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1.
J Environ Manage ; 359: 121058, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38714036

RESUMEN

Water pollution remains a pressing environmental issue, with diverse pollutants such as heavy metals, pharmaceuticals, dyes, and aromatic hydrocarbon compounds posing a significant threat to clean water access. Historically, biomass-derived activated carbons (ACs) have served as effective adsorbents for water treatment, owing to their inherent porosity and expansive surface area. Nanocomposites have emerged as a means to enhance the absorption properties of ACs, surpassing conventional AC performance. Biomass-based activated carbon nanocomposites (ACNCs) hold promise due to their high surface area and cost-effectiveness. This review explores recent advancements in biomass-based ACNCs, emphasizing their remarkable adsorption efficiencies and paving the way for future research in developing efficient and affordable ACNCs. Leveraging real-time communication for ACNC applications presents a viable approach to addressing cost concerns.


Asunto(s)
Carbón Orgánico , Frutas , Nanocompuestos , Verduras , Purificación del Agua , Nanocompuestos/química , Carbón Orgánico/química , Purificación del Agua/métodos , Frutas/química , Adsorción , Verduras/química , Contaminantes Químicos del Agua/química , Biomasa
2.
Sci Total Environ ; 931: 172816, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38679090

RESUMEN

The development of advanced materials for efficient photocatalytic H2 production and CO2 reduction is highly recommended for addressing environmental issues and producing clean energy sources. Specifically, MXenes have emerged as two-dimensional (2D) materials extensively used as high-performance cocatalysts in photocatalyst systems owing to their outstanding features of structure and properties such as high conductivity, large specific surface area, and abundant active sites. Nevertheless, there is a lack of deep and systematic studies concerning the application of these emerging materials for CO2 reduction reaction (CRR) and H2 production (HER). This review first outlines the essential features of MXenes, encompassing the synthesis methods, composition, surface terminations, and electronic properties, which make them highly active as cocatalysts. It then examines the recent progress in MXene-based photocatalysts, emphasizing the synergy achieved by coupling MXenes as co-catalysts with semiconductors, utilizing MXenes as a support for the consistent growth of photocatalysts, leading to finely dispersed nanoparticles, and exploiting MXene as exceptional precursors for creating MXene/metal oxide photocomposite. The roles of engineering surface terminations of MXene cocatalysts, MXene quantum dots (QDs), and distinctive morphologies in MXenes-based photocatalyst systems to enhance photocatalytic activity for both HER and CRR have been explored both experimentally and theoretically using DFT calculations. Challenges and prospects for MXene-based photocatalysts are also addressed. Finally, suggestions for further research and development of effective and economical MXenes/semiconductors strategies are proposed. This comprehensive review article serves as a valuable reference for researchers for applying MXenes in photocatalysis.

3.
Sci Total Environ ; 926: 171859, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38518825

RESUMEN

Environmental pollution of heavy metal(loid)s (HMs) caused adverse impacts, has become one of the emerging concerns and challenges worldwide. Metal(loid)s can pose significant threats to living organisms even when present in trace levels within environmental matrices. Extended exposure to these substances can lead to adverse health consequences in humans. Removing HM-contaminated water and moving toward sustainable development goals (SDGs) is critical. In this mission, biochar has recently gained attention in the environmental sector as a green and alternative material for wastewater removal. This work provides a comprehensive analysis of the remediation of typical HMs by biochars, associated with an understanding of remediation mechanisms, and gives practical solutions for ecologically sustainable. Applying engineered biochar in various fields, especially with nanoscale biochar-aided wastewater treatment approaches, can eliminate hazardous metal(loid) contaminants, highlighting an environmentally friendly and low-cost method. Surface modification of engineered biochar with nanomaterials is a potential strategy that positively influences its sorption capacity to remove contaminants. The research findings highlighted the biochars' ability to adsorb HM ions based on increased specific surface area (SSA), heightened porosity, and forming inner-sphere complexes with oxygen-rich groups. Utilizing biochar modification emerged as a viable approach for addressing lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), and chromium (Cr) pollution in aqueous environments. Most biochars investigated demonstrated a removal efficiency >90 % (Cd, As, Hg) and can reach an impressive 99 % (Pb and Cr). Furthermore, biochar and advanced engineered applications are also considered alternative solutions based on the circular economy.


