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1.
Environ Res ; 259: 119439, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38901811

RESUMO

Increasing amounts of wastewater is the most pervasive and challenging environmental problem globally. Conventional treatment methods are costly and entail huge energy, carbon consumption and greenhouse gas emissions. Owing to their unique ability of carbon capturing and resource recovery, microalgae-microbiome based treatment is a potential approach and is widely used for carbon-neutral wastewater treatment. Microalgae-bacteria synergy (i.e., the functionally beneficial microbial synthetic communities) performs better and enhances carbon-sequestration and nutrient recovery from wastewater treatment plants. This review presents a comprehensive information regarding the potential of microalgae-microbiome as a sustainable agent for wastewater and discusses synergistic approaches for effective nutrient removal. Moreover, this review discusses, the role of omics-biology and Insilco approaches in unravelling and understanding the algae-microbe synergism and their response toward wastewater treatment. Finally, it discusses various microbiome engineering approaches for developing the effective microalgae-bacteria partners for carbon sequestration and nutrient recovery from wastewater, and summarizes future research perspectives on microalgae-microbiome based bioremediation.

2.
Environ Res ; 259: 119533, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38960354

RESUMO

The degradation of persistent and refractory pollutants, particularly plastic and resins manufacturing wastewater, poses a significant challenge due to their high toxicity and high concentrations. This study developed a novel hybrid ACoO3 (A = La, Ce, Sr)/PMS perovskite system for the treatment of multicomponent (MCs; ACN, ACM and ACY) from synthetic resin manufacturing wastewater. Synthesized perovskites were characterized by various techniques i.e., BET, XRD, FESEM with EDAX, FTIR, TEM, XPS, EIS, and Tafel analysis. Perovskite LaCoO3 exhibited the highest degradation of MCs i.e., ACN (98.7%), ACM (86.3%), and ACY (56.4%), with consumption of PMS (95.2%) under the optimal operating conditions (LaCoO3 dose 0.8 g/L, PMS dose 2 g/L, pH 7.2 and reaction temperature 55 °C). The quantitative contribution (%) of reactive oxygen species (ROS) reveals that SO4•- are the dominating radical species, which contribute to ACN (58.3% for SO4•- radicals) and ACM degradation (46.4% for SO4•- radicals). The tafel plots and EIS spectra demonstrated that perovskites LaCoO3 have better charge transfer rates and more reactive sites that are favorable for PMS activation. Further, four major degradation pathways were proposed based on Fukui index calculations, as well as GC-MS characterization of intermediate byproducts. Based on a stability and reusability study, it was concluded that LaCoO3 perovskites are highly stable, and minimal cobalt leaching occurs (0.96 mg/L) after four cycles. The eco-toxicity assessment performed using QSAR model indicated that the byproducts of the LaCoO3/PMS system are non-toxic nature to common organism (i.e., fish, daphnids and green algae). In addition, the cost of the hybrid LaCoO3/PMS system in a single cycle was estimated to be $34.79 per cubic meter of resin wastewater.

3.
Environ Res ; 252(Pt 4): 119133, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38735379

RESUMO

Phosphorus in wastewater poses a significant environmental threat, leading to water pollution and eutrophication. However, it plays a crucial role in the water-energy-resource recovery-environment (WERE) nexus. Recovering Phosphorus from wastewater can close the phosphorus loop, supporting circular economy principles by reusing it as fertilizer or in industrial applications. Despite the recognized importance of phosphorus recovery, there is a lack of analysis of the cyber-physical framework concerning the WERE nexus. Advanced methods like automatic control, optimal process technologies, artificial intelligence (AI), and life cycle assessment (LCA) have emerged to enhance wastewater treatment plants (WWTPs) operations focusing on improving effluent quality, energy efficiency, resource recovery, and reducing greenhouse gas (GHG) emissions. Providing insights into implementing modeling and simulation platforms, control, and optimization systems for Phosphorus recovery in WERE (P-WERE) in WWTPs is extremely important in WWTPs. This review highlights the valuable applications of AI algorithms, such as machine learning, deep learning, and explainable AI, for predicting phosphorus (P) dynamics in WWTPs. It emphasizes the importance of using AI to analyze microbial communities and optimize WWTPs for different various objectives. Additionally, it discusses the benefits of integrating mechanistic and data-driven models into plant-wide frameworks, which can enhance GHG simulation and enable simultaneous nitrogen (N) and Phosphorus (P) removal. The review underscores the significance of prioritizing recovery actions to redirect Phosphorus from effluent to reusable products for future considerations.


