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1.
J Environ Manage ; 343: 118222, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37235991

RESUMEN

Biochar, a promising carbon-rich and carbon-negative material, can control water pollution, harness the synergy of sustainable development goals, and achieve circular economy. This study examined the performance feasibility of treating fluoride-contaminated surface and groundwater using raw and modified biochar synthesized from agricultural waste rice husk as problem-fixing renewable carbon-neutral material. Physicochemical characterizations of raw/modified biochars were investigated using FESEM-EDAX, FTIR, XRD, BET, CHSN, VSM, pHpzc, Zeta potential, and particle size analysis were analyzed to identify the surface morphology, functional groups, structural, and electrokinetic behavior. In fluoride (F-) cycling, performance feasibility was tested at various governing factors, contact time (0-120 min), initial F- levels (10-50 mg L-1), biochar dose (0.1-0.5 g L-1), pH (2-9), salt strengths (0-50 mM), temperatures (301-328 K), and various co-occurring ions. Results revealed that activated magnetic biochar (AMB) possessed higher adsorption capacity than raw biochar (RB) and activated biochar (AB) at pH 7. The results indicated that maximum F- removal (98.13%) was achieved using AMB at pH 7 for 10 mg L-1. Electrostatic attraction, ion exchange, pore fillings, and surface complexation govern F- removal mechanisms. Pseudo-second-order and Freundlich were the best fit kinetic and isotherm for F- sorption, respectively. Increased biochar dose drives an increase in active sites due to F- level gradient and mass transfer between biochar-fluoride interactions, which reported maximum mass transfer for AMB than RB and AB. Fluoride adsorption using AMB could be described through chemisorption processes at room temperature (301 K), though endothermic sorption follows the physisorption process. Fluoride removal efficiency reduced, from 67.70% to 53.23%, with increased salt concentrations from 0 to 50 mM NaCl solutions, respectively, due to increased hydrodynamic diameter. Biochar was used to treat natural fluoride-contaminated surface and groundwater in real-world problem-solving measures, showed removal efficiency of 91.20% and 95.61%, respectively, for 10 mg L-1 F- contamination, and has been performed multiple times after systematic adsorption-desorption experiments. Lastly, techno-economic analysis was analyzed for biochar synthesis and F- treatment performance costs. Overall, our results revealed worth output and concluded with recommendations for future research on F- adsorption using biochar.


Asunto(s)
Agua Subterránea , Oryza , Contaminantes Químicos del Agua , Purificación del Agua , Fluoruros , Oryza/química , Purificación del Agua/métodos , Carbón Orgánico/química , Adsorción , Agua Subterránea/química , Cinética , Concentración de Iones de Hidrógeno
2.
Environ Res ; 214(Pt 4): 114043, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36029838

RESUMEN

Fluoride (F-) is one of the essential elements found in soil and water released from geogenic sources and several anthropogenic activities. Fluoride causes fluorosis, dental and skeletal growth problems, teeth mottling, and neurological damage due to prolonged consumption, affecting millions worldwide. Adsorption is an extensively implemented technique in water and wastewater treatment for fluoride, with significant potential due to efficiency, cost-effectiveness, ease of operation, and reusability. This review highlights the current state of knowledge for fluoride adsorption using biochar-based materials and the limitations of biochar for fluoride-contaminated groundwater and industrial wastewater treatment. Biochar materials have shown significant adsorption capacities for fluoride under the influence of low pH, biochar dose, initial concentration, temperature, and co-existing ions. Modified biochar possesses various functional groups (-OH, -CC, -C-O, -CONH, -C-OH, X-OH), in which enhanced hydroxyl (-OH) groups onto the surface plays a significant role in fluoride adsorption via electrostatic attraction and ion exchange. Regeneration and reusability of biochar sorbents need to be performed to a greater extent to improve removal efficiency and reusability in field conditions. Furthermore, the present investigation identifies the limitations of biochar materials in treating fluoride-contaminated drinking groundwater and industrial effluents. The fluoride removal using biochar-based materials at an industrial scale for understanding the practical feasibility is yet to be documented. This review work recommend the feasibility of biochar-based materials in column studies for fluoride remediation in the future.


