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1.
Proc Natl Acad Sci U S A ; 120(42): e2306870120, 2023 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-37812714

RESUMEN

The Classic Maya (c. 250 to 900 CE) in the tropical southern lowlands of Central America dealt with water scarcity during annual dry seasons and periods of climate instability via sophisticated urban reservoir systems they relied on for over a thousand years. Surface water is limited because typically rain percolates through the karstic terrain. I posit that Maya reservoirs functioned as do constructed wetlands (CWs) at present. Still-water systems like CWs and Maya reservoirs can become stagnant and nonpotable due to the build-up of nutrients that promote algal growth. Stagnant waters also serve as breeding grounds for mosquitoes that spread endemic diseases. CWs keep water clean via certain aquatic plants since all plants uptake nutrients (e.g., nitrogen, phosphorus) and decomposing plant matter supports microbial biofilms that break down nutrients. CWs also support diverse zooplankton that prey on pathogens and bacteria that assist to denitrify water. CWs do not require the use of chemicals or fossil fuels and after the initial labor-intensive output become self-cleaning and self-sufficient with some maintenance. I posit that the Maya used a diverse array of aquatic plants and other biota to keep water clean in the same manner as do CWs, which I demonstrate using evidence from excavations and settlement maps, sediment cores and current wetlands, and the iconographic and hieroglyphic records. The next step is to combine what we know about ancient Maya reservoirs in conjunction with what is currently known about CWs to better address future water needs.


Asunto(s)
Agua , Humedales , Fitomejoramiento , Clima , Lluvia , Nitrógeno
2.
Environ Sci Technol ; 58(1): 704-716, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38109774

RESUMEN

With increasing water scarcity, many utilities are considering the potable reuse of wastewater as a source of drinking water. However, not all chemicals are removed in conventional wastewater treatment, and disinfection byproducts (DBPs) can form from these contaminants when disinfectants are applied during or after reuse treatment, especially if applied upstream of advanced treatment processes to control biofouling. We investigated the chlorination of seven priority emerging contaminants (17ß-estradiol, estrone, 17α-ethinylestradiol, bisphenol A (BPA), diclofenac, p-nonylphenol, and triclosan) in ultrapure water, and we also investigated the impact of chlorination on real samples from different treatment stages of an advanced reuse plant to evaluate the role of chlorination on the associated cytotoxicity and estrogenicity. Many DBPs were tentatively identified via liquid chromatography (LC)- and gas chromatography (GC)-high resolution mass spectrometry, including 28 not previously reported. These encompassed chlorinated, brominated, and oxidized analogs of the parent compounds as well as smaller halogenated molecules. Chlorinated BPA was the least cytotoxic of the DBPs formed but was highly estrogenic, whereas chlorinated hormones were highly cytotoxic. Estrogenicity decreased by ∼4-6 orders of magnitude for 17ß-estradiol and estrone following chlorination but increased 2 orders of magnitude for diclofenac. Estrogenicity of chlorinated BPA and p-nonylphenol were ∼50% of the natural/synthetic hormones. Potential seasonal differences in estrogen activity of unreacted vs reacted advanced wastewater treatment field samples were observed.


Asunto(s)
Desinfectantes , Agua Potable , Contaminantes Químicos del Agua , Purificación del Agua , Desinfección , Halogenación , Aguas Residuales , Estrona , Diclofenaco/análisis , Contaminantes Químicos del Agua/análisis , Desinfectantes/análisis , Desinfectantes/química , Estrógenos , Agua Potable/análisis , Agua Potable/química , Estradiol , Purificación del Agua/métodos
3.
Environ Res ; 241: 117654, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37980990

