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Potential for natural and enhanced attenuation of sulphanilamide in a contaminated chalk aquifer

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Journal of environmental sciences 2017年第12期29卷 39-48页

作者： Karen A.Bennett simon D.Kelly Xiangyu Tang Brian J.Reid school of environmental sciences University of East AngliaNorwich Research ParkNorwich NR4 7TJUK Food and environmental protection Laboratory International Atomic Energy Agency1400 ViennaAustria Key Laboratory of Mountain surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academyof SciencesChengdu 610041China

understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass spectrometry（IRMs）method was developed to evaluate the extent of biodegradation of the antibiotic,sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ^（13）C of8.44‰ from-26.56（at the contaminant source） to-18.12‰（300 m downfield of the source）.These results confirm reductions in sulphanilamide concentrations（from 650 to 10 mg/L）across the contaminant plume to be attributable to biodegradation（56%） vs. other natural attenuation processes, such as dilution or dispersion（42%）. To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity（~50% mineralisation） to degrade sulphanilamide under high（263 mg/L）, moderate（10 mg/L） and low（0.02 mg/L） substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions.

关键词： Antibiotics sulphonamide Groundwater contamination Biodegradation stable isotope fractionation IRMs

suspended particulate mercury associated with tidal fluxes in a lagoon environment impacted by cinnabar mining activity(northern Adriatic sea)

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Journal of environmental sciences 2018年第6期30卷 100-113页

作者： Alisè Turritto Alessandro Acquavita Annelore Bezzi stefano Covelli Giorgio Fontolan Elisa Petranich Raffaella Piani simone Pillon Department of Mathematics and Geoscience University of Trieste Via Weiss 2 34128 Trieste Italy Co.N.I.s.Ma. Consorzio Nazionale Interuniversitario per le scienze del Mare Piazzale Flaminio 9 00196 Rome Italy ARPA FVG Environmental Protection Agency of Friuli Venezia Giulia Via Cairoli 14 33057 Palmanova (Udine) Italy

The Isonzo River has been demonstrated to be a continuing point source of mercury（Hg）in the Gulf of Trieste although the Idrija mine was last active in 1996. The present study aims to investigate the role of the suspended particulate matter（sPM） associated with tidal fluxes to disperse particulate Hg（PHg） into the Grado coastal lagoon system. PHg concentrations（avg. 3.11 ± 2.62 μg/g, d.w.）, notwithstanding the ebb or flood tides, were significantly higher than the local sediment background（0.13 μg/g）. The relative affinity of Hg for the particulate phase in surface waters was confirmed by higher average distribution coefficient（Kd） values（5.6–6.7）. PHg contents showed the highest values in ebb tide conditions, thus suggesting their origin from the erosion of tidal flats and saltmarshes of the lagoon. When compared to river discharge, high PHg surface concentrations in flood tide are related to rainfall events occurring within the river basin. Results can be used to make an indicative assessment of the amount of Hg bound to sPM which is transported in and out of the lagoon basin following the action of tidal fluxes. A simple estimation provides a negative budget for the Grado lagoon sub-basin which loses between 0.14 and 1.16 kg of PHg during a tidal semi-cycle. This conclusion is in agreement with the evidence of morphological deterioration which has emerged from recent studies on the lagoon environment, and which testifies to a current sedimentary loss from the lagoon into the northern Adriatic sea.

关键词： Mercury Tidal fluxes suspended particulate matter Lagoon

A novel approach to enhance decrepitation temperature and reducibility of ultrafine iron ore concentrate pellets

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Journal of Iron and steel Research International 2024年第11期31卷 2622-2632页

