Pub Date : 2019-11-28DOI: 10.1080/10934529.2019.1694817
R. Mines
Abstract This paper provides a review of the essential equations and parameters that are used to design bioreactor aeration systems. Major objectives were to determine if the log-deficit method (LDM) and non-linear regression method (NLRM) yielded different results for the volumetric oxygen mass transfer coefficient (KL a)T and dissolved oxygen (DO) saturation concentration (Cs)T . Another objective was to compare and evaluate oxygen uptake rates (OURs) from the traditional BOD bottle technique with OURs determined from mass balances around completely-mixed activated sludge (CMAS) reactors. Full- and bench-scale, non-steady state reaeration tests were performed using sodium sulfite and cobalt chloride in addition to operating bench-scale CMAS reactors. Full-and bench-scale reaeration testing indicated there was no significant difference in the estimate of (KL a)T in tap water using the LDM or NLRM. Similarly, (Cs)T values were the same for the LDM and NLRM for 70 out of 119 reaeration tests. Actual oxygen uptake rates (AOURs) measured using the BOD bottle technique versus calculated oxygen uptake rates (COURS) were the same for 26 out of 51 data sets evaluated. The alpha-factor (α) increased as the solids retention time (SRT) was increased.
{"title":"Oxygen transfer parameters and oxygen uptake rates revisited","authors":"R. Mines","doi":"10.1080/10934529.2019.1694817","DOIUrl":"https://doi.org/10.1080/10934529.2019.1694817","url":null,"abstract":"Abstract This paper provides a review of the essential equations and parameters that are used to design bioreactor aeration systems. Major objectives were to determine if the log-deficit method (LDM) and non-linear regression method (NLRM) yielded different results for the volumetric oxygen mass transfer coefficient (KL a)T and dissolved oxygen (DO) saturation concentration (Cs)T . Another objective was to compare and evaluate oxygen uptake rates (OURs) from the traditional BOD bottle technique with OURs determined from mass balances around completely-mixed activated sludge (CMAS) reactors. Full- and bench-scale, non-steady state reaeration tests were performed using sodium sulfite and cobalt chloride in addition to operating bench-scale CMAS reactors. Full-and bench-scale reaeration testing indicated there was no significant difference in the estimate of (KL a)T in tap water using the LDM or NLRM. Similarly, (Cs)T values were the same for the LDM and NLRM for 70 out of 119 reaeration tests. Actual oxygen uptake rates (AOURs) measured using the BOD bottle technique versus calculated oxygen uptake rates (COURS) were the same for 26 out of 51 data sets evaluated. The alpha-factor (α) increased as the solids retention time (SRT) was increased.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"54 1","pages":"345 - 353"},"PeriodicalIF":0.0,"publicationDate":"2019-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86893067","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 : 2019-11-26DOI: 10.1080/10934529.2019.1688020
X. He, Huandi Huang, Ying Tang, Lu-lu Guo
Abstract Prednisone acetate (PNSA) is one of the regular glucocorticoid medicines that have been detected in surface water. In this work, the removal of PNSA by ozone was systematically studied under various conditions, and degradation intermediates and reaction pathways were proposed. The results showed that aqueous ozonation was able to remove PNSA effectively, and low pH favored this reaction. The addition of tertiary butanol did not inhibit the oxidation of PNSA by ozone, suggesting that the degradation was caused mainly by the direct oxidation effect of ozone molecules. Moreover, the presence of carboxylated or hydroxylated multiwalled carbon nanotubes can enhance the removal efficiency of PNSA by ozone. Under neutral and acidic conditions, the degradation of PNSA followed pseudo-first-order reaction. Seven intermediates were detected via liquid chromatography-mass spectrometry, and the degradation pathways were then proposed by considering the relative charge density of the frontier orbitals calculated with the Gaussian program. The electrophilic reaction and the Criegee mechanism were the primary reaction mechanisms in the degradation of PNSA by ozone. Formic acid, acetic acid, and oxalic acid were detected as the final reaction products via ion chromatography. Additionally, the aquatic toxicity of the ozonation products was predicted using ECOSAR method. The biodegradation potentials of the pollutant and the ozonation products were estimated using BIOWINTM, suggesting that O3 treatment could significantly enhance the biodegradable potentials of PNSA and its transformation intermediates in the biological post-treatment process. This work can provide useful information for the treatment of PNSA-containing wastewaters.