Asunto(s)
Fluoruros , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Estudios de Factibilidad , Cinética , Agua , Contaminantes Químicos del Agua/análisis
3.
Chem Eng J ; 441: 135936, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35345777

RESUMEN

The global data on the temporal tracking of the COVID-19 through wastewater surveillance needs to be comparatively evaluated to generate a proper and precise understanding of the robustness, advantages, and sensitivity of the wastewater-based epidemiological (WBE) approach. We reviewed the current state of knowledge based on several scientific articles pertaining to temporal variations in COVID-19 cases captured via viral RNA predictions in wastewater. This paper primarily focuses on analyzing the WBE-based temporal variation reported globally to check if the reported early warning lead-time generated through environmental surveillance is pragmatic or latent. We have compiled the geographical variations reported as lead time in various WBE reports to strike a precise correlation between COVID-19 cases and genome copies detected through wastewater surveillance, with respect to the sampling dates, separately for WASH and non-WASH countries. We highlighted sampling methods, climatic and weather conditions that significantly affected the concentration of viral SARS-CoV-2 RNA detected in wastewater, and thus the lead time reported from the various climatic zones with diverse WASH situations were different. Our major findings are: i) WBE reports around the world are not comparable, especially in terms of gene copies detected, lag-time gained between monitored RNA peak and outbreak/peak of reported case, as well as per capita RNA concentrations; ii) Varying sanitation facility and climatic conditions that impact virus degradation rate are two major interfering features limiting the comparability of WBE results, and iii) WBE is better applicable to WASH countries having well-connected sewerage system.

4.
Chem Eng J ; 425: 130635, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34149304

RESUMEN

In the initial pandemic phase, effluents from wastewater treatment facilities were reported mostly free from Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) RNA, and thus conventional wastewater treatments were generally considered effective. However, there is a lack of first-hand data on i) comparative efficacy of various treatment processes for SARS-CoV-2 RNA removal; and ii) temporal variations in the removal efficacy of a given treatment process in the backdrop of active COVID-19 cases. This work provides a comparative account of the removal efficacy of conventional activated sludge (CAS) and root zone treatments (RZT) based on weekly wastewater surveillance data, consisting of forty-four samples, during a two-month period. The average genome concentration was higher in the inlets of CAS-based wastewater treatment plant (WWTP) in the Sargasan ward (1.25 × 103 copies/ L), than that of RZT-based WWTP (7.07 × 102 copies/ L) in an academic institution campus of Gandhinagar, Gujarat, India. ORF 1ab and S genes appeared to be more sensitive to treatment i.e., significantly reduced (p < 0.05) than N genes (p > 0.05). CAS treatment exhibited better RNA removal efficacy (p = 0.014) than RZT (p = 0.032). Multivariate analyses suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. The present study stresses that treated effluents are not always free from SARS-CoV-2 RNA, and the removal efficacy of a given WWTP is prone to exhibit temporal variability owing to variations in active COVID-19 cases in the vicinity and genetic material accumulation over the time. Disinfection seems less effective than the adsorption and coagulation processes for SARS-CoV-2 removal. Results stress the need for further research on mechanistic insight on SARS-CoV-2 removal through various treatment processes taking solid-liquid partitioning into account.