Asunto(s)
Arsénico , Mercurio , Metales Pesados , Humanos , Aguas Residuales , Cadmio/análisis , Desarrollo Sostenible , Plomo/análisis , Metales Pesados/análisis , Carbón Orgánico , Arsénico/análisis , Mercurio/análisis , Cromo/análisis , Contaminación del Agua/análisis , Suelo
4.
Sci Total Environ ; 912: 169331, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38103619

RESUMEN

In today's era, nanoparticles (NPs) have become an integral part of human life, finding extensive applications in various fields of science, pharmacy, medicine, industry, electronics, and communication. The increasing popularity of NP usage worldwide is a testament to their tremendous potential. However, the widespread deployment of NPs unavoidably leads to their release into the environmental matrices, resulting in persistence in ecosystems and bioaccumulation in organisms. Understanding the environmental behavior of NPs poses a significant challenge due to their nanoscale size. Given the current environmental releases of NPs, known negative consequences, and the limited knowledge available for risk management, comprehending the toxicity of NPs in ecosystems is both awaiting and crucial. The present review aims to unravel the potential environmental influences of nano-scaled materials, and provides in-depth inferences of the current knowledge and understanding in this field. The review comprehensively summarizes the sources, fate, transport, toxicity, health risks, and remediation solutions associated with NP pollution in aquatic and soil ecosystems. Furthermore, it addresses the knowledge gaps and outlines further investigation priorities for the sustainable control of NP pollution in these environments. By gaining a holistic understanding of these aspects, we can work toward ensuring the responsible and sustainable use of NPs in today's fast-growing world.


Asunto(s)
Ecosistema , Nanopartículas , Humanos , Nanopartículas/toxicidad , Suelo , Contaminación Ambiental , Gestión de Riesgos
5.
Environ Res ; 238(Pt 2): 117177, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37751831

RESUMEN

The need for novel healthcare treatments and drugs has increased due to the expanding human population, detection of newer diseases, and looming pandemics. The development of nanotechnology offers a platform for cutting-edge in vivo non-invasive monitoring and point-of-care-testing (POCT) for rehabilitative disease detection and management. The advancement and uses of nanobiosensors are currently becoming more common in a variety of scientific fields, such as environmental monitoring, food safety, biomedical, clinical, and sustainable healthcare sciences, since the advent of nanotechnology. The identification and detection of biological patterns connected to any type of disease (communicable or not) have been made possible in recent years by several sensing techniques utilizing nanotechnology concerning biosensors and nanobiosensors. In this work, 2218 articles are drawn and screened from six digital databases out of which 17 were shortlisted for this review by using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) technique. As a result, this study uses a systematic methodology to review some recently developed extremely sensitive nanobiosensors, along with their biomedical, point-of-care diagnostics (POCD), or healthcare applications and their capabilities, particularly for the prediction of some fatal diseases based on a few of the most recent publications. The potential of nanobiosensors for medicinal, therapeutic, or other sustainable healthcare applications, notably for ailments diagnostics, is also recognized as a way forward in the manifestation of future trends.


Asunto(s)
Técnicas Biosensibles , Nanotecnología , Humanos , Nanotecnología/métodos , Pandemias , Inocuidad de los Alimentos , Atención a la Salud
6.
J Environ Manage ; 346: 118982, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37741192

RESUMEN

The production of plastic has exponentially increased in recent years, leading to the release of millions of tons of plastic waste into the environment annually. This waste can break down into smaller micro- and nanoplastics (MNPs) that are toxic and reactive to life forms, including humans. MNPs are particularly concerning for marine biologists and environmental scientists due to their toxic impacts on aquatic organisms, including algae, which are the foundation of the food chain. The review provides a comprehensive overview of the (eco)toxicity assessment of MNPs on aquatic algal communities, highlighting the novel insights gained into the ecotoxicity of various MNPs on algae and the associated health risks for aquatic ecosystems, food chains, and humans. This article also discusses current challenges and future research opportunities to address these challenges, making it a valuable contribution to the field of environmental science. Overall, this work is one of the first efforts to comprehensively assess the effects of MNPs on aquatic algae, emphasizing the significant risks that MNPs pose to essential ecosystems and human health.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Humanos , Microplásticos/toxicidad , Contaminantes Químicos del Agua/análisis , Ecosistema , Organismos Acuáticos , Plantas , Plásticos/toxicidad
7.
Sci Total Environ ; 904: 166021, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37543323

