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1.
Sci Total Environ ; 784: 147208, 2021 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-34088045

RESUMEN

Information on how key environmental conditions such as natural dissolved organic matter (DOM) and water pH alter the possible risks posed by pharmaceuticals (PPCPs) is still scarce. In our previous study, the presence of natural DOM at high pH reduced the toxicity of a mix of waterborne PPCPs to algae. DOM-complexation and pH effect on speciation of the more hydrophobic and neutral compounds of the mix was suggested to be driving this behaviour. However, the study design did not allow the verification of this hypothesis. Here, the DOM- PPCPs interaction at different pH was investigated for 6 PPCPs through equilibrium dialysis, under the same conditions of DOM and pH as our previous study. Association with DOM was confirmed for the more hydrophobic PPCPs at high pH. The results suggest the binding was driven by i) the presence of carboxylic groups of PPCPs, ii) high pH shifting the structural configuration of DOM, making it more suited to bind some of the PPCPs. A non-linear change of binding capacity with increasing DOM concentration was also observed among the tested PPCPs.


Asunto(s)
Cosméticos , Preparaciones Farmacéuticas , Contaminantes Químicos del Agua , Cosméticos/análisis , Interacciones Hidrofóbicas e Hidrofílicas , Agua , Contaminantes Químicos del Agua/análisis
2.
Sci Total Environ ; 784: 147186, 2021 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-34088052

RESUMEN

Assessments for groundwater quality and potential health risk are significant for better utilization and exploitation. In the present study, seventy groundwater samples were collected from domestic tube wells and public water-supply wells in the Nanchong area, southwestern China. The integration of statistical analysis, ion correlation, geomodelling analysis, entropy water quality index and health risks assessment were compiled in this study. Statistical analysis indicated the cations followed the concentration order as Ca2+ > Na+ > Mg2+ > K+, while anions' concentrations were HCO3- > SO42- > Cl- > NO3- > F- based on Box and Whisker plot. Piper triangle diagram proposed the hydrochemical type was characterized as Ca-HCO3. Correlations of ions and geomodelling revealed the concentrations of major ions were mainly determined by calcite dissolution and ion exchange process and NO3- concentrations were controlled by agriculture activities. Entropy water quality index computation demonstrated that 96% of groundwater samples possessed the EWQI values of 29-95, and thus were suitable for drinking purpose. The HITotal values for 66% groundwater samples exceeded the acceptable limit for non-carcinogenic risk (HI =1) for infants, followed by 41% for children, 37% for adult males, and 30% for adult females. The non-carcinogenic human health risk of different population groups followed the order of infants > children > adult males > adult females. In future, targeted measures for human health risks of NO3- will focus on the improvements for agricultural activities, including reducing the use of nitrogenous fertilizer, changing irrigation pattern, etc. Our study provides the vital knowledge for groundwater management in the Nanchong and development of the Cheng -Yu Economic Circle.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Adulto , Niño , China , Monitoreo del Ambiente , Femenino , Indicadores de Salud , Humanos , Lactante , Masculino , Nitratos/análisis , Contaminantes Químicos del Agua/análisis , Calidad del Agua
3.
Sci Total Environ ; 784: 147167, 2021 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-34088063

RESUMEN

This study aimed to investigate the effect of imidacloprid on structural (invertebrates and primary producers) and functional (organic matter decomposition and physicochemical parameters) characteristics of tropical freshwaters using acute single species and mesocosm studies performed in Ethiopia. The recovery of affected endpoints was also studied by using a mesocosm study period of 21 weeks. Our acute toxicity test showed that Cloeon dipterum (96-h EC50 = 1.5 µg/L) and Caenis horaria (96-h EC50 = 1.9 µg/L) are relatively sensitive arthropods to imidacloprid. The mesocosm experiment evaluated the effects of four applications of imidacloprid with a weekly interval and the results showed that the macroinvertebrate and zooplankton community structure changed significantly due to imidacloprid contamination in mesocosms repeatedly dosed with ≥0.1 and ≥ 0.01 µg/L, respectively (time weighted average concentrations of 112 days (TWA112d) of ≥0.124 and ≥ ≈0.02 µg/L, respectively). The largest responses were found for C. dipterum, C. horaria, Brachionus sp. and Filinia sp. Chlorophyll-a concentrations of periphyton and phytoplankton significantly increased in the ≥0.1 µg/L treatments levels which are indirect effects as a result of the release of grazing pressure. A significant, but quantitatively small, decrease of organic matter decomposition rate was observed in mesocosms treated with repeated doses of 1 µg/L (TWA112d of 2.09 µg/L). No recovery was observed for the macroinvertebrates community during the study period of 21 weeks, but zooplankton recovered after 9 weeks. We observed spatio-temporal related toxicity differences between tropical and temperate aquatic taxa, with tropical taxa generally being more sensitive. This suggests that use of temperate toxicity data for the risk assessment of imidacloprid in tropical region is not recommended.


