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1.
Heliyon ; 10(1): e23823, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38192764

RESUMO

Self-supply water has been acknowledged as a viable alternative to meeting the water needs of inhabitants. This study was designed to determine the main issues that influence self-supply water coverage in five (5) communities in the Kumasi Metropolis. The research employed a well-structured questionnaires and a total of 369 households were surveyed. The Statistical Package for Social Sciences (SPSS) version 26 and Microsoft Excel (2016) tools were used to analyse the data. The outcomes of the research show that a greater number of the respondents (77 %) did not have connections to the Ghana Water Company Limited (GWCL) distribution system. Approximately, 69 % of respondents had access to alternative water sources with mechanized boreholes forming the majority (32 %). However, a greater number of the respondents (64 %) did not disinfect their water to make it potable. The most favourable drinking water source for a greater number of the residents (51 %) was sachet water. The study showed there was a significant association between respondents' type or source of water with religion (p < 0.000), household size (p < 0.000), duration of stay (p = 0.026) and number of dependents (p = 0.006). However, there was no association between type or source of water with educational level (p = 0.130), occupation (p = 0.310), income level (p = 0.139) and type of home (p = 0.102). This study revealed that self-supply is contributing to the water needs of some residents in Kumasi and could contribute to the country's accomplishment of SDG 6.1 if residents ensure that it is safely managed. To broaden the scope of the study and the impact of self-supply groundwater, additional studies should be conducted in other communities, as well as the extent of other beneficiaries who have access to self-supply facilities other than the owners.

2.
Environ Res ; 234: 116545, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37429404

RESUMO

Although biological treatment of textile effluent is a preferred option for industries avoiding toxic chemical sludge production and disposal, requirement of several extra pre-treatment units like neutralization, cooling systems or additives, results in higher operational cost. In the present study, a pilot scale sequential microbial-based anaerobic-aerobic reactor technology (SMAART) was developed and operated for the treatment of real textile effluent in the industrial premises in continuous mode for 180 d. The results showed an average ∼95% decolourization along with ∼92% reduction in the chemical oxygen demand establishing the resilience against fluctuations in the inlet parameters and climate conditions. Moreover, the pH of treated effluent was also reduced from alkaline range (∼11.05) to neutral range (∼7.76) along with turbidity reduction from ∼44.16 NTU to ∼0.14 NTU. A comparative life cycle assessment (LCA) of SMAART with the conventional activated sludge process (ASP) showed that ASP caused 41.5% more negative impacts on environment than SMAART. Besides, ASP had 46.15% more negative impact on human health, followed by 42.85% more negative impact on ecosystem quality as compared to SMAART. This was attributed to less electricity consumption, absence of pre-treatment units (cooling and neutralization) and less volume of sludge generation (∼50%) while using SMAART. Hence, integration of SMAART within the industrial effluent treatment plant is recommended to achieve a minimum waste discharge system in pursuit of sustainability.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Humanos , Animais , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Ecossistema , Reatores Biológicos , Tecnologia , Têxteis , Estágios do Ciclo de Vida , Resíduos Industriais/análise , Indústria Têxtil
3.
Environ Sci Pollut Res Int ; 30(23): 64313-64341, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37067715

RESUMO

The study on the fate and transport of Pharmaceuticals and Personal Care Products, PPCPs (FTP) in the environment, has received particular attention for over two decades. The PPCPs threaten ecology and human health even at low concentrations due to their synergistic effects and long-range transport. The research aims to provide an inclusive map of the scientific background of FTP research over the last 25 years, from 1996 to 2020, to identify the main characteristics, evolution, salient research themes, trends, and research hotspots in the field of interest. Bibliometric networks were synthesized and analyzed for 577 journal articles extracted from the Scopus database. Consequently, seven major themes of FTP research were identified as follows: (i) PPCPs category; (ii) hazardous effects; (iii) occurrence of PPCPs; (iv) PPCPs in organisms; (v) remediation; (vi) FTP-governing processes; and (vii) assessment in the environment. The themes gave an in-depth picture of the sources of PPCPs and their transport and fate processes in the environment, which originated from sewage treatment plants and transported further to sediment/soils/groundwater/oceans that act as the PPCPs' major sink. The article provided a rigorous analysis of the research landscape in the FTP study conducted during the specified years. The prominent research themes, content analysis, and research hotspots identified in the study may serve as the basis of real-time guidance to lead future research areas and a prior review for policymakers and practitioners.