RESUMEN

Water is a fundamental requirement for the survival of human beings. Although water is abundantly available across the globe, access to freshwater still remains a major concern. Most of the water available is saline or brackish, which is not fit for human consumption. Desalination is the optimum solution for production of potable water from saline water. A major shortcoming of conventional desalination technologies is their dependence on fossil fuel that results in environmental degradation, global warming, etc. Therefore, sustainable desalination technology has evolved as a need of hour. Among all renewable energy resources, solar energy is abundantly available and can be potentially harvested. Therefore, solar energy can be used to drive sustainable desalination technologies. A solar still converts saline water into freshwater in a single step using solar energy. But the major drawbacks of solar still are relatively lower efficiency and lower yield. Nanofluids are widely used to overcome these limitations due to their extraordinary and unique properties. This paper critically reviews the recent research performed on the application of nanofluids in solar desalination systems. Methods of nanofluid preparation, their types and properties are also discussed in detail. Application of nanofluids in solar desalination systems is discussed with special attention on performance enhancement of solar stills. Combinations of nanofluids with various other performance enhancement techniques are also considered. The effectiveness of nanofluids in solar stills is found to be dependent majorly on the nature and concentration of the nanofluid used.


Asunto(s)
Energía Solar , Humanos , Combustibles Fósiles , Agua Dulce , Calentamiento Global , Aguas Salinas
4.
Mikrochim Acta ; 191(3): 146, 2024 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-38372811

RESUMEN

Salmonella contamination is a major global health challenge, causing significant foodborne illness. However, current detection methods face limitations in sensitivity and time, which mostly rely on the culture-based detection techniques. Hence, there is an immediate and critical need to enhance early detection, reduce the incidence and impact of Salmonella contamination resulting in outbreaks. In this work, we demonstrate a portable non-faradaic, electrochemical sensing platform capable of detecting Salmonella in potable water with an assay turnaround time of ~ 9 min. We evaluated the effectiveness of this sensing platform by studying two sensor configurations: one utilizing pure gold (Au) and the other incorporating a semiconductor namely a zinc oxide thin film coated on the surface of the gold (Au/ZnO). The inclusion of zinc oxide was intended to enhance the sensing capabilities of the system. Through comprehensive experimentation and analysis, the LoD (limit of detection) values for the Au sensor and Au/ZnO sensor were 0.9 and 0.6 CFU/mL, respectively. In addition to sensitivity, we examined the sensing platform's precision and reproducibility. Both the Au sensor and Au/ZnO sensor exhibited remarkable consistency, with inter-study percentage coefficient of variation (%CV) and intra-study %CV consistently below 10%. The proposed sensing platform exhibits high sensitivity in detecting low concentrations of Salmonella in potable water. Its successful development demonstrates its potential as a rapid and on-site detection tool, offering portability and ease of use. This research opens new avenues for electrochemical-based sensors in food safety and public health, mitigating Salmonella outbreaks and improving water quality monitoring.


Asunto(s)
Agua Potable , Óxido de Zinc , Reproducibilidad de los Resultados , Oro , Salmonella
5.
Molecules ; 29(12)2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38930920

RESUMEN

A promising method was established for the determination of nine halobenzoquinones (HBQs) in potable water by membrane solid-phase extraction (MSPE) pretreatment and the liquid chromatography-mass spectrometry (LC-MS) method. A 500 mL water sample was taken for enrichment by the SDB-RPS membrane, which was previously activated by methanol and ultrapure water. The sample was eluted with methanol and re-dissolved with the initial mobile phase after nitrogen blowing. Then, it was detected in negative ion mode using the working curve, and HBQs were quantified by the external standard method. The linearity was satisfactory in the concentration range of 4-1000 ng/L, with correlation coefficients of 0.9963~0.9994. The recoveries were 73.5~126.6% at three spiked levels, with relative standard deviations (RSDs) of 6.8~15.5%. The limits of detection (LOD, S/N = 3) values were 0.1~0.7 ng/L. The results demonstrate that the MSPE-LC-MS method is reliable, rapid, and sensitive for the simultaneous analysis of nine HBPs in potable water.