Asunto(s)
Insecticidas , Contaminantes Químicos del Agua , Animales , Ecosistema , Etiopía , Agua Dulce , Insecticidas/análisis , Insecticidas/toxicidad , Neonicotinoides , Nitrocompuestos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
4.
Sci Total Environ ; 783: 147021, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34088124

RESUMEN

We screened for the presence of 66 different pharmaceutical residues in surface waters and in multiple invertebrate and fish species of the Tejo estuary to produce an environmental risk assessment of individual pharmaceuticals and their mixtures, as well as evaluate the bioaccumulation of pharmaceuticals in one of Europe's largest estuarine systems. Sixteen pharmaceutical residues, from seven therapeutic classes, were detected in estuarine waters, with environmental mixture concentrations ranging from 42 to 1762 ng/L. Environmental risk assessment via the determination of risk quotients, demonstrated high ecological risk for the antibiotic amoxicillin and angiotensin II receptor blockers irbesartan and losartan. Moderate risk was estimated for antidepressants, antiepileptics, anxiolytics and beta-blockers, but the risk quotient of the accumulated mixture of compounds was over 380-fold higher than the no risk threshold, driven by antibiotics and angiotensin II receptor blockers. In biota, higher risk therapeutic groups were found in higher concentrations, with nine pharmaceutical residues detected, including six antibiotics and two neuroactive compounds, and maximum tissue concentrations up to 250 µg/kg. Bioaccumulation was species- and compound-specific, with only two compounds found simultaneously in water and biota, likely a result of the complex dynamics and fate of pharmaceuticals in estuarine waters. Nonetheless, higher detection frequencies were observed in species living directly on or just above the substrate (i.e. benthic and demersal species), underpinning the importance of habitat use, as well the potential role of sediment and diet based routes for pharmaceutical uptake. Ultimately, results support urgent action on managing the impact of pharmaceuticals in coastal environments, striving for improved monitoring schemes tailored to the dynamic nature and ecological diversity of estuaries and coastal ecosystems.


Asunto(s)
Preparaciones Farmacéuticas , Contaminantes Químicos del Agua , Animales , Bioacumulación , Ecosistema , Monitoreo del Ambiente , Estuarios , Medición de Riesgo , Contaminantes Químicos del Agua/análisis
5.
Sci Total Environ ; 783: 147154, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34088136

RESUMEN

The water bodies are greatly influenced by chemical contamination and global increasing temperature. As an emerging pollutant, microplastics are widely distributed in the freshwater environment, raising concerns regarding their potential toxicity to organisms. Especially for zooplankton filter feeders, many of microplastics are in similar size as their food. Individually, both microplastics and temperature have profound effects on zooplankton populations and their function in ecosystems. However, the strength and direction of their interactive effects are still not clear. Here, we performed a comprehensive biotoxicity assessment providing empirical evidence that the temperature played a key role in shaping the sensitivity of the zooplankter, Daphnia magna, against microplastic toxicity. We found that exposure to microplastics generally caused negative effects on Daphnia individual fitness, such as increased lethality, declined fecundity and reduced population growth rate. This microplastic toxicity was more prominent at 30 °C than at 20 °C, and was rather minor at 15 °C. Moreover, the warming accelerated the ingestion of microplastics, and triggered abnormal ultrastructure of intestinal epithelial cells. In addition, the expression profiling of candidate genes revealed oxidative damage, fecundity impairment and energy retardation by microplastics were amplified with increasing temperature, which may contribute to the enhancement of microplastic toxicity under warming. Given that high temperature fluctuations are becoming more common and difficult to predict, the interactive effects of microplastics and climate warming on Daphnia population dynamics and biomass production may become increasingly aggravated in nature. Collectively, extrapolation for environmental risk assessment studies conducted under different temperature contexts may broaden our knowledge microplastic toxicity on aquatic organism fitness.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Animales , Daphnia , Ecosistema , Expresión Génica , Aptitud Genética , Plásticos/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
6.
Sci Total Environ ; 783: 147065, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34088143

