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Sadika M. Baladi Catherine M. Lewis Amitava Ganguly Alvin G. Morrow Lisel R. Shoffner Robert F. Blundy Patrick F. Nakagawa Sara T. Mundy Larry Anderson Karen Adams 《补救:环境净化治理成本、技术与工艺杂志》2003,14(1):5-20
Enhanced bioremediation is quickly developing into an economical and viable technology for the remediation of contaminated soils. Until recently, chlorinated organic compounds have proven difficult to bioremediate. Environmentally recalcitrant compounds, such as polychlorinated biphenyls (PCBs) and persistent organic pesticides (POPs) such as dichlorodiphenyl trichloroethane (DDT) have shown to be especially arduous to bioremediate. Recent advances in field‐scale bioremedial applications have indicated that biodegradation of these compounds may be possible. Engineers and scientists at the Savannah River Site (SRS), a major DOE installation near Aiken, South Carolina, are using enhanced bioremediation to remediate soils contaminated with pesticides (DDT and its metabolites, heptachlor epoxide, dieldrin, and endrin) and PCBs. This article reviews the ongoing remediation occurring at the Chemicals, Metals, and Pesticides (CMP) Pits using windrow turners to facilitate microbial degradation of certain pesticides and PCBs. © 2003 Wiley Periodicals, Inc. 相似文献
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Ravikumar KVG Debayan Ghosh Mrudula Pulimi Chandrasekaran Natarajan Amitava Mukherjee 《Frontiers of Environmental Science & Engineering》2020,14(1):16
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Pulses of metabolic activity are a common ecological response to intermittently available resources, and in soils these pulses often occur in response to wetting. To better understand variation in soil pulses, we conducted a distributed field experiment at seven sites along a 2200-m elevation transect in southern California, USA. Treatments included both water and water + substrate additions and two measurements of soil respiration within one hour. These experiments were repeated 11 times throughout 2009-2010. Additions of substrate led to consistently higher pulse fluxes, exceeding 10 micromol CO2 x m(-2( x s(-1), than additions of water alone. These results support a sequential limitation by two resources where an initial limiting resource acts as a switch and, after activation, processes are regulated by a second resource. In contrast to general expectations of increasing pulses with higher soil organic matter (SOM), pulses exhibited strong scale dependencies. Pulses during the summer period and SOM were correlated positively within sites and negatively between sites. This cross-scale divergence implies that, at low elevations, the proportion of SOM available for pulse metabolism was a much larger fraction than at higher elevations. With expected climate changes leading to more frequent drying-wetting cycles, regulation of metabolic pulses will increasingly influence long-term biogeochemical dynamics. 相似文献
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In this work the effect of organic reducing reagents, namely, ascorbic acid, oxalic acid and L-cysteine on dissolution of commercial TiO(2) has been investigated. Kinetic studies showed that a maximum of about 45% of TiO(2) was dissolved by ascorbic acid in 4h when oxide:acid molar ratio was kept at 1:2. The dissolution of TiO(2) increased with increase in ascorbic acid and oxalic acid concentration up to 0.15M in 4h (corresponding to molar ratio of oxide to acid of 1:3) and further addition did not affect the dissolution. Nearly 45% TiO(2) dissolution was obtained with ascorbic acid alone while oxalic acid yielded 40% dissolution. When oxalic acid was added along with ascorbic acid in equi-molar concentrations, dissolution of TiO(2) was enhanced to 60% in 2.5h but when cysteine was added to ascorbic acid the dissolution was about 50% in just 1h. 相似文献
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Distinctive effects of nano-sized permethrin in the environment 总被引:1,自引:0,他引:1
R. S. Suresh Kumar P. J. Shiny C. H. Anjali Jayakumar Jerobin Katrin Margulis Goshen Shlomo Magdassi Amitava Mukherjee N. Chandrasekaran 《Environmental science and pollution research international》2013,20(4):2593-2602
Pesticides are an essential tool in integrated pest management. Nanopermethrin was prepared by solvent evaporation from an oil-in-water volatile microemulsion. The efficacy of the formulated nanopermethrin was tested against Aedes aegypti and the results compared to those of regular, microparticular permethrin. The 24 h LC50 for nanopermethrin and permethrin was found to be 0.0063 and 0.0199 mg/L, respectively. The formulated nanopermethrin was tested for toxicity against non-target organisms. Nanopermethrin did not show antibacterial activity against Escherichia coli (ATCC 13534 and 25922) or against Bacillus subtilis. Phytotoxicity studies of nanopermethrin to the seeds of Lycopersicum esculentum, Cucumis sativus, and Zea mays showed no restraint in root length and germination percentage. In the Allium cepa test, regular microparticular permethrin treatment of 0.13 mg/L showed a mitotic index (MI) of 46.8 % and chromosomal aberration of 0.6 %, which was statistically significant (p?<?0.05) compared to control. No significant differences were observed in 0.13 mg/L nanopermethrin exposure as compared to control (MI of 52.0 and 55.03 % and chromosomal aberration of 0.2 and 0 %, respectively). It was concluded that formulated nanopermethrin can be used as a safe and effectual alternative to commercially available permethrin formulation in agricultural practices. 相似文献