5.
Environ Monit Assess ; 191(12): 777, 2019 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-31781968

RESUMEN

Arsenic (As) is one of the most important dangerous elements as more than 100 million of people are exposed to risk, globally. The permissible threshold of As for drinking water is 10 µg/L according to both the WHO's drinking water guidelines and the Iranian national standard. However, several studies have indicated that As concentrations exceed this threshold value in several regions of Iran. This research evaluates an As-susceptible region, the Tajan River watershed, using the following data-mining models: multivariate adaptive regression splines (MARS), functional data analysis (FDA), support vector machine (SVM), generalized linear model (GLM), multivariate discriminant analysis (MDA), and gradient boosting machine (GBM). This study considers 12 factors for elevated As concentrations: land use, drainage density, profile curvature, plan curvature, slope length, slope degree, topographic wetness index, erosion, village density, distance from villages, precipitation, and lithology. The susceptibility mapping was conducted using training (70%) and validation (30%). The results of As contamination in sediment showed that classifications into 4 levels of concentration are very similar for two models of GLM and FDA. The GBM calculated the areas of highest arsenic contamination risk by MARS and SVM with percentages of 30.0% and 28.7%, respectively. FDA, GLM, MARS, and MDA models calculated the areas of lowest risk to be 3.3%, 23.0%, 72.0%, 25.2%, and 26.1%, respectively. The results of ROC curve reveal that the MARS, SVM, and MDA had the highest accuracies with area under the curve ROC values of 84.6%, 78.9%, and 79.5%, respectively. Land use, lithology, erosion, and elevation were the most important predictors of contamination potential with a value of 0.6, 0.59, 0.57, and 0.56, respectively. These are the most important factors. Finally, these data-mining methods can be used as appropriate, inexpensive, and feasible options to identify As-susceptible areas and can guide managers to reduce contamination in sediment of the environment and the food chain.


Asunto(s)
Arsénico , Minería de Datos , Monitoreo del Ambiente , Contaminantes Ambientales , Sedimentos Geológicos , Modelos Teóricos , Arsénico/análisis , Agua Potable/análisis , Agua Potable/normas , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Sedimentos Geológicos/química , Irán , Curva ROC
7.
Environ Monit Assess ; 189(4): 184, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28342052

RESUMEN

The presence of high levels of arsenic (As) in rice fields has negative effects on the health of those consuming rice as their subsistence food. This study determined the variation in total As concentration in local aromatic rice (LAR) (kalijira) and two high-yielding varieties (HYVs) (BRRI dhan 32 and BRRI dhan 28) grown in paddy fields in Matlab, Bangladesh, an As hotspot with elevated As levels in groundwater. Mature rice grain samples and soil samples were collected from different paddy fields, and the As concentrations in both the de-husked grains and the husks of the three rice cultivars were analysed to identify the safest of the three cultivars for human consumption. The results showed that the total As concentration was higher (0.09-0.21 mg As kg-1) in the de-husked grains of LAR than in the husks, while the opposite was found for the HYV rice. Moreover, the As concentration in soil samples was 2 to 5-fold higher for the LAR than for the HYVs, but the As accumulation factor (AF) was lower in the LAR (0.2-0.4%) than in the HYVs (0.9-1%). Thus, LAR can be considered the safest of the three cultivars for human consumption owing to its low AF value. Furthermore, due to the low AF, growing LAR instead of HYVs in soils with slightly elevated As levels could help improve the food safety level in the food chain.


Asunto(s)
Arsénico/análisis , Exposición a Riesgos Ambientales/estadística & datos numéricos , Contaminación de Alimentos/análisis , Oryza/química , Contaminantes del Suelo/análisis , Bangladesh , Exposición a Riesgos Ambientales/análisis , Cadena Alimentaria , Contaminación de Alimentos/estadística & datos numéricos , Humanos , Riesgo , Suelo
9.
Int J Surg ; 110(1): 507-519, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37830948