RESUMEN

Many methods have been used to isolate and identify microplastics from biological matrices. In biological samples, Nile Red can stain undigested residues, such as fats, soaps, and gels formed during organic matter removal, hindering the identification of fluorescent microplastics (≥2 µm). Thus, adjustments on sample preparation (e.g., fat removal) are required for the accurate identification of Nile Red stained microplastics. Multiples tests allowed to identify that digestion with 10% KOH at 60 °C for 24 h, followed by treatments with boiling water, acetone, and staining, produced good results in fourteen biological samples, including vertebrates and invertebrates. Digestion efficiencies were 94-100%, except for feces, which were 87%. Recovery rates of spiked microplastics were 97-100%, and few effects were observed in the infrared spectra and carbonyl index of seven polymers, with only the occasional yellowing suggesting surface changes. Filtration rates were improved by reducing the amount of sample. Small fluorescent microplastics could be identified in all samples under the microscope. Overall, the proposed method was efficient in removing natural organic matter from biological samples for Nile Red staining, requiring minimal sample handling, improving sample throughput, and allowing quantification of fluorescent microplastics in biological samples.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Oxazinas , Plásticos , Contaminantes Químicos del Agua/análisis
7.
Sci Total Environ ; 783: 146981, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34088153

RESUMEN

Freshwater riverbeds are a major repository of microplastics (MPs) from inland activities. Benthic macroinvertebrates that live in close contact with sediments seem to ingest a considerable amount of such plastic particles. The effects of MPs on life-history traits are relatively well-known, but the suborganismal mechanisms underlying such effects remain unclear. This study addressed the potential effects of low-density polyethylene (LDPE) MPs on Chironomus riparius larvae at cellular and molecular levels. Fourth instar C. riparius larvae were exposed to 0.025 and 2.5 g/kg LDPE of dry sediment (sizes: <32 and 32-45 µm; with irregular shape) under laboratory conditions for 48 h. These short-term exposures to environmental concentrations of LDPE MPs induced changes in the energy reserves (mostly by decreasing carbohydrates and increasing lipids), increased antioxidant and detoxification responses (tGSH, CAT, and GST), and induced increases in the activity of AChE (related to neurotransmission). In addition, at the gene level, exposure to MPs modified mRNA levels of InR, Dis, EcR, Dronc, Met (endocrine system), Def (immune system), PARP, ATM, NLK, and Decay (DNA repair), generating important alterations in the C. riparius development and response to unfavorable situations. This study provides new evidence of the effects of LDPE MPs at the suborganismal level, filling the gap in knowledge regarding the mechanisms underlying the toxicity of MPs and spotlighting gene expression analyses as early indicators of MP toxicity in C. riparius which were confirmed by Integrated biomarker response analyses highlighting the gene expression as sensible and useful endpoints for LPDE pollution in freshwaters. These results, coupled with previous investigations on responses at the organismal level, emphasizes the potential adverse effects of LDPE MPs on C. riparius, which may compromise freshwater benthic communities, considering its ecological role within these habitats.


Asunto(s)
Chironomidae , Contaminantes Químicos del Agua , Animales , Larva , Microplásticos , Plásticos/toxicidad , Polietileno/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
8.
Sci Total Environ ; 783: 147076, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34088154

