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1.
Sci Total Environ ; 691: 322-331, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31323577

RESUMO

A detailed comparison of sand filtration (SF) and ultrafiltration (UF) was conducted in this study with the aim to provide systematic support for alternative UF and SF technologies. The results of natural organic matter (NOM) removal indicated that SF conferred a slightly higher removal rate for UV-absorbing compounds, humic-like substances and protein-like substances than UF, with removal efficiencies of 21.9%, 19.8% and 26.1%, respectively. In addition, SF and UF exhibited different removal performances for organic fractions: UF better removed high molecular-weight (MW) organics, while SF exhibited higher removal of medium-MW organics. Furthermore, chlorine and chlorine dioxide were used as disinfectants to compare the different influences of SF and UF on disinfection by-product (DBP) formation. Unexpectedly, SF exhibited a better capacity for reducing the formation of chlorite than the UF process, with concentrations of 0.57 mg/L and 0.69 mg/L, respectively. Importantly, for the emergency scenario, e.g. seasonal algae pollution, the UF process achieved significantly higher removal of algae cells (98.7%) than SF due to size exclusion, indicating substantial resistance to algae load shocks. Therefore, these findings are beneficial for making practical decisions to adopt SF or UF technology in drinking water treatment plants.


Assuntos
Ultrafiltração/métodos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Desinfetantes/análise , Desinfecção , Água Potável/química , Membranas Artificiais
2.
Environ Sci Pollut Res Int ; 26(22): 22485-22493, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31161546

RESUMO

A sensitive and reliable analytical method has been developed and validated for the determination of five Alternaria toxins, including tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), and tentoxin (TEN), in drinking water using a one-step enrichment and clean-up strategy followed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Drinking water samples were preprocessed using excess sodium sulfite to remove residual chlorine, and the pH was adjusted by formic acid. Analytes were concentrated and purified from the water samples using hydrophilic-lipophilic balanced (HLB) solid-phase extraction (SPE) cartridges. Chromatographic separation was performed on an Acquity HSS C18 column using 0.1 mM ammonium carbonate and methanol as the mobile phase. The average recoveries at three spiked levels (0.1, 0.5, and 1 ng/L for TeA, AOH, and ALT; 0.01, 0.05, and 0.1 ng/L for TEN and AME) were 76.1-106.5%, with an intra-day precision less than 15.5% and inter-day precision of 11.8-16.5%. The limits of detection (LODs) were 0.05 ng/L for TeA, AOH, and ALT and 0.005 ng/L for TEN and AME. The limits of quantification (LOQs) were 0.1 ng/L for TeA, AOH, and ALT and 0.01 ng/L for TEN and AME. The developed method was applied to monitor 289 drinking water samples collected in Beijing from 2015 to 2017, and TeA and TEN were found in 28 samples, with concentrations ranging from 0.16 to 2.7 ng/L and 0.21 to 2.2 ng/L, respectively.


Assuntos
Alternaria , Água Potável/química , Micotoxinas/análise , Poluentes da Água/análise , Pequim , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Lactonas , Limite de Detecção , Extração em Fase Sólida , Espectrometria de Massas em Tandem/métodos
3.
Environ Sci Pollut Res Int ; 26(22): 22945-22957, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177420

RESUMO

Groundwater is a major source of drinking water for many Canadians, and contamination by heavy metals poses a significant risk to people and the environment. In this study, three water quality indices are studied in the vicinity of an unlined landfill in a semiarid climate. The study investigates indices using geostatistical analysis and ordinary kriging. This study employs a novel coupling technique in order to compare the index-based maps to a groundwater quality map from overlapping heavy metal kriged maps. A total of 11 heavy metals were evaluated in preliminary analysis, but only four (Mn, As, Fe, and U) had higher concentrations than allowable limits in some or all of the monitoring wells at the site. Results from mean-based classification of indices suggest the aquifer in proximity to the landfill has been impacted by metal contaminants. Kriged maps show that the spatial variations of Mn and U are similar, while results of Fe and As are also similar. However, the two sets of maps have distinctly different patterns. Maps for indices show an elevated plateau extending from the unlined landfill to the southeast corner, implying that the landfill may have negatively impacted groundwater quality. A groundwater quality map is developed by overlaying the heavy metal maps. The resulting map shows that the north and west parts of the study have lower groundwater pollution with respect to metal contaminants. The groundwater quality map may be more applicable for practitioners who need comprehensive water quality measurement.