RESUMEN

BACKGROUND: Surgical site infections (SSIs) pose a global challenge, impacting patients and healthcare expenditures. This second-order meta-analysis endeavors to assess the efficacy of antibiotic sutures in averting SSIs by amalgamating data from various meta-studies. MATERIALS AND METHODS: This research adhered to the PRISMA 2020 guidelines. The quality and comprehensiveness of the encompassed meta-analyses were assessed through the QUOROM checklist and AMSTAR techniques. The primary study overlap was evaluated via measures such as pairwise intersection heat maps, corrected covered area, and the citation matrix of evidence. The statistical power at the study-level was determined utilizing the meta-meta package. Data synthesis employed random and fixed effects models at a 95% CI. A meta-regression analysis was conducted to explore potential correlations between the CDC classification of SSIs, trial types, and the observed effect sizes in the studies. RESULTS: This investigation revealed a significant reduction in SSI rates due to antimicrobial-coated sutures, evidenced by a relative risk (RR) of 0.68 (95% CI: 0.59-0.76), with a prediction interval of 0.38-1.19. The analysis encompassed 18 studies with 22 meta-analyses, demonstrating a median QUOROM score of 13.6 out of 18 and an AMSTAR score of 9.1 out of 11. The presence of moderate heterogeneity was noted ( Q =106.611, I2 =54.038%), with nonrandomized controlled trials exhibiting an RR of 0.56 (95% CI: 0.39-0.80), and RCTs displaying an RR of 0.71 (95% CI: 0.63-0.81). Subgroup analysis unveiled variable RR reductions for specific surgical procedures. CONCLUSION: Antimicrobial-coated sutures offer a promising approach to mitigating SSIs risk. However, their efficacy is optimally realized when employed in conjunction with other robust practices.


Asunto(s)
Antiinfecciosos Locales , Antiinfecciosos , Humanos , Antibacterianos/uso terapéutico , Infección de la Herida Quirúrgica/prevención & control , Suturas
10.
Heliyon ; 10(3): e25125, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38352798

RESUMEN

Lake Victoria is the world's largest tropical lake and the third-largest water body, providing significant water resources for surrounding environments including the cultural, societal, and livelihood needs of people in its basin and along the White Nile. The aim of this study was to use decade-long time series of measured lake flow in the lake system and phosphorus deposition to develop a suitable numerical model based on shallow water equations (SWE) for assessing water quality in Lake Victoria, an increasingly important tool under climate variation. Different techniques were combined to identify a numerical model that included: i) a high-resolution SWE model to establish raindrop diffusion to trace pollutants; ii) a two-dimensional (2D) vertically integrated SWE model to establish lake surface flow and vertically transported wind speed flow acting on lake surface water by wind stress; and iii) a site-specific phosphorus deposition sub-model to calculate atmospheric deposition in the lake. A smooth (non-oscillatory) solution was obtained by applying a high-resolution scheme for a raindrop diffusion model. Analysis with the vertically integrated SWE model generated depth averages for flow velocity and associated changes in water level profile in the lake system and showed unidirectional whole lake wind blowing from the southwest to northeast. The atmospheric phosphorous deposition model enabled water value assessment for mass balances with different magnitudes of both inflows and outflows demonstrating annual total phosphorus at 13,500 tons concentrating at mid-lake western and eastern parts. The model developed here is simple and suitable for use in assessing flow changes and lake level changes and can serve as a tool in studies of lake bathymetry and nutrient and pollution transport processes. Our study opens towards refining models of complex shallow-water systems.

11.
J Microbiol ; 62(5): 337-354, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38777985

RESUMEN

Reverse zoonosis reveals the process of transmission of a pathogen through the human-animal interface and the spillback of the zoonotic pathogen. In this article, we methodically demonstrate various aspects of reverse zoonosis, with a comprehensive discussion of SARS-CoV-2 and MPXV reverse zoonosis. First, different components of reverse zoonosis, such as humans, different pathogens, and numerous animals (poultry, livestock, pets, wild animals, and zoo animals), have been demonstrated. Second, it explains the present status of reverse zoonosis with different pathogens during previous occurrences of various outbreaks, epidemics, and pandemics. Here, we present 25 examples from literature. Third, using several examples, we comprehensively illustrate the present status of the reverse zoonosis of SARS-CoV-2 and MPXV. Here, we have provided 17 examples of SARS-CoV-2 reverse zoonosis and two examples of MPXV reverse zoonosis. Fourth, we have described two significant aspects of reverse zoonosis: understanding the fundamental aspects of spillback and awareness. These two aspects are required to prevent reverse zoonosis from the current infection with two significant viruses. Finally, the One Health approach was discussed vividly, where we urge scientists from different areas to work collaboratively to solve the issue of reverse zoonosis.