RESUMEN

Microplastics (MPs) attract global concern due to their ubiquitous existence in aquatic environments. However, the genotoxic effect of MPs on aquatic organisms in the natural environment remains controversial. Therefore, this meta-analysis was conducted by recompiling 44 individual studies from 12 publications to determine whether MPs could induce genotoxicity in aquatic organisms at environmentally relevant concentrations (≤1 mg/L, median = 0.5 mg/L). Multiple genotoxic endpoints were involved, including the percentage of DNA in tail (TDNA%), tail length (TL), olive tail moment (OTM), and the number of micronuclei (NM), and their increases represented the biologically adverse effects (i.e. genotoxicity). The results showed that all included endpoints tended to increase after exposure to MPs, among which TDNA%, TL and NM were significantly increased by 20%, 32% and 81% compared with the control group, respectively. The overall estimate of all endpoints in the MPs-treated groups was remarkably increased by 24%, with high statistical power and no obvious publication bias, suggesting the evident genotoxicity caused by MPs. In addition, the magnitudes of MPs-induced genotoxicity were independent of selected endpoint, MP composition, morphology, exposure concentration and duration, but closely correlated with particle size, living habitat and tested species. Overall, this work provided a reference for the health risk assessment of MPs in the natural environment, contributing to our understanding the action mode of MPs at environmentally relevant concentrations.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Organismos Acuáticos , Daño del ADN , Plásticos/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
9.
Environ Monit Assess ; 193(7): 389, 2021 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-34097151

RESUMEN

The present investigation has been carried out in the Ottapidaram taluk to evaluate the suitability of groundwater for drinking purposes and to assess the non-carcinogenic health risks. Twenty groundwater samples were collected, and the major physicochemical parameters were measured along with the heavy metals lead (Pb2+) and chromium (Cr2+). The analyzed anions and cations follow the average dominance order, Cl- > PO43- > SO42- > NO3- > F-, and Mg2+ > Ca2+ > Na+ > K+, respectively. From the water quality index to know the 45% of the water samples are unsuitable for drinking purposes. The statistical analysis of the data infers that major geochemical process of the region is leaching of salts by contaminated water, followed by industrial pollution and geogenic sources. The spatial representation of the different parameters reveals that the western part of the study area is predominated by geogenic sources and the eastern part is contaminated by industrial effluents. The non-carcinogenic risks of F-, NO3-, Cr2+, and Pb2+ were assessed. The findings show 40% of the samples exceeds the chromium hazard quotient, and 50% exceed the lead hazard quotient value of 1 recommended by the US Environmental Protection Agency (USEPA). The present investigation shows that Cr2+ and Pb2+ highly pollute the groundwater due to the industrial impacts. The present study suggests that the groundwater from this taluk is worse, and people from this taluk have health risks due to groundwater drinking.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Humanos , Plomo , Contaminantes Químicos del Agua/análisis , Calidad del Agua
10.
Environ Monit Assess ; 193(7): 391, 2021 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-34100139

RESUMEN

Groundwater quality assessment in urban areas is one of significant endeavours to ensure safety of urban residents who use groundwater especially in areas with erratic tap water supply. The study assessed groundwater quality and vulnerability of residents to water contamination-related diseases in Mkoba 19 suburb in Gweru, Zimbabwe. The research employed a mixed methods research design using both quantitative and qualitative research methods. Laboratory tests, questionnaires, interviews, focus group discussions and observations were used to solicit data. Statistical package for social scientist (SPSS) version 20.0 and Microsoft excel package were adopted for data analysis in this study. The study revealed that Mkoba 19 suburb has more wells than boreholes. Boreholes were evenly distributed over the residential area than wells which were clustered to the southern and northern edges of the suburb. All boreholes in Mkoba 19 were drilled to the depth of 40 m, but wells were dug to varying depths. The study confirmed that borehole water in Mkoba 19 was acidic and thus unsafe for human consumption. Water from wells in Mkoba 19 was confirmed positive of Escherichia coli which shows contamination from sewage and waste dump leachates. The findings of this research indicated that both borehole and well water sources in Mkoba suburb had permissible levels of dissolved oxygen and turbidity. Chi-square tests conducted confirmed that there was an association between water source depth and level of E. coli contamination in water whereas there is no association between water source depth and water pH level. The research confirmed that residents of Mkoba 19 were highly vulnerable to water borne illnesses as they were using contaminated water for domestic purposes without treating it. Basing on similar studies conducted in the past 3 years, it was shown that groundwater quality in Mkoba 19 mimics that of other countries of the developing world, especially in sub-Saharan Africa, which shows that vulnerability to ground water contamination in urban areas is an issue that requires critical attention and almost similar solution. The research recommends that Gweru City Council should upgrade its water supply system especially the pumping system to improve water supply in Mkoba suburb. To minimize water-borne disease outbreaks in the future, urban residents who rely on secondary or tertiary sources of water for domestic purposes should treat water using chlorine, water guards and other water cleansing measures on a regular basis.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , África del Sur del Sahara , Ciudades , Monitoreo del Ambiente , Escherichia coli , Humanos , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Abastecimiento de Agua , Zimbabwe
11.
Environ Monit Assess ; 193(7): 390, 2021 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-34100164