{"title":"Kinetics and mechanistic study on degradation of prednisone acetate by ozone","authors":"X. He, Huandi Huang, Ying Tang, Lu-lu Guo","doi":"10.1080/10934529.2019.1688020","DOIUrl":"https://doi.org/10.1080/10934529.2019.1688020","url":null,"abstract":"Abstract Prednisone acetate (PNSA) is one of the regular glucocorticoid medicines that have been detected in surface water. In this work, the removal of PNSA by ozone was systematically studied under various conditions, and degradation intermediates and reaction pathways were proposed. The results showed that aqueous ozonation was able to remove PNSA effectively, and low pH favored this reaction. The addition of tertiary butanol did not inhibit the oxidation of PNSA by ozone, suggesting that the degradation was caused mainly by the direct oxidation effect of ozone molecules. Moreover, the presence of carboxylated or hydroxylated multiwalled carbon nanotubes can enhance the removal efficiency of PNSA by ozone. Under neutral and acidic conditions, the degradation of PNSA followed pseudo-first-order reaction. Seven intermediates were detected via liquid chromatography-mass spectrometry, and the degradation pathways were then proposed by considering the relative charge density of the frontier orbitals calculated with the Gaussian program. The electrophilic reaction and the Criegee mechanism were the primary reaction mechanisms in the degradation of PNSA by ozone. Formic acid, acetic acid, and oxalic acid were detected as the final reaction products via ion chromatography. Additionally, the aquatic toxicity of the ozonation products was predicted using ECOSAR method. The biodegradation potentials of the pollutant and the ozonation products were estimated using BIOWINTM, suggesting that O3 treatment could significantly enhance the biodegradable potentials of PNSA and its transformation intermediates in the biological post-treatment process. This work can provide useful information for the treatment of PNSA-containing wastewaters.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"13 1","pages":"292 - 304"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85377521","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 : 2019-11-24DOI: 10.1080/10934529.2019.1694346
Xiaofang Wang, Luyi Zou, Chenyu Mi, Hongyan Yu, Mengxue Dong, Y. Teng
Abstract Triclosan (TCS) is widely used in personal care products and acts as an antibacterial agent. Residues of TCS may have potential effects on the human health. In this article, the interaction between TCS and bovine serum albumin (BSA) has been characterized by using multi-spectroscopic approaches and molecular docking method under physiological conditions. Thermodynamic investigations revealed that TCS spontaneously bound to a binding site of BSA and hydrogen bonds played a dominant role in this process. The site marker competition experiments indicated that TCS bound at site II (subdomain IIIA) of BSA, which was well substantiated by molecular docking. The binding of TCS further led to changes of conformation and microenvironment of BSA. This work explored the interaction of TCS with BSA, which might be beneficial for evaluating the binding mechanism of other environmental pollutant at molecular level.