RESUMEN

In recent years, the COVID-19 pandemic is currently wreaking havoc on the planet. SARS-CoV-2, the Severe Acute Respiratory Syndrome Coronavirus, is the current term for this outbreak. Reports about this novel coronavirus have been presented since the pandemic's breakout, and they have demonstrated that it transmits rapidly from person to person, primarily by droplets in the air. Findings have illustrated that SARS-CoV-2 can survive on surfaces from hours to days. Therefore, it is essential to find practical solutions to reduce the virus's impact on human health and the environment. This work evaluated common sterilization methods that can decontaminate the environment and items. The goal is that healthcare facilities, disease prevention organizations, and local communities can overcome the new challenge of finding eco-friendly solutions. Further, a foundation of information encompassing various sterilization procedures and highlighting their limits to choose the most appropriate method to stop disease-causing viruses in the new context has been presented. The findings of this crucial investigation contribute to gaining insight into the comprehensive sterilization approaches against the coronavirus for human health protection and sustainable environmental development.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/prevención & control , Pandemias/prevención & control , Descontaminación/métodos , Esterilización
8.
Chemosphere ; 339: 139735, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37544527

RESUMEN

We report the preparation of Ag nanoparticles functionalized MoS2 nanoflakes by using the chemical reduction method followed by the hydrothermal method. Field emission scanning electron microscopy and elemental mapping reveals the uniform functionalization of Ag nanoparticles with MoS2 nanoflakes. High density of Ag plasmonic nanoparticles onto MoS2 nanoflakes demonstrates tremendously improved charge separation behavior in Ag-MoS2 nanohybrids. Photodecomposition capability of plasmonic Ag-MoS2 nanohybrids was explored by the decomposition of industrial pollutant molecules, showing a direct correlation between the Ag content over the MoS2 surface with their photodecomposition ability. The SERS-based detection profiles of the plasmonic were investigated by the ultra-low detection of MB molecules. The Ag-MoS2 nanohybrids SERS substrate manifests the detection of MB molecules solution up to a concentration of 10-9 M with an enhancement factor of 107. In the current study, we proposed and elucidated the probable efficient charge transfer mechanism for improved photocatalytic behavior and SERS-based sensing performance.


Asunto(s)
Contaminantes Ambientales , Nanopartículas del Metal , Nanopartículas del Metal/química , Molibdeno/química , Espectrometría Raman/métodos , Plata/química
9.
J Environ Manage ; 344: 118499, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37480638

RESUMEN

The increase of microplastic contamination in Vietnam is a growing concern due to various domestic, agricultural, and industrial activities. The use of plastic mulch and sludge application in agricultural farmland, textile production, daily consumer items, cleaning agents, and health/personal care products contribute significantly to the increasing microplastic pollution in the aquatic ecosystem. The concentration of microplastics reported in surface water ranged from 0.35 to 519,000 items m-3, with fibers and fragments being the most prevalent shapes. Notably, the high concentration of microplastics was observed in lakes, canals, and megacities such as Ha Noi and Ho Chi Minh City, which poses potential health risks to the local community via drinking-water supply and food chains. As an emerging pollutant, MPs are the transport vectors for contaminants in environmental matrices that act as a carrier of hazardous pollutants, release toxic compounds, and evenly aggregate/accumulate in biota. Recent studies have reported the presence of microplastics in various marine organisms, including fish and shellfish, highlighting the risk of ingestion of these particles by humans and wildlife. Thus, it is imperative to monitor microplastic contamination in the ecosystem to provide helpful information for the government and local communities. Efforts should be taken to reduce microplastic pollution at the source to minimize potential effects on ecological and health safety. This review paper emphasizes the urgent need for further research on microplastic pollution in Vietnam and highlights potential solutions to mitigate this emerging environmental threat. KEYWORKS: single-use plastics; microplastics; ecosystems; plastic waste; health risk; ecological and health safety; pollution mitigation.