Asunto(s)
COVID-19 , SARS-CoV-2 , Zoonosis , Animales , Humanos , COVID-19/transmisión , COVID-19/epidemiología , COVID-19/virología , Zoonosis/transmisión , Zoonosis/virología , Monkeypox virus/genética , Monkeypox virus/patogenicidad , Monkeypox virus/aislamiento & purificación , Animales Salvajes/virología , Salud Única , Mpox/transmisión , Mpox/epidemiología , Mpox/virología
12.
Chemosphere ; 359: 142305, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38740338

RESUMEN

The widespread presence of arsenic (As) and fluoride (F-) in groundwater poses substantial risks to human health on a global scale. These elements have been identified as the most prevalent geogenic contaminants in groundwater in northern Mexico. Consequently, this study aimed to evaluate the human health and ecological risks associated with the content of As and F- in the Meoqui-Delicias aquifer, which is in one of Mexico's most emblematic irrigation districts. Concentrations of As and F- were measured in 38 groundwater samples using ICP-MS and ion chromatography, respectively. Overall, these elements showed a similar trend across the aquifer, revealing a positive correlation between them and pH. The concentration of As and F- in the groundwater ranged from 5.3 µg/L to 303 µg/L and from 0.5 mg/L to 8.8 mg/L, respectively. Additionally, the levels of As and F- surpassed the established national standards for safe drinking water in 92% and 97% of samples, respectively. Given that groundwater is used for both agricultural purposes and human activities, this study also assessed the associated human health and ecological risks posed by these elements using Monte Carlo simulation and Species Sensitivity Distribution. The findings disclosed a significant noncarcinogenic health risk associated with exposure to As and F-, as well as an unacceptable carcinogenic health risk to As through water consumption for both adults and children. Furthermore, a high ecological risk to aquatic species was identified for F- and high to medium risks for As in the sampling sites. Therefore, the findings in this study provide valuable information for Mexican authorities and international organizations (e.g., WHO) about the adverse effects that any exposure without treatment to groundwater from this region represents for human health.


Asunto(s)
Arsénico , Monitoreo del Ambiente , Fluoruros , Agua Subterránea , Método de Montecarlo , Contaminantes Químicos del Agua , Agua Subterránea/química , Fluoruros/análisis , Contaminantes Químicos del Agua/análisis , Arsénico/análisis , México , Humanos , Medición de Riesgo , Agua Potable/química
13.
Environ Sci Technol ; 47(2): 1120-7, 2013 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-23198808

RESUMEN

This study investigates the risk of arsenic (As) exposure to the communities in rural Bengal, even when they have been supplied with As safe drinking water. The estimates of exposure via dietary and drinking water routes show that, when people are consuming water with an As concentration of less than 10 µg L(-1), the total daily intake of inorganic As (TDI-iAs) exceeds the previous provisional tolerable daily intake (PTDI) value of 2.1 µg day(-1) kg(-1) BW, recommended by the World Health Organization (WHO) in 35% of the cases due to consumption of rice. When the level of As concentration in drinking water is above 10 µg L(-1), the TDI-iAs exceeds the previous PTDI for all the participants. These results imply that, when rice consumption is a significant contributor to the TDI-iAs, supplying water with an As concentration at the current national drinking water standard for India and Bangladesh would place many people above the safety threshold of PTDI. We also found that the consumption of vegetables in rural Bengal does not pose a significant health threat to the population independently. This study suggests that any effort to mitigate the As exposure of the villagers in Bengal must consider the risk of As exposure from rice consumption together with drinking water.