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Deepak Kumar A. Rajeshwari Pradeep Singh Jadon Gouri Chaudhuri Anita Mukherjee Natarajan Chandrasekaran Amitava Mukherjee 《环境科学学报(英文版)》2015,38(12):150-157
The current study evaluates the cytogenetic effects of chromium (III) oxide nanoparticles on the root cells of Allium cepa. The root tip cells of A. cepa were treated with the aqueous dispersions of Cr2O3 nanoparticles (NPs) at five different concentrations (0.01, 0.1, 1, 10, and 100 μg/mL) for 4 hr. The colloidal stability of the nanoparticle suspensions during the exposure period were ascertained by particle size analyses. After 4 hr exposure to Cr2O3 NPs, a significant decrease in mitotic index (MI) from 35.56% (Control) to 35.26% (0.01 μg/mL), 34.64% (0.1 μg/mL), 32.73% (1 μg/mL), 29.6% (10 μg/mL) and 20.92% (100 μg/mL) was noted. The optical, fluorescence and confocal laser scanning microscopic analyses demonstrated specific chromosomal aberrations such as—chromosome stickiness, chromosome breaks, laggard chromosome, clumped chromosome, multipolar phases, nuclear notch, and nuclear bud at different exposure concentrations. The concentration-dependent internalization/bio-uptake of Cr2O3 NPs may have contributed to the enhanced production of anti oxidant enzyme, superoxide dismutase to counteract the oxidative stress, which in turn resulted in observed chromosomal aberrations and cytogenetic effects. These results suggest that A. cepa root tip assay can be successfully applied for evaluating environmental risk of Cr2O3 NPs over a wide range of concentrations. 相似文献
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Assessing the current practice and policy with recommendations for emission control strategy for coal‐fired thermal power plants under Indian regulatory framework emphasizing the roles of R&D 下载免费PDF全文
Amitava Bandyopadhyay 《环境质量管理》2017,27(1):49-55
On December 7, 2015, the Ministry of Environment, Forest and Climate Change (MoEFCC), Government of India (GoI), promulgated stack emission standards for sulfur dioxide (SO2), oxides of nitrogen (NOx), and mercury (Hg) from coal‐fired thermal power plants (TPPs). These standards were promulgated in addition to tightening the emission standard for particulate matter. Thus far, the GoI and a non‐governmental organization (NGO) have recommended the use of limestone‐based flue‐gas desulfurization (FGD) technology for removing only SO2 emissions, which would then require the application of additional technologies to remove the other regulated pollutants. A single technology, such as the Multi‐pollutants Control Technology (MPCT), which was recently developed elsewhere in the world and can remove all of the pollutants from the TPP, could be more economical than introducing separate technologies for the removal of each pollutant. Furthermore, unlike the limestone‐based FGD technology, which generates carbon dioxide (CO2) during the desulfurization process, the MPCT does not increase power plant CO2 emissions. Water consumption is also lower in MPCT than with the limestone‐based FGD technology. Thus, MPCT offers a lower carbon footprint as well as a lower water footprint than the limestone‐based FGD technology in accordance with the United Nations Environmental Programme's Sustainable Development Goals. In light of these observations, this article aims to assess current practices and policies and offers policy recommendations for Indian TPPs with the goal of providing a cogent technological solution that also strengthens the Decision Support System for the holistic protection of the Indian environment. 相似文献
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Development of Zinc Oxide Sensors for Detecting Ammonia Gas in the Ambient Air: A Critical Short Review 下载免费PDF全文
Ammonia (NH3) is emitted into the atmosphere by various industries and other sources and causes environmental pollution. Considering the hazards of ammonia, detecting leakage from vessels and pipes demands the use of sensors. Therefore, the development of NH3 gas sensors assumes considerable importance to researchers and regulators and to industry, businesses, and facilities that make, store, or use ammonia. The use of metal oxide sensors (MOS) for detecting NH3 gas, such as zinc oxide (ZnO), has been a topic of interest to researchers seeking methods to detect NH3 gas, even at low concentrations. In this article, an attempt has been made to review the research thus far published on the synthesis of ZnO‐based NH3 gas sensor materials, their characterization, and analyses of their performance. Finally, we make several recommendations regarding the scope of future research. For example, the kinetics of the sensor materials should be determined. Furthermore, extensive studies of gas–solid (NH3–ZnO) adsorption are proposed to ascertain the exact adsorption mechanism in terms of isotherm, kinetics, and diffusive mass transport, and to determine “reversibility” and “recovery” of sensor materials so they can continue sensing and activating alarms when necessary for practical applications. 相似文献