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671.
Mohammad Abbas Mahmood Sunandan Baruah Anil Kumar Anal Joydeep Dutta 《Environmental Chemistry Letters》2012,10(2):145-151
Increasing water pollution by microbes has become a source of serious health concern across the globe. Production of potentially
carcinogenic disinfection by-products has marred credibility of traditional water purification techniques like chlorination.
Photocatalysis has emerged as a promising alternative technique for the disinfection of water with minimal risk of harmful
by-products. The process involves a wide band gap semiconductor material which, upon irradiation of light, produces electrons
and holes with high redox potential to degrade organic contaminants and microbes. In this review, we analyze the research
trends in photocatalytic inactivation of water borne microorganisms. This report analyzes the major factors that affect the
disinfection efficiency using this process. The discussion also includes plausible mechanisms of microbial degradation as
well as a kinetic model of the inactivation process. Different approaches, like doping of semiconductors or energy band engineering
or plasmon coupling, have been reported for the enhancement and utilization of ambient solar light. Photocatalysis could be
a cost-effective and environmentally friendly water purification technique though further research is required to enhance
its efficiency with the use of solar light. 相似文献
672.
Yusuf M Fariduddin Q Varshney P Ahmad A 《Environmental science and pollution research international》2012,19(1):8-18
Introduction
This study was hypothesized that salicylic acid elevates the level of antioxidant system that will protect plants from the stress generated by nickel and/or salinity. 相似文献673.
Mohammad T. Dastorani Alireza Moghadamnia Jamshid Piri Miguel Rico-Ramirez 《Environmental monitoring and assessment》2010,166(1-4):421-434
Hydrological yearbooks, especially in developing countries, are full of gaps in flow data series. Filling missing records is needed to make feasibility studies, potential assessment, and real-time decision making. In this research project, it was tried to predict the missing data of gauging stations using data from neighboring sites and a relevant architecture of artificial neural networks (ANN) as well as adaptive neuro-fuzzy inference system (ANFIS). To be able to evaluate the results produced by these new techniques, two traditionally used methods including the normal ratio method and the correlation method were also employed. According to the results, although in some cases all four methods presented acceptable predictions, the ANFIS technique presented a superior ability to predict missing flow data especially in arid land stations with variable and heterogeneous data. Comparing the results, ANN was also found as an efficient method to predict the missing data in comparison to the traditional approaches. 相似文献
674.
Use of Geosynthetic Clay Liners (GCLs) in landfill barrier design has been the focus of recent studies investigating their ability to prevent contaminant transport to groundwater. In this paper, the hydration of two GCL products placed in contact with clay subsoils at different initial moisture contents is described under both isothermal conditions at room temperature, and daily thermal cycles. The rate of hydration of the GCL and its final equilibrium moisture content were significantly influenced by the amount of moisture made available to it through the subsoil. The two types of GCLs were also found to exhibit different hydration behaviors under similar experimental conditions. The study revealed that GCLs undergoing daily thermal cycles absorbed much less moisture over time than the GCLs kept at constant room temperature (ratio 1:4). In comparison with other types of subsoils, the final equilibrium moisture content attained by the GCL from clay subsoil was significantly less than that for sand subsoil. 相似文献
675.
Ali Behnamfard Mohammad Mehdi Salarirad Francesco Veglio 《Waste management (New York, N.Y.)》2013,33(11):2354-2363
A novel hydrometallurgical process was proposed for selective recovery of Cu, Ag, Au and Pd from waste printed circuit boards (PCBs). More than 99% of copper content was dissolved by using two consecutive sulfuric acid leaching steps in the presence of H2O2 as oxidizing agents. The solid residue of 2nd leaching step was treated by acidic thiourea in the presence of ferric iron as oxidizing agent and 85.76% Au and 71.36% Ag dissolution was achieved. The precipitation of Au and Ag from acidic thiourea leachate was investigated by using different amounts of sodium borohydride (SBH) as a reducing agent. The leaching of Pd and remained gold from the solid reside of 3rd leaching step was performed in NaClO-HCl-H2O2 leaching system and the effect of different parameters was investigated. The leaching of Pd and specially Au increased by increasing the NaClO concentration up to 10 V% and any further increasing the NaClO concentration has a negligible effect. The leaching of Pd and Au increased by increasing the HCl concentration from 2.5 to 5 M. The leaching of Pd and Au were endothermic and raising the temperature had a positive effect on leaching efficiency. The kinetics of Pd leaching was quite fast and after 30 min complete leaching of Pd was achieved, while the leaching of Au need a longer contact time. The best conditions for leaching of Pd and Au in NaClO-HCl-H2O2 leaching system were determined to be 5 M HCl, 1 V% H2O2, 10 V% NaClO at 336 K for 3 h with a solid/liquid ratio of 1/10. 100% of Pd and Au of what was in the chloride leachate were precipitated by using 2 g/L SBH. Finally, a process flow sheet for the recovery of Cu, Ag, Au and Pd from PCB was proposed. 相似文献
676.
