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ALKALINITY GENERATION ASSOCIATED WITH THE FORMATION OF ESTER SULFATES - COMMENT

LIMNOLOGY AND OCEANOGRAPHY 1989年第6期34卷 1144-1146页

作者： URBAN, NR BAKER, LA Environmental Engineering Program Department of Civil & Mineral Engineering University of Minnesota Minneapolis 55455

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METHANOGENIC TRANSFORMATION OF AROMATIC-HYDROCARBONS AND PHENOLS IN GROUNDWATER AQUIFERS

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GEOMICROBIOLOGY JOURNAL 1990年第3-4期8卷 167-200页

作者： GRBICGALIC, D Environmental Engineering and Science Program Department of Civil Engineering Stanford University Stanford CA 94305-4020 United States

Fermentative and methanogenic bacteria have been found repeatedly as important members of microbial flora in anoxic zones of the subsurface-in pristine as well as in contaminated groundwater aquifers. These bacteria, which together with obligate proton reducers form complex methanogenic communities, are significant as decomposers of organic matter under conditions of exogenous electron acceptor depletion. Their metabolic activity has been demonstrated in laboratory microcosms derived from aquifer material, and also in the subsurface in situ. Methanogenic communities have been shown to transform numerous organic pollutants, or even to completely degrade these compounds with the production of carbon dioxide and methane. Depending on the chemical structure of the pollutant, such a compound can be used as an electron donor and a carbon/energy source for fermentative microorganisms (which is typically the case with highly reduced compounds);alternatively, a highly oxidized pollutant can be used as a potential electron acceptor or electron sink. This review addresses fermentative/methanogenic degradation of chlorinated and nonchlorinated aromatic hydrocarbons and phenols by subsurface microorganisms;for comparison, it briefly relates also other types of anaerobic transformations (under sulfate-reducing, iron-reducing, and denitrifying conditions). Furthermore, it outlines transformation pathways, those that are proposed as well as those that are already partially proved, for aromatic hydrocarbons and phenols under fermentative/methanogenic conditions;finally, it discusses the relevance of these processes to bioremediation of contaminated groundwater aquifers.

关键词： ANAEROBIC HABITATS AROMATIC HYDROCARBONS BIOREMEDIATION CHLOROBENZENES CHLOROPHENOLS GROUNDWATER AQUIFERS INTERSPECIES TRANSFER OF HYDROGEN AND INTERMEDIATES METHANOGENIC COMMUNITIES PHENOLS

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The sorption of nonionic pesticides onto clays and the influence of natural organic carbon

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CHEMOSPHERE 1997年第7期35卷 1549-1565页

作者： Torrents, A Jayasundera, S Environmental Engineering Program Department of Civil Engineering University of Maryland College Park MD 20742 U.S.A.

The sorption and desorption of alachlor, metolachlor and linuron onto kaolinite and Na-montmorillonite and the influence of natural organic matter sorbed to these clays was examined. The intensity of adsorption was a function of the herbicide and clay. Sorption isotherms conformed to the Freundlich equation with K-f(ads) values ranging from 1.63 x 10(-3) for metolachlor to 2.84 x 10(-2) for linuron onto Na-montmorillonite. The n values ranged from 0.78 for linuron to 1.92 for metolachlor. The three herbicides adsorbed to kaolinite to a much lesser extent. When Na-montmorillonite was coated with organic matter, alachlor sorption decreased proportionally to the f(oc) sorbed to the clay. However, for metolachlor and linuron, sorption effects were more sensitive to the type of organic coating. Desorption isotherms deviated from sorption isotherms and both K-f and n varied. (C) 1997 Elsevier Science Ltd.