{"title":"Characterization of binding interaction of triclosan and bovine serum albumin","authors":"Xiaofang Wang, Luyi Zou, Chenyu Mi, Hongyan Yu, Mengxue Dong, Y. Teng","doi":"10.1080/10934529.2019.1694346","DOIUrl":"https://doi.org/10.1080/10934529.2019.1694346","url":null,"abstract":"Abstract Triclosan (TCS) is widely used in personal care products and acts as an antibacterial agent. Residues of TCS may have potential effects on the human health. In this article, the interaction between TCS and bovine serum albumin (BSA) has been characterized by using multi-spectroscopic approaches and molecular docking method under physiological conditions. Thermodynamic investigations revealed that TCS spontaneously bound to a binding site of BSA and hydrogen bonds played a dominant role in this process. The site marker competition experiments indicated that TCS bound at site II (subdomain IIIA) of BSA, which was well substantiated by molecular docking. The binding of TCS further led to changes of conformation and microenvironment of BSA. This work explored the interaction of TCS with BSA, which might be beneficial for evaluating the binding mechanism of other environmental pollutant at molecular level.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"15 1","pages":"318 - 325"},"PeriodicalIF":0.0,"publicationDate":"2019-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85065421","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 : 2019-11-14DOI: 10.1080/10934529.2019.1686890
Austin Taterka, R. Miskewitz, R. Sharp, J. Patoczka
Abstract Combined sewer overflow (CSO) water introduces pathogens to receiving waters. To control pathogenic releases, chlorine may be added to disinfect CSO water. The added chlorine may react with water constituents to form oxidative species known as chlorine-produced oxidants (CPO). CPO are the sum of free and combined oxidative species that form upon adding free chlorine-bearing compounds (e.g. gaseous chlorine or hypochlorite) to water. CPO discharge is often regulated by governing agencies. Current methods to model CPO behavior do not account for CPO decay and dilution simultaneously in receiving water. This study creates a novel model for CPO demand and dilution in receiving water from chlorinated effluent in order to determine site-specific practices for implementation of a CSO water disinfection regime. To do this, representative receiving water was collected and dosed with 1, 2, and 4 mg/L chlorine. The residual chlorine was measured at intervals up to 30 min after dosing. The immediate and subsequent chlorine demand was calculated, with the subsequent demand modeled by simultaneous application of dilution and decay using pseudo-first-order decay kinetics. A comparison of model calculations indicates that application of dilution before decay underestimates CPO demand, while application of decay before dilution overestimates CPO demand.
{"title":"Modeling chlorine-produced oxidant demand and dilution in chlorinated combined sewer overflow discharges","authors":"Austin Taterka, R. Miskewitz, R. Sharp, J. Patoczka","doi":"10.1080/10934529.2019.1686890","DOIUrl":"https://doi.org/10.1080/10934529.2019.1686890","url":null,"abstract":"Abstract Combined sewer overflow (CSO) water introduces pathogens to receiving waters. To control pathogenic releases, chlorine may be added to disinfect CSO water. The added chlorine may react with water constituents to form oxidative species known as chlorine-produced oxidants (CPO). CPO are the sum of free and combined oxidative species that form upon adding free chlorine-bearing compounds (e.g. gaseous chlorine or hypochlorite) to water. CPO discharge is often regulated by governing agencies. Current methods to model CPO behavior do not account for CPO decay and dilution simultaneously in receiving water. This study creates a novel model for CPO demand and dilution in receiving water from chlorinated effluent in order to determine site-specific practices for implementation of a CSO water disinfection regime. To do this, representative receiving water was collected and dosed with 1, 2, and 4 mg/L chlorine. The residual chlorine was measured at intervals up to 30 min after dosing. The immediate and subsequent chlorine demand was calculated, with the subsequent demand modeled by simultaneous application of dilution and decay using pseudo-first-order decay kinetics. A comparison of model calculations indicates that application of dilution before decay underestimates CPO demand, while application of decay before dilution overestimates CPO demand.