Asunto(s)
Benzoquinonas , Agua Potable , Extracción en Fase Sólida , Extracción en Fase Sólida/métodos , Cromatografía Liquida/métodos , Benzoquinonas/química , Benzoquinonas/análisis , Agua Potable/análisis , Agua Potable/química , Espectrometría de Masas/métodos , Límite de Detección , Contaminantes Químicos del Agua/análisis , Cromatografía Líquida con Espectrometría de Masas
6.
Environ Monit Assess ; 196(11): 1054, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39404931

RESUMEN

Freshwater habitat is a natural reservoir for antimicrobial resistance (AMR). AMR poses serious human, animal, and environmental public health threats. This study aimed to evaluate the physicochemical and microbiological quality of five selected rivers (Apitipiti 1, Apitipiti 2, Apitipiti 3, Sogidi, and Aba Apa Akinmorin) in Oyo town, Nigeria, as well as the antibiotic resistance pattern of isolated bacterial species, using conventional methods. Most physicochemical parameters were within WHO and NIS permissible limits. Pearson's correlation matrix indicated that there were significant (p < 0.05) interactions among pH, electrical conductivity, temperature, sulphate and chloride salts, and BOD and COD. A total of thirty-two (32) bacterial species were isolated and identified as: Aeromonas (9), Bacillus (2), Corynebacterium (13), Lactobacillus (1), Pseudomonas (2), Staphylococcus (4), and Streptococcus (1). Of the rivers, Sogidi had the highest microbial load (6.36 log CFU/mL) while Apititipiti 1 had the lowest (5.76 log CFU/mL). With regard to antibiotic sensitivity, 81.8% were multidrug-resistant, with Corynebacterium kutscheri and Aeromonas spp. isolated from Apitipiti 2 and Aba Apa Akinmorin rivers, respectively, exhibiting a relatively high antibiotic resistance of 90.9%. This study reveals that these rivers may be unfit for consumption as multidrug-resistant bacteria of public health risk were associated with them.


Asunto(s)
Bacterias , Agua Potable , Monitoreo del Ambiente , Ríos , Ríos/microbiología , Ríos/química , Agua Potable/microbiología , Agua Potable/química , Bacterias/aislamiento & purificación , Bacterias/efectos de los fármacos , Microbiología del Agua , Nigeria , Farmacorresistencia Bacteriana Múltiple , Antibacterianos/farmacología
7.
Sensors (Basel) ; 23(16)2023 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-37631603

RESUMEN

A microbial fuel cell (MFC) biosensor with an anode as a sensing element is often unreliable at low or significantly fluctuating organic matter concentrations. To remove this limitation, this work demonstrates capillary action-aided carbon source delivery to an anode-sensing MFC biosensor for use in carbon-depleted environments, e.g., potable water. First, different carbon source delivery configurations using several thread types, silk, nylon, cotton, and polyester, are evaluated. Silk thread was determined to be the most suitable material for passive delivery of a 40 g L-1 acetate solution. This carbon source delivery system was then incorporated into the design of an MFC biosensor for real-time detection of toxicity spikes in tap water, providing an organic matter concentration of 56 ± 15 mg L-1. The biosensor was subsequently able to detect spikes of toxicants such as chlorine, formaldehyde, mercury, and cyanobacterial microcystins. The 16S sequencing results demonstrated the proliferation of Desulfatirhabdium (10.7% of the total population), Pelobacter (10.3%), and Geobacter (10.2%) genera. Overall, this work shows that the proposed approach can be used to achieve real-time toxicant detection by MFC biosensors in carbon-depleted environments.


Asunto(s)
Fuentes de Energía Bioeléctrica , Carbono/toxicidad , Cloruros , Electrodos , Formaldehído , Sustancias Peligrosas
8.
J Environ Manage ; 331: 117189, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36634420

RESUMEN

This study developed a comprehensive techno-economic assessment (TEA) framework to evaluate an innovative algae resource recovery and near zero-liquid discharge potable reuse system (i.e., the main system) in comparison with a conventional potable water reuse system (i.e., the benchmark system). The TEA study aims to estimate the levelized costs of water of individual units and integrated processes including secondary wastewater treatment, advanced water purification for potable reuse, and sludge treatment. This would provide decision-makers valuable information regarding the capital and operational costs of the innovative main system versus a typical potable water reuse treatment train, along with possible routes of cost optimization and improvements for the design of full-scale facilities. The main system consists of (i) a novel algal-based wastewater treatment coupled with a dual forward osmosis and seawater reverse osmosis (Algal FO-SWRO) membranes system for potable water reuse and hydrothermal liquefaction (HTL) to produce bioenergy and subsequent nutrients extraction from the harvested algal biomass. The benchmark system includes (ii) an advanced water purification facility (AWPF) that consists of a conventional activated sludge biological treatment (CAS), microfiltration (MF), brackish water reverse osmosis (BWRO), ultraviolet/advanced oxidation process (UV-AOP), and granular activated carbon (GAC), with anaerobic digestion for sludge treatment. Capital expenditures (CAPEX) and operational expenditures (OPEX) were calculated for each unit of both systems (i.e., sub-systems). Based on a 76% overall water recovery designed for the benchmark system, the water cost was estimated at $2.03/m3. The highest costs in the benchmark system were found on the CAS and the anaerobic digester, with the UV-AOP combined with GAC for hydrogen peroxide (H2O2) quenching as the driving factor in the increased costs of the system. The cost of the main system, based on an overall 88% water recovery, was estimated to be $1.97/m3, with costs mostly driven by the FO and SWRO membranes. With further cost reduction and optimization for FO membranes such as membrane cost, water recovery, and flux, the main system can provide a much more economically viable alternative in its application than a typical benchmark system.