RESUMEN

The implications and health effects of microplastics (MPs) ingestion are still unclear, yet researchers and organizations around the world are increasingly examining the levels of microplastics and nanoplastics in the environment. This study investigated the presence and the quantity of microplastics in bottled and tap water from five regions in Saudi Arabia and estimated the dietary intake of microplastics. Thirty samples of drinking water were collected from the retail markets in Saudi Arabia. The samples included plastic bottled drinking water, 2 glass bottles, and 2 samples of tap water to represent ground water and desalinated seawater. Sample preparation in the laboratory involved a vacuum-assisted filtration with an inorganic filter membrane (0.2-µm pore size). Identification and classification of microplastics particles using Fourier-transform infrared microspectroscopy (FTIR microspectroscopy). The particle size range screened for in this study was 25-500 µm. Microplastics were identified in 17 out of 30 samples. The average of the detected microplastic particles was 1.9 pcs/L (lower bound estimate, LB) and 4.7 pcs/L (upper bound estimate, UB), respectively. The most frequently identified plastic type was polyethylene (PE), followed by polystyrene (PS), and polyethylene terephthalate (PET). Given an average recommended water intake of 3.7 and 2.7 L per day for men and women, respectively, the corresponding daily exposure to microplastics would result in 0.1-0.2 pcs/kg bw. The estimate for high water consumers increases to a daily exposure of 1.7-1.9 pcs/kg bw based on the recommended intake for water in hot weather by the WHO. From these results, we conclude that the level of dietary intake of microplastics from drinking water in Saudi Arabia is low, and according to current state of knowledge, microplastics from drinking water do not pose any concern to the consumers in Saudi Arabia.


Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Agua Potable/análisis , Ingestión de Alimentos , Monitoreo del Ambiente , Humanos , Microplásticos , Plásticos , Arabia Saudita , Contaminantes Químicos del Agua/análisis
12.
Water Sci Technol ; 83(11): 2714-2723, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34115625

RESUMEN

The textile industry is one of the main generators of industrial effluent due to the large volumes of water containing a wide variety of pollutants, including dyes. Thus, the present study aimed to remove the Disperse Blue 56 dye present in synthetic textile effluent using ionic flocculation through surfactant flocs produced from animal/vegetable fat, assessing the system at different surfactant concentrations and temperatures. The process kinetics, adsorption mechanism and equilibrium were evaluated. The results show that the kinetics was better described by the Elovich model when compared to pseudo-first order and pseudo-second order models, indicating that chemical adsorption occurs during the process. The study of the adsorption mechanism obtained lower outer layer diffusivities than their intra-particle counterparts, demonstrating that the dye transport to the surfactant floc is controlled through the outer layer. The Langmuir isotherm was suitable for equilibrium data and the separation factor calculated showed that the isotherm is classified as favorable. Dye removal efficiency reached 87% after 360 minutes of contact between the effluent and the surfactant flocs, indicating that ionic flocculation is an efficient alternative in the treatment of textile effluent containing disperse dye.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Antraquinonas , Colorantes , Floculación , Concentración de Iones de Hidrógeno , Cinética , Industria Textil , Textiles , Contaminantes Químicos del Agua/análisis
13.
Water Sci Technol ; 83(11): 2732-2743, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34115627

RESUMEN

A novel photocatalytic continuous system has been proposed for the treatment of tannery waste water, which has high levels of environmental pollutants. The purification process was performed by passing wastewater on a titanium dioxide (TiO2)-coated surface, which is continuously activated by irradiation of ultraviolet light. To improve the yield of the process, ferric chloride (FeCl3) was used as a coagulation agent. The organic and inorganic compounds, as well as the microorganisms in the tannery wastewater media, were degraded through a photocatalytic process. The results revealed that total dissolved solids and total suspended solids contents were significantly decreased from 8,450 and 8,990 mg·L-1 to 4,032 and 4,127 mg·L-1, respectively. Furthermore, the chemical oxygen demand content of the sample was reduced from 370 to 50 mg·L-1 after the addition of 100 mL of FeCl3 and 4 h of treatment. The same results were observed for the elimination of sulfate and chromium ions, which led to a decline in electrical conductivity. This suggests that introducing 100 mL of FeCl3 as the coagulation agent and continuous treatment with photocatalityc set-up could be considered as an effective method for the purification of tannery wastewaters.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Catálisis , Titanio , Aguas Residuales , Contaminantes Químicos del Agua/análisis
14.
Water Sci Technol ; 83(11): 2793-2808, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34115632