Asunto(s)
Arsénico/análisis , Exposición a Riesgos Ambientales/análisis , Contaminación de Alimentos/análisis , Oryza/química , Contaminantes Químicos del Agua/análisis , Abastecimiento de Agua/análisis , Bangladesh , Dieta , Ingestión de Líquidos , Femenino , Humanos , India , Masculino , Gestión de Riesgos , Población Rural , Verduras/química
14.
Environ Monit Assess ; 185(12): 9979-94, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23990252

RESUMEN

Chemical weathering is one of the major geochemical processes that control the mobilization of heavy metals. The present study provides the first report on heavy metal fractionation in sediments (8-156 m) of Lake Titicaca (3,820 m a.s.l.), which is shared by the Republic of Peru and the Plurinational State of Bolivia. Both contents of total Cu, Fe, Ni, Co, Mn, Cd, Pb, and Zn and also the fractionation of these heavy metals associated with four different fractions have been determined following the BCR scheme. The principal component analysis suggests that Co, Ni, and Cd can be attributed to natural sources related to the mineralized geological formations. Moreover, the sources of Cu, Fe, and Mn are effluents and wastes generated from mining activities, while Pb and Zn also suggest that their common source is associated to mining activities. According to the Risk Assessment Code, there is a moderate to high risk related to Zn, Pb, Cd, Mn, Co, and Ni mobilization and/or remobilization from the bottom sediment to the water column. Furthermore, the Geoaccumulation Index and the Enrichment Factor reveal that Zn, Pb, and Cd are enriched in the sediments. The results suggest that the effluents from various traditional mining waste sites in both countries are the main source of heavy metal contamination in the sediments of Lake Titicaca.


Asunto(s)
Sedimentos Geológicos/química , Lagos/química , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis , Bolivia , Fraccionamiento Químico , Monitoreo del Ambiente , Perú , Análisis de Componente Principal , Medición de Riesgo , Contaminación Química del Agua/estadística & datos numéricos
15.
Sci Rep ; 13(1): 11168, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37429943

RESUMEN

Although geogenic Arsenic (As) contamination is well-recognized in northern Chile, it is not restricted to this part of the country, as the geological conditions favoring As release to the human environment exist across the country as well, although not at the same level, based on comparatively fewer studies in central and southern Chile. The present work provides a critical evaluation of As sources, pathways, and controls with reports and case studies from across the country based on an exhaustive bibliographic review of its reported geogenic sources and processes that affect its occurrence, systematization, and critical revision of this information. Arc magmatism and associated geothermal activities, identified as the primary As sources, are present across the Chilean Andes, except for the Pampean Flat Slab and Patagonian Volcanic Gap. Metal sulfide ore zones, extending from the country's far north to the south-central part, are the second most important geogenic As source. While natural leaching of As-rich mineral deposits contaminates the water in contact, associated mining, and metallurgical activities result in additional As release into the human environment through mining waste and tailings. Moreover, crustal thickness has been suggested as a principal controlling factor for As release, whose southward decrease has been correlated with lower As values.