Asunto(s)
Agua Potable , Purificación del Agua , Aguas Residuales , Aguas del Alcantarillado , Peróxido de Hidrógeno , Carbón Orgánico , Ósmosis , Membranas Artificiales
9.
J Environ Manage ; 331: 117293, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36657205

RESUMEN

This study applied a life cycle assessment (LCA) methodology for a comparative environmental analysis between an innovative algae resource recovery and near zero-liquid discharge potable reuse system (i.e., the main system) versus a conventional potable reuse system (i.e., the benchmark system) through energy use and greenhouse gas (GHG) emissions. The objective of this study is to demonstrate that pilot-scale data coupled with LCA would provide valuable information for system optimization, integration, and improvements for the design of environmentally sustainable full-scale systems. This study also provides decision-makers valuable information regarding the energy demand and environmental impact of this innovative main system compared to a typical tried-and-true system for potable water reuse. The main system consists of a novel algal-based wastewater treatment coupled with a dual forward osmosis and seawater reverse osmosis (Algal FO-SWRO) membranes system for potable water recovery and hydrothermal liquefaction (HTL) to recover biofuels and valuable nutrients from the harvested algal biomass. The benchmark system refers to the current industry standard technologies for potable water reuse and waste management including a secondary biological treatment, microfiltration (MF), brackish water reverse osmosis (BWRO), ultraviolet/advanced oxidation process (UV-AOP), and granular activated carbon (GAC), as well as anaerobic digestion for sludge treatment. Respective energy and GHG emissions of both systems were normalized and compared considering 1 m3 of water recovered. Based on an overall water recovery of 76% designed for the benchmark system, the energy consumption totaled 4.83 kWh/m3, and the system was estimated to generate 2.42 kg of CO2 equivalent/m3 with most of the emissions coming from the biological treatment. The main system, based on an overall water recovery of 88%, was estimated to consume 4.76 kWh/m3 and emit 1.49 kg of CO2 eq/m3. The main system has high environmental resilience and can recover bioenergy and nutrients from wastewater with zero waste disposal. With the application of energy recovery devices for the HTL and the SWRO, increase in water recovery of the FO membrane, and replacement of the SWRO membrane with BWRO, the main system provides an energy-competitive and environmentally positive alternative with an energy demand of 2.57 kWh/m3 and low GHG emissions of 0.94 kg CO2 eq/m3.


Asunto(s)
Agua Potable , Gases de Efecto Invernadero , Purificación del Agua , Animales , Dióxido de Carbono , Purificación del Agua/métodos , Aguas Residuales , Agua de Mar , Ósmosis , Estadios del Ciclo de Vida
10.
Toxicol Mech Methods ; : 1-5, 2023 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-37254444

RESUMEN

Third-party certification to drinking water product consensus standards is how products for potable water systems are deemed suitable for public health and safety in North America. Drinking water product consensus standards are a type of standard developed through a process that includes participation from expert volunteers and requires general agreement from all stakeholders. Certification to drinking water product consensus standards is required via plumbing codes and state or local regulations in most of the United States and Canada, making third-party certification essential for products intended for sale and installation in North America. Third-party certification bodies (CBs) test and certify products to these drinking water product consensus standards through an evaluation process that includes a thorough review of each product's composition, laboratory testing, and inspection of each facility where the product is manufactured. Products that comply with the consensus standard requirements are entitled to bear a certification mark that demonstrates their suitability for use in potable water systems. Drinking water product standards developed by NSF reference NSF/ANSI/CAN 600: Health Effects Evaluation and Criteria for Chemicals in Drinking Water for the toxicological criteria to evaluate chemical leachates derived from material extraction testing. Here, we review the third-party product certification process for evaluating products used in potable water systems and describe how the certification process relies on the health effects criteria and toxicological evaluation procedures described in NSF/ANSI/CAN 600.