RESUMEN

In this work, mixed oxides of LaxCa1-xMnO3 perovskite type (x = 0, 0.5 and 1.0) were synthesized through modified proteic method using collagen and calcination process at 700 °C/2 h in order to remove the commercial textile dye Bezaktiv Blue S-MAX from water. Oxides were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 physisorption, scanning electron microscopy (SEM) and point of zero charge (PZC) techniques while the dye only by the first two techniques. The XRD showed that perovskite monophase was obtained for x = 0.5 and 1.0. However, for x = 0, the low crystalline perovskite phase was obtained in the midst of precursor oxides. FTIR showed the adsorption process did not damage the adsorbents structure. The successful obtained materials have meso and macroporous with slit or cavity shape, rough surface and particles with varying sizes. The pseudo-second-order model was the one that best fit the kinetic data. The process must occur through electrostatic surface interactions between the adsorbent surface and the dye molecule. For the equilibrium study, Langmuir isotherm is the most suitable when using LaMnO3 adsorbent, while Freundlich isotherm was better suited when used the other two materials. The adsorbents were termally regenerated and reused five times. The best performance was exhibited by LaMnO3.


Asunto(s)
Contaminantes Químicos del Agua , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Espectroscopía Infrarroja por Transformada de Fourier , Agua , Contaminantes Químicos del Agua/análisis
15.
Water Sci Technol ; 83(11): 2809-2828, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34115633

RESUMEN

The horizontal subsurface flow constructed wetland (HFCW) is widely studied for the treatment of wastewater containing emerging organic contaminants (EOCs): pharmaceuticals, personal care products, and steroidal hormones. This study evaluates the performance of HFCW for the removal of these types of EOCs based on the data collected from peer-reviewed journal publications. In HFCW, anaerobic biodegradation is an important removal mechanism of EOCs besides their removal by the filter media (through sedimentation, adsorption, and precipitation) and plant uptake. The average removal efficiency of 18 selected EOCs ranged from 39% to 98%. The moderate to higher removal efficiency of 12 out of 18 selected EOCs in HFCW indicates the suitability of this type of constructed wetland (CW) for the treatment of wastewater containing these EOCs. The reasonably good removal (>50% in most of the cases) of these EOCs in HFCW might be due to the occurrence of anaerobic biodegradation as one of their major removal mechanisms in CWs. Although the effluent concentration of EOCs was substantially decreased after the treatment, the environmental risk posed by them was not fully reduced in most of the cases. For instance, estimated risk quotient of 11 out of 18 examined EOCs was extremely high for the effluent of HFCW.


Asunto(s)
Contaminantes Químicos del Agua , Humedales , Anaerobiosis , Biodegradación Ambiental , Eliminación de Residuos Líquidos , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisis
16.
Water Sci Technol ; 83(11): 2829-2840, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34115634

RESUMEN

First flush is a common phenomenon in urban runoff pollution. Typical cement roof and asphalt road runoff in Beijing, China were monitored for 2 years. Based on the M(v) curve, the suspended solids (SS), chemical oxygen demand (COD), total phosphorus (TP) and particulate phosphorus in cement roof runoff presented a stronger first flush than those in asphalt road runoff. The first flush volume (VFF) of SS, COD, total nitrogen (TN) and TP in asphalt road runoff differed slightly from the cement roof. There were also differences in the first flush assessment depending on which method was used. We proposed a new method based on the runoff depth versus pollutant cumulative mass curve. According to the national standards in China (VFF = 3 mm), various masses of different pollutants, such as 91.42 ± 9.80% (cement roof) and 78.49 ± 19.41% (asphalt road) of SS and 86.85 ± 13.54% (cement roof) and 72.80 ± 25.79% (asphalt road) of COD, can be effectively controlled, but our mass control efficiencies were 55.91%-66.65% when VFF = 1 mm. The new method proposed in this study provides an alternative approach for assessing runoff pollution control efficiency of different VFF.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Beijing , China , Ciudades , Monitoreo del Ambiente , Nitrógeno/análisis , Fósforo/análisis , Lluvia , Movimientos del Agua , Contaminantes Químicos del Agua/análisis
17.
Environ Monit Assess ; 193(7): 418, 2021 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-34120273

