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Surface-enhanced Raman spectroscopy for emerging contaminant analysis in drinking water

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Frontiers of environmental Science & Engineering 2023年第5期17卷 51-65页

作者： Seo Won Cho Haoran Wei environmental Chemistry and Technology program University of Wisconsin–MadisonMadisonWI 53706USA Department of Civil and environmental Engineering University of Wisconsin–MadisonMadisonWI 53706USA

Emerging contaminants(ECs)in drinking water pose threats to public health due to their environmental prevalence and potential toxicity.The occurrence of ECs in our drinking water supplies depends on their physicochemical properties,discharging rate,and susceptibility to removal by water treatment processes.Uncertain health effects of long-term exposure to ECs justify their regular monitoring in drinking water supplies.In this review article,we will summarize the current status and future opportunities of surface-enhanced Raman spectroscopy(SERS)for EC analysis in drinking water.Working principles of SERS are first introduced and a comparison of SERS and liquid chromatography-tandem mass spectrometry in terms of cost,time,sensitivity,and availability is made.Subsequently,we discuss the strategies for designing effective SERS sensors for EC analysis based on five categories—per-and polyfluoroalkyl substances,novel pesticides,pharmaceuticals,endocrine-disrupting chemicals,and microplastics.In addition to maximizing the intrinsic enhancement factors of SERS substrates,strategies to improve hot spot accessibilities to the targeting ECs are equally important.This is a review article focusing on SERS analysis of ECs in drinking water.The discussions are not only guided by numerous endeavors to advance SERS technology but also by the drinking water regulatory policy.

关键词： Emerging contaminant Surface-enhanced Raman spectroscopy Drinking water monitoring Sensor Regulatory policy

Local scour around two side-by-side cylindrical bridge piers under ice-covered conditions

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International Journal of Sediment Research 2019年第4期34卷 355-367页

作者： Mohammad reza Namaee Jueyi Sui environmental Engineering program University of Northern British Columbia

In the current study, 108 flume experiments with non-uniform, cohesionless sediments have been done to investigate the local scour process around four pairs of side-by-side bridge piers under both open channel and ice-covered flow conditions. Similar to local scour around bridge piers under open channel conditions and a single bridge pier, it was observed in the experiments that the maximum scour depth always occurred at the upstream face of the pier under ice-covered conditions. Further, the smaller the pier size and the greater the spacing distance between the bridge piers, the weaker the horseshoe vortices around the bridge piers, and, thus, the shallower the scour holes around them. Finally, empirical equations were developed to estimate the maximum scour depth around two side-by-side bridge piers under both open channel and ice-covered flow conditions.

关键词： Bridge pier Local scour Maximum scour depth Non-uniform sediment Roughness of cover Scour pattern

Characterization of halogenated DBPs and identification of new DBPs trihalomethanols in chlorine dioxide treated drinking water with multiple extractions

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Journal of environmental Sciences 2017年第8期58卷 83-92页

作者： Jiarui Han Xiangru Zhang Jiaqi Liu Xiaohu Zhu Tingting Gong environmental Engineering program Department of Civil and Environmental Engineering The Hong Kong University of Science and Technology School of the Environment Nanjing University

Chlorine dioxide(ClO2) is a widely used alternative disinfectant due to its high biocidal efficiency and low-level formation of trihalomethanes and haloacetic acids. A major portion of total organic halogen(TOX), a collective parameter for all halogenated DBPs, formed in ClO2-treated drinking water is still unknown. A commonly used pretreatment method for analyzing halogenated DBPs in drinking water is one-time liquid–liquid extraction(LLE), which may lead to a substantial loss of DBPs prior to analysis. In this study, characterization and identification of polar halogenated DBPs in a ClO2-treated drinking water sample were conducted by pretreating the sample with multiple extractions. Compared to one-time LLE, the combined four-time LLEs improved the recovery of TOX by 2.3 times. The developmental toxicity of the drinking water sample pretreated with the combined four-time LLEs was 1.67 times higher than that pretreated with one-time LLE.With the aid of ultra-performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, a new group of polar halogenated DBPs, trihalomethanols,were detected in the drinking water sample pretreated with multiple extractions; two of them,trichloromethanol and bromodichloromethanol, were identified with synthesized standard compounds. Moreover, these trihalomethanols were found to be the transformation products of trihalomethanes formed during ClO2disinfection. The results indicate that multiple LLEs can significantly improve extraction efficiencies of polar halogenated DBPs and is a better pretreatment method for characterizing and identifying new polar halogenated DBPs in drinking water.