16.
Sci Rep ; 13(1): 18703, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37907513

RESUMEN

Septage refers to the semi-liquid waste material that accumulates in septic tanks and other onsite sanitation systems. It is composed of a complex mixture of human excreta, wastewater, and various solid particles. Septage is a potential source of water pollution owing to presence of high organic content, significant pathogen concentrations, and a range of nutrients like nitrogen and phosphorus. The harmful impacts of septage pollution poses significant risks to public health through the contamination of drinking water sources, eutrophication of water bodies and spread of water borne diseases. Conventional septage treatment technologies often face limitations such as high operational costs, energy requirements, and the need for extensive infrastructure. Therefore, with an aim to treat septage through an alternative cost effective and energy-efficient technology, a laboratory-scale constructed wetland (CW) system (0.99 m2) consisting of a sludge drying bed and a vertical flow wetland bed was utilized for the treatment of septage. The sludge drying bed and vertical flow beds were connected in series and filled with a combination of gravel with varying sizes (ranging from 5 to 40 mm) and washed sand. Canna indica plants were cultivated on both beds to facilitate phytoremediation process. The system was operated with intermittent dosing of 30 Ltrs of septage every day for 2 months. The HRT of the system was fixed at 48 h. The average inlet loads of Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and Total Suspended Solids (TSS) were measured as 150 ± 65.7 g m-2 day-1, 713 ± 443.9 g m-2 day-1, and 309 ± 66.3 g m-2 day-1, respectively. After treatment, the final effluent had an average load of 6 g m-2 day-1 for BOD5, 15 g m-2 day-1 for COD, and 51 g m-2 day-1 for TSS, indicating that the CW system achieved an average removal efficiency of 88% for BOD, 87% for COD, and 65% for TSS. The average load of total coliforms and helminthes eggs in the influent was recorded as 4 × 108 Colony-Forming Units (CFU) m-2 day-1 and 3 × 107 eggs m-2 day-1, respectively. However, the CW system demonstrated significant effectiveness in reducing microbial contamination, with an average removal efficiency of 99% for both total coliforms and helminthes eggs. The vertical flow constructed wetland system, equipped with pretreatment by sludge drying bed, has proven to be efficient in treatment of septage.


Asunto(s)
Aguas del Alcantarillado , Humedales , Humanos , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos , Aguas Residuales , Análisis de la Demanda Biológica de Oxígeno , Agua , Nitrógeno
17.
Sci Total Environ ; 872: 161932, 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-36796696

RESUMEN

Access to safe drinking water in rural Bangladesh remains a perpetual challenge. Most households are exposed to either arsenic or faecal bacteria in their primary source of drinking water, usually a tubewell. Improving tubewell cleaning and maintenance practices might reduce exposure to faecal contamination at a potentially low cost, but whether current cleaning and maintenance practices are effective remains uncertain, as does the extent to which best practice approaches might improve water quality. We used a randomized experiment to evaluate how effectively three approaches to cleaning a tubewell improved water quality, measured by total coliforms and E. coli. The three approaches comprise the caretaker's usual standard of care and two best-practice approaches. One best-practice approach, disinfecting the well with a weak chlorine solution, consistently improved water quality. However, when caretakers cleaned the wells themselves, they followed few of the steps involved in the best-practice approaches, and water quality declined rather than improved, although the estimated declines are not consistently statistically significant. The results suggest that, while improvements to cleaning and maintenance practices might help reduce exposure to faecal contamination in drinking water in rural Bangladesh, achieving widespread adoption of more effective practices would require significant behavioural change.


Asunto(s)
Arsénico , Agua Potable , Escherichia coli , Calidad del Agua , Pozos de Agua , Arsénico/análisis , Bangladesh , Abastecimiento de Agua
18.
Case Stud Chem Environ Eng ; : 100410, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-38620170

RESUMEN

The ongoing global pandemic caused by the SARS-CoV-2 virus, known as COVID-19, has disrupted public health, businesses, and economies worldwide due to its widespread transmission. While previous research has suggested a possible link between environmental factors and increased COVID-19 cases, the evidence regarding this connection remains inconclusive. The purpose of this research is to determine whether or not there is a connection between the presence of fine particulate matter (PM2.5) and meteorological conditions and COVID-19 infection rates in Bangkok, Thailand. The study employs a statistical method called Generalized Additive Model (GAM) to find a positive and non-linear association between RH, AH, and R and the number of verified COVID-19 cases. The impacts of the seasons (especially summer) and rainfall on the trajectory of COVID-19 cases were also highlighted, with an adjusted R-square of 0.852 and a deviance explained of 85.60%, both of which were statistically significant (p < 0.05). The study results assist in preventing the future seasonal spread of COVID-19, and public health authorities may use these findings to make informed decisions and assess their policies.