作者： B.L.Wen Z.H.Fan J.X.Li D.L.Liu J.L.Yang school of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243032AnhuiChina Jianlong(Liaoning)Energy saving and environmental protection

utilizing ultrafine iron ore concentrate for pellet production can expand domestic iron ore resources in China and promote the utilization of low-grade ***,a challenge arises with the low decrepitation temperature and reducibility in the preparation process of ultrafine iron ore concentrate *** address the challenge,a novel approach was proposed,which incorporated straw powder as an additive to enhance pellet porosity,thereby improving the decrepitation temper-ature and reducibility of ultrafine iron ore concentrate *** effect of varying proportions of straw powder(0.0-2.0%)on the characteristics of ultrafine iron ore concentrate pellets was *** indicate that at a 2.0%straw powder ratio,pellet decrepitation temperature notably rises from 380 to 540℃,while the reducibility index escalates from 25.7%to 48.1%.Nevertheless,the addition of straw powder results in diminished drop strength,compressive strength of green pellets,and cold crushing strength of fired *** addition,enhanced pellet reducibility leads to exacerbated reduction swelling index and reduction degradation *** these effects,all parameters remain within an acceptable range.

关键词： ultrafine iron ore concentrate:straw powder Green pellet quality Decrepitation temperature:Metallurgical property

Nutrient alterations following biochar application to a Cd-contaminated solution and soil

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Biochar 2021年第4期3卷 457-468页

作者： Liqiang Cui James A.Ippolito Matt Noerpel Kirk G.scheckel Jinlong Yan school of environmental science and Engineering Yancheng Institute of TechnologyNo.211 Jianjun RoadYancheng 224003China Department of soil and Crop sciences Colorado State UniversityFort Collins 80523USA Center for environmental solutions and Emergency Response Land Remediation and Technology DivisionUnited States Environmental Protection AgencyCincinnatiOH 45224-1701USA

Biochars,when applied to contaminated solutions or soils,may sequester potentially toxic elements while releasing neces-sary plant *** purpose of this study focused on quantifying both phenomenon following wheat straw(Triticum aestivum L.)biochar application(0,5,and 15%by wt)to a Cd containing solution and a Cd-contaminated paddy soil using 240-day laboratory batch *** both experiments,solid phases were analyzed for elemental associations using a combination of wet chemical sequential extractions and synchrotron-based X-ray absorption spectroscopy(XAs).When wheat straw biochar was applied at 15%to Cd containing solutions,Cd and Zn concentrations decreased to below detection in some instances,Ca and Mg concentrations increased by up to 290%,and solution pH increased as compared to the 5%biochar application *** responses were observed when biochar was added to the Cd-contaminated paddy soil,suggesting that this particular biochar has the ability to sequester potentially toxic elements while releasing necessary plant nutrients to the soil *** significant,positive correlations existed between nutrient release over time,while negative correlations were present between biochar application rate,potentially toxic element sorption and *** latter suggests that potentially toxic elements were sorbed by a combination of organic functional groups or mineral precipitation based on whether pH was above or below~*** support of this contention,the wet chemical sequential extraction procedure in conjunction with previously observed Cd or current Zn XAs showed that biochar application promoted the formation of layered double hydroxides,sorption to(oxy)hydroxides,and organically bound to biochar as Zn *** a multi-functional material,biochar appears to play an important role in sequestering Cd while releasing essential plant *** findings suggest that biochar may be a‘win-win’for improving environmental quality in pot

关键词： Biochar Cadmium Nutrient availability sequential extraction procedure X-ray absorption spectroscopy Zinc

Magnesium activation affects the properties and phosphate sorption capacity of poultry litter biochar

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Biochar 2023年第1期5卷 1117-1130页

作者： Joshua T.Padilla Donald W.Watts Jeffrey M.Novak Vasile Cerven James A.Ippolito Ariel A.szogi Mark G.Johnson united states Department of Agriculture Agricultural Research ServiceCoastal Plains SoilWater and Plant Research CenterFlorenceSC 29501USA school of Environment and Natural Resources The Ohio State UniversityColumbusOH 43210USA Center for Public Health and environmental Assessment United States Environmental Protection AgencyCorvallisOR 97331USA