关键词： Disinfection byproducts DBPs Chlorine dioxide treatment Multiple extractions Toxicity

Potential recovery of precious metals from waste laptops in Jordan

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Rare Metals 2015年第7期34卷 517-521页

作者： Mohammad A.T.Alsheyab program Manager of Civil and environmental Engineering Qatar Foundation

To achieve a sustainable development in the electronic and electrical equipment(EEE) industry, it is necessary to protect the available natural resources.In addition, to satisfy the increasing demand on EEE, it is necessary to provide alternative sources of raw materials.In this paper, laptops were imported to Jordan in 2011 as an example to show the potential recovery of metals and precious metals from high grade waste electronic and electrical equipment by conducting a mass flow rate analysis using the STAN program.The results show that considerable amounts of gold, silver, cobalt, palladium,and copper could be recovered.This will reduce the amounts needed from primary natural resources and offset the CO2 emissions produced from mining the primary raw material resources.

关键词： Precious metals Laptops Waste of electronic and el

Comparison of different disinfection processes in the effective removal of antibiotic-resistant bacteria and genes

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Journal of environmental Sciences 2014年第6期26卷 1238-1242页

作者： Junsik Oh Dennis Espineli Salcedo Carl Angelo Medriano Sungpyo Kim program in environmental Technology and Policy Korea University Department of environmental Engineering College of Science and Technology Korea University

This study compared three different disinfection processes （chlorination, E-beam, and ozone） and the efficacy of three oxidants （H202, S2O8-, and peroxymonosulfate （MPS）） in removing antibiotic resistant bacteria （ARB） and antibiotic resistance genes （ARGs） in a synthetic wastewater. More than 30 mg/L of chlorine was needed to remove over 90% of ARB and ARG. For the E-beam method, only 1 dose （kGy） was needed to remove ARB and ARG, and ozone could reduce ARB and ARG by more than 90% even at 3 mg/L ozone concentration. In the ozone process, CT values （concentration × time） were compared for ozone alone and combined with different catalysts based on the 2-log removal of ARB and ARG. Ozone treatment yielded a value of 31 and 33 （mg·min）/L for ARB and ARGs respectively. On the other hand, ozone with persulfate yielded 15.9 and 18.5 （mg.min）/L while ozone with monopersulfate yielded a value of 12 and 14.5 （mg·min）/L. This implies that the addition of these catalysts significantly reduces the contact time to achieve a 2-log removal, thus enhancing the process in terms of its kinetics.

关键词： antibiotic resistance ozonation catalyst oxidants disinfection

Relationship between PM_(10) and PM_(2.5) levels in high-traffic area determined using path analysis and linear regression

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Journal of environmental Sciences 2018年第7期30卷 105-114页

作者： Narut Sahanavin Tassanee Prueksasit Kraichat Tantrakarnapa Interdisciplinary program of environmental Science Graduate School Chulalongkorn University Department of environmental Science Faculty of Science Chulalongkorn University Department of Social and environmental Medicine Faculty of Tropical Medicine Mahidol University

The objective of this study was to determine the relationship between PM10 and PM2.5 levels as related to meteorological conditions and traffic flow using both a linear regression analysis and a path analysis. The Particulate matter（PM） samples were collected from Sukhumvit road, Bangkok, Thailand, at both open（104 samples） and covered（92 samples）areas along the road. Fifteen percent of all samples were separated before the statistical models were run and used for model validation. The results from the path analysis were more elaborate than those from the linear regression, thus indicating that meteorological conditions had a direct effect on the particulate levels and that the effects of traffic flow were more variable in open areas. The model also indicated that meteorological conditions had an indirect effect and that traffic flow had a direct effect on particulate levels in covered areas. The model validation results indicated that for open areas, the R^2 values were not very different between the path analysis and the linear regression model, but that the path analysis was more accurate than the linear regression model at very low PM concentrations. At high PM concentrations, the path analysis model also had a better fit than did the linear regression, so the predictions from the path analysis model were more accurate than those from the linear regression.

关键词： Path analysis PM10 PM2.5 Open roadside area Covered roadside area

Nexus between polymer support and metal oxide nanoparticles in hybrid nanosorbent materials （HNMs） for sorption/desorption of target ligands

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Frontiers of environmental Science & Engineering 2015年第5期9卷 929-938页

作者： Ryan C. SMITH Jinze LI Surapol PADUNGTHON Arup K. SENGUPTA environmental Engineering program Department of Civil and Environmental Engineering Lehigh University Bethlehem PA 18015 USA

Metal oxide nanoparticles like hydrated ferric oxide （HFO） or hydrated zirconium oxide （HZrO） are excellent sorbents for environmentally significant ligands like phosphate, arsenic, or fluoride, present at trace concentrations. Since the sorption capacity is surface dependent for HFO and HZrO, nanoscale sizes offer significant enhancement in performance. However, due to their miniscule sizes, low attrition resistance, and poor durability they are unable to be used in typical plug-flow column setups. Meanwhile ion exchange resins, which have no specific affinity toward anionic ligands, are durable and chemically stable. By impregnating metal oxide nanoparticles inside a polymer support, with or without functional groups, a hybrid nanosorbent material （HNM） can be prepared. A HNM is durable, mechanically strong, and chemically stable. The functional groups of the polymeric support will affect the overall removal effi- ciency of the ligands exerted by the Donnan Membrane Effect. For example, the removal of arsenic by HFO or the removal of fluoride by HZrO is enhanced by using anion exchange resins. The HNM can be precisely tuned to remove one type of contaminant over another type. Also, the physical morphology of the support material, spherical bead versus ion exchange fiber, has a significant effect on kinetics of sorption and desorption. HNMs also possess dual sorption sites and are capable of removing multiple contaminants, namely, arsenate and perchlorate, concurrently.