Assuntos
Cosméticos , Poluentes Químicos da Água , Humanos , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Cosméticos/análise , Ecologia , Preparações Farmacêuticas
4.
Sci Total Environ ; 858(Pt 2): 159833, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36374754

RESUMO

The absence of effective wastewater treatment technology to eliminate emerging pollutants from municipal sewage has become a pressing issue. In this study, the efficacy of a novel modified trickling filter (MTF), conventional activated sludge process (ASP) and two tertiary systems (UV and ozonation) were compared in eliminating antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs) and pharmaceuticals and personal care products (PPCPs) from urban sewage. MTF and ASP resulted in >1 log unit reduction in the abundance of ARB, while for ARGs, the removal was observed in the range of 0.1 to 1.7 log units. In MTF, ARGs were substantially removed in the aerobic zone compared to the anoxic zone. The relative abundance of most of the ARGs either decreased or remained unchanged during MTF and ASP operations. However, the relative abundance of most of the ARGs increased in the secondary sludge generated from ASP. The concentration of PPCPs such as atenolol, sulfamethazine, triclosan, and ranitidine was reduced by MTF by >80 %. Overall, the results indicated that MTF followed by ozonation is the most effective combination for removing emerging contaminants from municipal sewage.


Assuntos
Poluentes Ambientais , Ozônio , Esgotos/microbiologia , Águas Residuárias/microbiologia , Genes Bacterianos , Antagonistas de Receptores de Angiotensina , Antibacterianos , Inibidores da Enzima Conversora de Angiotensina
5.
J Environ Manage ; 325(Pt A): 116453, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36274305

RESUMO

Heavy metals contamination in sediment poses serious threats to bacterial communities that play critical roles in sediment biogeochemical processes. However, the physicochemical factors and the major heavy metals fractions that affect sediment bacterial communities are still unclear. Here, we performed heatmap and redundancy analyses to examine the effects of physico-chemical characteristics and heavy metals fractions on the sediment bacterial community from rivers in the UK (River Tyne and Ouseburn) and India (River Ganga and Yamuna). The results revealed that physicochemical characteristics and heavy metals fractions altered the diversity, richness, and structures of the bacterial community. Moreover, the fractions of Co, Zn, Pb, Cr, and Cu played significant roles in shaping the bacterial community structure, and physicochemical variables, particularly NH4+-N and NO2--N, also influenced the bacterial diversity and structure. Firmicutes showed strong associations with both physicochemical factors and heavy metals fractions. Chloroflexi and Actinobacteriota can be used as biomarkers for Zn contamination. Overall, our study identified the significance of sediment chemical characteristics and heavy metals fractions in determining the bacterial community structure as well as bioremediation and environmental management of metals contaminated sites.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Rios/química , Sedimentos Geológicos/química , Metais Pesados/análise , Índia , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , China
6.
Sci Total Environ ; 857(Pt 1): 159059, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36174689

RESUMO

Heavy metal pollution can enhance the level of antibiotic resistance, posing concerns to ecosystem and public health. Here, we investigated heavy metal concentrations, heavy metal resistant bacteria and antibiotic resistant bacteria and their corresponding resistant genes, and integrons in four different river environments, i.e., low heavy metals and low wastewater, high heavy metals and low wastewater, low heavy metals and high wastewater, and high heavy metals and high wastewater levels. Heavy metals were found to show positive and significant correlations with heavy metal resistance and antibiotic resistance and integrons (r > 0.60, p < 0.05), indicating that heavy metal selective pressure can cause heavy metal and antibiotic resistance to be transmitted simultaneously via integrons, which can result in the development of multi-resistant bacteria in the heavy metal-polluted environments. Moreover, there were significant associations between heavy metal resistance and antibiotic resistance (r > 0.60, p < 0.05), demonstrating heavy metal and antibiotic resistance are connected via a same or related mechanism. Class 1 integrons were found to have strong correlations with heavy metals and heavy metal resistance and antibiotic resistance (r > 0.60, p < 0.05), indicating a higher occurrence of antibiotic resistance co-selection in the heavy metal-polluted environments.