Assuntos
Água Potável/análise , Água Subterrânea/análise , Metais Pesados/análise , Canadá , Água Potável/química , Metais Pesados/química , Análise Espacial , Instalações de Eliminação de Resíduos , Qualidade da Água
4.
Sci Total Environ ; 685: 380-391, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31176223

RESUMO

Water treatments that provide efficient removal of organic and inorganic disinfection by-product (DBP) precursors across variable natural organic matter (NOM) sources are desirable. Treatments that effectively remove inorganic DBP precursors such as bromide, which significantly shift the speciation of DBP formation towards more toxic DBPs, are of particular interest and have been less investigated. This study characterised NOM isolated from three major drinking water sources in Southeast Queensland (SEQ), Australia, and compared it to the International Humic Substances Society (IHSS) Suwannee River NOM isolate (SR) in terms of DBP precursor removal treatments and DBP formation. Each NOM isolate was used to make synthetic water samples with otherwise identical water quality parameters, that were treated with enhanced coagulation (EC) or EC followed by; anion exchange (MIEX® resin), powdered activated carbon (PAC), granular activated carbon (GAC) or silver impregnated activated carbon (SIAC), to investigate the removal of DBP precursors (bromide and DOC), minimisation of DBPs, as well as the change in specific chlorine demand. EC/SIAC treatment was the most effective method of DBP control studied, due to the efficient simultaneous NOM and bromide adsorption of the SIAC (99 ±â€¯1% bromide removal regardless of NOM source). This treatment also resulted in >92% removal of each of the measured DBPs across all NOM sources, with the exception of DBAN and 1,1-DCP, which achieved >80% removal across all NOM sources. Increases in tribromomethane (TBM) and dibromoacetonitrile (DBAN) formation were observed after all other treatment/NOM-isolate combinations, due to increased Br:DOC ratio after treatment, whereas chlorinated DBPs were generally well-controlled by all treatment/NOM-isolate combinations. Differences in reactivity of the individual NOM isolates were found to be related to both the origin of the isolate and the treatment employed, however, bromide removal capacity for each treatment was independent of NOM source.


Assuntos
Monitoramento Ambiental , Substâncias Húmicas/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Austrália , Desinfetantes/análise , Desinfecção , Água Potável/química , Poluentes Químicos da Água/normas
5.
Sci Total Environ ; 685: 410-418, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31176226

RESUMO

Polar, low molecular weight pesticides such as metaldehyde are challenging and costly to remove from drinking water using conventional treatment methods. Although biological treatments can be effective at treating micropollutants, through biodegradation and sorption processes, only some operational biofilters have shown the ability to remove metaldehyde. As sorption plays a minor role for such polar organic micropollutants, biodegradation is therefore likely to be the main removal pathway. In this work, the biodegradation of metaldehyde was monitored, and assessed, in an operational slow sand filter. Long-term data showed that metaldehyde degradation improved when inlet concentrations increased. A comparison of inactive and active sand batch reactors showed that metaldehyde removal happened mainly through biodegradation and that the removal rates were greater after the biofilm was acclimated through exposure to high metaldehyde concentrations. This suggested that metaldehyde removal was reliant on enrichment and that the process could be engineered to decrease treatment times (from days to hours). Through-flow experiments using fluidised bed reactors, showed the same behaviour following metaldehyde acclimation. A 40% increase in metaldehyde removal was observed in acclimated compared with non-acclimated columns. This increase was sustained for >40 days, achieving an average of 80% removal and compliance (<0.1 µâ€¯L-1) for >20 days. An initial microbial analysis of the acclimated and non-acclimated biofilm from the same filter materials, showed that the microbial community in acclimated sand was significantly different. This work presents a novel conceptual template for a faster, chemical free, low cost, biological treatment of metaldehyde and other polar pollutants in drinking water. In addition, this is the first study to report kinetics of metaldehyde degradation in an active microbial biofilm at a WTW.