Asunto(s)
Ecosistema , Contaminantes Ambientales , Animales , Humanos , Microplásticos/toxicidad , Plásticos , Vietnam , Cadena Alimentaria
10.
Sci Total Environ ; 899: 165323, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37422238

RESUMEN

In recent years, pharmaceutical active compounds (PhACs) have attained global prevalence. The behavior of PhACs in agricultural soils is complex and depends on several factors, such as the nature of the compounds and their physicochemical characteristics, which affect their fate and potential threats to human health, ecosystems, and the environment. The detection of residual pharmaceutical content is possible in both agricultural soils and environmental matrices. PhACs are commonly found in agricultural soil, with concentrations varying significantly, ranging from as low as 0.048 ng g-1 to as high as 1420.76 mg kg-1. The distribution and persistence of PhACs in agriculture can lead to the leaching of these toxic pollutants into surface water, groundwater, and vegetables/plants, resulting in human health risks and environmental pollution. Biological degradation or bioremediation plays a critical role in environmental protection and efficiently eliminates contamination by hydrolytic and/or photochemical reactions. Membrane bioreactors (MBRs) have been investigated as the most recent approach for the treatment of emerging persistent micropollutants, including PhACs, from wastewater sources. MBR- based technologies have proven to be effective in eliminating pharmaceutical compounds, achieving removal rates of up to 100%. This remarkable outcome is primarily facilitated by the processes of biodegradation and metabolization. In addition, phytoremediation (i.e., constructed wetlands), microalgae-based technologies, and composting can be highly efficient in remediating PhACs in the environment. The exploration of key mechanisms involved in pharmaceutical degradation has revealed a range of approaches, such as phytoextraction, phytostabilization, phytoaccumulation, enhanced rhizosphere biodegradation, and phytovolatilization. The well-known advanced/tertiary removal of sustainable sorption by biochar, activated carbon, chitosan, etc. has high potential and yields excellent quality effluents. Adsorbents developed from agricultural by-products have been recognized to eliminate pharmaceutical compounds and are cost-effective and eco-friendly. However, to reduce the potentially harmful impacts of PhACs, it is necessary to focus on advanced technologies combined with tertiary processes that have low cost, high efficiency, and are energy-saving to remove these emerging pollutants for sustainable development.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Humanos , Eliminación de Residuos Líquidos/métodos , Ecosistema , Contaminantes Químicos del Agua/análisis , Agricultura , Suelo , Preparaciones Farmacéuticas
11.
Waste Biomass Valorization ; : 1-10, 2023 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-37363338

RESUMEN

Air pollution and infectious diseases (such as the COVID-19 pandemic) have attracted considerable attention from governments and scientists worldwide to find the best solutions to address these issues. In this study, a new simultaneous antibacterial and particulate matter (PM) filtering Ag/graphene-integrated non-woven polypropylene textile was fabricated by simply immersing the textile into a Ag/graphene-containing solution. The Ag/graphene nanocomposite was prepared by reducing Ag ions on the surface of graphene nanoplatelets (GNPs) using the leaf extract. The prepared Ag/graphene textile was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Energy Dispersive X-ray (EDX), and contact angle measurements. The results showed excellent integration of the Ag/GNP nanocomposite into the non-woven polypropylene textile matrix. The prepared textile exhibited superhydrophobicity with a contact angle of 152°. The maximum PM removal percentage of the Ag/GNP-integrated textile was determined to be 98.5% at an Ag/GNP content of 1.5% w/w and a silicon adhesive of 1% w/w. The Ag/GNP textile exhibited high antibacterial activity toward Escherichia coli with no sign of bacteria on the surface. Remarkably, the as-prepared Ag/GNP textile was highly durable and stable and could be reused many times after washing.