11.
Cent Eur J Public Health ; 31(3): 155-165, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37934478

RESUMEN

OBJECTIVES: The use of alternative water sources such as rainwater or greywater (i.e., wastewater excluding water from toilets) for non-potable purposes may save water but, on the other hand, can also pose health risks to users. The main health risks come from microorganisms (such as bacteria, viruses, fungi, and protozoa). This work aims to analyse especially microbiological quality of rainwater and greywater used inside buildings in detail and to expand the existing knowledge about the potential health risks associated with these alternative water sources. It also considers methodological problems during E. coli and coliform bacteria detection. The final objective is to discuss requirements and appropriate indicators for monitoring recycled water quality. METHODS: We examined 30 buildings with non-potable water systems in the Czech Republic and analysed a total of 137 samples of rainwater and 120 samples of greywater. From these 30 buildings, eleven, 5 of which used rainwater and 6 of which used greywater, were sampled regularly for 1-2 years for basic chemical parameters, various faecal indicators, C. perfringens, Legionella spp. and P. aeruginosa. Occasionally, samples were analysed also for the presence of environmental mycobacteria, amoebas, viruses, and selected pathogens. RESULTS: Nearly three quarters of rainwater samples contained the faecal indicators E. coli or enterococci, or both, and in samples from several buildings also Clostridium perfringens was repeatedly detected. Untreated and treated rainwater were in respect to microbiological quality similar, suggesting that treatment processes were not very efficient. In greywater samples, beside faecal indicators, also P. aeruginosa and thermotolerant amoebas were repeatedly detected. Treatment technologies used for greywater were more efficient than those for rainwater systems. CONCLUSION: Based on the results we evaluated appropriate indicators for monitoring recycled water quality and drafted the first Czech regulation for non-potable water.


Asunto(s)
Escherichia coli , Humanos , República Checa , Heces
12.
Environ Sci Technol ; 56(19): 14038-14047, 2022 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-36150164

RESUMEN

Nanofiltration (NF), highly prospective for drinking water treatment, faces a challenge in simultaneously removing emerging contaminants while maintaining mineral salts, particularly divalent cations. To overcome this challenge, NF membranes possessing small pores concomitant with highly negatively charged surfaces were synthesized via a two-step fabrication strategy. The key is to generate a polyamide active layer having a loose and carboxyl group-abundant segment on top and a dense barrier segment underneath. This was achieved by restrained interfacial polymerization between trimesoyl chloride and partly protonated piperazine to form a highly depth-heterogeneous polyamide network, followed by second amidation in an organic environment to remove untethered polyamide fragments and associate malonyl chlorides with reserved amine groups to introduce more negative charges. Most importantly, on first-principle engineering the spatial architecture of the polyamide layer, amplifying asymmetric charge distribution was paired with the thinning of the vertical structure. The optimized membrane exhibits high salt/organic rejection selectivity and water permeance superior to most NF membranes reported previously. The rejections of eight emerging contaminants were in the range of 66.0-94.4%, much higher than the MgCl2 rejection of 41.1%. This new fabrication strategy, suitable for various diacyl chlorides, along with the new membranes so produced, offers a novel option for NF in potable water systems.