Assuntos
Fósforo , Eliminação de Resíduos Líquidos , Águas Residuárias , Fósforo/análise , Águas Residuárias/química , Águas Residuárias/análise , Eliminação de Resíduos Líquidos/métodos , Inteligência Artificial , Purificação da Água/métodos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
4.
Water Sci Technol ; 90(1): 213-224, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39007315

RESUMO

Wastewater-based epidemiology (WBE) is a valuable disease surveillance tool. However, little is known on how factors such as transportation, storage, and wastewater characteristics influence the accuracy of the quantification methods. Hence, this study investigated the impact of storage temperatures and physicochemical characteristics of wastewater on SARS-CoV-2 and influenza A stability using droplet digital PCR. Additionally, strategies to enhance viral recovery were explored. Municipal influent wastewater stored between ±25 and -80 °C was assessed for a period of 84 days to determine viral degradation. Degradation up to 94.1% of influenza A and SARS-CoV-2 was observed in all samples with the highest at ±25 °C. Viral degradation was correlated to the changes in wastewater physicochemical characteristics. The low degradation observed of SARS-CoV-2 in the spiked pellets were indicative of viral adhesion to wastewater solids, which correlated with changes in pH. Ultrasonication frequencies ranging from 4 to 16 kHz, increased SARS-CoV-2 concentrations in the supernatant between 3.30 and 35.65%, indicating viral RNA attachment to wastewater solids. These results highlight the importance of additional pretreatment methods for maximizing RNA recovery from wastewater samples. Based on these findings, it was deduced that wastewater preservation studies are essential, and pretreatment should be included in the WBE methodology.


Assuntos
SARS-CoV-2 , Águas Residuárias , SARS-CoV-2/isolamento & purificação , Águas Residuárias/virologia , COVID-19/virologia , RNA Viral/genética , Biomarcadores , Vírus da Influenza A , Vigilância Epidemiológica Baseada em Águas Residuárias , Humanos , Temperatura
5.
World J Microbiol Biotechnol ; 40(3): 81, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38285224

RESUMO

An integrated approach to nutrient recycling utilizing microalgae could provide feasible solutions for both environmental control and energy production. In this study, an axenic microalgae strain, Chlorella sorokiniana ASK25 was evaluated for its potential as a biofuel feedstock and textile wastewater (TWW) treatment. The microalgae isolate was grown on TWW supplemented with different proportions of standard BG-11 medium varying from 0 to 100% (v/v). The results showed that TWW supplemented with 20% (v/v) BG11 medium demonstrated promising results in terms of Chlorella sorokiniana ASK25 biomass (3.80 g L-1), lipid production (1.24 g L-1), nutrients (N/P, > 99%) and pollutant removal (chemical oxygen demand (COD), 99.05%). The COD level dropped by 90% after 4 days of cultivation, from 2,593.33 mg L-1 to 215 mg L-1; however, after day 6, the nitrogen (-NO3-1) and total phosphorus (TP) levels were reduced by more than 95%. The biomass-, total lipid- and carbohydrate- production, after 6 days of cultivation were 3.80 g L-1, 1.24 g L-1, and 1.09 g L-1, respectively, which were 2.15-, 2.95- and 3.30-fold higher than Chlorella sorokiniana ASK25 grown in standard BG-11 medium (control). In addition, as per the theoretical mass balances, 1 tonne biomass of Chlorella sorokiniana ASK25 might yield 294.5 kg of biodiesel and 135.7 kg of bioethanol. Palmitic acid, stearic acid, and oleic acid were the dominant fatty acids found in the Chlorella sorokiniana ASK25 lipid. This study illustrates the potential use of TWW as a microalgae feedstock with reduced nutrient supplementation (20% of TWW). Thus, it can be considered a promising feedstock for economical biofuel production.