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Carbon dioxide, global boiling, and climate carnage, from generation to assimilation, photocatalytic conversion to renewable fuels, and mechanism

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Science of the Total Environment 2025年 965卷 178629页

作者： Khan, Muhammad Sun, Xiaohui Zada, Amir Azizi, Shohreh Shah, Muhammad Ishaq Ali Khan, Javed Ali Ragab, Ahmed H. Taher, Mostafa A. Abbas, Qumber Han, Changseok College of Civil and Transportation Engineering Shenzhen University 3688 Nanhai Avenue Guangdong Province Shenzhen518060 China Department of Chemistry Abdul Wali Khan University Mardan Mardan23200 Pakistan UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology College of Graduate Studies University of South Africa Muckleneuk Ridge PO Box 392 Pretoria0002 South Africa Chemistry Department Faculty of Science King Khalid University P.O. Box 9004 Abha61413 Saudi Arabia Biology Department Faculty of Science and Arts King Khalid University Mohail Assir 61321 Saudi Arabia Department of Technologies and Installations for Waste Management Faculty of Energy and Environmental Engineering Silesian University of Technology Gliwice44-100 Poland Program in Environmental and Polymer Engineering of INHA University 100 Inha-ro Michuhol-gu Incheon22212 Korea Republic of Department of Environmental Engineering INHA University 100 Inha-ro Michuhol-gu Incheon22212 Korea Republic of

The increasing CO2 concentration in the atmosphere has substantial impacts on the global temperature. For energy sustainability and minimization of the effects of global warming, an approach to understand CO2 capturing and a carbon neutral culture is extremely essential in the present circumstances. The CO2 emission from vehicles and industries can be minimized using energy cost-effective techniques and can be converted more selectively into reusable fuels via thermochemical, electrochemical, photochemical, photocatalytic, electrocatalytic, biological and inorganic carbonate-based approaches. In this review article, we have discussed the effects of increased global temperature on human beings, economy and climate change. Further, we have discussed the photocatalytic conversion of CO2 (PC-CO2) into gaseous and liquid fuels under solar light driven photocatalysis. The adsorption and activation of CO2, its conversion into various intermediates, their stability and selectivity of the final products have been elaborated comprehensively. The conversion mechanisms of CO2 into CO, CH4, alcohol, aldehyde and carboxylic acid have been discussed in detail. The role of defects and exposed facets of photocatalysts, effect of metal and non-metal dopants, and the additive role of co-catalyst on the mechanisms and selectivity of the conversion products have been discussed comprehensively. Finally, future perspective is discussed to highlight the research gap in the PC-CO2. We hope that this article will help to understand the mechanisms of PC-CO2 and will direct researchers to add their role in the reduction of CO2 to control global warming and make life easier on earth in the coming years. © 2025 Elsevier B.V.

关键词： Kyoto Protocol

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INTERNAL PHOSPHORUS LOADING IN A SHALLOW EUTROPHIC LAKE

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WATER RESEARCH 1982年第6期16卷 911-919页

作者： JACOBY, JM LYNCH, DD WELCH, EB PERKINS, MA Environmental Engineering and Science Program Department of Civil Engineering University of Washington Seattle WA 98195 U.S.A.

Internal loading of P was implicated as a major eutrophicating factor in Long Lake, Washington (Kitsap County) [USA]. As a result of such loading, summer total P concentrations approach or exceed 100 .mu.g P l-1. Most of the summer loading of P is thought to have been released directly from the rich, flocculent sediment in the mid and northern part of the lake as a result of high pH (up to 10) related to phytoplankton photosynthesis. The lake also supports a dense submersed macrophyte crop (areal weighted mean dry weight of .apprx. 220 g m-2) composed primarily of Elodea densa. Although excretion of P from healthy E. densa was minimal, the potential contribution of P indirectly from sediment via macrophyte uptake and subsequent decomposition in the winter was on the order of 200-400 kg yr-1 or .apprx. 25-50% of the external loading. Nevertheless, loading of P during predrawdown summers is thought to have originated largely as a direct release from sediment due to high pH. Estimates of sediment P release determined from laboratory experiments, mass balance and core analyses ranged from 2.2-5.6 mg m-2 day-1. As a component of the restoration program, the lake (mean depth of 2 m) was drawn down nearly 2 m for 4 mo. during the summer and fall of 1979. The lake''s trophic status was expected to improve due to sediment consolidation and/or macrophyte reduction. The drawdown resulted in an 84% reduction in macrophyte biomass in 1980 but minimal sediment consolidation (0.1 m). Winter decomposition of the much smaller macrophyte crop, apparently provided insufficient P in the spring to stimulate phytoplankton and to enrich midlake sediments, which has probably occurred in previous years. Low water column pH during the postdrawndown summer of 1980 resulted from relatively low rates of plankton photosynthesis. During the summer of 1980 internal loading of P was reduced and total P remained below 50 .mu.g l-1.