RESUMEN

Mexican Lake Chapala is used as water supply for human consumption. Consequently, water quality of this lake is of paramount importance for the lake's wellbeing. The contribution presented in this paper investigates monitoring and assessment of lake water quality using water quality index (WQI), metal chemical speciation, and multivariate statistical techniques. Descriptive statistics shows total metal concentrations undetected conferring the lake a healthy status. Dissolved Cd and Pb exceed criterion continuous concentration limit, whereas Zn is below this limit indicating that water quality is satisfactory for aquatic life. However, WQI indicates poor water quality attributed to failure of conductivity, total solids, nitrogen, and phosphates, due to industrial and agro-industrial effluents. Metal speciations indicate that the presence of low concentrations of dissolved metals reflect interactions with gills of fish through metal-biotic ligand complexes affecting water quality. Positive correlations are obtained between conductivity and nitrates, indicating that agricultural activities and fertilizer runoffs increase the conductivity and that the environmental state of lake is being altered by human activities. Factors F1 (31%), F2 (19%), and F3 (11%) represent 61% of variability; F1 and F2 corroborate the pressure exerted by pollutants related with fertilizers and agrochemicals; F3 contains Zn and Pb with positive loads attributed to influx of tourist visitors. Sites S4, S5, S6, and S9 are identified as the most environmentally affected by COD, Alk*, pH, Cl-, nitrites, phosphates, and TS. Multivariate techniques permit to conclude that environmental stress of Lake Chapala is caused by variables pertaining to agrochemical, fertilizers and municipal wastes.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Humanos , Lagos , Metales Pesados/análisis , México , Contaminantes Químicos del Agua/análisis , Calidad del Agua
18.
J Chromatogr A ; 1650: 462256, 2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34082187

RESUMEN

An analytical method based on low-temperature partitioning extraction (LTPE) followed by high performance liquid chromatography coupled to triple quadrupole mass spectrometry analysis was developed and validated for the determination of eight multiclass antibiotics in wastewater. The analyzed target antibiotics included one ß-lactam, two sulfonamides, three fluoroquinolones, one macrolide and one diaminopyrimidine. LTPE parameters such as sample pH, volume ratio between sample and extractor solvent, ultra-sonic extraction time, extraction tube material, solvent and volume to reconstitute the sample extracts, were optimized. Additionally, the influence of solids on extraction efficiency was evaluated. Quantification of the target antibiotics was performed by double consecutive injection method, without the use of a labeled compound, in order to correct matrix effects. The whole samples were analyzed, including, liquid and solid fractions of wastewater. The results revealed that the filtration step can underestimate the total antibiotics concentration, particularly to the hydrophobic compounds that have higher affinity for solids, indicating that the suspended wastewater particulate should not be neglected. The method detection limit ranged from 18.54 ng L-1 (trimethoprim) to 78.49 ng L-1 (ciprofloxacin). Intra-day precision of less than 12.3% was achieved. The recoveries values ranged from 13.9% (sulfadiazine) to 48.9% (erythromycin) in influent samples and from 19.1% (sulfadiazine) to 57.2% (ciprofloxacin) in effluent samples. The method was applied to the measurement of antibiotic residues in influent and effluent from wastewater treatment plants. The majority target antibiotics were detected in wastewater samples. Their concentrations ranged from 237 to 9553 ng L-1 in influent and from 212 to 1660 ng L-1 in effluent. This work provides new insights on the applicability of LTPE for antibiotic residues extraction from wastewater. In addition, the performed analysis highlights the importance of measuring total concentrations of analytes in whole sample.