Assuntos
Chlorella , Microalgas , Biocombustíveis , Ácidos Graxos , Têxteis
6.
Environ Res ; 231(Pt 1): 115911, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37105295

RESUMO

Tuberculosis (TB) remains a persistent challenge to public health and presents a substantial menace, especially in developing nations of sub-Saharan Africa. It exerts a considerable strain on healthcare systems in these regions. Effective control requires reliable surveillance, which can be improved by incorporating environmental data alongside clinical data. Molecular advances have led to the development of alternative surveillance methods, such as wastewater-based epidemiology. This studyinvestigated the presence, concentration, and diversity of Mycobacterium tuberculosis complex, the cause of TB, in from six African countries: Ghana, Nigeria, Kenya, Uganda, Cameroon, and South Africa. Samples were collected from wastewater treatment plants. All samples were found to contain Mycobacterium species that have been linked to TB in both humans and animals, including Mycobacterium tuberculosis complex, Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium africanum, and Mycobacterium caprae, at varying concentrations. The highest median concentration was found in Ghana, reaching up to 4.7 Log copies/ml for MTBC, 4.6 Log copies/ml for M. bovis, and 3.4 Log copies/ml for M. africanum. The presence of M. africanum outside of West Africa was found in South Africa, Kenya, and Uganda and could indicate the spread of the pathogen. The study underscores the usefulness of wastewater-based epidemiology for tracking TB and shows that even treated wastewater may contain these pathogens, posing potential public health risks.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Animais , Humanos , Vigilância Epidemiológica Baseada em Águas Residuárias , Filogenia , Tuberculose/epidemiologia , Gana/epidemiologia
7.
Parasitol Res ; 123(1): 62, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38114766

RESUMO

The One-Health approach recognizes the intricate connection between human, animal, and environmental health, and that cooperative effort from various professionals provides comprehensive awareness and potential solutions for issues relating to the health of people, animals, and the environment. This approach has increasingly gained appeal as the standard strategy for tackling emerging infectious diseases, most of which are zoonoses. Treatment with anthelmintics (AHs) without a doubt minimizes the severe consequences of soil-transmitted helminths (STHs); however, evidence of anthelmintic resistance (AR) development to different helminths of practically every animal species and the distinct groups of AHs is overwhelming globally. In this regard, the correlation between the application of anthelmintic drugs in both human and animal populations and the consequent development of anthelmintic resistance in STHs within the context of a One-Health framework is explored. This review provides an overview of the major human and animal STHs, treatment of the STHs, AR development and drug-related factors contributing towards AR, One-Health and STHs, and an outline of some One-Health strategies that may be used in combating AR.


Assuntos
Anti-Helmínticos , Helmintíase , Helmintos , Saúde Única , Animais , Humanos , Helmintíase/tratamento farmacológico , Helmintíase/prevenção & controle , Helmintíase/parasitologia , Solo/parasitologia , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico
8.
Environ Res ; 203: 111877, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34390718

RESUMO

Wastewater-based epidemiology has been used as a tool for surveillance of COVID-19 infections. This approach is dependent on the detection and quantification of SARS-CoV-2 RNA in untreated/raw wastewater. However, the quantification of the viral RNA could be influenced by the physico-chemical properties of the wastewater. This study presents the first use of Adaptive Neuro-Fuzzy Inference System (ANFIS) to determine the potential impact of physico-chemical characteristics of wastewater on the detection and concentration of SARS-CoV-2 RNA in wastewater. Raw wastewater samples from four wastewater treatment plants were investigated over four months. The physico-chemical characteristics of the raw wastewater was recorded, and the SARS-CoV-2 RNA concentration determined via amplification with droplet digital polymerase chain reaction. The wastewater characteristics considered were chemical oxygen demand, flow rate, ammonia, pH, permanganate value, and total solids. The mean SARS-CoV-2 RNA concentrations ranged from 648.1(±514.6) copies/mL to 1441.0(±1977.8) copies/mL. Among the parameters assessed using the ANFIS model, ammonia and pH showed significant association with the concentration of SARS-CoV-2 RNA measured. Increasing ammonia concentration was associated with increasing viral RNA concentration and pH between 7.1 and 7.4 were associated with the highest SARS-CoV-2 concentration. Other parameters, such as total solids, were also observed to influence the viral RNA concentration, however, this observation was not consistent across all the wastewater treatment plants. The results from this study indicate the importance of incorporating wastewater characteristic assessment into wastewater-based epidemiology for a robust and accurate COVID-19 surveillance.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , RNA Viral , Carga Viral , Águas Residuárias
9.
BMC Public Health ; 22(1): 145, 2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-35057793