Soudeh Farzadfar Fatemeh Zarinkamar Seyed Ali Mohammad Modarres-Sanavy Mostafa Hojati 《Environmental science and pollution research international》2013,20(3):1413-1422
Cadmium (Cd) toxicity in plants leads to serious disturbances of physiological processes, such as inhibition of chlorophyll synthesis, oxidative injury to the plant cells and water and nutrient uptake. Response of Matricaria chamomilla L. to calcium chloride (CaCl2) enrichment in growth medium for reducing Cd toxicity were studied in this study. Hydroponically cultured seedlings were treated with 0, 0.1, 1, and 5 mM CaCl2, under 0, 120, and 180 μM CdCl2 conditions, respectively. The study included measurements pertaining to physiological attributes such as growth parameters, Cd concentration and translocation, oxidative stress, and accumulation of phenolics. Addition of CaCl2 to growth media decreased the Cd concentration, activity of antioxidant enzymes, and reactive oxygen species accumulation in the plants treated with different CdCl2, but increased the growth parameters. Malondialdehyde and total phenolics in shoots and roots were not much affected when plants were treated only with different CaCl2 levels, but it showed a rapid increase when the plants were exposed to 120 and 180 CdCl2 levels. CaCl2 amendment also ameliorated the CdCl2-induced stress by reducing oxidative injury. The beneficial effects of CaCl2 in ameliorating CdCl2 toxicity can be attributed to the Ca-induced reduction of Cd concentration, by reducing the cell-surface negativity and competing for Cd2+ ion influx, activity enhancement of antioxidant enzymes, and biomass accumulation. 相似文献
677.
678.
Mohammad A. Sattar 《Chemosphere》1981,10(9):1011-1017
Two typical neutral soils were treated with 10, 200 and 2000 ppm 4-chloro-o-cresol and 5-chloro-3-methylcatechol under field capacity condition, and incubated for 12 weeks at room temperature. The samples were collected after 0, 2, 4, 8 and 12 weeks to study the fate of the compounds by gas chromatography. The two compounds were rapidly degraded and degradation was almost complete (90–96 %) after 4 weeks with a level of 10 ppm. The rate of persistence was similar in the two soils after different periods of incubation. 相似文献
679.
M. Melissa Rojas-Downing A. Pouyan Nejadhashemi Mohammad Abouali Fariborz Daneshvar Sabah Anwer Dawood Al Masraf Matthew R. Herman Timothy Harrigan Zhen Zhang 《Mitigation and Adaptation Strategies for Global Change》2018,23(3):405-431
Among livestock systems, grazing is likely to be most impacted by climate change because of its dependency to feed quality and availability. In order to reduce the impact of climate change on grazing livestock systems, adaptation measures should be implemented. The goal of this study is to identify the best pasture composition for a representative grazing dairy farm in Michigan in order to reduce the impacts of climate change on production. In order to achieve the goal of this study, three objectives were sought: (1) identify the best pasture composition, (2) assess economic and resource use impacts of pasture compositions under future climate scenarios, and (3) evaluate the resiliency of pasture compositions. A representative farm was developed based on a livestock practices survey and incorporated into the Integrated Farm System Model (IFSM). For the pasture compositions, four cool-season grass species and two legumes were evaluated under both current and future climate scenarios. The effectiveness of adaptation measures based on economic and resource use criteria was evaluated. Overall, the pasture composition with 50% perennial ryegrass (Lolium multiflorum) and 50% red clover (Trifolium pratense) was identified as the best. In addition, the increase in precipitation and temperature of the most intensive climate scenario could significantly improve farm net return per cow (Bos taurus) and whole farm profit while no significant impact was observed on resource use criteria. Finally, the overall sensitivity assessment showed that the most resilient pasture composition under future climate scenarios was ryegrass with red clover and the least resilient was orchardgrass (Dactylis glomerata) with white clover (Trifolium repens). 相似文献
680.
Mohammad A. Sattar 《Chemosphere》1981,10(4):423-430
The fresh and long preservation of the stock solution of the pentafluorobenzyl bromide were applied to determine the recovery yield of MCPA, 4-chloro-o-cresol and 5-chloro-3-methylcatechol from and preserved samples. Both fresh and preserved solution of the pentafluorobenzyl bromide confirmed almost the similar effect on the derivative yield of the compounds treated with fresh/preserved samples. The overall results differed significantly within different treatments. The yield decreased only 2 % with 5-chloro-3-methylcatechol. 相似文献