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1.
Water Sci Technol ; 82(6): 1025-1030, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33055393

RESUMO

Microalgae can synthesise the ozone depleting pollutant and greenhouse gas nitrous oxide (N2O). Consequently, significant N2O emissions have been recorded during real wastewater treatment in high rate algal ponds (HRAPs). While data scarcity and variability prevent meaningful assessment, the magnitude reported (0.13-0.57% of the influent nitrogen load) is within the range reported by the Intergovernmental Panel on Climate Change (IPCC) for direct N2O emissions during centralised aerobic wastewater treatment (0.016-4.5% of the influent nitrogen load). Critically, the ability of microalgae to synthesise N2O challenges the IPCC's broad view that bacterial denitrification and nitrification are the only major cause of N2O emissions from wastewater plants and aquatic environments receiving nitrogen from wastewater effluents. Significant N2O emissions have indeed been repeatedly detected from eutrophic water bodies and wastewater discharge contributes to eutrophication via the release of nitrogen and phosphorus. Considering the complex interplays between nitrogen and phosphorus supply, microalgal growth, and microalgal N2O synthesis, further research must urgently seek to better quantify N2O emissions from microalgae-based wastewater systems and eutrophic ecosystems receiving wastewater. This future research will ultimately improve the prediction of N2O emissions from wastewater treatment in national inventories and may therefore affect the prioritisation of mitigation strategies.


Assuntos
Gases de Efeito Estufa , Microalgas , Ecossistema , Óxido Nitroso/análise , Águas Residuárias/análise
2.
Sci Total Environ ; 741: 140466, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32886993

RESUMO

There is a growing concern about the fate of antibiotic resistance genes (ARGs) during wastewater treatment and their potential impacts on the receiving water bodies. We hypothesised that the quantity of ARGs in effluents may be related to the size of wastewater treatment plants (WWTPs) and sampling season. To date, only several attempts have been made to investigate the impact of the above factors at the catchment scale. Therefore, the goal of the present study was to explore possible differences in the quantity of ARGs in treated wastewater from small, medium-sized and large WWTPs in the catchment of the Pilica River (9258 km2). The impact of treated wastewater on the concentration of ARGs was also determined along the river continuum from upland to lowland segments to the point of confluence with the Vistula (342 km). Treated effluent was sampled in 17 WWTPs, and river water was sampled in 7 sampling sites in four seasons. The concentrations of blaTEM, tet(A), ermF, sul1 and aac(6')-Ib-cr genes, the integrase gene intI1 and the 16S rRNA gene were analysed by quantitative PCR. The physical and chemical parameters and nutrient concentrations (23 various parameters) in the analysed samples were determined. The highest absolute concentrations of the studied genes were noted in effluent samples from small WWTPs (p < 0.01). The concentration of ARGs (gene copies/mL) peaked in winter and spring samples (p < 0.04). The results of statistical analyses indicate that in small WWTPs, the absolute concentration of ARGs can be predicted based on the biochemical oxygen demand, in routine water analyses. However, none of the studied parameters supported predictions of ARG abundance in medium-sized and large WWTPs or in river water.


Assuntos
Rios , Águas Residuárias/análise , Antibacterianos , Resistência Microbiana a Medicamentos , Genes Bacterianos , Prevalência , RNA Ribossômico 16S , Estações do Ano
3.
Sci Total Environ ; 741: 139514, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887017

RESUMO

Organic micropollutants enter rivers mainly with discharges of wastewater treatment plants (WWTP) and pose a risk to aquatic ecosystems and water quality. A considerable knowledge gap exists for disentangling overlapping processes and driving conditions that control the fate of these pollutants. Thus, the aim of this study was to identify the driving parameters for attenuation of selected pharmaceuticals (carbamazepine, diclofenac, tramadol and venlafaxine) under field conditions. The presented study was performed at a small river (Ammer River, mean discharge 0.87 m3 s-1) which is hydrologically complex due to karstification, numerous artificial discharges, and engineered modifications of the channel. We applied a Lagrangian sampling scheme at two sequential river reaches. In general, for the investigated compounds and over the length of the tested reaches, the absolute net attenuation representative for 24 h was low (≤ 23% net attenuation), yet calculated half-lives were comparable to literature. Photodegradation is specifically relevant for the first river reach characterized by a higher net attenuation of the photosensitive compound diclofenac (14.5% ±11.3%) compared to the second section (9.8% ±13.7%). This is likely due to a spatial difference in canopy shading, which is supported by significant correlations (R2 ≥ 0.8) of the temporally changing 'temperature' and 'solar radiation' with time-specific degradation rate constants of photosensitive compounds for consecutive hourly water parcels. In general, the presented spatially and temporally resolved approach is a suitable tool to determine the attenuation of organic micropollutants and to narrow down the interpretation of net attenuation to a few reasonable processes.


