Pub Date : 2020-02-23DOI: 10.1080/10934529.2019.1682366
Cherng-Yuan Lin, S. Tsai
Abstract Solketal is a promising oxygenate additive that can be chemically derived from bioglycerol. Emulsification by a microwave-irradiating method was used to prepare the micro- and nanoemulsions of solketal dispersed in continuous ultra-low sulfur diesel (ULSD) due to the immiscibility of solketal with ULSD. The emissions from a direct-injection, four-stroke and naturally aspirated diesel engine fueled with each of these emulsions, and with neat ULSD, were analyzed and compared. The experimental results show that the nanoemulsion and microemulsions were successfully produced. In addition, an increasing engine speed resulted in lower NOx, CO and O2 but higher CO2 emissions. The nanoemulsion was found to produce the lowest NOx emission while neat ULSD produced the highest NOx emission among these three test fuels. The lowest CO emission was formed by fueling the micro-emulsion of dispersed solketal-in-ULSD. Moreover, the burning of the nanoemulsion in the diesel engine formed the highest CO2 along with the lowest O2 emissions. Hence, the nanoemulsion had the highest burning efficiency among the three test fuels for the diesel engine.
{"title":"Emission characteristics of a diesel engine fueled with nanoemulsions of continuous diesel dispersed with solketal droplets","authors":"Cherng-Yuan Lin, S. Tsai","doi":"10.1080/10934529.2019.1682366","DOIUrl":"https://doi.org/10.1080/10934529.2019.1682366","url":null,"abstract":"Abstract Solketal is a promising oxygenate additive that can be chemically derived from bioglycerol. Emulsification by a microwave-irradiating method was used to prepare the micro- and nanoemulsions of solketal dispersed in continuous ultra-low sulfur diesel (ULSD) due to the immiscibility of solketal with ULSD. The emissions from a direct-injection, four-stroke and naturally aspirated diesel engine fueled with each of these emulsions, and with neat ULSD, were analyzed and compared. The experimental results show that the nanoemulsion and microemulsions were successfully produced. In addition, an increasing engine speed resulted in lower NOx, CO and O2 but higher CO2 emissions. The nanoemulsion was found to produce the lowest NOx emission while neat ULSD produced the highest NOx emission among these three test fuels. The lowest CO emission was formed by fueling the micro-emulsion of dispersed solketal-in-ULSD. Moreover, the burning of the nanoemulsion in the diesel engine formed the highest CO2 along with the lowest O2 emissions. Hence, the nanoemulsion had the highest burning efficiency among the three test fuels for the diesel engine.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"11 1","pages":"224 - 229"},"PeriodicalIF":0.0,"publicationDate":"2020-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88352656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-23DOI: 10.1080/10934529.2019.1682367
Bo Zhang, Gail Joseph, Lijun Wang, Xin Li, A. Shahbazi
Abstract Thermophilic anaerobic digestion (AD) of cattail followed by hydrothermal carbonization (HTC) was studied. The intent of the research was to develop agricultural waste-based biorefining technologies for bioenergy production along with value-added products. Cattail was anaerobically digested at 55 °C for 14 days and protein and cellulose components were partially degraded. The average methane yield was 230–280 mL/g volatile solids and the total solids decreased by 33–55%. When the particle size of cattail was reduced from 1 in. to 1 mm, the lag phase was shortened from 1.48 to 0 d. Following the AD process of cattail, the AD digestate was hydrothermally carbonized at 250 °C for 4 h, yielding approximately 6.7–7.5 wt % gaseous products, 64 wt % liquid products and 28 wt % hydrochar. The gaseous products contained >5000 ppm H2S and liquid products possessed fewer chemicals and higher ratio of phenolic compounds compared to the liquid products from HTC of original cattail. The hydrochar had a higher carbon content (76.8–79.8%) and a higher specific surface area (∼10 m2/g) than those of the feedstock. Hydrochar was further activated by using Na2CO3, NaHCO3 and NaCl. The activation process increased the carbon content and specific surface area to 84–93% and 250–630 m2/g, respectively.