RESUMO

BACKGROUND: The Mycobacterium tuberculosis complex (MTBC) consists of causative agents of both human and animal tuberculosis and is responsible for over 10 million annual infections globally. Infections occur mainly through airborne transmission, however, there are possible indirect transmissions through a faecal-oral route which is poorly reported. This faecal-oral transmission could be through the occurrence of the microbe in environments such as wastewater. This manuscript, therefore, reviews the source and fate of MTBC in the wastewater environment, including the current methods in use and the possible risks of infections. RESULTS: The reviewed literature indicates that about 20% of patients with pulmonary TB may have extra-pulmonary manifestations such as GITB, resulting in shedding in feaces and urine. This could potentially be the reason for the detection of MTBC in wastewater. MTBC concentrations of up to 5.5 × 105 (±3.9 × 105) copies/L of untreated wastewater have been reported. Studies have indicated that wastewater may provide these bacteria with the required nutrients for their growth and could potentially result in environmental transmission. However, 98.6 (± 2.7) %, removal during wastewater treatment, through physical-chemical decantation (primary treatment) and biofiltration (secondary treatment) has been reported. Despite these reports, several studies observed the presence of MTBC in treated wastewater via both culture-dependent and molecular techniques. CONCLUSION: The detection of viable MTBC cells in either treated or untreated wastewater, highlights the potential risks of infection for wastewater workers and communities close to these wastewater treatment plants. The generation of aerosols during wastewater treatment could be the main route of transmission. Additionally, direct exposure to the wastewater containing MTBC could potentially contribute to indirect transmissions which may lead to pulmonary or extra-pulmonary infections. This calls for the implementation of risk reduction measures aimed at protecting the exposed populations.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Tuberculose , Purificação da Água , Animais , Humanos , Tuberculose/diagnóstico , Tuberculose Pulmonar/epidemiologia , Águas Residuárias
10.
Bioprocess Biosyst Eng ; 45(1): 187-201, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34668053

RESUMO

Chlamydomonas reinhardtii produces a variety of compounds that can be beneficial to human and animal health. Among these compounds, application of photosynthetic pigments, such as chlorophylls and carotenoids, has gained considerable interest in numerous industries. A better understanding on the interactive effects of essential nutrients and light on microalgal physiology and pigment production would be beneficial in improving cultivation strategies. Therefore, this study evaluated biomass, carotenoid and chlorophyll yield and the following fluorescence parameters: quantum yield in PS II [Y(II)] and electron transport rate (ETR) using response surface methodology (RSM). The Fv/Fm, Y(NO) and Y(NPQ) were also monitored; however, no significant relationship was observed. From the investigation it was apparent that nitrogen and carbon; as well as the interactive effects of (nitrogen and carbon) and (carbon and light irradiance) were significant factors. The model predicted the optimum conditions for maximum carotenoids (8.15 ± 0.389 mg g-1) were 08.7 mol l-1 of nitrogen, 0.2 mol l-1 and 50 µmol photon m-2 s-1 of light irradiance. While maximum chlorophyll (33.6 ± 0.854 mg g-1) required a higher nitrogen (11.21 mol l-1). The photosynthetic parameters [Y(II), ETR] was correlated with the primary pigments and biomass production. Increased photosynthetic activity was associated with high carbon and light. The Y(II)and ETR of PSII under these conditions were 0.2 and ~ 14, respectively. This approach was accurate in developing the model, optimizing factors and analysing interaction effects. This study served to provide a better understanding on the interactions between factors influencing pigment biosynthesis and photosynthetic performance of Chlamydomonas reinhardtii.