Assuntos
Rios , Poluentes Químicos da Água/análise , Ecossistema , Monitoramento Ambiental , Águas Residuárias/análise
4.
Chemosphere ; 254: 126926, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957303

RESUMO

In less than a decade, bioelectrochemical systems/microbial fuel cell integrated constructed wetlands (electroactive wetlands) have gained a considerable amount of attention due to enhanced wastewater treatment and electricity generation. The enhancement in treatment has majorly emanated from the electron transfer or flow, particularly in anaerobic regions. However, the chemistry associated with electron transfer is complex to understand in electroactive wetlands. The electroactive wetlands accommodate diverse microbial community in which each microbe set their own potential to further participate in electron transfer. The conductive materials/electrodes in electroactive wetlands also contain some potential, due to which, several conflicts occur between microbes and electrode, and results in inadequate electron transfer or involvement of some other reaction mechanisms. Still, there is a considerable research gap in understanding of electron transfer between electrode-anode and cathode in electroactive wetlands. Additionally, the interaction of microbes with the electrodes and understanding of mass transfer is also essential to further understand the electron recovery. This review mainly deals with the electron transfer mechanism and its role in pollutant removal and electricity generation in electroactive wetlands.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Transporte de Elétrons , Águas Residuárias , Purificação da Água/métodos , Áreas Alagadas , Eletrodos , Microbiota , Águas Residuárias/análise , Águas Residuárias/microbiologia
5.
Water Sci Technol ; 82(4): 773-786, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32970628

RESUMO

Petrochemical wastewater is difficult to process because of various types of pollutants with high toxicity. With the improvement in the national discharge standard, traditional biochemical treatment methods may not meet the standards and further advanced treatment techniques would be required. In this study, electrochemical oxidation with boron doped diamond (BDD) anode as post-treatment was carried out for the treatment of real biotreated petrochemical wastewater. The effects of current density, pH value, agitation rate, and anode materials on chemical oxygen demand (COD) removal and current efficiency were studied. The results revealed the appropriate conditions to be a current density of 10 mA·cm-2, a pH value of 3, and an agitation rate of 400 rpm. Moreover, as compared with the graphite electrode, the BDD electrode had a higher oxidation efficiency and COD removal efficiency. Furthermore, GC-MS was used to analyze the final degradation products, in which ammonium chloride, formic acid, acetic acid, and malonic acid were detected. Finally, the energy consumption was estimated to be 6.24 kWh·m-3 with a final COD of 30.2 mg·L-1 at a current density of 10 mA·cm-2 without the addition of extra substances. This study provides an alternative for the upgrading of petrochemical wastewater treatment plants.


Assuntos
Diamante , Poluentes Químicos da Água , Boro , Eletrodos , Cinética , Oxirredução , Águas Residuárias/análise
6.
Ecotoxicol Environ Saf ; 203: 110984, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888605

