg g^?1, corresponding to an improvement of 33.7%. Further, the prepared porous carbon exhibited a strong anti-interference against metal ions and humic acid. The adsorption process was confirmed to be an endothermic reaction dominated by physical adsorption, indicating that an increase in temperature is conducive to adsorption. The results of this study show that nitrogen-doped lignin-based porous carbon prepared by in-situ doping is a promising material to significantly alleviate water pollution owing to its low cost, excellent pore structure and good adsorption properties.

     

Constructing 3D magnetic flower-like Fe3O4@SiO2@Co3O4@BiOCl heterojunction photocatalyst for degrading rhodamine B

Environmental Science and Pollution Research - In this work, the 3D magnetic flower-like Fe3O4@SiO2@Co3O4@BiOCl heterojunction photocatalyst was successfully prepared. The combination of BiOCl with...     

Increasing collaboration between China and India in the environmental sciences to foster global sustainability

As the two largest countries by population, China and India have pervasive effects on the ecosphere. Because of their human population size and long international boundary, they share biodiversity and the threats to it, as well as crops, pests and diseases. We ranked the two countries on a variety of environmental challenges and solutions, illustrating quantitatively their environmental footprint and the parallels between them regarding the threats to their human populations and biodiversity. Yet we show that China and India continue to have few co-authorships in environmental publications, even as their major funding for scientific research has expanded. An agenda for collaboration between China and India can start with the shared Himalaya, linking the countries’ scientists and institutions. A broader agenda can then be framed around environmental challenges that have regional patterns. Coordinated and collaborative research has the potential to improve the two countries’ environmental performance, with implications for global sustainability.     

电极配置和操作条件对静电油烟净化效率的影响

以有机气溶胶发生器产生的0.02～2.02μm癸二酸二辛酯颗粒模拟餐饮业排出的油烟PM2 5组分,利用静电低压撞击器颗粒物检测仪测定各粒径范围的颗粒个数和质量浓度,并系统研究了电极配置、电场风速和供电电压等因素对静电油烟净化效率的影响.结果表明:油烟荷电量以及荷电颗粒迁移距离是影响净化效率的关键因素,优化电极配置的增效...