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"28 9","pages":"266 - 274"},"PeriodicalIF":0.0,"publicationDate":"2019-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91497989","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 : 2019-11-10DOI: 10.1080/10934529.2019.1688044
Zhi-Qing Zhao, Xiaoli Shen, T. Zheng, Liang Lv, Yao Su, Abbas Ghulam
Abstract Among three monofluoroanilines, 2-fluoroaniline (2-FA) and 3-fluoroaniline (3-FA) exhibit relatively poor biodegradability. This work examined their degradation characteristics in a mixed culture system and also analyzed the microorganism community. After acclimation for 58 d and 43 d, the high removal efficiency of 100% of 2-FA and 95.3% of 3-FA was obtained by adding 25 mg L−1 of 2-FA or 3-FA to the two reactors, respectively. In addition, the high defluorination rates of 2-FA and 3-FA were observed to be 87.0% and 89.3%, respectively. The degradation kinetics showed that the maximum specific degradation rates of 2-FA and 3-FA were (21.23 ± 0.91) mg FA (g•VSS·h)−1, and (11.75 ± 0.99) mg FA (g•VSS·h)−1, respectively. PCR-DGGE analysis revealed that the unique bacteria degrading 2-FA were mainly composed of six genera (Novosphingobium, Bradyrhizobium, Aquaspirillum, Aminobacter, Ochrobactrum, and Labrys), and five genera that degraded 3-FA (Ochrobactrum, Aquaspirillum, Lachnobacterium, Bradyrhizobium, and Variovorax). Analysis of the key catabolic enzyme activities indicated that the simultaneous hydroxylation and dehalogenation were involved in monooxygenase elimination of 2-FA and conversion of 3-FA to 4-fluorocatechol by dioxygenase, indicating that enriched mixed cultures were effective to metabolize 2-FA or 3-FA by unconventional pathways to prevent the accumulation of toxic metabolites.
摘要在三种单氟苯胺中，2-氟苯胺(2-FA)和3-氟苯胺(3-FA)的生物降解性相对较差。本文研究了它们在混合培养系统中的降解特性，并分析了微生物群落。驯化58 d和43 d后，在两个反应器中分别添加25 mg L−1的2-FA和3-FA, 2-FA的去除率达到100%，3-FA的去除率达到95.3%。2-FA和3-FA的除氟率分别为87.0%和89.3%。降解动力学表明，2-FA和3-FA的最大特定降解率分别为(21.23±0.91)mg FA (g•VSS·h)−1和(11.75±0.99)mg FA (g•VSS·h)−1。PCR-DGGE分析显示，降解2-FA的独特细菌主要由6个属(Novosphingobium、Bradyrhizobium、Aquaspirillum、Aminobacter、Ochrobactrum和Labrys)和5个属(Ochrobactrum、Aquaspirillum、Lachnobacterium、Bradyrhizobium和Variovorax)组成。关键分解代谢酶活性分析表明，双加氧酶对2-FA的消除和3-FA向4-氟儿茶酚的转化同时发生羟基化和脱卤作用，表明富集的混合培养可以有效地通过非常规途径代谢2-FA或3-FA，以防止有毒代谢物的积累。
{"title":"Aerobic degradation of 2- and 3-fluoroaniline in mixed culture systems and microbial community analysis","authors":"Zhi-Qing Zhao, Xiaoli Shen, T. Zheng, Liang Lv, Yao Su, Abbas Ghulam","doi":"10.1080/10934529.2019.1688044","DOIUrl":"https://doi.org/10.1080/10934529.2019.1688044","url":null,"abstract":"Abstract Among three monofluoroanilines, 2-fluoroaniline (2-FA) and 3-fluoroaniline (3-FA) exhibit relatively poor biodegradability. This work examined their degradation characteristics in a mixed culture system and also analyzed the microorganism community. After acclimation for 58 d and 43 d, the high removal efficiency of 100% of 2-FA and 95.3% of 3-FA was obtained by adding 25 mg L−1 of 2-FA or 3-FA to the two reactors, respectively. In addition, the high defluorination rates of 2-FA and 3-FA were observed to be 87.0% and 89.3%, respectively. The degradation kinetics showed that the maximum specific degradation rates of 2-FA and 3-FA were (21.23 ± 0.91) mg FA (g•VSS·h)−1, and (11.75 ± 0.99) mg FA (g•VSS·h)−1, respectively. PCR-DGGE analysis revealed that the unique bacteria degrading 2-FA were mainly composed of six genera (Novosphingobium, Bradyrhizobium, Aquaspirillum, Aminobacter, Ochrobactrum, and Labrys), and five genera that degraded 3-FA (Ochrobactrum, Aquaspirillum, Lachnobacterium, Bradyrhizobium, and Variovorax). Analysis of the key catabolic enzyme activities indicated that the simultaneous hydroxylation and dehalogenation were involved in monooxygenase elimination of 2-FA and conversion of 3-FA to 4-fluorocatechol by dioxygenase, indicating that enriched mixed cultures were effective to metabolize 2-FA or 3-FA by unconventional pathways to prevent the accumulation of toxic metabolites.