Biochars with a high affinity for phosphorus(P)are promising soil amendments for reducing P in agricultural *** litter(PL)is an abundant biochar ***,PL-derived biochars are typically high in soluble P and therefore require chemical modification to become effective P *** study investigated the effect of magnesium(Mg)activation on extractable P(EP)and P sorption capacities of PL-derived *** was produced at 500-900℃ from PL activated with 0-1 M *** differentially aged PL feedstocks were evaluated(1-,3-5-,and 7-9-year-old).Increased Mg activation level and pyrolysis temperature both resulted in EP reductions from the ***,biochars produced at temperatures≥700℃ from PL activated with≥0.25 M Mg had negligible EP.X-ray diffractograms indicated that increased Mg loading favored the formation of stable Mg_(3)(PO_(4))_(2) phases while increasing temperature favored the formation of both Mg_(3)(PO_(4))_(2) and Ca_(5)(PO_(4))_(3)*** P sorption capacities(Pmax)of the biochars were estimated by fitting Langmuir isotherms to batch sorption data and ranged from 0.66-10.35 mg g^(−1).Average Pmax values were not affected by PL age or pyrolysis temperature;however,biochars produced from 1 M Mg-activated PL did have significantly higher average Pmax values(pue to a greater abundance of ***,the results demonstrated that Mg activation is an effective strategy for producing PLderived biochars with the potential ability to reduce P loading into environmentally sensitive ecosystems.

关键词： sorption activation pyrolysis

A New Thiele＇s Modulus for the Monod Biofilm Model

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Chinese Journal of Chemical Engineering 2008年第2期16卷 277-286页

作者：方元祥 GOVIND Rakesh National Risk Management and Research Laboratory U.S. Environmental Protection Agency 26 W. Martin Luther King Dr. Cincinnati OH45268 USA Department of Chemical and Materials Engineering University of Cincinnati Cincinnati OH45221 USA

A new Thiele＇s modulus, φF, was developed to provide a gradual transition between zero and the first order of kinetics, and to accurately calculate the mass transfer flux and the effectiveness factor for the Monod biofilm. Values of the effectiveness factor, calculated using the new Thiele＇s modulus, were compared with those obtained from numerical solutions and from other published moduli and empirical formulae. The comparison indi- cated that the new Thiele＇s modulus was the best modulus for the Monod biofilm model. In addition, another Thiele＇s modulus, φG, was developed for a Monod biofilm, covered with an external water layer. The overall effectiveness factor can also be calculated by using both moduli φF and φG. The criteria that were proposed for identifica- tion were based on the values of φF and φG, the limiting processes for biomass growth, and substrate conversion. Developed from φF, a new parameter ψ was related uniquely to such features as the depth and shallowness of the generalized substrate concentration profiles inside a Monod biofilm. Criteria were developed to identify the types of concentration distribution inside a Monod biofilm. These methods were used to estimate the substrate flux and the concentration distribution of the biofilms defined in the first benchmark problem （BM1）, by a task group of the International Water Association on Biofilm Modeling.

关键词： Monod biofilm kinetic model effectiveness factor Thieles modulus generalized concentration profiles

Tuning the Morphology of Pharmaceutical Compounds via Model Based solvent selection

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Chinese Journal of Chemical Engineering 2008年第3期16卷 465-473页

作者： ArunPrakash T. Karunanithi Charles Acquah LukeE. K. Achenie National Risk Management Research Laboratory U.S. Environmental Protection Agency Cincinnati Ohio USA Department of Chemical Materials ＆ Biomolecular Engineering University of Connecticut Storrs Connecticut USA Department of Chemical Engineering Virginia Polytectmic Institute and State University Blacksburg Virginia USA

In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a product design stage and a post-design experimental verification stage is presented. The pre-design stage addresses the tormulation of the property constraint tor crystal morphology. This involves crystallization experiments aria development of property models and constraints for morphology. In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming *** design stage provides an optimal solvent/list of candidate solvents. similar to the pre-design stage, in the post design experimental verification stage, the morphology of the crystals （precipitated from the designed solvent） is verified through crystallization experiments followed by product characterization via scanni＇ng electron microscopy, powder X-ray diffraction imaging and Fourier transform spectra analysis.