Assuntos
Acetaldeído/análogos & derivados , Reatores Biológicos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Acetaldeído/análise , Biodegradação Ambiental , Água Potável/química
6.
Ecotoxicol Environ Saf ; 181: 194-201, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31195228

RESUMO

Due to potential adverse effects and bioaccumulation in biota and humans, perfluoroalkyl substances (PFASs) have raised wide attention in recent years. Ingestion is a vital pathway for PFASs to transmit to humans especially through water and fish. In present study, PFASs in water and fish from the drinking water source of Beijing in China were investigated. Three layers of water were collected in order to find the connection between concentrations of PFASs and depth of water, which showed no prominent correlation. PFASs in water from Miyun Reservoir with concentrations of 5.30-8.50 ng/L, were relatively lower compared with other reports on raw drinking water. Perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) were the dominant PFASs. In addition, six species of fish (including Cyprinus carpio, Carassius auratus, Erythroculter dabryi, Pseudohemiculter dispar, Hypophthalmichthys molitrix and Siniperca chuatsi) were analyzed, with concentrations of PFASs ranging from 1.70 to 14.32 ng/g wet weight (w.w.). Due to relatively stronger bioaccumulation potential, long chain perfluorinated carboxylates (PFCAs) and perfluorinated sulfonates (PFSAs) were detected with higher concentrations, especially perfluoroundecanoic acid (PFUdA) and perfluorodecanoic acid (PFDA). The estimated daily intake (EDI) of PFASs through drinking water and fish consumption were 0.20-0.34 and 3.44-12.61 ng/kg bw/day based on Exposure Factors Handbook of Chinese Population, respectively. In addition, the EDI of high-priority concern PFASs via pork, chicken and dust were also calculated, with value of 0.015-0.043, 0.003-0.013 and 0.074-0.390 ng/kg bw/day, respectively. The total EDI of PFOS and PFOA via diverse pathways were less than suggested tolerable daily intake (PFOS, 150 ng/kg bw/day; PFOA, 1500 ng/kg bw/day), indicating that the detected levels would not cause severe health effects on Beijing residents.


Assuntos
Água Potável/química , Peixes/metabolismo , Fluorcarbonetos/análise , Alimentos Marinhos , Poluentes Químicos da Água/análise , Adulto , Ácidos Alcanossulfônicos/análise , Animais , Pequim , Caprilatos/análise , Carpas/metabolismo , Criança , Ácidos Decanoicos/análise , Exposição Ambiental , Ácidos Graxos/análise , Fluorcarbonetos/toxicidade , Humanos , Medição de Risco
7.
Ecotoxicol Environ Saf ; 181: 241-247, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31200196

RESUMO

The coexistence of parent polycyclic aromatic hydrocarbons (PPAHs) and halogenated PAHs (HPAHs) in drinking water has generated much concern recently. However, a method to simultaneously determine these compounds has not been developed. In this study, a method using solid-phase extraction combined with gas chromatography-mass spectrometry for determination of PPAHs and HPAHs in drinking water was established. Forty-two target compounds including 16 PPAHs and 26 HPAHs (16 chlorinated PAHs (Cl-HPAHs) and 10 brominated PAHs (Br-PAHs)) were selected to evaluate the performance. Our results indicate enriching compounds with a LC18 cartridge and eluting with dichloromethane is optimal with recovery of 74.88-119.4%. Method detection limits ranged from 0.34 to 3.37 ng L-1 when only using 1 L samples. The method accomplished the analysis of trace PPAHs and HPAHs. We found the coexistence of PPAHs and HPAHs including 12 PPAHs, 2 Cl-PAHs and 3 Br-PAHs in tap water samples. Maximum total concentration of PPAHs and HPAHs reached 33.69 ng L-1 and 3.04 ng L-1, respectively. Trace Br-PAHs were first detected in drinking water. 6-bromobenzene[a]pyrene was dominated among the HPAHs with a concentration from 2.30 to 2.69 ng L-1. The simultaneous occurrence of PPAHs and HPAHs in drinking water should receive more attention, and their formation mechanism should be further explored.


Assuntos
Água Potável/química , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos Policíclicos Aromáticos/análise , Extração em Fase Sólida , Halogenação , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação
8.
Anal Chim Acta ; 1072: 75-80, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31146867

RESUMO

A highly specific and sensitive isothermal method for mercury detection using DNA-conjugated upconversion nanoparticles is reported. A single-stranded DNA containing thymine bases, used as the Hg2+-capturing element through the formation of thymine-Hg2+-thymine complex, is covalently attached to the NaYF4: Yb3+, Tm3+ nanoparticles. Luminescence resonance energy transfer takes place between the NaYF4: Yb3+, Tm3+ nanoparticles as donor and DNA-intercalating SYBR Green I as the acceptor upon excitation of 980 nm. The sensitivity and selectivity toward Hg2+ are enhanced using the nicking enzyme, Nt. Alwl, which leads to signal amplification. By monitoring the ratio of acceptor emission to a reference peak, the presence of Hg2+ ions are quantitatively determined with a lower detection limit of 0.14 nM, which is much lower than the US Environmental Protection Agency (EPA) limit of Hg2+ in drinking water.