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"86 1","pages":"305 - 317"},"PeriodicalIF":0.0,"publicationDate":"2019-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87685653","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 : 2019-11-08DOI: 10.1080/10934529.2019.1688019
G. Gómez, M. Salinas, N. Ruiz-Tagle, Katherine E Sossa, G. Vidal
Abstract The objective of this research was to evaluate the distribution of the molecular weights of the recalcitrant organic matter contained in kraft mill effluents and identify microbial consortia responsible for an anaerobic biodegradable fraction. As a result, the average removal efficiencies of chemical organic demand (COD) and biological oxygen demand (BOD5) during the entire period of operation were 28% and 53%, respectively. The non-biodegradable organic matter was detected at molecular weights less than 1000 Da. However, most of the organic matter was in the molecular weight fraction higher than 10000 Da with 32 ± 11.6% COD as well as color (42.3 ± 8.7%), total phenolic compounds (35.9 ± 7.9%) and adsorbable organic compounds (AOX) (13.0 ± 2.7%). Methanogenic acetoclastic archaea of the genera Methanomethylovorans and Methanosarcina were found in the surface and middle zones of the reactor. Moreover, Methanosaeta and Methanolinea were identified in the low zone of the reactor. In all zones of the reactor, Desulfomicrobium and Desulfovibrio were found to be the most dominant genera of sulfate-reducing bacteria (SRB).
{"title":"Molecular weight distribution of the recalcitrant organic matter contained in kraft mill effluents and the identification of microbial consortia responsible for an anaerobic biodegradable fraction","authors":"G. Gómez, M. Salinas, N. Ruiz-Tagle, Katherine E Sossa, G. Vidal","doi":"10.1080/10934529.2019.1688019","DOIUrl":"https://doi.org/10.1080/10934529.2019.1688019","url":null,"abstract":"Abstract The objective of this research was to evaluate the distribution of the molecular weights of the recalcitrant organic matter contained in kraft mill effluents and identify microbial consortia responsible for an anaerobic biodegradable fraction. As a result, the average removal efficiencies of chemical organic demand (COD) and biological oxygen demand (BOD5) during the entire period of operation were 28% and 53%, respectively. The non-biodegradable organic matter was detected at molecular weights less than 1000 Da. However, most of the organic matter was in the molecular weight fraction higher than 10000 Da with 32 ± 11.6% COD as well as color (42.3 ± 8.7%), total phenolic compounds (35.9 ± 7.9%) and adsorbable organic compounds (AOX) (13.0 ± 2.7%). Methanogenic acetoclastic archaea of the genera Methanomethylovorans and Methanosarcina were found in the surface and middle zones of the reactor. Moreover, Methanosaeta and Methanolinea were identified in the low zone of the reactor. In all zones of the reactor, Desulfomicrobium and Desulfovibrio were found to be the most dominant genera of sulfate-reducing bacteria (SRB).","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"26 1","pages":"281 - 291"},"PeriodicalIF":0.0,"publicationDate":"2019-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79677227","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 : 2019-10-08DOI: 10.1080/10934529.2019.1673609
Z. Amini, M. Givianrad, M. Saber-Tehrani, P. A. Azar, S. W. Husain