RESUMO

The use of water for drinking and agriculture requires knowledge of its toxicity. In this study, we compared the use of genetically modified bioluminescent (GMB) bacteria whose luminescence increases in the presence of toxicants and Chinese Hamster Ovary (CHO) cells for the characterization of the toxicity of water samples collected from a lake and streams, hydroponic and aquaponic farms, and a wastewater treatment plant. GMB bacteria were used to probe genotoxicity, cytotoxicity and reactive oxygen species-induced effects in the whole water samples. Unlike GMB bacteria, the use of CHO cells requires XAD resin-based pre-concentration of toxic material present in water samples for the subsequent cytotoxicity assay. In addition to the examination of the toxicity of the water from the different sources, the GMB bacteria were also used to test the XAD extracts diluted to the concentrations causing 50% growth inhibition of the CHO cells. The two biomonitoring tools provided different results when they were used to test the above-mentioned diluted XAD extracts. A pre-concentration procedure based on adsorption by XAD resins with subsequent elution was not sufficient to represent the material responsible for the toxicity of the whole water samples toward the GMB bacteria. Therefore, the use of XAD resin extracts may lead to major underestimates of the toxicity of water samples. Although the toxicity findings obtained using the GMB bacteria and CHO cells may not correlate with each another, the GMB bacteria assay did provide a mechanism-specific biomonitoring tool to probe the toxicity of water samples without a need for the pre-concentration step.


Assuntos
Bactérias , Monitoramento Biológico/métodos , Água Potável/análise , Lagos/análise , Rios , Águas Residuárias/análise , Animais , Bactérias/genética , Células CHO , Cricetulus , Hidroponia , Luminescência , Microrganismos Geneticamente Modificados/genética , Eliminação de Resíduos Líquidos
7.
J Environ Manage ; 272: 111057, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32854876

RESUMO

Petroleum refinery and petrochemical plants (PRPP) are one of the major contributors to toxic and recalcitrant organic polluted water, which has become a significant concern in the field of environmental engineering. Several contaminants of PRPP wastewater are genotoxic, phytotoxic, and carcinogenic, thereby imposing detrimental effects on the environment. Many biological processes were able to achieve chemical oxygen demand (COD) removal ranging from 60% to 90%, and their retention time usually ranged from 10 to 100 days. These methods were not efficient in removing the petroleum hydrocarbons present in PRPP wastewater and produced a significant amount of oily sludge. Advanced oxidation processes achieved the same COD removal efficiency in a few hours and were able to break down recalcitrant organic compounds. However, the associated high cost is a significant drawback concerning PRPP wastewater treatment. In this context, constructed wetlands (CWs) could effectively remove the recalcitrant organic fraction of the wastewater because of the various inherent mechanisms involved, such as phytodegradation, rhizofiltration, microbial degradation, sorption, etc. In this review, we found that CWs were efficient in handling large quantities of high strength PRPP wastewater exhibiting average COD removal of around 80%. Horizontal subsurface flow CWs exhibited better performance than the free surface and floating CWs. These systems could also effectively remove heavy oil and recalcitrant organic compounds, with an average removal efficiency exceeding 80% and 90%, respectively. Furthermore, modifications by varying the aeration system, purposeful hybridization, and identifying the suitable substrate led to the enhanced performance of the systems.


Assuntos
Petróleo , Purificação da Água , Biodegradação Ambiental , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Áreas Alagadas
8.
J Environ Manage ; 272: 111094, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32854894

RESUMO

There are different physicochemical and biological methods to treat effluents. However, their efficiency is not enough to meet the effluents discharge limits. For this reason, it could be possible to employ a polished treatment. A suitable alternative for this goal could be constructed wetlands (CWs). The aim of the present research was to evaluate contaminants removal efficiency of a pilot scale horizontal subsurface flow constructed wetland (HSSFW) for tertiary treatment of dairy wastewater. A vegetation study was also conducted in order to determine the role of plants on nutrient removal. A pilot scale HSSFW planted with Typha domingensis was built in a dairy factory, after the biological treatment. The substrate used was river gravel. During a seven-month research period, thirty-two samples (influent and effluent) were taken and analyzed to determine physicochemical and microbiological parameters as well as removal efficiencies. Biomass, TP, TKN and organic matter content in plants was determined at the beginning and end of the monitoring period. Suspended solids showed significant differences between inlet and outlet, with a mean removal efficiency of 78.4%. For BOD and COD, mean removal efficiencies were respectively 57.9 and 68.7%. Removal percentages for TKN, Nitrates and TP were lower than other parameters (25.7%, 47.8% and 29.9%, respectively). Fecal Coliform bacteria decreased one order of magnitude in final effluent. In the case of Escherichia coli and Pseudomona aeruginosa results were variable. Total biomass increased 4.6 times at the end of the monitoring period. The study of plants indicated its important contribution in terms of contaminant uptake and retention. HSSFW would be an advisable alternative as a tertiary treatment of dairy wastewater.