Asunto(s)
Agua Potable , Nylons , Aminas , Cationes Bivalentes , Cloruros , Membranas Artificiales , Minerales , Nylons/química , Piperazina , Estudios Prospectivos , Sales (Química)
13.
Environ Sci Technol ; 56(15): 10954-10962, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35819002

RESUMEN

To enhance the use of nanofiltration in the production of quality drinking water, particularly through the efficient removal of micropollutants yet still preserving essential minerals, the targeted nanofiltration membranes (NFMs) are required to have small pore dimensions coupled with a high, net-negative charge density. Herein, after the formation of a separation layer using piperazine interfacially polymerized with trimesoyl chloride, the exploitation of residual amine groups was systematically investigated by different diacyl chlorides in an organic milieu, which caused the upper part of the final separation layer to be denser and highly negatively charged. Hence, this protocol offers a novel means to fabricate NFMs simultaneously endowed with a low molecular cutoff (MWCO) of 145-238 Da and a reduced rejection of MgCl2 (48%-80%) as well as a competitive water permeance. Those features are ideally applicable to the goal of removing small micropollutants while preserving mineral ions, as needed for the energy-efficient production of safe, quality drinking water. Furthermore, an attempt was made to correlate MWCO with MgCl2 rejection, which provides some insights on the nexus of the electrostatic effects constrained by size exclusion. The significance of residual amine groups and the modification environment was unveiled, and this method paves a new avenue for designing functional NFMs.


Asunto(s)
Agua Potable , Nylons , Aminas , Cationes Bivalentes , Membranas Artificiales
14.
J Environ Manage ; 304: 114295, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-35021589

RESUMEN

This study investigated the impact of seasonal variation and operating conditions on recovery of potable quality water from municipal wastewater effluent using an integrated algal treatment process with a dual forward osmosis (FO)-reverse osmosis (RO) membrane system. Pilot study of the algal process treating primary effluent validated the technical viability and seasonal performance during warm weather (May to October, 25-55 °C) using an extremophilic algal strain Galdieria sulphuraria, and during cold weather (November to April, 4-17 °C) using polyculture strains of algae and bacteria. Algal effluents from both seasons were used as the feed solution for the laboratory FO-RO study. In addition, pilot-scale FO-RO experiments were conducted to compare the system performance during treatment of algal effluent and secondary effluent from the conventional treatment facility. At 90% water recovery, the FO-RO achieved over 90% overall rejection of major ions and organic matter using the bench-scale system and over 99% rejection of all contaminants in pilot-scale studies. Detailed water quality analysis indicated that the product water from the integrated system met both the primary and secondary drinking water standards. This study demonstrated that the FO-RO system can be engineered as a viable alternative to treat algal effluent and secondary effluent for potable water reuse independent of seasonal variations and operating conditions.


Asunto(s)
Agua Potable , Purificación del Agua , Membranas Artificiales , Ósmosis , Proyectos Piloto , Aguas Residuales
15.
J Environ Manage ; 320: 115781, 2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-35944319

RESUMEN

Sustainable production of potable water is one of the United Nations sustainable development goals set for 2030. Among available renewable energy resources, solar energy is abundantly available in most of the fresh water scarce rural and remote locations. Moreover, solar distillation units and solar photovoltaic (PV) modules have been acknowledged as suitable candidates for addressing rising fresh water and electricity demands in these regions. In recent years, researchers have proposed a number of novel hybrid solar distillation units where the solar PV modules are integrated with solar thermal distillation units in different ways to harvest both electric power and potable water. In this work, a detailed review highlighting the classification, working principle, performance and features of these novel hybrid units have been carried out. In most of these hybrid units, integration is highly beneficial for solar thermal distillation units rather than for PV modules. Direct utilization of PV module as absorber, condenser and reflector in solar stills has few drawbacks. However, indirect utilization like utilizing electric power and waste heat energy recovered from PV module in distillation units has posed significant distillate yield enhancement up to 300.0%. In some cases, the integrated PV module has even generated sufficient power for carrying out essential domestic activities. Integrated PV module's performance has also improved significantly in few studies but the magnitude of improvement has not been disclosed clearly in most of the studies as more focus has been given to distillation units rather than PV modules. However, these novel hybrid configurations have not been fully explored & optimized and their techno-enviro-economic aspects have not yet been disclosed in these available precious literatures and they are still available as a potential research gap.