Abstract N-doped TiO2/SiO2/Fe3O4 as a new magnetic photocatalyst that is active in visible light has been prepared by simple sol–gel method. The prepared samples were characterized by XRD, FESEM, EDX, TEM, BET, BJH, VSM, XPS, FT-IR, and DRS–UV/Vis analysis. The photocatalytic effect of synthesized samples on naproxen degradation was studied. The operational parameters were optimized through central composite design to achieve maximum efficiency. The optimum values for maximum efficiency were obtained at pH of 4.29, catalyst mass of 0.06 g, naproxen concentration of 9.33 mg L−1, and irradiation time of 217.06 min. At these optimum conditions, the maximum photocatalytic degradation percentages of naproxen were found to be 96.32% at desirability function value of 1.0. Coupling the electrical current with the photocatalytic process proved that the electrical current was considerably efficient in decreasing the degradation time of removing the naproxen from aqueous solutions. The photocatalytic activity of the nanoparticles was also studied under sunlight. Considering the results provided by UV–Vis spectrophotometry and total organic carbon, it was found that the prepared samples are extraordinarily efficient to degrade naproxen under both purple LED and solar lights. Furthermore, the effect of different scavenger agents on naproxen degradation has been studied.
{"title":"Synthesis of N-doped TiO2/SiO2/Fe3O4 magnetic nanocomposites as a novel purple LED illumination-driven photocatalyst for photocatalytic and photoelectrocatalytic degradation of naproxen: optimization and different scavenger agents study","authors":"Z. Amini, M. Givianrad, M. Saber-Tehrani, P. A. Azar, S. W. Husain","doi":"10.1080/10934529.2019.1673609","DOIUrl":"https://doi.org/10.1080/10934529.2019.1673609","url":null,"abstract":"Abstract N-doped TiO2/SiO2/Fe3O4 as a new magnetic photocatalyst that is active in visible light has been prepared by simple sol–gel method. The prepared samples were characterized by XRD, FESEM, EDX, TEM, BET, BJH, VSM, XPS, FT-IR, and DRS–UV/Vis analysis. The photocatalytic effect of synthesized samples on naproxen degradation was studied. The operational parameters were optimized through central composite design to achieve maximum efficiency. The optimum values for maximum efficiency were obtained at pH of 4.29, catalyst mass of 0.06 g, naproxen concentration of 9.33 mg L−1, and irradiation time of 217.06 min. At these optimum conditions, the maximum photocatalytic degradation percentages of naproxen were found to be 96.32% at desirability function value of 1.0. Coupling the electrical current with the photocatalytic process proved that the electrical current was considerably efficient in decreasing the degradation time of removing the naproxen from aqueous solutions. The photocatalytic activity of the nanoparticles was also studied under sunlight. Considering the results provided by UV–Vis spectrophotometry and total organic carbon, it was found that the prepared samples are extraordinarily efficient to degrade naproxen under both purple LED and solar lights. Furthermore, the effect of different scavenger agents on naproxen degradation has been studied.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"40 1","pages":"1254 - 1267"},"PeriodicalIF":0.0,"publicationDate":"2019-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73742094","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 : 2019-09-19DOI: 10.1080/10934529.2019.1631087
C. Estrada-Vázquez, Abimael Salinas-Pacheco, E. Peralta-Reyes, H. Poggi‐Varaldo, A. Regalado-Méndez
Abstract In this work, the parametric optimization of real domestic wastewater treated in an activated sludge sequencing batch reactor (SBR) was performed by means of the response surface methodology (RSM). The influences of influent organic matter concentration as chemical oxygen demand (CODinf), biomass concentration (Xs) and aeration time (t) on the COD, organic matter removal efficiency as COD (η) and sludge volume index (SVI) were determined to evaluate the performance of activated sludge SBR. The results showed that organic matter efficiency and maximum SVI were obtained at a t of 12 h, 300 mg L−1 of CODinf and 2000 mg L−1 of Xs. The SBR-activated sludge exhibited a η of 73% and an SVI of 119 mL g−1. Both values indicated a very good performance. Furthermore, the COD of the effluent under these conditions complied with Mexican regulations for wastewater discharged into water bodies.