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ON THE EFFICIENCY OF NUCLEATION SCAVENGING

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TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY 1984年第5期36卷 367-375页

作者： JENSEN, JB CHARLSON, RJ Environmental Engineering and Science Program Department of Civil Engineering (FC-05) University of Washington Seattle WA 98195 USA

The activation process near cloud base for submicrometer, soluble atmospheric aerosols is described and special attention is focused on the fraction, ε, of the total aerosol mass concentration that form cloud droplets. The variation of ε with updraft speed for various aerosol size distributions is calculated by means of an adiabatic, one-dimensional Lagrangian cloud model. Calculations are made for aerosol particles consisting of pure ammonium bisulphate, (NH4)HSO4and the results show that for a clean continental background aerosol population. ε should be very near unity for all updraft speeds. For an average urban aerosol population, ε is close to unity for convective clouds. but for stratiform cases ε decreases rapidly as the updraft velocity is lowered.

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RESPONSES OF PERIPHYTON TO CHANGES IN CURRENT VELOCITY, SUSPENDED SEDIMENT AND PHOSPHORUS CONCENTRATION

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FRESHWATER BIOLOGY 1990年第2期24卷 215-232页

作者： HORNER, RR WELCH, EB SEELEY, MR JACOBY, JM Environmental Engineering and Science Program Department of Civil Engineering University of Washington. Seattle Washington U.S.A

1. Research was performed in laboratory streams to evaluate periphytic biomass accrual, export, and community composition over a range of limiting nutrient (phosphorus) concentrations with variable velocity, and suspended sediment addition, in comparison to constant velocity and no suspended sediment. In fixed-velocity treatments, velocity increase to 60 cm s-1 significantly enhanced biomass accrual, but further increase resulted in substantial biomass reduction. Average biomass loss rates did not change significantly over a velocity range of 10-80 cms-1. Diatoms were favoured at relatively high velocities and low phosphorus concentrations, whereas the blue-green Phormidium tended to dominate at higher SRP concentrations and the green Mougeotia seemed to prefer lower velocities. 2. Sudden increases in velocity raised instantaneous loss rates by an order of magnitude or more, but these high rates persisted only briefly. As a result, marked biomass reductions were not apparent a day after the velocity change. Dominance change from filamentous green or blue-green to diatoms immediately after the increase was reversed within 2 days. Loss rate increases due to solids addition were much smaller than those accompanying velocity increase, but simultaneous velocity elevation and solids addition produced instantaneous loss rates approximately double those with velocity increase alone. 3. The experiments demonstrated that an elevation in velocity, above that to which algae were accustomed, led to increased loss rates and temporarily reduced biomass. However, recolonization and growth after biomass reduction were apparently rapid. Substantial export of periphyton following solids addition required erosion of the protective boundary layer accompanied by a velocity increase. These results are applicable to understanding the response of lotic periphytic algae to elevated, turbid storm discharges and similar runoff or high-flow events. 4. Areal uptake rates of P by algae growing in

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KINETICS AND MECHANISM OF THE OXIDATION OF SULFIDE BY OXYGEN - CATALYSIS BY HOMOGENEOUS METAL-PHTHALOCYANINE COMPLEXES

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environmental SCIENCE & TECHNOLOGY 1979年第11期13卷 1406-1414页

作者： HOFFMANN, MR LIM, BC Environmental Engineering Program Department of Civil & Mineral Engineering University of Minnesota Minneapolis Minn. 55455 United States