Asunto(s)
Agua Potable , Energía Solar , Destilación , Electricidad , Luz Solar
16.
J Environ Manage ; 324: 116361, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36198222

RESUMEN

Towards an efficient, low-cost solution to the problem of contamination of groundwater by selenium leached out from earth's mineral crust, a new system is developed using a novel graphene-based nanocomposite membrane. The system not only purified selenium-contaminated groundwater with high degree but also ensured safe disposal of the rejected selenium through algorithmic chemical stabilization in a mineral matrix. All experiments were conducted with live contaminated water from selenium affected area rather than using synthetic solution in a semi-pilot unit involving a largely fouling-free flat sheet cross-flow membrane module. Pure water flux of up to 190 Lm-2h-1(LMH) with 96-97% selenium rejection at an optimum operating pressure of only 14 bar could be achieved. Rejected selenium was stabilized in mineral matrix through chemical coagulation-precipitation using suitable coagulants following prior optimization of the critical operating parameters by Model-based calibration toolbox (MATLAB R2020a). A high degree of stabilization efficiency (99.8%) could be achieved as reflected in an error-index of only 1.13%. For selenium-affected region, the membrane-integrated hybrid treatment system proved to be a potential candidate technology offering safe drinking water at an approximate cost of only 1.77 $/m3 which was found to be affordable to the consumers in subsequent willingness to pay survey.


Asunto(s)
Agua Potable , Agua Subterránea , Selenio , Contaminantes Químicos del Agua , Purificación del Agua , Contaminación del Agua , Contaminantes Químicos del Agua/análisis , Membranas Artificiales
17.
J Environ Manage ; 323: 116163, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36103791

RESUMEN

Despite having abundant water sources, some Brazilian regions are likely to face water scarcity within the following decades. In this sense, rainwater harvesting (RWH) systems are considered viable solutions. This study evaluates the influence of rainfall time series indicators on the tank sizes, volumetric reliability and potential for potable water savings in residential buildings in Brazil. The study aimed to determine the most suitable rainfall conditions for RWH systems design. RWH systems were simulated for 27 Brazilian cities considering a daily water balance model. Total water demands and rainfall time series were considered for each city, and RWH-relevant indicators characterised each time series. Generally, cities with higher rainfall availability required smaller tank sizes and yielded greater volumetric reliabilities and potential for potable water savings. Cluster analysis was also used to investigate if similar rainfall patterns generate similar simulation results. Euclidean distance criteria grouped similar time series into ten clustering schemes. Coefficients of variation for tank sizes decreased within each scenario as more clusters were used, i.e. this method is feasible to design rainwater storage tanks. The remaining performance indicators did not show significant variation among the tested clustering scenarios. Similarity analysis resulted in increasingly similar results within each group as the clustering became more refined. As the main conclusion, correlation analysis presented the Seasonality index and indicators related to dry periods as the most influential towards the performance of RWH systems.


Asunto(s)
Agua Potable , Abastecimiento de Agua , Conservación de los Recursos Naturales/métodos , Lluvia , Reproducibilidad de los Resultados , Factores de Tiempo
18.
Molecules ; 27(8)2022 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-35458747

RESUMEN

Drinking water containing nitrate ions at a higher concentration level of more than 10 mg/L, according to the World Health Organization (WHO), poses a considerable peril to humans. This danger lies in its reduction of nitrite ions. These ions cause methemoglobinemia during the oxidation of hemoglobin into methemoglobin. Many protocols can be applied to the remediation of nitrate ions from hydra solutions such as Zn metal and amino sulfonic acid. Furthermore, the electrochemical process is a potent protocol that is useful for this purpose. Designing varying parameters, such as the type of cathodic electrode (Sn, Al, Fe, Cu), the type of electrolyte, and its concentration, temperature, pH, and current density, can give the best conditions to eliminate the nitrate as a pollutant. Moreover, the use of accessible, functional, and inexpensive adsorbents such as granular ferric hydroxide, modified zeolite, rice chaff, chitosan, perlite, red mud, and activated carbon are considered a possible approach for nitrate removal. Additionally, biological denitrification is considered one of the most promising methodologies attributable to its outstanding performance. Among these powerful methods and materials exist zero-valent iron (ZVI), which is used effectively in the deletion process of nitrate ions. Non-precious synthesis pathways are utilized to reduce the Fe2+ or Fe3+ ions by borohydride to obtain ZVI. The structural and morphological characteristics of ZVI are elucidated using UV-Vis spectroscopy, zeta potential, XRD, FE-SEM, and TEM. The adsorptive properties are estimated through batch experiments, which are achieved to control the feasibility of ZVI as an adsorbent under the effects of Fe0 dose, concentration of NO3- ions, and pH. The obtained literature findings recommend that ZVI is an appropriate applicant adsorbent for the remediation of nitrate ions.


Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Humanos , Hierro/química , Nitratos/análisis , Óxidos de Nitrógeno , Contaminantes Químicos del Agua/análisis
19.
Wiad Lek ; 75(4 pt 2): 987-992, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35633330

RESUMEN

OBJECTIVE: The aim: Determination of circulation interrelations between antibiotic-resistant microorganisms of Enterobacteriaceae family and their resistance genes in clinical strains and potable water samples taken in Uzhhorod and Uzhhorod district. PATIENTS AND METHODS: Materials and methods: We carried out generic identification of the microorganisms isolated from clinical samples of the oral cavity of 64 patients suffering from periodontal inflammatory diseases, and potable water samples taken from sources of public centralized and decentralized water supply; the isolated microorganisms were tested for antibiotic sensitivity by the Kirby-Bauer disc diffusion method according to EUCAST. With the help of molecular-genetic methods, the total DNA of potable water was isolated and tested for the presence of the following genetic resistance determinants: carbapenems blaNDM; blaOXA48-like; tetracyclines blaTet-M; cephalosporins blaCTX-M. RESULTS: Results: In the microbiota of the clinical material and potable water samples, the same spectrum of microorganisms belonging to Enterobacteriaceae family dominated; the isolated bacteria showed a high resistance level to beta-lactam antibiotics and to natural antibiotic preparations. The highest level of resistance was established for microorganisms isolated from well water samples, where genetic resistance determinants to blaCTX-M cephalosporins and blaTet tetracyclins were also revealed. CONCLUSION: Conclusions: The obtained results proved high probability of the spread of antibiotic-resistant microorganisms and their genetic resistance determinants via potable water.


Asunto(s)
Antibacterianos , Agua Potable , Antibacterianos/farmacología , Cefalosporinas , Farmacorresistencia Microbiana/genética , Enterobacteriaceae/genética , Humanos
20.
Ecotoxicol Environ Saf ; 208: 111422, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33091776

RESUMEN

Potable water in developing countries often contains levels of toxic metals that exceed the recommended international limits, with impacts on human health. The aim of the present study was to develop a low cost aerogel synthesised from graphene oxide (GO) cross-linked with alginate to remove Pb2+ from potable water. Aerogels were made by a sol-gel of the composite materials followed by a freeze drying method. The shape of the aerogels were 50 mm diameter disks, 5 mm deep and characterised by an open porous network of 50 to 150 micrometres which are mechanically robust upon hydration. Firstly, the study was conducted using a batch adsorption method from a starting concentration 0.48 mM (100 mg/l) of Pb2+ in ultrapure water over 240 min, n = 4 with controls. A second series of experiments compared the adsorption of different competing ions at different valencies (Na+, Ca2+, Cu2+, La3+) in an equivalent media. A third series of experiments explored Pb2+ desorption from the aerogel at low pH and in highly acidic conditions. This simple filter system, based on a batch adsorption methodology expresses a high affinity for Pb2+ resulting in an ultra-high mean maximum adsorption capacity of 504 mg/g of Pb2+ within 240 mins at pH 5. The aerogel can also adsorb other toxic metal salts such as La3+ and Cu2+ with a capacity of 146 and 193 mg/g respectively. Furthermore, the aerogel structure can be acid washed removing 98% of the Pb2+ from the structure within three minutes. Overall, the data shows that GO alginate aerogels are highly effective at removing Pb2+ from water and the primary mechanism involved is ion exchange, although other phenomenon such as proton tunnelling may be a contributing factor to the ultra-high efficiency of the aerogel for Pb2+ remediation.


Asunto(s)
Agua Potable/química , Grafito/química , Plomo/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Adsorción , Alginatos/química , Biopolímeros , Humanos , Intercambio Iónico
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