摘要采用响应面法(RSM)对活性污泥序批式反应器(SBR)处理的实际生活污水进行了参数优化。通过测定进水有机物浓度如化学需氧量(CODinf)、生物量浓度(Xs)和曝气时间(t)对COD、有机物去除率如COD (η)和污泥体积指数(SVI)的影响，评价活性污泥SBR的性能。结果表明，在CODinf浓度为300 mg L−1、Xs浓度为2000 mg L−1的条件下，12 h有机质效率和SVI最大。sbr活性污泥的η值为73%，SVI为119 mL g−1。这两个值都表明性能非常好。此外，在这些条件下，废水的COD符合墨西哥关于向水体排放废水的规定。
{"title":"Parametric optimization of domestic wastewater treatment in an activated sludge sequencing batch reactor using response surface methodology","authors":"C. Estrada-Vázquez, Abimael Salinas-Pacheco, E. Peralta-Reyes, H. Poggi‐Varaldo, A. Regalado-Méndez","doi":"10.1080/10934529.2019.1631087","DOIUrl":"https://doi.org/10.1080/10934529.2019.1631087","url":null,"abstract":"Abstract In this work, the parametric optimization of real domestic wastewater treated in an activated sludge sequencing batch reactor (SBR) was performed by means of the response surface methodology (RSM). The influences of influent organic matter concentration as chemical oxygen demand (CODinf), biomass concentration (Xs) and aeration time (t) on the COD, organic matter removal efficiency as COD (η) and sludge volume index (SVI) were determined to evaluate the performance of activated sludge SBR. The results showed that organic matter efficiency and maximum SVI were obtained at a t of 12 h, 300 mg L−1 of CODinf and 2000 mg L−1 of Xs. The SBR-activated sludge exhibited a η of 73% and an SVI of 119 mL g−1. Both values indicated a very good performance. Furthermore, the COD of the effluent under these conditions complied with Mexican regulations for wastewater discharged into water bodies.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"1 1","pages":"1197 - 1205"},"PeriodicalIF":0.0,"publicationDate":"2019-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89886994","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 : 2019-09-06DOI: 10.1080/10934529.2019.1656498
T. Stafilov, R. Šajn
Abstract The purpose of the study was to determine the spatial distribution and pollution assessment of 39 chemical elements in soil from the Republic of North Macedonia. From the whole territory of the country top soil samples (0–30 cm) were collected from 995 locations with a grid of 5 × 5 km distance between the sampling locations. Two analytical techniques were used for the analysis of soil samples: inductively coupled plasma–atomic emission spectrometry and inductively coupled plasma–mass spectrometry. Based on a comparison of statistical parameters, spatial distribution of particular elements and results of cluster and factor analysis, four mаin geochemical associations were identified: (1) association connected with the Neogene and Quaternary volcanism (Ba, Be, Ce, Hf, K, La, Rb, Th, Tl, U and Zr); (2) association of siderophile elements (Co, Cu, Fe, Mn, Sc, Ti and V); (3) association connected with ophiolites and Mesozoic ultrabasic magmatic rocks of Vardar zone (Cr and Ni) and (4) chalcophile (sulphide) elements (As, Bi, Cd, Pb, Sb, Sn and Zn). The regional distribution was prepared according to the eight statistical regions in Macedonia, distribution according to 15 most common geological formation and distribution according to 13 pedological units.