Asunto(s)
Antibacterianos , Técnicas de Química Analítica , Cromatografía Líquida de Alta Presión , Espectrometría de Masas en Tándem , Aguas Residuales , Contaminantes Químicos del Agua , Antibacterianos/análisis , Técnicas de Química Analítica/instrumentación , Técnicas de Química Analítica/métodos , Frío , Interacciones Hidrofóbicas e Hidrofílicas , Extracción en Fase Sólida , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis
19.
Environ Monit Assess ; 193(7): 424, 2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-34132904

RESUMEN

The low ionic concentration meltwaters of the rivers originating from the Himalayan glaciers play a significant role in diluting the high solute load emanating from Ganga plain catchments. Hence, any change in the qualitative and quantitative characteristics of the Himalayan tributaries of River Ganga under the changing climatic scenario will impact the hydrochemical parameters of River Ganga as well. Hydrochemical investigations have been carried out in the River Alaknanda, a tributary of River Ganga during the period September 2016-May 2018 and revealed that TSS and COD values were observed above the prescribed criteria limit of 10 mg/L for drinking purpose for river as prescribed by CPCB. The anions for all sampling sites and seasons were observed to be in decreasing order of HCO3- > SO42- > Cl- > NO3- and cations Ca2+ > Mg2+ > Na+ > K+. The weathering of rock forming minerals of drainage basin is responsible for the chemical composition of river water. HCO3- being the dominant anion in the study area accounts for its presence due to carbonate and silicate weathering. Ion exchange process controls the major ion chemistry of the river water. The assessment and management of non-point sources (NPS) pollution are difficult by any deterministic method and require a vast amount of data to compensate for their extent of contamination, in the account of their prevailing nature in response to hydrological processes and land use patterns. In the present investigation, the application of a simple chemical mass balance approach based on law of conservation of mass/matter has been applied on River Alaknanda, a tributary of River Ganga for measuring the chemical mass loadings of some selected water quality constituents, viz., major cations (sodium, potassium, calcium, magnesium, and ammonium) and major anions (chloride, sulfate, nitrate, and phosphate) at upstream and downstream of different point source locations for examining the contribution made by non-point sources of pollution to the river. Time series analysis of various ion concentrations at point source sites and upstream/downstream sites inferred that the fluvial variations pertaining to ion concentration and flux are strongly dependent on the seasonal changes. More contribution (> 30-50%) for almost all constituents from uncharacterized sources was observed in the months of November to February, which may be attributed to intensified agricultural activities during the winter months particularly cereals and vegetables.


Asunto(s)
Monitoreo del Ambiente , Contaminantes Químicos del Agua , India , Ríos , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Tiempo (Meteorología)
20.
Chemosphere ; 279: 130555, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34134404

RESUMEN

This study investigates the effectiveness of non-activated peroxymonosulfate (PMS) as oxidative agent for water purification in the presence and absence of natural solar radiation. The inactivation of three pathogens (Escherichia coli, Enterococcus faecalis and Pseudomonas aeruginosa) and degradation of three Contaminants of Emerging Concern (CECs) (Trimethoprim-TMP, Sulfamethoxazole-SMX and Diclofenac-DCF) was simultaneously assessed in isotonic water (IW) by testing a wide range of PMS concentrations (from 0.0001 to 0.01 mM). A significant oxidative effect of PMS in darkness was obtained for both bacteria and CEC abatement, but when irradiated with solar light, results demonstrated a great enhancement on all bacterial kinetic rates, reaching >5 Log reduction in 30 min (1.5 kJL-1 of QUV) with 0.005 mM of oxidant as the best concentration. For CECs, higher degradation performance was obtained with 0.01 mM, 80% removal of DCF, SMX and TMP was achieved in 16 min (1.5 kJL-1), 27 min (9.4 kJL-1) and 150 min (16.8 kJL-1), respectively. Besides, the influence of inorganic species on the global PMS/solar system performance was assessed by testing its effectiveness in distilled water (DW), natural well water (WeW) and diluted well water (d-WeW) at 0.01 mM. Results revealed that (i) high chloride concentration (IW) has an important positive effect, (ii) the presence of a complex inorganic chemical water composition reduced the system efficiency (WeW), and (iii) no differences were obtained from the presence of low or high contents of carbonates/bicarbonates (WeW versus d-WeW), obtaining the following global PMS/solar efficiency performance order: IW > DW > WeW = d-WeW.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Oxidación-Reducción , Peróxidos , Agua , Contaminantes Químicos del Agua/análisis
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