19.
J Infect Public Health ; 16(10): 1562-1590, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37572572

RESUMEN

The newly discovered coronavirus SARS-CoV-2 has sparked a worldwide pandemic of COVID-19, which has caused havoc on medical infrastructures, economies, and cultures around the world. Determining the whole scenario is essential since SARS-CoV-2 variants and sub-variants keep appearing after vaccinations and booster doses. The objective of this secondary meta-analysis is to analysis co-infection, secondary infections, and antimicrobial resistance (AMR) in COVID-19 patients. This study used five significant databases to conduct a systematic review and an overlap meta-analysis to evaluate the pooled estimates of co-infections and secondary infections. The summary of the meta-analysis showed an overall co-infection effect of 26.19% (95% confidence intervals CI: 21.39-31.01, I2 =98.78, n = 14 meta-analysis) among patients with COVID-19. A coinfection effect of 11.13% (95% CI: 9.7-12.56, I2 =99.14, n = 11 meta-analysis) for bacteria; 9.69% (95% CI: 1.21-7.90, I2 =98.33) for fungal and 3.48% (95% CI: 2.15-4.81, I2 =95.84) for viruses. A secondary infection effect of 19.03% (95% CI: 9.53-28.54, I2 =85.65) was pooled from 2 meta-analyses (Ave: 82 primary studies). This is the first study that compiles the results of all the previous three years meta-analyses into a single source and offers strong proof of co-infections and secondary infections in COVID-19 patients. Early detection of co-infection and AMR is crucial for COVID-19 patients in order to effective treatment.


Asunto(s)
COVID-19 , Coinfección , Humanos , Coinfección/microbiología , SARS-CoV-2 , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana
20.
Sci Total Environ ; 892: 163774, 2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37230352

RESUMEN

Avirulent halotolerant plant growth-promoting rhizobacteria (HPGPR) located on the roots' periphery can reduce abiotic stressors (such as salinity and drought), enhance plant productivity. Salinity poses a significant challenge for growing agricultural products, like rice, in the coastal regions. It is crucial to enhance production because of limited arable land and the high growth rate of the population. This study targeted to identify HPGPR from legume root nodules and assessed their effects on rice plants experiencing salt stress in coastal regions of Bangladesh. Based on the culture morphology, biochemical, salt, pH, and temperature tolerance traits, sixteen bacteria were isolated from the root nodules of leguminous plants (Common bean, Yardlong bean, Dhaincha, and Shameplant). All the bacterial strains can tolerate 3 % salt concentration, and capable to survive at the highest 45 °C temperature and pH 11 (without isolate 1). Three preeminent bacteria, Agrobacterium tumefaciens (B1), Bacillus subtilis (B2), and Lysinibacillus fusiformis (B3) were specified through morpho-biochemical and molecular (16S rRNA gene sequence) exploration for inoculation. To assess the plant growth-promoting activities, germination tests are applied where bacterial inoculation increased germination in saline and non-saline conditions. Control group (C) showed 89.47 % and bacterial treated groups (C + B1, C + B2, and C + B3) 95 %, 90 %, and 75 % germination after 2 days of inoculation. In (1 % NaCl) saline condition control group revealed 40 % whereas three groups with bacteria showed 60 %, 40 %, and 70 % germination after 3 days, which increased 70 %, 90 %, 85 %, and 95 % respectively after 4 days of inoculation. The HPGPR significantly improved plant development metrics such as root length, shoot length, fresh and arid biomass yield, chlorophyll content, etc. Our results suggest that the salt-resistant bacteria (Halotolerant) have a great potential role in recuperating plant growth and would be cost-effective as a bio-inoculant in saline conditions to be used as a prospective bio-fertilizer for rice production. These findings indicate that the HPGPR has a substantially promising function in reviving plant development in an eco-friendly manner.


Asunto(s)
Oryza , Plantones , Oryza/genética , ARN Ribosómico 16S/genética , Estudios Prospectivos , Plantas Tolerantes a la Sal/genética , Estrés Salino , Bacterias , Salinidad , Raíces de Plantas/microbiología
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