{"title":"Thermophilic anaerobic digestion of cattail and hydrothermal carbonization of the digestate for co-production of biomethane and hydrochar","authors":"Bo Zhang, Gail Joseph, Lijun Wang, Xin Li, A. Shahbazi","doi":"10.1080/10934529.2019.1682367","DOIUrl":"https://doi.org/10.1080/10934529.2019.1682367","url":null,"abstract":"Abstract Thermophilic anaerobic digestion (AD) of cattail followed by hydrothermal carbonization (HTC) was studied. The intent of the research was to develop agricultural waste-based biorefining technologies for bioenergy production along with value-added products. Cattail was anaerobically digested at 55 °C for 14 days and protein and cellulose components were partially degraded. The average methane yield was 230–280 mL/g volatile solids and the total solids decreased by 33–55%. When the particle size of cattail was reduced from 1 in. to 1 mm, the lag phase was shortened from 1.48 to 0 d. Following the AD process of cattail, the AD digestate was hydrothermally carbonized at 250 °C for 4 h, yielding approximately 6.7–7.5 wt % gaseous products, 64 wt % liquid products and 28 wt % hydrochar. The gaseous products contained >5000 ppm H2S and liquid products possessed fewer chemicals and higher ratio of phenolic compounds compared to the liquid products from HTC of original cattail. The hydrochar had a higher carbon content (76.8–79.8%) and a higher specific surface area (∼10 m2/g) than those of the feedstock. Hydrochar was further activated by using Na2CO3, NaHCO3 and NaCl. The activation process increased the carbon content and specific surface area to 84–93% and 250–630 m2/g, respectively.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"271 1","pages":"230 - 238"},"PeriodicalIF":0.0,"publicationDate":"2020-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77169845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-28DOI: 10.1080/10934529.2019.1673089
Dariush Elami, K. Seyyedi
Abstract Recently, the advanced oxidation processes have been used to treat wastewater containing various dye pollutants via various methods of purification. In this work, the removal of the Carmoisine dye from contaminated waters by a photocatalytic method in a recirculating thin-film fixed bed reactor (TFFBR) was investigated and was compared with photolysis. By the surface response method via Minitab software, the experiments were designed in such a way that the effects of different parameters on the process were studied. The effect of various parameters, for instance, pH of solution, reaction time, initial dye concentration, flow rate, hydrogen peroxide concentration on the dye removal efficiency has been investigated. By the screening and optimization stages in the response surface method, the optimal conditions for performing the process were as follows: 45 min of time, pH 2, 13.33 mM of H2O2 concentration, the flow rate of 0.25 Lmin−1, and 10 mg/L of dye concentration. The proficiency of removing color by advanced oxidation is more than 97% under optimum conditions. Graphical Abstract
{"title":"Removing of carmoisine dye pollutant from contaminated waters by photocatalytic method using a thin film fixed bed reactor","authors":"Dariush Elami, K. Seyyedi","doi":"10.1080/10934529.2019.1673089","DOIUrl":"https://doi.org/10.1080/10934529.2019.1673089","url":null,"abstract":"Abstract Recently, the advanced oxidation processes have been used to treat wastewater containing various dye pollutants via various methods of purification. In this work, the removal of the Carmoisine dye from contaminated waters by a photocatalytic method in a recirculating thin-film fixed bed reactor (TFFBR) was investigated and was compared with photolysis. By the surface response method via Minitab software, the experiments were designed in such a way that the effects of different parameters on the process were studied. The effect of various parameters, for instance, pH of solution, reaction time, initial dye concentration, flow rate, hydrogen peroxide concentration on the dye removal efficiency has been investigated. By the screening and optimization stages in the response surface method, the optimal conditions for performing the process were as follows: 45 min of time, pH 2, 13.33 mM of H2O2 concentration, the flow rate of 0.25 Lmin−1, and 10 mg/L of dye concentration. The proficiency of removing color by advanced oxidation is more than 97% under optimum conditions. Graphical Abstract","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"19 1","pages":"193 - 208"},"PeriodicalIF":0.0,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82189394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-28DOI: 10.1080/10934529.2019.1674591