关键词： morphology solvent selection nonlinear programming crystallization product design

Low temperature selective catalytic reduction of NO by C_3H_6 over Ce O_x loaded on AC treated by HNO_3

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Journal of Rare Earths 2015年第4期33卷 371-381页

作者：楚英豪张腾腾郭家秀刘超尹华强朱晓帆刘勇军 College of Architecture and Environment Sichuan University National Engineering Technology Research Center for Flue Gas Desulfurization Sichuan University sichuan Provincial environmental protection & environmental Catalytic Materials Engineering Technology Center Sichuan University

The activated carbons from coal were treated by HNO3 （named as NAC） and used as carriers to load 7% Ce （named as Ce（0.07）/NAC） by impregnation method. The physical and chemical properties were investigated by thermogravimetric-differential thermal analysis （TG-DTA）, Brunauer-Emmett-Teller （BET）, X-ray diffraction （XRD）, X-ray photoelectron spectra （XPs）, scanning electron microscopy （sEM） and NH3-temperature programmed desorption （NH3-TPD） and NO-temperature programmed desorption techniques. The catalytic activities of Ce（0.07）/NAC were evaluated for the low temperature selective catalytic reduction （sCR） of NO with C3H6 using temperature-programmed reaction （TP-reaction） in NO, C3H6, 02 and N2 as a balance. The results showed that the specific surface area of Ce（0.07）/NAC was 850.8 m2/g and less than NAC, but Ce oxides could be dispersed highly on the acti- vated carbons. Ce oxides could change acid sites and NO adsorption as well as oxygen-containing functional groups of activated car- bons, and Ce4＋ and Ce〉 coexisted in catalysts. The conversion of NO with C3H6 achieved 70% at 280 ~C over Ce（0.07）/NAC, but with the increase of 02 concentration, heat accumulation and nonselective combustion were exacerbated, which could cause surface ashing and roughness, resulting in a sharp decrease of catalytic activities. The optimum 02 concentration used in the reaction system was 3% and achieved the high conversion of NO and the widest temperature window. The conversion of NO was closely related to the NO concentrations and [NO]/[C3H6] ratios, and the stoichiometric number was just close to 2：1, but the presence of H20 could af- fect the denitration efficiency of catalyst.

关键词： low temperature activated carbon cerium oxides selective catalytic reduction hydrocarbon rare earths

Characterization of dissolved organic matter fractions from Lake Hongfeng, southwestern China Plateau

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Journal of environmental sciences 2009年第5期21卷 581-588页

作者： WANG Liying Wu Fengchang ZHANG Runyu LI Wen LIAO Haiqing state Key Laboratory of environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China state environmental protection Key Laboratory for Lake Pollution Control Research Center of Lake Eco-Environment Chinese Research Academy of Environmental Sciences Beifing 100012 China

With XAD-series and ion exchange resins, dissolved organic matter （DOM） from Lake Hongfeng in southwestern China Plateau was isolated into 6 fractions, i.e., humic acid （HA）, fulvic acid （FA）, hydrophobic neutrals （HON）, hydrophilic acids （HIA）, hydrophilic bases （HIB） and hydrophilic neutrals （HIN）. Those fractions were characterized by high performance size exclusion chromatography, fluorescence spectroscopy and uV absorbance. Among the 6 fractions, FA was predominant and accounted for 51% of the total DOM. The weight-average （Mw） and number-averaged （Mn） molecular weight of these fractions ranged from 1688 to 2355 Da and from 1338 to 1928 Da, respectively. A strong correlation was observed between specific uV absorbance at 280 nm, E2/E3 （absorbance at 250 nm to 365 nm）, and the molecular weight for DOM fractions. uV-Vis fulvic-like fluorescence peaks were found in all fractions. Proteinlike fluorescence peaks existed in HON may indicate that microbial activity was severely in Lake Hongfeng. There was a significant relationship between fluorescence intensities and specific uV absorbance at 254 nm for those DOM fractions, suggesting their similar luminescence characteristics. The values of fluorescence index （f450/500） indicated that hydrophobic fractions may derive from terrestrial sources, and the hydrophilic fractions from microbial and terrestrial origins. Those results suggest that there were inter-relationships between molecular weight, fluorescence and absorbance characteristics, and also subtle consistencies between the hydrophilic and hydrophobic properties and the sources for these 6 fractions from Lake Hongfeng.

关键词： dissolved organic matter fractionation molecular weight uV absorbance fluorescence spectroscopy