Assuntos
Typhaceae , Poluentes Químicos da Água/análise , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Áreas Alagadas
9.
Sci Total Environ ; 744: 140997, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32755790

RESUMO

The occurrence and fate of antibiotics and antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) in Municipal Wastewater Treatment Plants (WWTPs) worldwide were reviewed. The prevalence of antibiotics in WWTPs among different periods (1999-2009 and 2010-2019) and geographical areas (Europe, America, Asia and Africa) was summarized, analyzed and evaluated. The classes of macrolides (clarithromycin, erythromycin/erythromycin-H2O, azithromycin, roxithromycin), sulfonamides (sulfamethoxazole), trimethoprim, quinolones (ofloxacin, ciprofloxacin, norfloxacin) and tetracyclines (tetracycline) were the antibiotics most frequently detected, while bla (blaCTXM, blaTEM), sul (sul1, sul2), tet (tetO, tetQ, tetW) and ermB genes were the ARGs commonly reported in WWTPs. There was a positive correlation between antibiotics and ARGs commonly detected in WWTPs, except for ß-lactam antibiotics and bla genes. The genes bla were found frequently, despite ß-lactam antibiotics were seldom detected owing to the hydrolysis. Most of antibiotics had lower levels in the period 2010-2019 in Asian countries than that in period 1999-2009 in North American and European countries. In the effluent of secondary treatment, the concentration of trimethoprim was the highest (138 ng/L in median) and the concentration of other antibiotics remained at lower than 80 ng/L, while the relative abundance of ARGs ranged 2.9-4.6 logs (copies/mL, in median). Future researches on the development of effective antibiotic removal technologies, such as advanced oxidation processes, are suggested to focus on antibiotics frequently detected and their corresponding ARGs in WWTPs.


Assuntos
Antibacterianos , Águas Residuárias/análise , África , Ásia , Bactérias/genética , Resistência Microbiana a Medicamentos , Europa (Continente) , Genes Bacterianos , RNA Ribossômico 16S , Eliminação de Resíduos Líquidos
10.
ACS Chem Neurosci ; 11(17): 2482-2484, 2020 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-32790273

RESUMO

The presence of SARS-CoV-2 in human wastewater together with poor quality of public drinking water supplies in developing countries is of concern. Additionally, the frequent use of contaminated water for bathing, nasal irrigation, swimming, and ablution can be a risk factor in contracting infectious agents such as the brain-eating amoebae and possibly SARS-CoV-2. The use of appropriate tap water filters should be encouraged to remove pathogenic microbes, together with restrained nasal irrigation (not forcing water inside nostrils vigorously) during ritual ablution or bathing to avoid dangerous consequences for populations residing in developing countries.


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Água Potável/virologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Águas Residuárias/virologia , Purificação da Água/métodos , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Água Potável/análise , Água Potável/normas , Humanos , Pneumonia Viral/epidemiologia , Águas Residuárias/análise , Purificação da Água/normas
11.
Water Res ; 185: 116196, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32738601