P. R. Ipte, Sriram Kumar, A. Satpati
Abstract Carbon nano spheres (CNSs) were synthesized by single step electrochemical synthesis route in ultra-pure water as a medium of synthesis. Characterization of synthesized CNSs was carried out using atomic force microscope (AFM), particle size analyzer, zeta potential analyzer and Fourier Transform Infrared (FTIR) measurements, from which the information about the morphology and functional groups present on the surface of the particles are obtained. The particle size of the CNSs was found to be 6 nm. FTIR spectrum shows the presence of functional groups such as –OH, C≡C, C = C and on the CNSs. Electrochemical and spectroscopic experiments were conducted to determine the interaction of the drug molecule ciprofloxacin (Cf) with CNSs, strong interaction between Cf and CNSs leads to the development of analytical method of detection of Cf using CNSs as the pre-concentrating agent. The detection of limit of the present method is obtained as 0.15 μM at (S/N) ratio of 3. CNSs can be considered as a potential candidate for the fabrication of sensor for high sensitive determination of Cf. Graphical Abstract
{"title":"Electrochemical synthesis of carbon nano spheres and its application for detection of ciprofloxacin","authors":"P. R. Ipte, Sriram Kumar, A. Satpati","doi":"10.1080/10934529.2019.1674591","DOIUrl":"https://doi.org/10.1080/10934529.2019.1674591","url":null,"abstract":"Abstract Carbon nano spheres (CNSs) were synthesized by single step electrochemical synthesis route in ultra-pure water as a medium of synthesis. Characterization of synthesized CNSs was carried out using atomic force microscope (AFM), particle size analyzer, zeta potential analyzer and Fourier Transform Infrared (FTIR) measurements, from which the information about the morphology and functional groups present on the surface of the particles are obtained. The particle size of the CNSs was found to be 6 nm. FTIR spectrum shows the presence of functional groups such as –OH, C≡C, C = C and on the CNSs. Electrochemical and spectroscopic experiments were conducted to determine the interaction of the drug molecule ciprofloxacin (Cf) with CNSs, strong interaction between Cf and CNSs leads to the development of analytical method of detection of Cf using CNSs as the pre-concentrating agent. The detection of limit of the present method is obtained as 0.15 μM at (S/N) ratio of 3. CNSs can be considered as a potential candidate for the fabrication of sensor for high sensitive determination of Cf. Graphical Abstract","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"45 1","pages":"142 - 150"},"PeriodicalIF":0.0,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80946599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-28DOI: 10.1080/10934529.2019.1678323
A. Moniakowska, G. Olszewski, K. Block, D. Strumińska-Parulska
Abstract The article presents the results of a study on the level of 210Pb efficiency extraction in Polish herbal teas as a possible additional source of this radioactive isotope in the human diet. The twelve most popular herbal teas available in Poland and their infusions in filtered and tap water were analyzed as well as 210Pb activity concentrations and effective doses (radiation) were calculated. The highest activity concentration of 210Pb in dried plants was determined in cistus – 35.5 Bq kg−1 dry wt, while the lowest was in milk thistle – 3.25 Bq kg−1 dry wt what gives respectively for cistus 46.1 ± 0.7 and 6.50 ± 0.29 mBq for milk thistle per one tea bag. The extraction efficiencies in the filtered water oscillated from 5.1 ± 0.5 for milk thistle to 27.3 ± 0.8% for cistus, while for the tap water they ranged from 7.3 ± 0.6% for lime to 33.3 ± 2.2% for white mulberry. Based on the study, it was found that the analyzed herbal tea consumption would give a small portion of the annual effective dose of 210Pb received in Poland – the annual effective radiation dose of 210Pb taken with herbal tea infusions (one glass daily) was calculated from 0.08 ± 0.01 to 3.17 ± 0.08 µSv.