Assuntos
Metais Pesados , Rios , Rios/microbiologia , Águas Residuárias/análise , Ecossistema , Resistência Microbiana a Medicamentos/genética , Metais Pesados/análise , Poluição da Água , Bactérias/genética , Antibacterianos/farmacologia , Reino Unido
7.
Sci Total Environ ; 853: 158331, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36041611

RESUMO

This study compares the performance and microbial composition of a conventional activated sludge process (ASP) with a modified trickling filter (MTF) for urban sewage treatment. MTF (2 h HRT with effluent recycling) and ASP (8 h HRT) showed >60 % removal efficiency for COD, NH3-N and PO43--P. MTF outperformed ASP in denitrification and 5 mg/L of NO3--N was detected in the effluent of MTF. The widespread distribution of nitrogen removal functional genes (amoA, nirK, nirS, napA, narG and nosZ) in MTF indicates simultaneous nitrification and denitrification (SND) as a key process controlling nitrogen removal. In addition, Miseq sequencing was used to examine the microbial community composition in MTF and ASP. The sequencing result revealed that Proteobacteria, Planctomycetes, Chloroflexi and Actinobacteriota were the dominant phyla in both MTF and ASP. Moreover, the co-occurrence of various nitrifiers, denitrifiers, aerobic denitrifiers, and ANAMMOX bacteria in MTF suggested their role in nitrogen removal.


Assuntos
Microbiota , Esgotos , Esgotos/microbiologia , Desnitrificação , Reatores Biológicos/microbiologia , Nitrificação , Nitrogênio , Bactérias/genética , Águas Residuárias/química
8.
Environ Pollut ; 308: 119649, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35724944

RESUMO

Sewage treatment plants (STPs) are considered as "hotspots" for the emergence and proliferation of antibiotic resistance. However, the impact of heavy metals contamination on dispersal of antibiotic resistance in STPs is poorly understood. This study simultaneously investigated the effect of removal of metal and antibiotic resistance as well as mobile elements at different treatment units of STPs in Delhi, India. Results showed that treatment technologies used in STPs were inefficient for the complete removal of metal and antibiotic resistance, posing an ecological risk of co-selection of antibiotic resistance. The strong correlations were observed between heavy metals, metal and antibiotic resistance, and integrons, implying that antibiotic resistance may be exacerbated in the presence of heavy metals via integrons, and that metal and antibiotic resistance share a common or closely associated mechanism. We quantified an MRG rcnA, conferring resistance to Co and Ni, and identified that it was more abundant than all MRGs, ARGs, integrons, and 16S rRNA, suggesting rcnA could be important in antibiotic resistance dissemination in the environment. The associations between heavy metals, metal and antibiotic resistance, and integrons highlight the need for additional research to better understand the mechanism of co-selection as well as to improve the removal efficacy of current treatment systems.


Assuntos
Metais Pesados , Esgotos , Antibacterianos/toxicidade , Proliferação de Células , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Metais Pesados/toxicidade , RNA Ribossômico 16S
9.
Environ Pollut ; 306: 119326, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35491000