Assuntos
DNA/química , Mercúrio/análise , Nanopartículas/química , Técnicas de Amplificação de Ácido Nucleico , Água Potável/química , Transferência Ressonante de Energia de Fluorescência
9.
J Chromatogr A ; 1601: 79-85, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31208796

RESUMO

Fluoro-functionalized paper was prepared and applied in solid phase extraction (SPE) for the analysis of trace-level perfluorinated compounds (PFCs). The proposed fluoro-functionalized paper-based solid-phase extraction (Fp-SPE) exhibits significant advantages for sample preparation, such as the biodegradability of paper-based adsorbent, simple manipulation and low cost. Owing to the fluorous affinity, the Fp-SPE technique with high sensitivity and high selectivity is more suitable for the selective enrichment of fluorine-containing molecules from the background of non-fluorinated organic compounds in a real water sample. Combined with high-performance liquid chromatography coupled with electrospray ionization-tandem mass spectrometry analysis (HPLC-MS/MS), the linear range of the PFCs, including perfluorobutyric acid (PFBA), perfluorooctanic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and perfluorodecanoic acid (PFDA), was 0.20-5.0 ng/L with the limits of detection (LOD) ranging from 0.04-0.05 ng/L and the limits of quantification (LOQ) ranging from 0.15-0.20 ng/L. The method was then applied to the analysis of tap water, river water and waste water samples. The results of the actual sample analysis are consistent with that by reverse phase SPE (RP-SPE).


Assuntos
Água Potável/química , Fluorcarbonetos/análise , Fluorcarbonetos/isolamento & purificação , Água Doce/química , Papel , Extração em Fase Sólida/métodos , Águas Residuárias/química , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Extração em Fase Sólida/instrumentação , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação
10.
J Environ Sci (China) ; 83: 123-132, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221375

RESUMO

The long-term persistence of antibiotic resistance in the environment, especially in drinking water, is a public health concern. Expression of an efflux pump, an important mechanism of resistance to antibiotics, usually confers a fitness cost in bacteria. In this study, we aimed to determine why antibiotic resistance conferred by overexpression of an efflux pump persisted in low-nutrient environments (TOC < 10 mg/L) such as drinking and source water in which antibiotic selective pressure might be very low or even absent. Competition experiments between wild-type Pseudomonas aeruginosa and ciprofloxacin-resistant mutants revealed that the fitness cost of ciprofloxacin resistance significantly decreased (p < 0.05) under low-nutrient (0.5 mg/L total organic carbon (TOC)) relative to high-nutrient (500 mg/L TOC) conditions. Mechanisms underlying this fitness cost were analyzed. The mexD gene expression in resistant bacteria (cip_3 strain) was significantly lower (p < 0.05) in low-nutrient conditions, with 10 mg/L TOC ((8.01 ±â€¯0.82)-fold), than in high-nutrient conditions, with 500 mg/L TOC ((48.89 ±â€¯4.16)-fold). Moreover, rpoS gene expression in resistant bacteria ((1.36 ±â€¯0.13)-fold) was significantly lower (p < 0.05) than that in the wild-type strain ((2.78 ±â€¯0.29)-fold) under low-nutrient conditions (10 mg/L TOC), suggesting a growth advantage. Furthermore, the difference in metabolic activity between the two competing strains was significantly smaller (p < 0.05) in low-nutrient conditions (5 and 0.5 mg/L TOC). These results suggest that nutrient levels are a key factor in determining the persistence of antibiotic resistance conferred by efflux pumps in the natural environment with trace amounts or no antibiotics.


Assuntos
Água Potável/microbiologia , Resistência Microbiana a Medicamentos/genética , Pseudomonas aeruginosa/genética , Poluentes da Água/análise , Ciprofloxacino , Água Potável/química , Aptidão Genética
11.
Environ Monit Assess ; 191(7): 469, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31243556