摘要:本文介绍了波兰草药茶中210Pb有效提取水平的研究结果，作为人类饮食中这种放射性同位素的可能额外来源。分析了波兰最受欢迎的12种草药茶及其在过滤水和自来水中的冲泡，并计算了210Pb活性浓度和有效剂量(辐射)。干植物中210Pb活性浓度最高的是山楂(35.5 Bq kg - 1)，最低的是水飞蓟(3.25 Bq kg - 1)，山楂(46.1±0.7)和水飞蓟(6.50±0.29)mBq / 1茶包。水飞蓟的提取率为5.1±0.5 ~ 27.3±0.8%，枸杞的提取率为27.3±0.8%，石灰的提取率为7.3±0.6% ~桑的提取率为33.3±2.2%。根据研究发现，所分析的凉茶消费量会给波兰收到的210Pb年有效剂量的一小部分-凉茶(每天一杯)的年有效辐射剂量计算为0.08±0.01至3.17±0.08µSv。
{"title":"The level of 210Pb extraction efficiency in Polish herbal teas and the possible effective dose to consumers","authors":"A. Moniakowska, G. Olszewski, K. Block, D. Strumińska-Parulska","doi":"10.1080/10934529.2019.1678323","DOIUrl":"https://doi.org/10.1080/10934529.2019.1678323","url":null,"abstract":"Abstract The article presents the results of a study on the level of 210Pb efficiency extraction in Polish herbal teas as a possible additional source of this radioactive isotope in the human diet. The twelve most popular herbal teas available in Poland and their infusions in filtered and tap water were analyzed as well as 210Pb activity concentrations and effective doses (radiation) were calculated. The highest activity concentration of 210Pb in dried plants was determined in cistus – 35.5 Bq kg−1 dry wt, while the lowest was in milk thistle – 3.25 Bq kg−1 dry wt what gives respectively for cistus 46.1 ± 0.7 and 6.50 ± 0.29 mBq for milk thistle per one tea bag. The extraction efficiencies in the filtered water oscillated from 5.1 ± 0.5 for milk thistle to 27.3 ± 0.8% for cistus, while for the tap water they ranged from 7.3 ± 0.6% for lime to 33.3 ± 2.2% for white mulberry. Based on the study, it was found that the analyzed herbal tea consumption would give a small portion of the annual effective dose of 210Pb received in Poland – the annual effective radiation dose of 210Pb taken with herbal tea infusions (one glass daily) was calculated from 0.08 ± 0.01 to 3.17 ± 0.08 µSv.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"1 1","pages":"161 - 167"},"PeriodicalIF":0.0,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90330832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-28DOI: 10.1080/10934529.2019.1681220
J. Kwon, Hyung-Joo Park, Yun-Yeong Lee, Kyung-Suk Cho
Abstract Effects of operational parameters (initial nitrite concentration, initial nitrate concentration, carbon source, and COD/N ratio) on denitrification performance was evaluated using a sequencing batch reactor (SBR) under intermittent aeration. Complete denitrification was observed without N2O accumulation when the initial nitrite concentration was 100–500 mg-N·L−1. When the initial nitrate concentration was 75–300 mg-N·L−1, 95–96% of NO3−-N was completely reduced to N2 gas. Acetate was the most effective sole carbon source for the complete denitrification of the SBR under intermittent aeration, and 99% of NO3−-N was reduced to N2 gas. The optimum COD/N ratio was 8–12 for the complete denitrification, while NO2− accumulation was observed at low COD/N ratios of 1 and 2. In this study, N2O accumulation was not observed during the denitrification process regardless of operational condition. Paracoccus (15–68%), a representative aerobic denitrifying bacterium, was dominant in the SBR during the denitrification process, and the intermittent aeration condition could affect the abundance of Paracoccus in this study.
{"title":"Evaluation of denitrification performance and bacterial community of a sequencing batch reactor under intermittent aeration","authors":"J. Kwon, Hyung-Joo Park, Yun-Yeong Lee, Kyung-Suk Cho","doi":"10.1080/10934529.2019.1681220","DOIUrl":"https://doi.org/10.1080/10934529.2019.1681220","url":null,"abstract":"Abstract Effects of operational parameters (initial nitrite concentration, initial nitrate concentration, carbon source, and COD/N ratio) on denitrification performance was evaluated using a sequencing batch reactor (SBR) under intermittent aeration. Complete denitrification was observed without N2O accumulation when the initial nitrite concentration was 100–500 mg-N·L−1. When the initial nitrate concentration was 75–300 mg-N·L−1, 95–96% of NO3−-N was completely reduced to N2 gas. Acetate was the most effective sole carbon source for the complete denitrification of the SBR under intermittent aeration, and 99% of NO3−-N was reduced to N2 gas. The optimum COD/N ratio was 8–12 for the complete denitrification, while NO2− accumulation was observed at low COD/N ratios of 1 and 2. In this study, N2O accumulation was not observed during the denitrification process regardless of operational condition. Paracoccus (15–68%), a representative aerobic denitrifying bacterium, was dominant in the SBR during the denitrification process, and the intermittent aeration condition could affect the abundance of Paracoccus in this study.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"173 1","pages":"179 - 192"},"PeriodicalIF":0.0,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74157138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-28DOI: 10.1080/10934529.2019.1672458