12.
Environ Res ; 231(Pt 1): 115984, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37156354

RESUMEN

In the quest of improving the photocatalytic efficiency of photocatalysts, the combination of two and more semiconductors recently has garnered significant attention among scientists in the field. The doping of conductive metals is also an effective pathway to improve photocatalytic performance by avoiding electron/hole pair recombination and enhancing photon energy absorption. This work presented a design and fabrication of porphyrin@g-C3N4/Ag nanocomposite using acid-base neutralization-induced self-assembly approach from monomeric porphyrin and g-C3N4/Ag material. g-C3N4/Ag material was synthesized by a green reductant of Cleistocalyx operculatus leaf extract. Electron scanning microscopy (SEM), X-ray diffraction (XRD), FT-IR spectroscopy, and UV-vis spectrometer were utilized to analyse the properties of the prepared materials. The prepared porphyrin@g-C3N4/Ag nanocomposite showed well integration of porphyrin nanostructures on the g-C3N4/Ag's surface, in which porphyrin nanofiber was of the diameter in nanoscales and the length of several micrometers, and Ag NPs had an average particle size of less than 20 nm. The photocatalytic behavior of the resultant nanocomposite was tested for the degradation of Rhodamine B dye, which exhibited a remarkable RhB photodegrading percentage. The possible mechanism for photocatalysis of the porphyrin@g-C3N4/Ag nanocomposite toward Rhodamine B dye was also proposed and discussed.


Asunto(s)
Nanocompuestos , Porfirinas , Espectroscopía Infrarroja por Transformada de Fourier , Colorantes , Electrones
13.
Sci Total Environ ; 867: 161361, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36610626

RESUMEN

This study examined >140 relevant publications from the last few years (2018-2021). In this study, classification was reviewed depending on the operation's progress. Electrocoagulation (EC), electrooxidation (EO), electroflotation (EF), electrodialysis (ED), and electro-Fenton (EFN) processes have received considerable attention. The type of action (individual or hybrid) for each electrochemical procedure was evaluated, and statistical analysis was performed to compare them as a new manner of reviewing cited papers providing a massive amount of information efficiently to the readers. Individual or hybrid operation progress of the electrochemical techniques is critical issues. Their design, operation, and maintenance costs vary depending on the in-situ conditions, as evidenced by surveyed articles and statistical analyses. This work also examines the variables affecting the elimination efficacy, such as the applied current, reaction time, pH, type of electrolyte, initial pollutant concentration, and energy consumption. In addition, owing to its efficacy in removing toxins, the hybrid activity showed a good percentage among the studies reviewed. The promise of each wastewater treatment technology depends on the type of contamination. In some cases, EO requires additives to oxidise the pollutants. EF and EFN eliminated lightweight organic pollutants. ED has been used to treat saline water. Compared to other methods, EC has been extensively employed to remove a wide variety of contaminants.

14.
Sci Total Environ ; 857(Pt 3): 159671, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36280066

RESUMEN

Researchers are still trying to achieve desirable results while treating actual wastewater at the field size when scaling up a microbial fuel cell (MFC). This pilot-scale project aimed to create a decentralised system for treating domestic wastewater and concurrent energy generation that may be used as a model for the decentralisation process. In this investigation, a cylindrical-shaped earthen membrane was utilized. The arrangement was deployed on-site at a residence for the treatment of domestic wastewater as well as simultaneous generation of power. From August until November 2021, the 36 L pilot-scale setup was operational for a period of 92 days. The setup's performance was affected by seasonal temperature variations during the operation period. The system's performance was measured in terms of COD, nitrate, and NH3-N removal, with the highest results being 93.52 %, 84.93 %, and 74.78 %, respectively. The pilot-scale setup achieved the highest current of 43.7 mA, and the output voltage of the setup was boosted to 4.1 V using a power management system. The sustainable operation of pilot household MFC showed a positive indication for field application with a low-cost solution.


Asunto(s)
Fuentes de Energía Bioeléctrica , Purificación del Agua , Aguas Residuales , Electricidad , Purificación del Agua/métodos , Compuestos Orgánicos , Electrodos
15.
Sci Total Environ ; 862: 160702, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36481155

