Research on the anti-interference capability of the tourism environment system for the core stakeholders of semi-arid valley-type cities: analysis based on the multi-scenario and time series diversity perspectives

Environmental Science and Pollution Research - Given the relatively harsh natural environment in semi-arid valley areas, the attraction and radiation functions of semi-arid valley cities have...     

The role of lime in dredged mud dewatered by a plate and frame filter press and potential substitutes

Environmental Science and Pollution Research - Dredged mud is a kind of construction material that can be reused as waste. It needs to be dehydrated before it is used. At present, plate and frame...     

Biodegradation of triazine herbicide metribuzin by the strain Bacillus sp. N1

By enrichment culturing of soil contaminated with metribuzin, a highly efficient metribuzin degrading bacterium, Bacillus sp. N1, was isolated. This strain grows using metribuzin at 5.0% (v/v) as the sole nitrogen source in a liquid medium. Optimal metribuzin degradation occurred at a temperature of 30ºC and at pH 7.0. With an initial concentration of 20 mg L^?1, the degradation rate was 73.5% in 120 h. If the initial concentrations were higher than 50 mg L^?1, the biodegradation rates decreased as the metribuzin concentrations increased. When the concentration was 100 mg L^?1, the degradation rate was only 45%. Degradation followed the pesticide degradation kinetic equation at initial concentrations between 5 mg L^?1 and 50 mg L^?1. When the metribuzin contaminated soil was mixed with strain N1 (with the concentration of metribuzin being 20 mg L^?1 and the inoculation rate of 10¹¹ g^?1 dry soil), the degradation rate of the metribuzin was 66.4% in 30 days, while the degradation rate of metribuzin was only 19.4% in the control soil without the strain N1. These results indicate that the strain N1 can significantly increase the degradation rate of metribuzin in contaminated soil.     

武汉市某地域交通噪声控制研究

随着社会经济的迅速发展，交通噪声污染对环境和人们健康的影响受到更多的关注。武珞路一珞瑜路和雄楚大街是武汉市“文化城”的交通主干道，该区域环境噪声在执行4类标准时应尽量遵楚大街交通噪声远大于武珞路循1类标准。对比监测了武珞路-珞瑜路和雄楚大街沿线的交通噪声污染状况，对雄-珞瑜路的状况进行了分析。对比研究表明，采用综合降噪措施能有效控制城市交通噪声污染。     

Citric and Oxalic Acids Effect on Pb and Zn Uptake by Maize and Winter Wheat

Abstract

A pot experiment was conducted to investigate the influence of citric and oxalic acids effect on Pb and Zn uptake by corn and winter wheat. The experiment was employed with citric acid (CA) applied at 3 rates (0, 1.5 and 3.0 mmol kg^?1 soil), oxalic acid (OA) at 3 rates (0, 1.5 and 3.0mmol kg^?1 soil) and citric acid combined with oxalic acid (1.5 mmol citric acid combined with 1.5 mmol oxalic acid kg^?1). Two types of soil were chose in the experiment. One was collected from the agricultural soil near a battery-recycling factory in Anhui province, China (site A) and the other was collected from a Pb-Zn mine residues in Hunan province, China (site B). The results showed that soil pH varied with the different treatment of citric and oxalic acids. However, there were no differences in all the treatments. 3.0mmol CA kg^?1 soil addition significantly increased the concentrations of the CaCl₂-extractable Pb and Zn and other treatments have no significantly increased. The highest shoot concentrations of Pb and Zn in both species occurred in application of 3.0 mmol CA/kg^?1 soil and shoot concentrations of Pb and Zn in both species were significantly higher than the controls in this treatment. Shoot yields declined with application of citric and oxalic acids, indicating that the plants were sensitive to the toxicity of the metals or the amendments. The highest Pb uptake values by maize and wheat werell2.3 and 77.2 μg pot1 in soil of site A, and occurred with the control and 3.0 mmol CA/kg^?1 soil respectively.     

粉煤灰制备含硫絮凝剂的研究进展

介绍了粉煤灰的来源、数量、危害、主要成分及性质,简介了粉煤灰的综合利用情况;综述了以粉煤灰为主要原料制备含硫絮凝剂的工艺、方法等研究现状和在水处理中的应用效果;分析了该类絮凝剂处理污水的机理;对进一步有效开发利用粉煤灰提出了建议。     

Enhanced 4-chlorophenol biodegradation by integrating Fe2O3 nanoparticles into an anaerobic reactor: Long-term performance and underlying mechanism

• 4-chlorophenol biodegradation could be enhanced in Fe₂O₃ coupled anaerobic system. • Metabolic activity and electron transport could be improved by Fe₂O₃ nanoparticles. • Functional microbial communities could be enriched in coupled anaerobic system. • Possible synergistic mechanism involved in enhanced dechlorination was proposed. Fe₂O₃ nanoparticles have been reported to enhance the dechlorination performance of anaerobic systems, but the underlying mechanism has not been clarified. This study evaluated the technical feasibility, system stability, microbial biodiversity and the underlying mechanism involved in a Fe₂O₃ nanoparticle-coupled anaerobic system treating 4-chlorophenol (4-CP) wastewater. The results demonstrated that the 4-CP and total organic carbon (TOC) removal efficiencies in the Fe₂O₃-coupled up-flow anaerobic sludge blanket (UASB) were always higher than 97% and 90% during long-term operation, verifying the long-term stability of the Fe₂O₃-coupled UASB. The 4-CP and TOC removal efficiencies in the coupled UASB increased by 42.9±0.4% and 27.5±0.7% compared to the control UASB system. Adding Fe₂O₃ nanoparticles promoted the enrichment of species involved in dechlorination, fermentation, electron transfer and acetoclastic methanogenesis, and significantly enhanced the extracellular electron transfer ability, electron transport activity and conductivity of anaerobic sludge, leading to enhanced 4-CP biodegradation performance. A possible synergistic mechanism involved in enhanced anaerobic 4-CP biodegradation by Fe₂O₃ nanoparticles was proposed.     

Level and origin of iodine-129 in the Baltic Sea

Environmental samples, such as seawater, seaweed, lake water, lake sediment and grass collected from the Baltic Sea area were analyzed for 129I and 127I by radiochemical neutron activation analysis. In 2000, the concentration of 129I in the seawater from Borholm and M?en in the Baltic Sea has reached 6.0 x 10(-13) and 16 x 10(-13) g/l, respectively, these are more than two orders of magnitude higher than the global fallout level. The highest value of 270 x 10(-13) g/l being found in the seawater from the Kattegat. By comparison of the level of 129I in the lake water and precipitation in this region, it is estimated that more than 95% of 129I in the Baltic Sea originates from reprocessing emissions, especially from the French nuclear fuel reprocessing plant at La Hague. More than 30% of 129I in the south Baltic and 93% in the Kattegat directly originates from the marine discharges of the European reprocessing plants.     

Strength, leachability and microstructure characterisation of Na2SiO3-activated ground granulated blast-furnace slag solidified MSWI fly ash.

The chemical composition and the leachability of heavy metals in municipal solid waste incinerator (MSWI) fly ash were measured and analysed. For the leachability of unstabilized MSWI fly ash it was found that the concentrations of Pb and Cr exceeded the leaching toxicity standard. Cementitious solidification of the MSWI fly ash by Na2SiO3-activated ground granulated blast-furnace slag (NS) was investigated. Results show that all solidified MSWI fly ash can meet the landfill standards after 28 days of curing. The heavy metals were immobilized within the hydration products such as C-S-H gel and ettringite through physical encapsulation, substitution, precipitation or adsorption mechanisms.