RESUMO

Mitigation of nitrous oxide (N2O) emissions is of primary importance to meet the targets of reducing carbon footprints of wastewater treatment plants (WWTPs). Despite of a large amount of N2O mitigation studies conducted in laboratories, full-scale implementation of N2O mitigation is scarce, mainly due to uncertainties of mitigation effectiveness, validation of N2O mathematical model, risks to nutrient removal performance and additional costs. This study aims to address the uncertainties by investigating the quantification, development and implementation of N2O mitigation strategies at a full-scale sequencing batch reactor (SBR). To achieve this, N2O emission dynamics, nutrient removal performance and operation of the SBR were monitored to quantify N2O emissions, and identify the N2O generation mechanisms. N2O mitigation strategies centered on reducing dissolved oxygen (DO) levels were consequently proposed and evaluated using a multi-pathway N2O production mathematical model before implementation. The implemented mitigation strategy resulted in a 35% reduction in N2O emissions (from the emission factor of 0.89 ± 0.05 to 0.58 ± 0.06%), which was equivalent to annual reduction of 2.35 tonne of N2O from the studied WWTP. This could be mainly attributed to reductions in N2O generated via the NH2OH oxidation pathway due to the lowering of DO level. As the first reported mitigation strategy permanently implemented at a full scale WWTP, it showcased that the mitigation of N2O emissions at full-scale is feasible and that widely accepted N2O mitigation strategies developed in laboratory studies are also likely effective in full-scale plants. Furthermore, the close agreement between the validated and predicted N2O emission factors (0.58% vs 0.55%, respectively), showed that the N2O mathematical model is a useful tool to evaluate N2O mitigation strategies at full-scale. Importantly this work demonstrated that N2O mitigation does not necessarily require additional operational cost to meet reduction targets. In contrast, the N2O mitigation applied here reduced energy requirements for aeration by 20%. Equally important, long-term monitoring identified that N2O mitigation did not affect the nutrient removal performance of the plant. Finally, with the knowledge acquired in this study, a standard approach for mitigating N2O emissions from full-scale treatment plants was proposed.


Assuntos
Óxido Nitroso , Águas Residuárias , Reatores Biológicos , Pegada de Carbono , Modelos Teóricos , Óxido Nitroso/análise , Águas Residuárias/análise
12.
Water Res ; 185: 116239, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32739702

RESUMO

Synthetic musks (SMs) are used extensively in household and personal care products and have acted significant concerns due to their environmental impacts and potential health effects. Here, we present a passive sampling approach based on diffusive gradients in thin films (DGT) for in situ measurement of SMs in urban wastewaters. XAD-2 binding gel, which has a rapid binding rate and high elution efficiency, was used in DGT device for the accumulation of six polycyclic musks and three nitro musks. The diffusion coefficients (D and DNL) of the SMs through agarose gel without and with a nylon filter membrane were 3.37-4.49 and 1.48-4.41 ×10-6cm2 s-1. The filter membrane caused an ~3 h lag phase and slowed the diffusion rates of the SMs through the diffusive phase. Solution pH (4.30-8.92), ionic strength (0.0001-0.5 M) and dissolved organic matter (0-20 mg L-1) showed no obvious influence on uptake of the SMs in DGT. The measured average SM concentrations in the effluent of wastewater treatment plants ranged from 0.45-696 ng/L for DGT deployment, without obvious membrane biofouling, and they were comparable to the concentrations determined by grab sampling. These results confirmed that the present method is reliable and convenient for in situ measurement of semivolatile hydrophobic SMs in complicated waters and is an available tool to investigate the environmental behaviors of SMs in the environment.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Difusão , Monitoramento Ambiental , Concentração Osmolar , Águas Residuárias/análise , Poluentes Químicos da Água/análise
13.
Water Res ; 185: 116273, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32805664

RESUMO

The widespread of antibiotic resistance genes (ARGs) in the environment can pose severe threats to public health. The wastewater treatment plant (WWTP) is regarded as an important hotspot of ARGs in the urban environment, but the removal of ARGs through conventional treatment techniques has been proven not sufficient. In this study, ferrate (Fe(VI)) was applied for the first time to remove intracellular ARGs from the secondary effluent of the WWTP. The results showed that Fe(VI) treatment could effectively remove 15 ARGs covering eight different types as well as intI1, the most common integron important to ARGs horizontal transfer. The removal efficiencies of tested genes could reach 1.10-4.37 log at the Fe(VI) dosage of 10 mg-Fe/L, which is significantly higher than those achieved through traditional disinfection methods. The DNA gel electrophoresis suggested that Fe(VI) could induce microbial DNA damage and consequently resulted in ARGs elimination. The presence of ARGs in settled residues indicated that coagulation initiated by Fe(VI) reduction products also contributed to ARGs removal from wastewater. In addition, the viability and relative abundances of potential ARGs hosts in the wastewater were decreased after Fe(VI) treatment. This study suggested a promising prospect for applying Fe(VI) to efficiently remove ARGs from wastewater, and consequently to control their proliferation and transfer in the environment.