RESUMEN

The purpose of this study was to examine the application of the mathematical model of drift flux to the experimental results of the effect of cationic trimethyl-ammonium bromide (CTAB)-aided continuous foam flotation harvesting on the lipid content in Chlorella vulgaris microalgae. An experiment was conducted to determine the effect of the operating conditions on the enrichment factor (EF) and percentage recovery efficiency (%RE), where the flow rates at the inlet and bottom outlet remained constant. Data for the binary system (without algae) and ternary system (with algae) in an equal-area foam column show that the EF decreases linearly with increasing initial CTAB concentrations ranging from 30 to 75 mg/L for three levels of the studied air volumetric flow rate range (1-3) L/min. The percentage harvesting efficiency increased with increasing initial CTAB concentration and air volumetric flow rate to 96 % in the binary systems and 94 % in the ternary systems. However, in the foam column with the riser used in the three systems, a lower volume of liquid foam in the upward outlet stream resulted in a lower RE% than that of the column without the riser. The objective function of EF for the system with algae increased when the initial CTAB concentration was increased from 30 to 45 mg/L in the foam column with a riser for all air flow rates, and after 45 mg/L, a sudden drop in the microalgae EF was observed. In the comparison between the foam column with and without the riser for the system with algae, the optimum EF was 145 for the design of the column with the riser and 139 for the column without the riser.


Asunto(s)
Chlorella vulgaris , Microalgas , Cetrimonio , Biocombustibles , Agua Dulce , Biomasa
16.
Sci Total Environ ; 862: 160802, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36493814

RESUMEN

In this study, the operation parameters of a partial nitrification process (PN) treating saline wastewater were optimized using the Box-Behnken design via the response surface methodology (BBD-RSM). A novel strategy based on the control of the carbon/nitrogen ratio (C/N), alkalinity/ammonia ratio (K/A), and salinity in three stages was used to achieve PN in a sequence batch reactor. The results demonstrated that a high and stable PN was completed after 50 d with an ammonia removal efficiency (ARE) of 98.37 % and nitrite accumulation rate (NAR) of 85.93 %. Next, BBD-RSM was applied, where ARE and NAR were the responses. The highest responses from the confirmation experiment were 99.9 % ± 0.04 and 95.25 % ± 0.32 when the optimum C/N, K/A, and salinity were identified as 0.84, 2, and 5.5 (g/L), respectively. The results were higher than those for the nonoptimized reactor. The developed regression model adequately forecasts the PN performance under optimal conditions. Therefore, this study provides a promising strategy for controlling the PN process and shows how the BBD-RSM model can improve the PN performance.


Asunto(s)
Nitrificación , Aguas Residuales , Amoníaco , Salinidad , Reactores Biológicos , Nitrógeno , Nitritos , Carbono , Oxidación-Reducción , Aguas del Alcantarillado , Desnitrificación
17.
Chemosphere ; 309(Pt 1): 136628, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36181849

RESUMEN

Adsorption in the continuous mode plays a significant role in wastewater treatment. In this study, Mimosa pigra-derived biochar modified with 2 M AlCl3 salt was used to pack a lab-scale column to eliminate PO43- from aqueous solutions. The influence of the operational factors, such as inlet PO43- concentration (25-100 mg/L), flow rate (6-18 mL/min), and biochar bed height (1.5-4.5 cm), on the breakthrough curve was evaluated. The kinetic models of Adam-Bohart and Yoon-Nelson were utilized to analyze the experimental results. The best conditions were determined to be the influent PO43- strength of 50 mg/L, injection speed of 6 mL/min, and column height of 4.5 cm. These results can be applied in the design of large-scale columns for the sequestration of PO43- from wastewater.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Aguas Residuales , Fosfatos , Carbón Orgánico , Purificación del Agua/métodos , Contaminantes Químicos del Agua/análisis , Agua
18.
Chemosphere ; 308(Pt 3): 136457, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36116628