The kinetics of the catalyzed autoxidation of H2S to S, S2O3 and sulfate in aqueous solution was investigated potentiometrically over the pH range 5-12. The catalytic effects of Co(II), Ni(II) and Cu(II) 4,4'',4",4"''-tetrasulfophthalocyanine were determined and differences in catalytic ability were explained in terms of relative capacity of the octahedral complexes to reversibly bind O2. Kinetic data were analyzed in terms of a bisubstrate Michaelis-Menten rate law. The rate law and other data indicate that the catalyzed reaction proceeds via the formation of a tertiary-activated complex in which HS- and O2 reversibly bind with CoTSP2-. pH variations were explained in terms of the acid dissociation of H2S, general base catalysis and deprotonation of pyrrole nitrogens within the phthalocyanine ring.

关键词： Autoxidation Phthalocyanine Sulfide Trace metal, catalysis Water pollution control

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DEGRADATION OF ORGANIC VAPORS IN UNSATURATED SOILS

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JOURNAL OF HAZARDOUS MATERIALS 1991年第1-2期28卷 55-63页

作者： ENGLISH, CW LOEHR, RC Environmental and Water Resources Engineering Program Department of Civil Engineering University of Texas Austin Austin TX 78712 USA

To predict the fate of volatile organic compounds (VOCs) in unsaturated soil, it is necessary to understand the physical and chemical processes that occur in the soil system. Two important removal mechanisms of organic vapors in soil are sorption and biodegradation. Modeling efforts to describe the removal of organic vapors in soil require constitutive relationships that are developed from laboratory data. This paper reports measurements of removal coefficients for three VOCs in a fine sandy loam soil. Sorption coefficients and degradation removal rates were determined from batch reactors for three compounds: benzene, trichloroethylene (TCE) and o-xylene. Results indicate organic vapors are sorbed and then removed by biodegradation in the unsaturated soil system. This information has potential for use in the bioremediation of soils contaminated with VOCs and for impacting decisions on air emissions, regulatory limits and on-site controls.

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Satellite-based spatial-statistical modeling of daily stream water temperatures at the CONUS scale

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Journal of Hydrology 2025年 661卷

作者： Daniel Philippus Claudia R. Corona Katie Schneider Ashley Rust Terri S. Hogue Hydrologic Science and Engineering Program Colorado School of Mines Golden CO 80401 USA Department of Civil and Environmental Engineering Colorado School of Mines Golden CO 80401 USA

Stream temperature (ST) is a key driver of water quality and ecosystem health, and the analysis and forecasting thereof benefit from the availability of high spatiotemporal resolution ST datasets. However, such datasets are limited spatially and temporally across the CONUS, particularly for small, remote streams. Available models are limited in domain (regional), spatial resolution ( ≥ 10 km), temporal resolution (monthly), or a combination thereof. We address these limitations by developing a satellite remote sensing-based spatial-statistical model, TempEst 2 (“stream TEMPerature ESTimation, version 2”), to estimate daily mean and maximum temperatures at 1 km resolution for ungaged streams of any size across the CONUS. This contrasts with an earlier version, TempEst 1, which used a random forest algorithm at monthly resolution. TempEst 2 also improves over TempEst 1 in interpretability and computational efficiency. In TempEst 2, the streams used for model training and testing cover a wide range of urban and rural land uses, climates, and geographies. TempEst 2 requires minimal input data and tolerates sparse training gage networks, supporting generalization outside the CONUS. For CONUS applications, TempEst 2 is trained on 1,316 USGS ST gages. Quantitative performance impacts from locally-sparse gage networks are reported. Model performance is evaluated using cross-validation, walk-forward validation, and extrapolation validations over regions and elevation. TempEst 2 estimates daily mean temperatures with a median cross-validation gage RMSE of 2.0 °C, NSE of 0.91, and bias of 0.10%. TempEst 2 supports the development and analysis of high-resolution, large-domain ST datasets across the CONUS.

关键词： Stream temperature River temperature Water temperature Statistical model Satellite remote sensing Contiguous United States Spatial statistics

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