RESUMO

Heavy metal pollution and the potential for co-selection of resistance to antibiotics in the environment is growing concern. However, clear associations between heavy metals and antibiotic resistance in river systems have not been developed. Here we investigated relationships between total and bioavailable heavy metals concentrations; metal resistance gene (MRG) and antibiotic resistance gene (ARG) abundances; mobile genetic elements; and the composition of local bacterial communities in low and high metal polluted rivers in UK and India. The results indicated that MRGs conferring resistance to cobalt (Co) and nickel (Ni) (rcnA), and Co, zinc (Zn), and cadmium (Cd) (czcA), and ARGs conferring resistance to carbapenem and erythromycin were the dominating resistant genes across the samples. The relative MRGs, ARGs, and integrons abundances tended to increase at high metal polluted environments, suggesting high metals concentrations have a strong potential to promote metal and antibiotic resistance by horizontal gene transmission and affecting bacterial communities, leading to the development of multi-metal and multi-antibiotic resistance. Network analysis demonstrated the positive and significant relationships between MRGs and ARGs as well as the potential for integrons playing a role in the co-transmission of MRGs and ARGs (r > 0.80, p < 0.05). Additionally, the major host bacteria of various MRGs and ARGs that could be accountable for greater MRGs and ARGs levels at high metal polluted environments were also identified by network analysis. Spearman's rank-order correlations and RDA analysis further confirm relationships between total and bioavailable heavy metals concentrations and the relative MRG, ARG, and integron abundances, as well as the composition of related bacterial communities (r > 0.80 (or < -0.80), p < 0.05). These findings are critical for assessing the possible human health concerns associated with metal-driven antibiotic resistance and highlight the need of considering metal pollution for developing appropriate measures to control ARG transmission.


Assuntos
Metais Pesados , Rios , Antibacterianos/farmacologia , Bactérias , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Humanos , Metais Pesados/toxicidade , Rios/microbiologia , Reino Unido
10.
Sci Total Environ ; 807(Pt 2): 150873, 2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-34634340

RESUMO

Antimicrobial resistance (AMR) is emerging as a severe concern due to the escalating instances of resistant human pathogens encountered by health workers. Consequently, there is a shortage of antibiotics to treat Multidrug Resistance (MDR) and Extensively Drug Resistance (XDR) patients. The primary cause of AMR is the vast array of anthropogenic disturbances in natural microfauna brought about by the extensive use of antibiotics. Coronavirus Disease of 2019 (COVID-19) has crashed antibiotic stewardship and single-handedly increased the global usage of antibiotics, Personal Protective Equipment (PPE), and biocide, causing a ripple effect in the existing global AMR problem. This surge in antibiotic usage has escalated the residual antibiotics reaching Wastewater Treatment Plants (WWTPs) from pharmaceutical companies, health care centers, and domestic settings. Ultimately the natural water bodies receiving their effluents will have higher concentrations of emerging contaminants as the WWTPs cannot remove the Pharmaceuticals and Personal Care Products (PPCPs) completely. Furthermore, increased biocides usage will increase AMR by co-resistance, and increasing plastics will turn into microplastics and get converted to plastisphere, which will further enhance its propagation. Therefore, it is crucial to curb antibiotic usage, implement antibiotic stewardship dynamically; and, ameliorate the present condition of WWTPs to remove residual PPCPs efficiently. The need of the hour is to address the grave threat of AMR, which is loitering silently; if not the mankind will endure more affliction hereafter.


Assuntos
Antibacterianos , COVID-19 , Efeitos Antropogênicos , Farmacorresistência Bacteriana , Humanos , Plásticos , SARS-CoV-2
11.
J Health Pollut ; 10(26): 200610, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32509411