Assuntos
Chlamydomonas reinhardtii/metabolismo , Luz , Fotossíntese , Pigmentos Biológicos
11.
Water Sci Technol ; 86(6): 1551-1564, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36178823

RESUMO

Anammox-mediated systems are thought to be cost-effective and efficient technologies for removing nitrogen from wastewater by converting nitrite and ammonium into dinitrogen gas. However, there are inhibitory substances that reduce the effectiveness and efficiency of these processes, preventing their widespread application. Antimicrobial agents are among these substances that have been observed to inhibit anammox-mediated processes. Therefore, this review provides a comprehensive overview of the effects of various antimicrobials on the anammox-based systems with emphasis on the effects in different reactor configurations, sludge types and microbial population of anammox-based systems. In addition, this review also discusses the mechanisms by which nitrifying bacteria are inhibited by the antimicrobials. Gaps in knowledge based on this review as well as future research needs have also been suggested. This review gives a better knowledge of antimicrobial effects on anammox-based systems and provides some guidance on the type of system to use to treat antimicrobial-containing wastewater using anammox-based processes.


Assuntos
Compostos de Amônio , Anti-Infecciosos , Oxidação Anaeróbia da Amônia , Anaerobiose , Reatores Biológicos/microbiologia , Desnitrificação , Nitritos , Nitrogênio , Oxirredução , Esgotos/microbiologia , Águas Residuárias/microbiologia
12.
Environ Sci Technol ; 55(1): 9-24, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33350826

RESUMO

ANAMMOX (anaerobic ammonium oxidation) represents an energy-efficient process for biological nitrogen removal, particularly from wastewater streams with low chemical oxygen demand (COD) to nitrogen (C/N) ratios. Its widespread application, however, is still hampered by a lack of access to biomass-enriched with ANAMMOX bacteria (AMX), slow growth rates of AMX, and their sensitivity to inhibition. Although the coupling of ANAMMOX processes with partial nitrification is already widespread, especially for sidestream treatment, maintaining a functional population density of AMX remains a challenge in these systems. Therefore, strategies that maximize retention of AMX-rich biomass are essential to promote process stability. This paper reviews existing methods of biomass retention in ANAMMOX-mediated systems, focusing on (i) granulation; (ii) biofilm formation on carrier materials; (iii) gel entrapment; and (iv) membrane technology in mainstream and sidestream systems. In addition, the microbial ecology of different ANAMMOX-mediated systems is reviewed.


Assuntos
Compostos de Amônio , Nitrogênio , Anaerobiose , Biomassa , Reatores Biológicos , Desnitrificação , Oxirredução , Águas Residuárias
13.
J Environ Manage ; 297: 113257, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34303940

RESUMO

Algae-based technologies are one of the emerging solutions to societal issues such as accessibility to clean water and carbon-neutral energy and are a contender for the circular bioeconomy. In this review, recent developments in the use of different algal species for nutrient recovery and biomass production in wastewater, challenges, and future perspectives have been addressed. The ratio and bioavailability of nutrients in wastewater are vital parameters, which significantly impact nutrient recovery efficiency and algal biomass production. However, the optimum nutrient concentration and ratio may vary depending upon the microalgal species as well as cultivation conditions. The use of indigenous algae and algae-based consortia with other microorganisms has been proved promising in improving nutrient recovery efficiency and biomass production in pilot scale operations. However, environmental and cultivation conditions also play a significant role in determining the feasibility of the process. This review further focused on the assessment of the potential benefits of algal biomass production, renewable biofuel generation, and CO2 sequestration using wastewater in different countries on the basis of available data on wastewater generation and estimated nutrient contents. It was estimated that 5-10% replacement of fossil crude requirement with algal biofuels would require ~952-1903 billion m3 of water, 10-21 billion tons of nitrogen, and 2-4 billion tons of phosphorus fertilizers. In this context, coupling wastewater treatment and algal biomass production seem to be the most sustainable option with potential global benefits of polishing wastewater through nutrients recycling and carbon dioxide sequestration.