RESUMO

Sapanca Lake is important as a source of drinking water. In this study, we aimed to detect the bacterial quality, the frequency of bacterial antibiotic and heavy metal resistance, and bioindicator bacteria in the water samples taken from Sapanca Lake in the period between 2008 and 2010. The resistance of bacterial isolates to certain antibiotics and heavy metal salts was investigated using disc diffusion and minimum inhibitory concentration techniques. Bacterial metabolic reactions were tested using the VITEK 2 Compact 30 micro identification system for identification of cultivable bacteria. Twenty-seven bacteria species belonging to three classes-Gammaproteobacteria, Bacilli, Flavobacteria-were recorded for the first time in Sapanca Lake. The highest indicator bacteria were recorded as 71 ± 3.1 × 104 CFU/100 ml in the summer season. The highest bacterial resistance was recorded as 90.47% against vancomycin in a total of 84 strains. Ampicillin (88.10%) and amoxicillin-clavulanate (64.29%) followed them. The resistance varied between 10.71 and 59.52% against cefuroxime, kanamycin, aztreonam, ceftazidime, cefotaxime, and oxacillin. The highest frequency against heavy metal salts was recorded as 74.19% against NiCl2. The heavy metal resistance against Cu, Zn, Hg, and Cd detected as 52.38%, 46.42%, 33.33%, and 26.19%, respectively. The results showed that the occurrence of heavy metals and antibiotic sources in Sapanca Lake induced a tolerance in bacteria for the metal salts and antibiotic derivatives tested. The fluctuations in the indicator bacteria and the occurrence of pathogenic bacteria also showed the possibility that the coastal areas of Sapanca Lake had been exposed to contamination due to inadequate sewage treatment.


Assuntos
Antibacterianos/farmacologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/fisiologia , Monitoramento Ambiental/métodos , Metais Pesados/farmacologia , Bacillus/isolamento & purificação , Bactérias/isolamento & purificação , Água Potável/química , Água Potável/microbiologia , Flavobacteriaceae/isolamento & purificação , Gammaproteobacteria/isolamento & purificação , Lagos , Testes de Sensibilidade Microbiana , Turquia , Poluentes Químicos da Água/farmacologia , Poluição da Água
12.
J Environ Sci (China) ; 82: 124-131, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31133257

RESUMO

Incorporation of a carbon-based nutrient enhancement strategy for drinking water biofiltration is an attractive option, especially for source waters which contain recalcitrant organics. This study compared biofilters that were operated in parallel and individually enhanced with amino acids (including alanine, phenylalanine, and tryptophan), inulin, and sucrose to increase biomass concentration and promote biodegradation of dissolved organic carbon (DOC) in the source water, including disinfection by-product (DBP) precursors. Biomass activity was characterized by measuring adenosine tri-phosphate (ATP), dissolved oxygen (DO) consumption, and through the use of laccase and esterase enzyme assays. Performance was evaluated in terms of headloss, turbidity, pH, DOC, UV254, and DBP formation potential (DBP FP). The introduction of carbon-based nutrients significantly increased biomass activity, where ATP values peaked at 976 ng/g of filter media, 853 ng/g, and 513 ng/g for amino acids, inulin, and sucrose-spiked biofilters, respectively, while a non-spiked control only reached 104 ng/g. DO utilization by the enhanced biofilters was significantly higher than the control, with a strong correlation between ATP and DO uptake observed for all filters (R2 > 0.74). Laccase and esterase enzyme activities of enhanced biofilters were also elevated (p > 0.05), suggesting greater biodegradation potential. Operational parameters such as headloss development and turbidity control were not impaired by carbon supplementation strategies or an increase in biomass concentration and activity. However, the enhancement strategy did not provide improvement in terms of source water carbon removal (DOC and UV254) or DBP FP when treated filters were compared to a control.


Assuntos
Carbono/análise , Água Potável/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Biodegradação Ambiental , Filtração/métodos
13.
Wei Sheng Yan Jiu ; 48(2): 295-302, 2019 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-31133111

RESUMO

OBJECTIVE: To verify the health effect and the point of departure(POD) of chromium in drinking water by animal experiment, and acquire the short-term health advisory(HA). METHODS: A total of 120 SPF SD rats were randomly divided into 6 groups. Deionized water was used as a negative control and the concentration of chromium was 0, 7. 2, 8. 3, 14. 4, 24. 0, 28. 8 mg/(kg·d) and the potassium chromate(K_2CrO_4) was used as a positive control. Blood analysis, blood biochemical parameters and histopathology were determined after exposure 14 and 28 days. The results were analyzed by one-way ANOVA, P<0. 05 showed that the difference was significant. RESULTS: After 28 days of chromium exposure, the liver weights of the female rats in each dose group were lower than the control group. There were significant differences between the 24. 0, 28. 8 mg/(kg·d) dose groups with the control group. The liver weight of female rats in the 24. 0, 28. 8 mg/(kg·d) groups were(6. 68±0. 90)g and(7. 08±0. 36)g, respectively, which were significantly higher than those in the control group(P<0. 05). After 28 days exposure, alanine transaminase(ALT) in male rats at 24. 0 and 28. 8 mg/(kg·d) levels were(59. 04±10. 98)U/L and(63. 78±5. 89)U/L, respectively, which were significantly higher than those in the control group(P<0. 05). Alkaline phosphatase(ALP) levels in blood of the two groups were lower than those in the control group, that were(130. 52±23. 22)U/L and(126. 34±28. 25)U/L(P<0. 05). CONCLUSION: With index of rat liver damage(liver weight, ALT, ALP) as indicators of health effect, LOAEL is 24 mg/(kg·d), and NOAEL is 14. 4 mg/(kg·d). Referring to the calculation method of HA value formulated by the United States Environmental Protection Agency(USEPA), the HA is 1. 44 mg/L, which is consistent with the result obtained by USEPA.