Assuntos
Antibacterianos , Águas Residuárias , Antibacterianos/farmacologia , DNA , Dano ao DNA , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Ferro , Águas Residuárias/análise
14.
Water Res ; 185: 116235, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32823195

RESUMO

Ozonation of secondary wastewater treatment plant effluent for the abatement of organic micropollutants requires an accurate process control, which can be based on monitoring ozone-induced changes in dissolved organic matter (DOM). This study presents a novel automated analytical system for monitoring changes in the electron donating capacity (EDC) and UV absorbance of DOM during ozonation. In a first step, a quantitative photometric EDC assay was developed based on electron-transfer reactions from phenolic moieties in DOM to an added chemical oxidant, the radical cation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS·+). The assay is highly sensitive (limit of quantification ∼0.5 mgDOC·L-1) and EDC values of model DOM isolates determined by this assay were in good agreement with values determined previously by mediated electrochemical oxidation (slope = 1.01 ± 0.07, R2 = 0.98). In a second step, the photometric EDC measurement method was transferred onto an automated fluidic system coupled to a photometer (EDC analyzer). The EDC analyzer was then used to monitor changes in EDC and UV absorbance of secondary wastewater effluent treated with ozone. While both parameters exhibited a dose-dependent decrease, a more pronounced decrease in EDC as compared to UV absorbance was observed at specific ozone doses up to 0.4 mgO3·gDOC-1. The concentration of 17α-ethinylestradiol, a phenolic micropollutant with a high ozone reactivity, decreased proportionally to the EDC decrease. In contrast, abatement of less ozone-reactive micropollutants and bromate formation started only after a pronounced initial decrease in EDC. The on-line EDC analyzer presented herein will enable a comprehensive assessment of the combination of EDC and UV absorbance as control parameters for full-scale ozonation.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Bromatos , Elétrons , Águas Residuárias/análise
15.
J Environ Manage ; 274: 111190, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32771773

RESUMO

The objectives of this study were to clarify the distribution as well as the removal mechanism of antibiotic resistance genes (ARGs) within three sludge treatment wetlands (STWs) during a loading period of two years. Three STW units were constructed and run during the loading period: Unit 1 (U1) built with aeration tubes, Unit 2 (U2) built with aeration tubes and reeds, and Unit 3 (U3) built with reeds only. All targeted ARGs, intI1, and 16S rRNA were detected in residual sludge in the order of magnitude: 16S rRNA>sul1>intI1>sul2>tetC>tetA>ermB. The abundance of the five targeted ARGs, intI1, and 16S rRNA increased in residual sludge, during the loading period, which may be due to the increase in bacteria caused by the continuous import of exogenous nutrients. However, STWs can also remove ARGs from sewage during the loading period and the mean removal efficiency of five resistance genes was 73.0%. The removal rates of intI1 and 16S rRNA were 73.5% and 78.6%, respectively. Positive correlations were detected in abundance of most ARGs and intI1, as well as 16S rRNA (P < 0.05), indicating intI1 plays a vital part in the propagation of ARGs. The removal of bacteria harboring these genes also occurs in the STW units.


Assuntos
Esgotos , Áreas Alagadas , Animais , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/genética , RNA Ribossômico 16S/genética , Águas Residuárias/análise
16.
J Environ Manage ; 274: 111081, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32810678

RESUMO

The present study evaluated the efficiency of a semi-closed horizontal tubular photobioreactor (PBR) at demonstrative scale to remove a total of 35 target compounds, including benzotriazoles, benzophenones, antibiotics and different pharmaceuticals present in irrigation water in a peri-urban rural area. This water run through an open channel and was a mixture of reclaimed wastewater from a nearby wastewater treatment plant (WWTP) and run-off from the different agricultural fields in the area. Most of the compounds studied are usually not fully eliminated during conventional wastewater treatment, which justifies the need to investigate alternative treatment strategies. A total of 21 of these compounds were detected in the irrigation water. Benzotriazoles were only partially removed after the microalgae treatment, with elimination rates similar to those of conventional WWTPs. The UV filter benzophenone-3 (BP3) showed variable removals, ranging from no elimination to 51%, whereas 4-methylbenzilidenecamphor (4MBC) was completely eliminated. Regarding pharmaceuticals, average removals were higher, in the range of 60-100%, with the exception of the antibiotics sulfamethoxazole (46%) and sulfapyridine, which was not removed. Despite the low biomass productivity of the PBR, parameters such as the size of the reactors, the specific mixed cultures developed and the high temperatures and pH in the closed system may account for the overall good results, The efficiency and sustainability of these systems make them a solid, feasible treatment choice.