RESUMO

BACKGROUND: Industries such as electroplating, mining and battery production are major sources of heavy metal-rich waste entering nearby water bodies. Irrigation with heavy metal contaminated water can deteriorate soil quality as well as agricultural produce and have further toxic effects on human health. OBJECTIVES: The objective of the present study was to estimate the concentration of hazardous heavy metals such as chromium (Cr), cadmium (Cd), copper (Cu), nickel (Ni), zinc (Zn) and lead (Pb), as well as physico-chemical variables (pH, electrical conductivity, total dissolved solids, chemical oxygen demand and dissolved oxygen) at sampling locations along the Najafgarh and Loha mandi drains in Delhi, National Capital Region, India. METHODS: The present study evaluated the quality of wastewater from the Najafgarh and Loha mandi drains, which are used for irrigational purposes in the Delhi region. Drain water quality was monitored for a period of 2 years for physico-chemical variables (pH, chemical oxygen demand, electrical conductivity and dissolved oxygen) as well as heavy metal concentrations (Cr, Cu, Cd, Zn, Ni and Pb). The two-year monitoring period (July 2012-March 2014) was chosen to represent three seasons: pre-monsoon, monsoon, and post-monsoon. RESULTS: Varied concentrations of multiple heavy metals were found due to the extensive discharge of untreated industrial effluents into the drain water. Punjabi Bagh of Najafgarh drain was the most contaminated sampling site with the maximum concentration of Zn (12.040 ± 0.361 mg L-1), followed by Cr (2.436 ± 0.073mg L-1) and Cu (2.617 ± 0.078 mg L-1). CONCLUSIONS: Consumption of heavy metal-contaminated agricultural products can cause deleterious human health effects, leading to further health problems. The presence of multi-heavy metal ions above the Food and Agriculture Organization of the United Nations (FAO) permissible limits indicated that drain water was not suitable for irrigational purposes, and adequate measures are required to remove the heavy metal load from drain water. COMPETING INTERESTS: The authors declare no competing financial interests.

12.
Environ Sci Pollut Res Int ; 25(1): 345-352, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29039036

RESUMO

A biological method was adopted to decolourize textile dyes, which is an economic and eco-friendly technology for textile wastewater remediation. Two fungal strains, i.e. Aspergillus lentulus and Aspergillus fumigatus, were used to study the removal of low to high concentrations (25 to 2000 mg L-1) of reactive remazol red, reactive blue and reactive yellow dyes by biosorption and bioaccumulation. The biosorption was successful only at the lower concentrations. A. lentulus was capable of removing 67-85% of reactive dyes during bioaccumulation mode of treatment at 500 mg L-1 dye concentration with an increased biomass uptake capacity. To cope up with the high dye concentration of 2000 mg L-1, a novel combined approach was successful in case of A. lentulus, where almost 76% removal of reactive remazol red dye was observed during bioaccumulation followed by biosorption. The scanning electron microscopy also showed the accumulation of dye on the surface of fungal mycelium. The results signify the application of such robust fungal strains for the removal of high concentration of dyes in the textile wastewaters.


Assuntos
Aspergillus/crescimento & desenvolvimento , Corantes/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Biomassa , Concentração de Íons de Hidrogênio , Modelos Teóricos , Indústria Têxtil
13.
Environ Sci Pollut Res Int ; 25(21): 20486-20496, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28965177

RESUMO

Presence of industrial dyes and heavy metal as a contaminant in environment poses a great risk to human health. In order to develop a potential technology for remediation of dyes (Reactive remazol red, Yellow 3RS, Indanthrene blue and Vat novatic grey) and heavy metal [Cu(II), Ni(II), Cd(II), Zn(II), Cr(VI) and Pb(II)] contamination, present study was performed with entomopathogenic fungi, Beauveria bassiana (MTCC no. 4580). High dye removal (88-97%) was observed during the growth of B. bassiana while removal percentage for heavy metals ranged from 58 to 75%. Further, detailed investigations were performed with Pb(II) in terms of growth kinetics, effect of process parameters and mechanism of removal. Growth rate decreased from 0.118 h-1 (control) to 0.031 h-1, showing 28% reduction in biomass at 30 mg L-1 Pb(II) with 58.4% metal removal. Maximum Pb(II) removal was observed at 30 °C, neutral pH and 30 mg L-1 initial metal concentration. FTIR analysis indicated the changes induced by Pb(II) in functional groups on biomass surface. Further, microscopic analysis (SEM and atomic force microscopy (AFM)) was performed to understand the changes in cell surface morphology of the fungal cell. SEM micrograph showed a clear deformation of fungal hyphae, whereas AFM studies proved the increase in surface roughness (RSM) in comparison to control cell. Homogenous bioaccumulation of Pb(II) inside the fungal cell was clearly depicted by TEM-high-angle annular dark field coupled with EDX. Present study provides an insight into the mechanism of Pb(II) bioremediation and strengthens the significance of using entomopathogenic fungus such as B. bassiana for metal and dye removal.