{"title":"Spatial distribution and pollution assessment of heavy metals in soil from the Republic of North Macedonia","authors":"T. Stafilov, R. Šajn","doi":"10.1080/10934529.2019.1656498","DOIUrl":"https://doi.org/10.1080/10934529.2019.1656498","url":null,"abstract":"Abstract The purpose of the study was to determine the spatial distribution and pollution assessment of 39 chemical elements in soil from the Republic of North Macedonia. From the whole territory of the country top soil samples (0–30 cm) were collected from 995 locations with a grid of 5 × 5 km distance between the sampling locations. Two analytical techniques were used for the analysis of soil samples: inductively coupled plasma–atomic emission spectrometry and inductively coupled plasma–mass spectrometry. Based on a comparison of statistical parameters, spatial distribution of particular elements and results of cluster and factor analysis, four mаin geochemical associations were identified: (1) association connected with the Neogene and Quaternary volcanism (Ba, Be, Ce, Hf, K, La, Rb, Th, Tl, U and Zr); (2) association of siderophile elements (Co, Cu, Fe, Mn, Sc, Ti and V); (3) association connected with ophiolites and Mesozoic ultrabasic magmatic rocks of Vardar zone (Cr and Ni) and (4) chalcophile (sulphide) elements (As, Bi, Cd, Pb, Sb, Sn and Zn). The regional distribution was prepared according to the eight statistical regions in Macedonia, distribution according to 15 most common geological formation and distribution according to 13 pedological units.","PeriodicalId":15733,"journal":{"name":"Journal of Environmental Science and Health, Part A","volume":"45 1","pages":"1457 - 1474"},"PeriodicalIF":0.0,"publicationDate":"2019-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80982396","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 : 2019-09-03DOI: 10.1080/10934529.2019.1656968
L. Hall, R. Alden, Ronald D. Anderson, W. D. Killen
Abstract Multivariate spatial patterns of 38 environmental variables (habitat metrics, metals, pyrethroids and sediment characteristics) and 14 benthic metrics were determined from over a decade of sampling in five California waterbodies. Canonical discriminant analyses produced very highly significant separations of the five watersheds based on environmental variables. The discriminant analyses based on benthic metrics also produced highly significant separations, although confidence ellipses were not quite as well separated as the environmental variables. Separation of creeks made ecological sense as Pleasant Grove Creek (PGC), which appeared to have greater habitat quality also had benthic metrics indicative of less stressed benthic communities, while the Santa Maria River watershed (SM) appeared to have lower habitat quality and more toxicants in the sediments also appeared to have benthic communities indicative of stress-tolerant taxa. The benthic community health of the other three creeks (Arcade Creek [ARC], Kirker Creek [KC] and Salinas Streams [SAL]) were considered intermediate in apparent stress between PGC and SM. Overall, benthic communities were somewhat more similar between creeks than were the environmental conditions. Benthic communities have greater overlap in characteristics than would be expected from environmental conditions, perhaps due to a greater resilience since they are generally dominated by tolerant benthic taxa.
摘要通过对加州5个水体10多年的采样，确定了38个环境变量(生境指标、金属、拟除虫菊酯和沉积物特征)和14个底栖生物指标的多变量空间格局。典型判别分析产生了基于环境变量的五个流域的非常显著的分离。基于底栖生物指标的判别分析也产生了高度显著的分离，尽管置信椭圆不像环境变量那样分离得很好。溪流的分离具有生态学意义，因为Pleasant Grove Creek (PGC)的栖息地质量较高，其底栖生物指标表明底栖生物群落的压力较小，而Santa Maria River流域(SM)的栖息地质量较低，沉积物中有毒物质较多，其底栖生物群落表明其具有耐压力的分类群。Arcade Creek [ARC]、Kirker Creek [KC]和Salinas Streams [SAL]的底栖生物群落健康处于PGC和SM之间的中等水平。总的来说，底栖生物群落在小溪之间比环境条件更相似。底栖生物群落在特征上的重叠比环境条件下的预期要大，这可能是由于它们通常由耐受性强的底栖生物类群主导，因此具有更大的复原力。
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