Assuntos
Microalgas , Águas Residuárias , Biocombustíveis , Biomassa , Fósforo
14.
J Environ Manage ; 293: 112862, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34049159

RESUMO

To ensure the safe discharge of treated wastewater to the environment, continuous efforts are vital to enhance the modelling accuracy of wastewater treatment plants (WWTPs) through utilizing state-of-art techniques and algorithms. The integration of metaheuristic modern optimization algorithms that are natlurally inspired with the Fussy Inference Systems (FIS) to improve the modelling performance is a promising and mathematically suitable approach. This study integrates four population-based algorithms, namely: Particle swarm optimization (PSO), Genetic algorithm (GA), Hybrid GA-PSO, and Mutating invasive weed optimization (M-IWO) with FIS system. A full-scale WWTP in South Africa (SA) was selected to assess the validity of the proposed algorithms, where six wastewater effluent parameters were modeled, i.e., Alkalinity (ALK), Sulphate (SLP), Phosphate (PHS), Total Kjeldahl Nitrogen (TKN), Total Suspended Solids (TSS), and Chemical Oxygen Demand (COD). The results from this study showed that the hybrid PSO-GA algorithm outperforms the PSO and GA algorithms when used individually, in modelling all wastewater effluent parameters. PSO performed better for SLP and TKN compared to GA, while the M-IWO algorithm failed to provide an acceptable modelling convergence for all the studied parameters. However, three out of four algorithms applied in this study proven beneficial to be optimized in enhancing the modelling accuracy of wastewater quality parameters.


Assuntos
Algoritmos , Águas Residuárias , Plantas Daninhas , África do Sul
15.
Artigo em Inglês | MEDLINE | ID: mdl-33378222

RESUMO

Acinetobacter spp. and Stenotrophomonas maltophilia are bacteria commonly associated with infections at the clinical settings. Reports of infections caused by environmental isolates are rare. Therefore, this study focused on determination of the antibiotic resistance patterns, antibiotic resistance genes, efflux pumps and virulence signatures of Acinetobacter spp. and S. maltophilia recovered from river water, plant rhizosphere and river sediment samples. The isolates were identified and confirmed using biochemical tests and PCR. The antimicrobial resistance profiles of the isolates were determined using Kirby Bauer disk diffusion assay and presence of antibiotic resistance and virulence genes were detected using PCR. S. maltophilia was more frequent in plant rhizosphere and sediment samples than the water samples. Acinetobacter spp. were mostly resistant to trimethoprim-sulfamethoxazole (96% of isolates), followed by polymyxin b (86%), cefixime (54%), colistin (42%), ampicillin (35%) and meropenem (19%). The S. maltophilia isolates displayed total resistance (100%) to trimethoprim- sulfamethoxazole, meropenem, imipenem, ampicillin and cefixime, while 80% of the isolates were resistant to ceftazidime. Acinetobacter spp. contained different antibiotic resistance genes such as sul1 (24% of isolates), sul2 (29%), blaOXA 23/51 (21%) and blaTEM (29%), while S. maltophilia harbored sul1 (8%) and blaTEM (20%). Additionally, efflux pump genes were present in all S. maltophilia isolates. The presence of multidrug resistant Acinetobacter spp. and Stenotrophomonas maltophilia in surface water raises concerns for community-acquired infections as this water is directly been used by the community for various purposes. Therefore, there is the need to institute measures aimed at reducing the risks of these infections and the resulting burden this may have on the health care system within the study area.


Assuntos
Acinetobacter/isolamento & purificação , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Água Doce/microbiologia , Genes Bacterianos , Infecções por Bactérias Gram-Negativas/microbiologia , Stenotrophomonas maltophilia/isolamento & purificação , Acinetobacter/efeitos dos fármacos , Acinetobacter/genética , Antibacterianos/farmacologia , Infecções Comunitárias Adquiridas/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Bactérias Gram-Negativas/prevenção & controle , Humanos , Testes de Sensibilidade Microbiana , Risco , Stenotrophomonas maltophilia/efeitos dos fármacos , Stenotrophomonas maltophilia/genética , Combinação Trimetoprima e Sulfametoxazol/farmacologia
16.
Environ Monit Assess ; 193(5): 294, 2021 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-33893564