关键词： ion exchange sorpfion arsenic perchlorat~,fluoride

A short climatology of black and brown carbon and their sources at a suburban site impacted by smoke in Brazil

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Journal of environmental Sciences 2024年第2期136卷 498-511页

作者： Admir Creso Targino Patricia Krecl Gabriel Yoshikazu Oukawa Eva Maria Mollinedo Graduate program in environmental Engineering Federal University of TechnologyAv.Pioneiros 3131LondrinaPR 86036-370Brazil Department of environmental Engineering Federal University of TechnologyAv.Pioneiros 3131LondrinaPR 86036-370Brazil

Emissions from biomass burning challenge efforts to curb air pollution in cities downwind of fire-prone regions,as they contribute large amounts of brown carbon(Br C)and black carbon(BC)particles.We investigated the patterns of Br C and BC concentrations using Aethalometer data(atλ=370 and 880 nm,respectively)spanning four years at a site impacted by the outflow of smoke.The data required to be post processed for the shadowing effect since,without correction,concentrations would be between 29%and 35%underestimated.The Br C concentrations were consistently higher than the BC concentrations,indicating the prevalence of aerosols from biomass burning.The results were supported by the Angstrom coefficient(A_(370/880)),with values predominantly larger than 1(mean±standard deviation:1.25±0.31).A_(370/880)values below 1 were more prevalent during the wet season,which suggests a contribution from fossil fuel combustion.We observed sharp Br C and BC seasonal signals,with mean minimum concentrations of 0.40μg/m^(3)and 0.36μg/m^(3),respectively,in the wet season,and mean maximum concentrations of 2.05μg/m^(3)and 1.53μg/m^(3)in the dry season.The largest concentrations were observed when northerly air masses moved over regions with a high density of fire spots.Local burning of residential solid waste and industrial combustion caused extreme Br C and BC concentrations under favourable wind directions.Although neither pollutant is included in any ambient air quality standards,our results suggest that transboundary smoke may hamper efforts to meet the World Health Organization guidelines for fine particles.

关键词： Light-absorbing carbonaceous matter Black carbon Wildfires Biomass burning Aethalometer

Assessing the utility of dissolved organic matter photoreactivity as a predictor of in situ methylmercury concentration

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Journal of environmental Sciences 2018年第6期30卷 160-168页

作者： Sara J.Klapstein Susan E.Ziegler David A.Risk Nelson J.O'Driscoll environmental Science program Memorial University of Newfoundland Department of Earth Sciences St. Francis Xavier University Department of Earth and environmental Science Acadia University

Methylmercury（MeHg） bioaccumulation is a growing concern in ecosystems worldwide. The absorption of solar radiation by dissolved organic matter（DOM） and other photoreactive ligands can convert MeHg into less toxic forms of mercury through photodemethylation. In this study, spectral changes and photoreactivity of DOM were measured to assess the potential to control photoreactions and predict in situ MeHg concentration. Water samples collected from a series of lakes in southwestern Nova Scotia in June, August, and September were exposed to controlled ultraviolet-A（UV-A） radiation for up to 24 hr. Dissolved organic matter photoreactivity, measured as the loss of absorbance at 350 nm at constant UV-A irradiation, was positively dependent on the initial DOM concentration in lake waters（r^2=0.94）. This relationship was consistent over time with both DOM concentration and photoreactivity increasing from summer into fall across lakes. Lake in situ MeHg concentration was positively correlated with DOM concentration and likely catchment transport in June（r = 0.77） but not the other sampling months. Despite a consistent seasonal variation in both DOM and Fe, and their respective correlations with MeHg, no discernable seasonal trend in MeHg was observed. However, a 3-year dataset from the 6 study lakes revealed a positive correlation between DOM concentration and both Fe（r = 0.91） and MeHg concentrations（r = 0.51） suggesting a more dominant landscape mobility control on MeHg.The DOM-MeHg relationships observed in these lakes highlights the need to examine DOM photoreactivity controls on MeHg transport and availability in natural waters particularly given future climate perturbations.

关键词： Methylmercury Dissolved organic carbon Photoreactions Kejimkujik National Park Freshwater lakes