RESUMEN

This study investigated the kinetic degradation of methylene blue (MB) by a UV/chlorine process and its combination with other advanced oxidation processes. The ∙OH and reactive chlorine species (RCS: Cl∙, ClO∙, etc.) were the primary reactive species, which accounted for 56.7% and 37.6% of MB degradation at pH 7, respectively. The second-order rate constant of Cl∙ towards MB was calculated to be 2.8 × 109 M-1 s-1. When the pH increased from 3 to 7, kMB by ∙OH increased from 0.15 to 0.21 min-1 before being reduced to 0.11 min-1 at pH 11. kMB by RCS continuously reduced from 0.16 to 0.13 min-1 when the pH was increased to 11. Humic acid (HA), Br-, and Cl- inhibited the degradation with kMB in the order: kMB (in HA) < kMB (in Br-) < kMB (in Cl-). HCO3- increased kMB from 0.37 to 0.48 min-1. The experimental and modeling methods fit well, indicating the effectiveness of using Kintecus® in predicting concentrations of free radicals in complex water matrices. TOC removal was achieved at 60% after 30 min in a control process and it was strongly inhibited by the presence of HA, with 22% removal achieved at 5 mgc L-1 HA. UV/chlorine/electrochemical oxidation (UV/chlorine/EO) significantly improves kMB from 0.37 to 0.94 min-1 at a high current (240 mA), while UV/chlorine/H2O2 decreased kMB at a low concentration of 0.01 mM H2O2 (kMB decreased by 6.1%). The results indicate that the energy cost for UV irradiation was the main cost in MB treatment in both UV/chlorine and UV/persulfate (UV/PS) processes, accounting for 91% and 84%, respectively.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Cloruros , Cloro , Halógenos , Sustancias Húmicas , Peróxido de Hidrógeno , Cinética , Azul de Metileno , Oxidación-Reducción , Rayos Ultravioleta , Agua , Purificación del Agua/métodos
19.
Sci Total Environ ; 852: 158203, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36044953

RESUMEN

Sulfur (S) is a crucial component in the environment and living organisms. This work is the first attempt to provide an overview and critical discussion on the roles, mechanisms, and environmental applications of sulfur-oxidizing bacteria (SOB). The findings reveal that key enzymes of SOB embarked on oxidation of sulfide, sulfite, thiosulfate, and elemental S. Conversion of reduced S compounds was oxidatively catalyzed by various enzymes (e.g. sulfide: quinone oxidoreductase, flavocytochrome c-sulfide dehydrogenase, dissimilatory sulfite reductase, heterodisulfide reductase-like proteins). Environmental applications of SOB discussed include detoxifying hydrogen sulfide, soil bioremediation, and wastewater treatment. SOB producing S0 engaged in biological S soil amendments (e.g. saline-alkali soil remediation, the oxidation of sulfide-bearing minerals). Biotreatment of H2S using SOB occurred under both aerobic and anaerobic conditions. Sulfide, nitrate, and sulfamethoxazole were removed through SOB suspension cultures and S0-based carriers. Finally, this work presented future perspectives on SOB development, including S0 recovery, SOB enrichment, field measurement and identification of sulfur compounds, and the development of mathematical simulation.


Asunto(s)
Sulfuro de Hidrógeno , Biodegradación Ambiental , Hidrogenosulfito Reductasa/metabolismo , Tiosulfatos , Nitratos/metabolismo , Azufre/metabolismo , Bacterias/metabolismo , Oxidación-Reducción , Oxidorreductasas/metabolismo , Sulfuros/metabolismo , Suelo , Sulfametoxazol/metabolismo , Sulfitos/metabolismo , Álcalis , Quinonas
20.
Environ Res ; 214(Pt 3): 113953, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35934147

RESUMEN

A popular approach to select optimal adsorbents is to perform parallel experiments on adsorbents based on an initially decided goal such as specified product purity, efficiency, or binding capacity. To screen optimal adsorbents, we focused on the max adsorption capacity of the candidates at equilibrium in this work because the adsorption capacity of each adsorbent is strongly dependent on certain conditions. A data-driven machine learning tool for predicting the max adsorption capacity (Qm) of 19 pharmaceutical compounds on 88 biochars was developed. The range of values of Qm (mean 48.29 mg/g) was remarkably large, with a high number of outliers and large variability. Modified biochars enhanced the Qm and surface area values compared with the original biochar, with a statistically significant difference (Chi-square value = 7.21-18.25, P < 0.005). K- nearest neighbors (KNN) was found to be the most optimal algorithm with a root mean square error (RMSE) of 23.48 followed by random forest and Cubist with RMSE of 26.91 and 29.56, respectively, whereas linear regression and regularization were the worst algorithms. KNN model achieved R2 of 0.92 and RMSE of 16.62 for the testing data. A web app was developed to facilitate the use of the KNN model, providing a reliable solution for saving time and money in unnecessary lab-scale adsorption experiments while selecting appropriate biochars for pharmaceutical adsorption.


Asunto(s)
Contaminantes Químicos del Agua , Agua , Adsorción , Carbón Orgánico , Aprendizaje Automático , Preparaciones Farmacéuticas , Contaminantes Químicos del Agua/análisis
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