RESUMO

Aquatic environments are hotspots for the spread of antibiotic-resistant bacteria and genes due to pollution caused mainly by anthropogenic activities. The aim of this study was to evaluate the impact of wastewater effluents, informal settlements, hospital, and veterinary clinic discharges on the occurrence, antibiotic resistance profile and virulence signatures of Aeromonas spp. and Pseudomonas spp. isolated from surface water and wastewater. High counts of Aeromonas spp. (2.5 (± 0.8) - 3.3 (± 0.4) log10 CFU mL-1) and Pseudomonas spp. (0.6 (± 1.0) - 1.8 (± 1.0) log10 CFU mL-1) were obtained. Polymerase chain reaction (PCR) and MALDI-TOF characterization identified four species of Aeromonas and five of Pseudomonas. The isolates displayed resistance to 3 or more antibiotics (71% of Aeromonas and 94% of Pseudomonas). Aeromonas spp. showed significant association with the antibiotic meropenem (χ2 = 3.993, P < 0.05). The virulence gene aer in Aeromonas was found to be positively associated with the antibiotic resistance gene blaOXA (χ2 = 6.657, P < 0.05) and the antibiotic ceftazidime (χ2 = 7.537, P < 0.05). Aeromonas recovered from both wastewater and surface water displayed high resistance to ampicillin and had higher multiple antibiotic resistance (MAR) indices close to the hospital. Pseudomonas isolates on the other hand exhibited low resistance to carbapenems but very high resistance to the third-generation cephalosporins and cefixime. The results showed that some of the Pseudomonas spp. and Aeromonas spp. isolates were extended-spectrum ß-lactamase producing bacteria. In conclusion, the strong association between virulence genes and antibiotic resistance in the isolates shows the potential health risk to communities through direct and indirect exposure to the water.


Assuntos
Aeromonas , Aeromonas/genética , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos , Monitoramento Ambiental , Testes de Sensibilidade Microbiana , Pseudomonas/genética , Virulência , Águas Residuárias , Água
17.
J Environ Manage ; 267: 110660, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32421681

RESUMO

During sludge bulking in wastewater treatment plants (WWTPs), high amounts of potentially pathogenic bacteria would release into the environment, causing various human-health risks. This is the first study attempting to assess the microbial infections associated with the reuse of WWTP effluents under various bulking conditions. Three common waterborne pathogens, viz., E. coli O157:H7, Salmonella, and Mycobacterium, were quantified from full-scale WWTPs using DNA extraction and qPCR at different sludge volume indices (SVIs). The detected pathogens were incorporated into a quantitative microbial risk assessment (QMRA) model to determine the applicability of WWTP discharge for recreational (bathing) activities and agricultural practices. The QMRA exposures were children, women, and men during swimming, and farmers and vegetable consumers during irrigation. Bacterial abundance in the treated wastewater increased in response to SVIs, and the QMRA values at all bulking events exceeded the tolerable risk of one case of infection per 10,000 people per year. Hence, various disinfection scenarios (chlorination, ultraviolet, and ozonation) were hypothetically tested to control the risks associated with pathogenic bacteria, allowing for safe disposal and reuse of the treated effluent. The ultraviolet application provided the highest ability to inactivate the pathogenic bacteria, except for the case of children exposed to Salmonella infection during swimming. The reduction of Mycobacterium infection risks with either chlorination or ozonation showed inefficient results. This study would be helpful for the management of human health risks associated with effluent wastewater containing pathogens, i.e., particularly concerning the case of sludge bulking.


Assuntos
Esgotos , Águas Residuárias , Bactérias , Criança , Desinfecção , Feminino , Humanos , Masculino , Medição de Risco
18.
Environ Monit Assess ; 192(11): 713, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33074388

RESUMO

The quality of surface water could be influenced by both anthropogenic and natural factors. This study was designed to determine the impact of informal settlement and wastewater treatment plants on helminth egg contamination of urban rivers and the risks associated with everyday use. We also ascertained the accumulation of these eggs in the river sediments. The study was carried out in two rivers in the eThekwini Municipality of South Africa. Grab samples were taken at different points over a 10-month period. Ascaris spp., hookworm, Toxocara spp., Trichuris spp. and Taenia spp. were the helminth eggs detected in both the water column and sediments, with mean Ascaris spp. eggs of 0-6.3 (± 5.1)/L in the water and 0-6.8 (± 5.2)/kg in sediment samples. The helminth egg concentrations showed seasonal variation, probably due to changes in infection levels of the populations or natural factors, such as rainfall. The informal settlements had a greater impact than treated wastewater. For every 10,000 recreational users of the rivers 19 to 58 may be infected under undisturbed conditions, increasing to 29-88 individuals when the riverbed is disturbed. The risk from agricultural use of the rivers was above the tolerable risk values applicable for wastewater reuse, recommended by the World Health Organization. This calls for a re-evaluation of the policies governing surface water quality assessment, where the inclusion of helminth eggs and sediment monitoring will be critical.