Chelsea H Lam, T. Kurobe, P. Lehman, Mine Berg, B. Hammock, Marie E Stillway, P. Pandey, S. Teh
Abstract The herbicides glyphosate, imazamox and fluridone are herbicides, with low toxicity towards fish and invertebrates, which are applied to waterways to control invasive aquatic weeds. However, the effects of these herbicides on natural isolates of phytoplankton and cyanobacteria are unknown. Three species of microalgae found in the San Francisco Estuary (SFE)/Sacramento-San Joaquin River Delta (Delta) (Microcystis aeruginosa, Chlamydomonas debaryana, and Thalassiosira pseudonana) were exposed to the three herbicides at a range of concentrations in 96-well plates for 5–8 days. All three algal species were the most sensitive to fluridone, with IC50 of 46.9, 21, and 109 µg L−1 for M. aeruginosa, T. pseudonana and C. debaryana, respectively. Imazamox inhibited M. aeruginosa and T. pseudonana growth at 3.6 × 104 µg L−1 or higher, and inhibited C. debaryana growth at 1.0 × 105 µg L−1 or higher. Glyphosate inhibited growth in all species at ca. 7.0 × 104 µg L−1 or higher. Fluridone was the only herbicide that inhibited the microalgae at environmentally relevant concentrations in this study and susceptibility to the herbicide depended on the species. Thus, the application of fluridone may affect cyanobacteria and phytoplankton community composition in water bodies where it is applied.
{"title":"Toxicity of herbicides to cyanobacteria and phytoplankton species of the San Francisco Estuary and Sacramento-San Joaquin River Delta, California, USA","authors":"Chelsea H Lam, T. Kurobe, P. Lehman, Mine Berg, B. Hammock, Marie E Stillway, P. Pandey, S. Teh","doi":"10.1080/10934529.2019.1672458","DOIUrl":"https://doi.org/10.1080/10934529.2019.1672458","url":null,"abstract":"Abstract The herbicides glyphosate, imazamox and fluridone are herbicides, with low toxicity towards fish and invertebrates, which are applied to waterways to control invasive aquatic weeds. However, the effects of these herbicides on natural isolates of phytoplankton and cyanobacteria are unknown. Three species of microalgae found in the San Francisco Estuary (SFE)/Sacramento-San Joaquin River Delta (Delta) (Microcystis aeruginosa, Chlamydomonas debaryana, and Thalassiosira pseudonana) were exposed to the three herbicides at a range of concentrations in 96-well plates for 5–8 days. All three algal species were the most sensitive to fluridone, with IC50 of 46.9, 21, and 109 µg L−1 for M. aeruginosa, T. pseudonana and C. debaryana, respectively. Imazamox inhibited M. aeruginosa and T. pseudonana growth at 3.6 × 104 µg L−1 or higher, and inhibited C. debaryana growth at 1.0 × 105 µg L−1 or higher. Glyphosate inhibited growth in all species at ca. 7.0 × 104 µg L−1 or higher. Fluridone was the only herbicide that inhibited the microalgae at environmentally relevant concentrations in this study and susceptibility to the herbicide depended on the species. Thus, the application of fluridone may affect cyanobacteria and phytoplankton community composition in water bodies where it is applied.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"10 2 1","pages":"107 - 118"},"PeriodicalIF":0.0,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83372944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-28DOI: 10.1080/10934529.2019.1676065
Chi H. Nguyen, J. Field, R. Sierra-Alvarez
Abstract III-V semiconductor materials such as gallium arsenide (GaAs) and indium arsenide (InAs) are increasingly used in the fabrication of electronic devices. There is a growing concern about the potential release of these materials into the environment leading to effects on public and environmental health. The waste effluents from the chemical mechanical planarization process could impact microorganisms in biological wastewater treatment systems. Currently, there is only limited information about the inhibition of gallium- and indium-based nanoparticles (NPs) on microorganisms. This study evaluated the acute toxicity of GaAs, InAs, gallium oxide (Ga2O3), and indium oxide (In2O3) particulates using two microbial inhibition assays targeting methanogenic archaea and the marine bacterium, Aliivibrio fischeri. GaAs and InAs NPs were acutely toxic towards these microorganisms; Ga2O3 and In2O3 NPs were not. The toxic effect was mainly due to the release of soluble arsenic species and it increased with decreasing particle size and with increasing time due to the progressive corrosion of the NPs in the aqueous bioassay medium. Collectively, the results indicate that the toxicity exerted by the arsenide NPs under environmental conditions will vary depending on intrinsic properties of the material such as particle size as well as on the dissolution time and aqueous chemistry.