Assuntos
Beauveria/metabolismo , Biodegradação Ambiental , Corantes/metabolismo , Poluentes Ambientais/metabolismo , Chumbo/metabolismo , Biomassa , Poluentes Ambientais/química , Concentração de Íons de Hidrogênio , Cinética , Chumbo/química , Microscopia de Força Atômica , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Water Res ; 127: 172-182, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29049966

RESUMO

Rapid emergence of antibiotic resistance (AR) in developing countries is posing a greater health risk and increasing the global disease burden. AR proliferation mediated by treated/untreated discharges from sewage treatment plants (STPs) is a prime public health concern. Efficient sewage treatment is among our key defenses against the dissemination of infectious diseases. The present study aims to estimate the efficiency of aerobic [activated sludge process (ASP) and modified trickling filter (MTF)] and anaerobic reactors (anaerobic flow-through reactor) along with the three disinfection techniques (UV, ozone and chlorination) in reducing ARB and ARGs present in the domestic sewage. The three treatment systems were operated at different HRTs for 1 year and their performances in terms of treatment of conventional and emerging pollutants (ARB and ARGs) were assessed. The results indicated higher removal of ARB and ARGs in aerobic reactors compared to anaerobic reactor. Treatment studies in various bioreactors showed that the use of MTF along with UV/Ozone was superior to ASP and anaerobic flow-through reactor in reducing both the conventional and emerging pollutants. However, higher reduction of the pollutants was observed at higher HRTs. Though complete removal of coliforms and ARB was observed by treating the wastewater using MTF followed by UV or ozone but substantial levels of ARGs were observed in the effluent. Therefore, different advanced and effective treatment technologies such as filtration (RO), use of zero valent iron, TiO2 photocatalysis and other strong oxidizing agents which can ensure complete removal of ARGs along with ARB need to be evaluated. Though addition of these units will increase the treatment cost, but the increased cost would be negligible compared to the present disease burden of AR.


Assuntos
Desinfecção/métodos , Farmacorresistência Bacteriana , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Reatores Biológicos , Desinfecção/instrumentação , Farmacorresistência Bacteriana/genética , Filtração , Halogenação , Ozônio , Esgotos/microbiologia , Raios Ultravioleta , Eliminação de Resíduos Líquidos/instrumentação , Águas Residuárias/microbiologia
15.
Adv Colloid Interface Sci ; 249: 2-16, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28935100

RESUMO

Among the various electrically conducting polymers, polyaniline (PANI) has gained attentions due to its unique properties and doping chemistry. A number of electrically conducting biodegradable polymers has been synthesized by incorporating a biodegradable content of cellulose, chitin, chitosan, etc. in the matrix of PANI. The hybrid materials are also employed as photocatalysts, antibacterial agents, sensors, fuel cells and as materials in biomedical applications. Furthermore, these biodegradable and biocompatible conducting polymers are employed in tissue engineering, dental implants and targeted drug delivery. This review presents state of the art of PANI based biodegradable polymers along with their synthesis routes and unique applications in diverse fields. In future, the synthesis of PANI-grafted biodegradable nanocomposite material is expected to open innovative ways for their outstanding applications.