Assuntos
Helmintos , Águas Residuárias , Animais , Monitoramento Ambiental , Humanos , Rios , África do Sul
19.
J Environ Manage ; 240: 293-302, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30953982

RESUMO

This study investigated the dual application of Scenedesmus obliquus for wastewater phycoremediation and biochemical component accumulation in microalgal cells. The microalgae grown in wastewater showed micro-elements uptake and removal efficiencies of 71.2 ±â€¯3.5% COD, 81.9 ±â€¯3.8% NH4+, ∼100.0% NO3-, and 94.1 ±â€¯4.7% PO43-. The growth profile of Scenedesmus obliquus indicated a specific growth rate of 0.42 ±â€¯0.02 1·d-1 and carrying capacity of 0.88 ±â€¯0.04 g L-1. The lipid, protein, and carbohydrate yields (w·w-1 of dry weight) were 26.5 ±â€¯1.5%, 28.5 ±â€¯1.5%, and 27.5 ±â€¯1.6%, respectively. The de-oiled biomass was subjected to biochemical extraction, achieving protein and carbohydrate yields of 25.3 ±â€¯1.4% and 21.4 ±â€¯1.2%, respectively. Fourier transform infrared spectroscopy showed several functional groups (e.g., NH, CH3, CH2, CO, CN, PO, and SiO) on the biomass surface, confirming the accumulation of biochemical elements in microalgae. The thermal analysis of microalgal biomass depicted sequential stages of dehydration (60-190 °C), devolatilization (200-490 °C), and solid residue decomposition (490-600 °C). The cost-benefit analysis of microalgae cultivated in wastewater was derived regarding amortization and operating costs and energy and environmental benefits. The net profit of phycoremediation was 16885 US$·y-1, resulting in a payback period of 14.8 years (i.e., shorter than the project lifetime). Accordingly, the proposed phycoremediation process was economically viable.


Assuntos
Microalgas , Scenedesmus , Biocombustíveis , Biomassa , Águas Residuárias
20.
Artigo em Inglês | MEDLINE | ID: mdl-30938573

RESUMO

A study was conducted to characterize the raw wastewater entering a modern cost effective municipal WWTP in Poland using two approaches; 1) a combination of modeling and carbonaceous oxygen demand (COD) fractionation using respirometric test coupled with model estimation (RT-ME) and 2) flocculation/filtration COD fractionation method combined with BOD measurements (FF-BOD). It was observed that the particulate fractions of COD obtained using FF-BOD method was higher than those estimated by RT-ME approach. Contrary to the above, the values of inert soluble fraction evaluated by FF-BOD method was significantly lower than RT-ME approach (2.4% and 3.9% respectively). Furthermore, the values for low colloidal and particulate fractions as well as soluble inert fractions were different than expected from a typical municipal wastewater. These observations suggest that even at low load (10% of the total wastewater treatment inflow), the industrial wastewater composition can significantly affect the characteristics of municipal wastewater which could also affect the performance and accuracy of respirometric tests. Therefore, in such cases, comparison of the respirometric tests with flocculation/filtration COD/BOD measurements are recommended. Oxygen uptake rate profile with settled wastewater and/or after coagulation-flocculation, however, could still be recommended as a "rapid" control method for monitoring/optimising modern cost-effective wastewater treatment plants.


Assuntos
Análise da Demanda Biológica de Oxigênio , Esgotos/química , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Análise da Demanda Biológica de Oxigênio/métodos , Análise da Demanda Biológica de Oxigênio/normas , Calibragem , Compostos Inorgânicos de Carbono/química , Fracionamento Químico/métodos , Cidades , Análise Custo-Benefício , Monitoramento Ambiental/métodos , Monitoramento Ambiental/normas , Filtração , Floculação , Humanos , Oxigênio/química , Polônia , Purificação da Água/economia , Purificação da Água/métodos , Purificação da Água/normas
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