{"title":"Microbial toxicity of gallium- and indium-based oxide and arsenide nanoparticles","authors":"Chi H. Nguyen, J. Field, R. Sierra-Alvarez","doi":"10.1080/10934529.2019.1676065","DOIUrl":"https://doi.org/10.1080/10934529.2019.1676065","url":null,"abstract":"Abstract III-V semiconductor materials such as gallium arsenide (GaAs) and indium arsenide (InAs) are increasingly used in the fabrication of electronic devices. There is a growing concern about the potential release of these materials into the environment leading to effects on public and environmental health. The waste effluents from the chemical mechanical planarization process could impact microorganisms in biological wastewater treatment systems. Currently, there is only limited information about the inhibition of gallium- and indium-based nanoparticles (NPs) on microorganisms. This study evaluated the acute toxicity of GaAs, InAs, gallium oxide (Ga2O3), and indium oxide (In2O3) particulates using two microbial inhibition assays targeting methanogenic archaea and the marine bacterium, Aliivibrio fischeri. GaAs and InAs NPs were acutely toxic towards these microorganisms; Ga2O3 and In2O3 NPs were not. The toxic effect was mainly due to the release of soluble arsenic species and it increased with decreasing particle size and with increasing time due to the progressive corrosion of the NPs in the aqueous bioassay medium. Collectively, the results indicate that the toxicity exerted by the arsenide NPs under environmental conditions will vary depending on intrinsic properties of the material such as particle size as well as on the dissolution time and aqueous chemistry.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"53 3","pages":"168 - 178"},"PeriodicalIF":0.0,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91419432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-28DOI: 10.1080/10934529.2019.1668654
Anna Doloman, R. Sims, C. D. Miller
Abstract There is a need for a broad study addressing different preservation conditions of anaerobic sludge and its activity after a prolonged storage. This study compared four different preservation methods of mesophilic anaerobic sludge for a period of up to 12 months: storage at 23 ± 2 °C, +4 °C, ‒20 °C, and freeze-dried. Anaerobic sludge was sampled from upper and bottom ports of an up flow anaerobic sludge blanket (UASB) reactor fed with microalgae and sodium acetate at organic loading rate of 5.4 gCOD/L·d. Specific methanogenic activity (SMA) tests were performed on the sludge samples after 2.5, 6, and 12 months of storage. Results demonstrated a statistically significant decrease in the SMA of the bottom port preserved sludge, but not of the upper port sludge, regardless of the method used for preservation. A varying susceptibility to the storage of the two types of the anaerobic sludge can be explained by the content of the methanogenic microorganisms, with bottom port sludge having a higher amount of the methane producing species. Interestingly, lyophilized samples were able to produce similar amounts of biogas when compared to the other three storage conditions, with the only difference of having a longer re-activation period.