16.
Chemosphere ; 188: 249-256, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28886559

RESUMO

Rapid emergence of antibiotic resistance (AR) in developing countries is posing a greater health risk and increasing the global disease burden. Lack of access to safe drinking water, poor sanitation and inadequate sewage treatment facilities in these countries are fueling the problem associated with emergence of AR. Rapid proliferation of AR mediated by treated and untreated discharges from sewage treatment plants (STPs) is a prime public health concern. This study aims to understand the occurrence, fate, and routes of proliferation of carbapenem (KPC) and extended spectrum ß-lactam (ESBL) resistant bacteria, and selected resistant genes in the samples collected from different unit operations in 12 STPs in New Delhi over two seasons. Strong correlation observed between faecal coliform levels and KPC (R = 0.95, p = 0.005, n = 60) and ESBL (R = 0.94, p = 0.004, n = 60) resistant bacteria levels indicates possible association of resistant bacteria with faecal matter. Different unit operations in STPs proved inefficient in treating resistant bacteria and genes present in the wastewater. However, inclusion of tertiary treatment (chlorination) unit and anaerobic digester in the present STPs resulted in better removal of AR. Significant correlations between antibiotic resistant genes (ARGs) and integron levels indicates a potential for higher rate of AR proliferation in the environment. Microbial culturing indicated the presence of clinically significant drug-resistant pathogens such as Escherichia coli, Pseudomonas putida, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae, Klebsiella oxytoca, Acinetobacter baumannii, Shigella dysentery and Aeromonas caviae in the STP effluents. The emergence and spread of resistant bacteria through STP effluents poses exposure risk for the residents of the city.


Assuntos
Resistência Microbiana a Medicamentos/genética , Poluição Ambiental , Esgotos/microbiologia , beta-Lactamas/farmacologia , Antibacterianos/farmacologia , Bactérias/genética , Países em Desenvolvimento , Humanos , Índia , Integrons/genética , Águas Residuárias/microbiologia
17.
Bioresour Technol ; 218: 388-96, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27387415

RESUMO

Towards the development of a potential remediation technology for multiple heavy metals [Zn(II), Cu(II), Cd(II), Cr(VI) and Ni(II)] from contaminated water, present study examined the growth kinetics and heavy metal removal ability of Beauveria bassiana in individual and multi metals. The specific growth rate of B. bassiana varied from 0.025h(-1) to 0.039h(-1) in presence of individual/multi heavy metals. FTIR analysis indicated the involvement of different surface functional groups in biosorption of different metals, while cellular changes in fungus was reflected by various microscopic (SEM, AFM and TEM) analysis. TEM studies proved removal of heavy metals via sorption and accumulation processes, whereas AFM studies revealed increase in cell surface roughness in fungal cells exposed to heavy metals. Present study delivers first report on the mechanism of bioremediation of heavy metals when present individually as well as multi metal mixture by entomopathogenic fungi.


Assuntos
Beauveria/metabolismo , Biodegradação Ambiental , Metais Pesados/análise , Microbiologia da Água , Adsorção , Biomassa , Reatores Biológicos , Glucose/química , Concentração de Íons de Hidrogênio , Cinética , Metais/química , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Temperatura , Águas Residuárias , Purificação da Água/métodos
18.
Water Res ; 94: 146-154, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26938500

RESUMO

The effect of temperature on selenium (Se) removal by upflow anaerobic sludge blanket (UASB) reactors treating selenate and nitrate containing wastewater was investigated by comparing the performance of a thermophilic (55 °C) versus a mesophilic (30 °C) UASB reactor. When only selenate (50 µM) was fed to the UASB reactors (pH 7.3; hydraulic retention time 8 h) with excess electron donor (lactate at 1.38 mM corresponding to an organic loading rate of 0.5 g COD L(-1) d(-1)), the thermophilic UASB reactor achieved a higher total Se removal efficiency (94.4 ± 2.4%) than the mesophilic UASB reactor (82.0 ± 3.8%). When 5000 µM nitrate was further added to the influent, total Se removal was again better under thermophilic (70.1 ± 6.6%) when compared to mesophilic (43.6 ± 8.8%) conditions. The higher total effluent Se concentration in the mesophilic UASB reactor was due to the higher concentrations of biogenic elemental Se nanoparticles (BioSeNPs). The shape of the BioSeNPs observed in both UASB reactors was different: nanospheres and nanorods, respectively, in the mesophilic and thermophilic UASB reactors. Microbial community analysis showed the presence of selenate respirers as well as denitrifying microorganisms.


Assuntos
Reatores Biológicos , Selênio/química , Temperatura , Eliminação de Resíduos Líquidos , Águas Residuárias/química , Anaerobiose , Reatores Biológicos/microbiologia , Nitratos/química , Ácido Selênico/química , Esgotos/química , Poluentes Químicos da Água/química
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