Assuntos
Cromo/toxicidade , Água Potável/química , Fígado/efeitos dos fármacos , Alanina Transaminase/metabolismo , Animais , Feminino , Fígado/patologia , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Abastecimento de Água
14.
Wei Sheng Yan Jiu ; 48(2): 303-306, 2019 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-31133112

RESUMO

OBJECTIVE: To develope a method for rapid determination of anionic synthetic detergent in drinking water by methylene blue spectrophotometry. METHODS: Added 20. 0 mL water sample into 50 mL plastic tube, then added 10. 0 mL chloroform and 200 µL methylene blue solution, oscillatied 1 min, layering, suck out the upper solution, calibrated zero using chloroform, determinated the absorbance of the bottom extraction solution at 650 nm wavelength. RESULTS: The regression equations of the rapid determination method showed a good linearity and the correlation coefficient was 0. 9995. The method minimum mass detection concentration was 0. 05 mg/L. The recoveries were between 92. 7% and 98. 3%, and the relative standard deviations were between 4. 8% and 5. 7%(n=6). Compared with the national standard method by significance test, the significant difference had no statistical significance(P=0. 79). The detection time(30 samples) was only 2 h which needed a day by using national standard method. The concentration range of anionic synthetic detergent of 30 samples in the Yanqing urban areas of Beijing were<0. 05-0. 26 mg/L. CONCLUSION: This method is simple, sensitive, accurate and efficient, and it is suitable for basic level laboratories rapid determination and drinking water surveillance.


Assuntos
Detergentes/análise , Água Potável/análise , Espectrofotometria/métodos , Pequim , Água Potável/química , Indicadores e Reagentes , Azul de Metileno , População Urbana
15.
Wei Sheng Yan Jiu ; 48(3): 477-481, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31133138

RESUMO

OBJECTIVE: To establish a liquid-liquid extraction and gas chromatography method for the determination of trichloroacetaldehyde in drinking water. METHODS: Chromatography parameters and extraction parameters, such as extraction solvent, salting out reagents, internal standards and pH were tested and selected. Using the optimized parameters, methods validation and comparison with the national standard examination method was also conducted. RESULTS: Employing the optimized extraction and instrumental analytic parameters, good correlation coefficient was obtained in the linear range of 0.20-20.0 µg/L, with r greater than 0.999. The methods detection limit was 0.030 µg/L. When spiked concentration was 1.0 µg/L for pure water and tap water, the recoveries were 94.8% and 93.7%, respectively, and relative standard deviation was 2.9% and 3.4%, respectively. When spiked concentration was 16.0 µg/L for pure water and tap water, the recoveries were both 101% and relative standard deviation was 1.0% and 1.3%, respectively. Paired samples t test showed that the result obtained with this method were generally lower than that acquired from the national standard examination method. CONCLUSION: This method is sensitive and accurate, and it is suitable for the determination of trichloroaldehyde in drinking water.


Assuntos
Água Potável/química , Cromatografia Gasosa , Limite de Detecção , Extração Líquido-Líquido , Poluentes Químicos da Água
16.
Chemosphere ; 230: 248-257, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31103871