Assuntos
Microalgas , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Fotobiorreatores , Eliminação de Resíduos Líquidos , Águas Residuárias/análise
17.
J Chromatogr A ; 1626: 461386, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797858

RESUMO

In this study, the microcrystalline cellulose/metal-organic framework 199 hybrid (MCC/MOF-199) was applied as sorbent for the dispersive micro-solid phase-extraction (D-µSPE) of chlorophenols. The D-µSPE method combined with high-performance liquid chromatography- ultraviolet detection (HPLC-UV) was employed to determine of four chlorophenols including 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,3-dichlorophenol (2,3-DCP), and 2,5-dichlorophenol (2,5-DCP) in aqueous. The main parameters of the D-µSPE process that influence the extraction (i.e. the amount of sorbent, elution condition, extraction time, and pH) were investigated and optimized. Based on the outputs, the presence of MCC on the surface of MOF-199 leads to improve the properties of MOF-199 and the MCC/MOF-199 has the highest sorption capacity, durability, and porosity in comparison with MCC and MOF-199. According to the validation study at the optimized conditions, the linearity for the analytes was achieved in the range from 0.1 to 200 ng mL-1 for 2-CP and 4-CP and 0.15 to 200 ng mL-1 for 2,3-DCP and 2,5-DCP with correlation coefficients between 0.9928 and 0.9965. The limits of detection calculated at S/N=3 were in the range of 0.03-0.05 ng mL-1. Besides, the relative standard deviations (RSDs) for three spiking levels (0.2, 10,100 ng mL-1) do not exceed 6.8% and extraction recoveries are between 81.0% and 88.3%. Finally, the D-µSPE-HPLC-UV method was successfully applied to the analysis of CPs in real water samples (mineral, river and wastewater samples) with good recoveries (95.8 to 99.5%) and satisfactory precisions (RSD < 6.8%).


Assuntos
Celulose/química , Clorofenóis/análise , Estruturas Metalorgânicas/química , Microextração em Fase Sólida/métodos , Clorofenóis/química , Clorofenóis/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Água Doce/análise , Concentração de Íons de Hidrogênio , Limite de Detecção , Rios/química , Espectrofotometria Ultravioleta , Águas Residuárias/análise
18.
Sci Total Environ ; 745: 140697, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32758738

RESUMO

The extent of prescription and illicit drug abuse in geographically isolated rural and micropolitan communities in the intermountain western United States (US) has not been well tracked. The goal of this pilot study was to accurately measure drug dose consumption rates (DCR) between two select populations, normalize the data and compare the DCRs to similar communities. To learn about patterns of drug abuse between the two disparate communities, we used the emergent field of wastewater-based epidemiology (WBE). A rapid, quantitative and systematic process for the determination of multiple classes of prescribed and illicit drugs was applied to influent wastewater samples. Influent samples were collected over the course of three months (April to June 2019) at two wastewater treatment plants representing a small urban and a rural community. Collection of sewage influent included 24-h composite samples and the use of polar organic chemical integrative samplers (POCIS), time-weighted samplers. Using the results from the composite sampling data, DCRs per 1000 population could be calculated from the concentration data and the use of excretion correction factors. The following 18 compounds: amphetamine, methamphetamine, MDA, MDMA, morphine, 6-acetylmorphine, methadone, EDDP, codeine, benzoylecgonine, hydrocodone, hydromorphone, oxycodone, noroxycodone, ketamine, fluoxetine, tramadol, and ritalinic acid; represent a subset of the targeted analytes that were consistently measured at detectable concentration levels, and present at both sites. Following normalization of the drug measurements to influent flow rates and per capita, the small urban community demonstrated greater collective excretion rates (CER) than the rural community, with the exceptions of amphetamine and methamphetamine.