{"title":"Activity of preserved anaerobic sludge","authors":"Anna Doloman, R. Sims, C. D. Miller","doi":"10.1080/10934529.2019.1668654","DOIUrl":"https://doi.org/10.1080/10934529.2019.1668654","url":null,"abstract":"Abstract There is a need for a broad study addressing different preservation conditions of anaerobic sludge and its activity after a prolonged storage. This study compared four different preservation methods of mesophilic anaerobic sludge for a period of up to 12 months: storage at 23 ± 2 °C, +4 °C, ‒20 °C, and freeze-dried. Anaerobic sludge was sampled from upper and bottom ports of an up flow anaerobic sludge blanket (UASB) reactor fed with microalgae and sodium acetate at organic loading rate of 5.4 gCOD/L·d. Specific methanogenic activity (SMA) tests were performed on the sludge samples after 2.5, 6, and 12 months of storage. Results demonstrated a statistically significant decrease in the SMA of the bottom port preserved sludge, but not of the upper port sludge, regardless of the method used for preservation. A varying susceptibility to the storage of the two types of the anaerobic sludge can be explained by the content of the methanogenic microorganisms, with bottom port sludge having a higher amount of the methane producing species. Interestingly, lyophilized samples were able to produce similar amounts of biogas when compared to the other three storage conditions, with the only difference of having a longer re-activation period.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"4 1","pages":"119 - 125"},"PeriodicalIF":0.0,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90043461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-28DOI: 10.1080/10934529.2019.1672457
Rushika V. Patel, Rajesh Chudasama, Rutujaben Solanki, P. Patel, K. Parmar, N. Munshi
Abstract On-line detection of aromatic hydrocarbon pollutants in aqueous environments can be achieved by biosensing strains having fusion of gene responsible for pollutant sensing protein with a reporter gene. Regulatory proteins TbuT, HbpR and PhnR are such proteins for recognizing one-, two-and three-ring aromatic hydrocarbon pollutants respectively, for which the structure is not known till date. Aim of the present study was to predict the structure of proteins and to determine their in-silico interaction with array of pollutants. Structure prediction of proteins was performed using I-TASSER and Phyre2 and refined with ModRefiner and 3DRefine. Total 14 models were obtained for each protein and the best model had more than 95% coverage in Ramachandran plot region. After successful structure prediction, molecular interaction of proteins with respective aromatic hydrocarbon pollutants categorized by United States Environmental Protection Agency was studied using AutoDockVina where the binding energy was found to fall in range of −4.6 to −8.4 kcal/mol. The types of protein-pollutant interaction were analyzed by LigPlus and Discovery Studio 2017 R2 Client which were found to be similar for standard and pollutant compounds. This study enables us to predict the range of pollutants possible to be detected using these regulatory protein-based biosensors.
摘要通过融合污染物传感蛋白基因和报告基因的生物传感菌株，可以实现对水环境中芳香烃污染物的在线检测。调控蛋白TbuT、HbpR和PhnR分别是识别一环、二环和三环芳烃污染物的蛋白，其结构至今尚不清楚。本研究的目的是预测蛋白质的结构，并确定它们与一系列污染物的硅相互作用。使用I-TASSER和Phyre2进行蛋白质结构预测，并用ModRefiner和3DRefine进行细化。每种蛋白共获得14个模型，最佳模型在Ramachandran样区覆盖率达95%以上。在结构预测成功后，利用AutoDockVina软件研究了蛋白质与美国环境保护署分类的各芳烃污染物的分子相互作用，发现结合能在−4.6 ~−8.4 kcal/mol之间。通过LigPlus和Discovery Studio 2017 R2 Client分析蛋白质-污染物相互作用的类型，发现标准化合物和污染物化合物相似。这项研究使我们能够预测使用这些基于调节蛋白的生物传感器可能检测到的污染物范围。
{"title":"Structure prediction and molecular docking studies of aromatic hydrocarbon sensing proteins TbuT, HbpR and PhnR to detect priority pollutants","authors":"Rushika V. Patel, Rajesh Chudasama, Rutujaben Solanki, P. Patel, K. Parmar, N. Munshi","doi":"10.1080/10934529.2019.1672457","DOIUrl":"https://doi.org/10.1080/10934529.2019.1672457","url":null,"abstract":"Abstract On-line detection of aromatic hydrocarbon pollutants in aqueous environments can be achieved by biosensing strains having fusion of gene responsible for pollutant sensing protein with a reporter gene. Regulatory proteins TbuT, HbpR and PhnR are such proteins for recognizing one-, two-and three-ring aromatic hydrocarbon pollutants respectively, for which the structure is not known till date. Aim of the present study was to predict the structure of proteins and to determine their in-silico interaction with array of pollutants. Structure prediction of proteins was performed using I-TASSER and Phyre2 and refined with ModRefiner and 3DRefine. Total 14 models were obtained for each protein and the best model had more than 95% coverage in Ramachandran plot region. After successful structure prediction, molecular interaction of proteins with respective aromatic hydrocarbon pollutants categorized by United States Environmental Protection Agency was studied using AutoDockVina where the binding energy was found to fall in range of −4.6 to −8.4 kcal/mol. The types of protein-pollutant interaction were analyzed by LigPlus and Discovery Studio 2017 R2 Client which were found to be similar for standard and pollutant compounds. This study enables us to predict the range of pollutants possible to be detected using these regulatory protein-based biosensors.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"65 1","pages":"126 - 141"},"PeriodicalIF":0.0,"publicationDate":"2020-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88953565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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