RESUMO

The efficiency of elimination of organic UV filters by ozonation and UV254nm/H2O2 processes was assessed and predicted in simulated treatments of sewage-impaired drinking water and wastewater effluent in bench-scale experiments. Second-order rate constants (k) for the reactions of the eight UV filters with ozone and OH were determined by quantum chemical calculations and competition kinetics methods, respectively. The UV filters containing phenolic (ethylhexyl-salicylate, homosalate, and benzophenone-3) and olefinic moieties (4-methylbenzylidene-camphor, benzyl-cinnamate, and 2-ethylhexyl-4-methoxycinnamate) showed high ozone reactivity (k ≥ 8 × 104 M-1s-1 at pH 7), while those without such electron-rich moieties (isoamyl-benzoate and benzophenone) were ozone-refractory. All the UV filters showed high OH reactivity (k ≥ 6.2 × 109 M-1s-1). In concordance with the rate constant information, the phenolic and olefinic UV filters were efficiently eliminated by ozone treatment, requiring specific ozone doses of <0.5 mgO3/mgDOC for ∼100% elimination. The UV filters were eliminated by ≤ 38% at a UV fluence of 1500 mJ/cm2 in the UV254nm-only treatment. Rapid photoisomerisation between the E and Z geometric isomers was observed for the olefinic UV filter, benzyl-cinnamate. The addition of H2O2 (10 mg/L) greatly enhanced the elimination of all UV filters, indicating that OH was the main contributor to their elimination in the UV254nm/H2O2 treatment. A chemical kinetics approach developed previously for ozonation and UV/H2O2 processes was shown to predict the elimination of the UV filters in the tested water matrices reasonably well, demonstrating that the chemical kinetics method can be used for a priori prediction of micropollutant elimination in oxidative treatment processes for potable reuse of municipal wastewater effluents.


Assuntos
Água Potável/química , Peróxido de Hidrogênio/química , Ozônio/química , Protetores Solares/análise , Raios Ultravioleta , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Cinética , Modelos Teóricos , Oxirredução , Protetores Solares/efeitos da radiação , Poluentes Químicos da Água/efeitos da radiação
17.
J Water Health ; 17(3): 477-489, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31095522

RESUMO

The occurrence of pharmaceuticals in the drinking water is a growing concern in China. In this study, we determined the concentration and distribution of 59 selected pharmaceuticals in raw, finished, and tap water samples from 79 drinking water treatment plants (DWTPs) in 15 cities, encompassing seven large river basins in China, using solid-phase extraction pretreatment and ultra-high-performance liquid chromatography-tandem mass spectrometry analysis. Forty-seven pharmaceuticals were detected in raw water samples, with detection rates of 1.27-96.20% and average concentrations of 0.09-128.87 ng/L. Forty-three pharmaceuticals were detected in finished water samples, with detection rates of 1.27-96.20% and average concentrations of 0.07-59.17 ng/L. Forty-two pharmaceuticals were detected in tap water samples, with detection rates of 1.27-94.94% and average concentrations of 0.07-58.43 ng/L. Purification methods implemented by DWTPs are capable of removing some pharmaceuticals from water treatment systems; however, low concentrations of pharmaceuticals were detected in drinking water, raising concerns about the possible human health implications of long-term exposure to low-dose pharmaceuticals. The detection and quantification of pharmaceuticals in municipal water samples presented in this study represent the most extensive analysis of commonly used pharmaceuticals and personal care products located in Chinese river basins.


Assuntos
Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análise , China , Cidades , Água Potável/química , Monitoramento Ambiental , Humanos , Rios/química
18.
Wei Sheng Yan Jiu ; 48(2): 265-268, 2019 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-31133105

RESUMO

OBJECTIVE: To investigate the water iodine content and distribution of drinking-water in Gansu Province, and provide scientific evidence for the implementation of strategies for prevention and treatment of iodine-related diseases. METHODS: The multilevel sampling method was adopted, take the township as sampling unit at the first level, and the administrative village with the median water iodine ≥10 µg/L as the second level sampling unit, different water supply modes(centralized, partial concentration and decentralized water supply) were sampled and the water iodine were detected by recommended iodine deficiency disease test method. RESULTS: A total of 8976 drinking water samples were detected from 1388 towns of 14 cities. the detection range was 0. 0-84. 6 µg/L, the median water iodine was 2. 3 µg/L, and 8301 samples were<10 µg/L, 663 samples were 10~<50 µg/L, 12 samples were ≥50 µg/L, with a ratio of total at 92. 5%, 7. 4% and 0. 1%, respectively. Water iodine content varies between three different water supply method(χ~2=8. 923, P<0. 05), decentralized water iodine was lower than partial concentration water supply(Z=-2. 891, P<0. 01). 71 townships of median water iodine were ≥10 µg/L(5. 1%), the water iodine median range was 10. 1~64. 3 µg/L, 76. 1% of townships were 10-<20 µg/L, 11. 3% were 20-<30 µg/L, 5. 6% were 30-<40 µg/L, 7. 0% were ≥40 µg/L(χ~2=13. 302, P<0. 05). Water samples of 895 administrative villages were detected, the median water iodine was 10. 8 µg/L, 466 administrative villages with a median water iodine ≥10 µg/L, the water iodine range was 10. 0~113. 1 µg/L, the median water iodine was 10. 8 µg/L, Administrative villages of 10-<50 µg/L, 50~<100 µg/L and ≥100 µg/L accounted for 96. 6%, 2. 4% and 1. 0%, respectively. CONCLUSION: Iodine deficiency areas were exist universally in Gansu Province, but there is high iodine point-like distribution areas in the administrative villages. While pay close attention to prevention of Iodine deficiency, the iodine nutrition status monitor in different iodine areas and the iodine supplementation strategy adjusting should be concerned too.