Assuntos
Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Poluentes Químicos da Água/análise , Humanos , Projetos Piloto , Detecção do Abuso de Substâncias , Estados Unidos , Águas Residuárias/análise , Vigilância Epidemiológica Baseada em Águas Residuárias
19.
Sci Total Environ ; 745: 141100, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32758752

RESUMO

The aims of this study were to select the most suitable macrophyte species and substrate to be used in horizontal subsurface flow (HSSF) wetlands for the treatment of a local cheese factory wastewater, and to quantify the influence of plant species and substrates by applying of a simple first-order kinetic model. Microcosms-scale HSSF wetlands were planted with Canna glauca or Typha domingensis. LECA and river stones were used as substrates. Both studied macrophytes showed a high tolerance to the treated wastewater. HSSF wetlands were efficient for the treatment of diluted cheese production wastewater. COD, TP, NH4+-N and TN showed high removal efficiencies in all the HSSF wetlands. HSSF wetlands planted with C. glauca showed the best performance for removal of NH4+-N. The highest SRP removal was obtained in HSSF wetlands planted C. glauca with LECA as substrate. A simple first-order kinetics model was applied. The fitted parameters of the modified first-order model k-C* allowed to demonstrate the effect of the plants in the treatment of the effluent. HSSF wetlands planted with C. glauca using river stones were the systems that showed the fastest TIN removal. According to the obtained results, it is proposed to use C. glauca and river stones as substrate in a HSSF wetland for the treatment of this wastewater. The present study provides useful data to design a wetland at a larger scale.


Assuntos
Queijo , Poluentes Químicos da Água/análise , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Áreas Alagadas
20.
Sci Total Environ ; 746: 141134, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768780

RESUMO

Pharmaceuticals may enter soils due to the application of treated wastewater or biosolids. Their leakage from soils towards the groundwater, and their uptake by plants is largely controlled by sorption and degradation of those compounds in soils. Standard laboratory batch degradation and sorption experiments were performed using soil samples obtained from the top horizons of seven different soil types and 6 pharmaceuticals (carbamazepine, irbesartan, fexofenadine, clindamycin and sulfamethoxazole), which were applied either as single-solute solutions or as mixtures (not for sorption). The highest dissipation half-lives were observed for citalopram (average DT50,S for a single compound of 152 ±â€¯53.5 days) followed by carbamazepine (106.0 ±â€¯17.5 days), irbesartan (24.4 ±â€¯3.5 days), fexofenadine (23.5 ±â€¯20.9 days), clindamycin (10.8 ±â€¯4.2 days) and sulfamethoxazole (9.6 ±â€¯2.0 days). The simultaneous application of all compounds increased the half-lives (DT50,M) of all compounds (particularly carbamazepine, citalopram, fexofenadine and irbesartan), which is likely explained by the negative impact of antibiotics (sulfamethoxazole and clindamycin) on soil microbial community. However, this trend was not consistent in all soils. In several cases, the DT50,S values were even higher than the DT50,M values. Principal component analyses showed that while knowledge of basic soil properties determines grouping of soils according sorption behavior, knowledge of the microbial community structure could be used to group soils according to the dissipation behavior of tested compounds in these soils. The derived multiple linear regression models for estimating dissipation half-lives (DT50,S) for citalopram, clindamycin, fexofenadine, irbesartan and sulfamethoxazole always included at least one microbial factor (either amount of phosphorus in microbial biomass or microbial biomarkers derived from phospholipid fatty acids) that deceased half-lives (i.e., enhanced dissipations). Equations for citalopram, clindamycin, fexofenadine and sulfamethoxazole included the Freundlich sorption coefficient, which likely increased half-lives (i.e., prolonged dissipations).


Assuntos
Microbiota , Poluentes do Solo/análise , Adsorção , Solo , Sulfametoxazol , Águas Residuárias/análise
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