Assuntos
Água Potável/química , Iodo/análise , Abastecimento de Água , China , Cidades , Água Potável/análise , Humanos , Estado Nutricional
19.
Environ Sci Pollut Res Int ; 26(20): 20364-20376, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31102220

RESUMO

Drinking water reservoirs are threatened globally by anthropogenic nitrogen pollution. Hydrochemistry and isotopes were analyzed to identify spatial and temporal varieties of main nitrate sources in a large drinking water reservoir in East China. The results showed that NO3- was the main nitrogen form in both the dry and wet seasons, but dissolved organic nitrogen (DON) was increased in the wet season. The δ15N-NO3- values (+ 1.3‰ to + 11.8‰) and δ18O-NO3- values (+ 2.5‰ to + 13.5‰), combined with principal component analysis (PCA), indicated that chemical fertilizer was the main nitrate source during the dry season, while chemical fertilizer, soil N, and sewage/manure were the main nitrate sources during the wet season in the Qiandao Lake area. And, the nitrate isotopes showed the significant nitrification and assimilation in the Qiandao Lake area. A Bayesian isotopic mixing model (Stable Isotope Analysis in R) was applied to the spatial and seasonal trends in the proportional contribution of four NO3- sources (chemical fertilizer (CF), soil nitrogen (SN), sewage and manure (SM), and atmospheric deposition (AD)) in the Qiandao Lake area. It was revealed that CF was the most important nitrate source in the dry season, accounting for 53.4% with 19.2% of SM and 18.9% of SN, while the contribution of SN increased in the wet season, accounting for 31.6%, followed by CF (30.8%) and then SM (24.2%). The main nitrate sources in the urban area, rural area, and central lake area were CF and SN, accounting for 66.1% in the urban area, 71.7% in the rural area, and 68.2% in the central lake area. Measures should be made to improve chemical fertilizer use efficiency and to reduce nitrogen loss in the Qiandao Lake area. Graphical abstract .


Assuntos
Lagos/análise , Isótopos de Nitrogênio/análise , Isótopos de Oxigênio/análise , Poluentes Químicos da Água/análise , Teorema de Bayes , China , Água Potável/análise , Água Potável/química , Monitoramento Ambiental/métodos , Fertilizantes , Lagos/química , Esterco , Modelos Teóricos , Nitratos/análise , Nitrificação , Estações do Ano , Esgotos , Solo/química
20.
Environ Pollut ; 250: 773-781, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31039472

RESUMO

The presence of pharmaceuticals in aquatic environments has become a major issue of concern for scientific community, since there is a lack of information about risks and impacts to the environment and public health. In the context of Brazil, many cities do not have Wastewater Treatment Plants (WWTPs) and domestic sewage is dumped directly into the water bodies, aggravating the problem. Thus, the present study aimed to evaluate the presence of 28 prescribed pharmaceuticals from different therapeutic classes in six full-scale Drinking Water Treatment Plants (DWTPs) in Minas Gerais state. Samples were collected in twelve field campaigns from August 2016 to August 2017 and water quality were monitored. Analytical methodology was based on solid phase extraction (C18 cartridge) followed by High Performance Liquid Chromatography (Prominence DGU/20A3 - Shimadzu) coupled to Mass Spectrometry (micrOTOF-QII - Bruker). Considering the 28 pharmaceuticals analyzed, 18 were detected in the surface water source at concentrations ranging from Method Quantification Limit (MQL) to 11,960 ng/L. In drinking water, the concentration of the 11 pharmaceuticals detected ranged from

Assuntos
Monitoramento Ambiental/métodos , Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Brasil , Cidades , Água Potável/química , Estações do Ano , Esgotos/química , Águas Residuárias/química , Abastecimento de Água
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