RESUMO
The development of biocompatible adsorbents is vital for environmental remediation to control and reduce pollution and waste accumulation in ecosystems. Biocompatible hydrogels represent an innovative class of materials that are primarily composed of polymer chain units forming their structural framework. They have a high affinity for water molecules. This research thus aims to incorporate iron oxide particles into the gelatin matrix to produce gelatin hydrogel beads to remove hexavalent chromium from an aqueous solution. The synthesized beads, known for their consistent size, low friction, high specific surface area, mechanical stability, and lightweight characteristics, demonstrated their suitability for various industrial applications. The effectiveness of these hydrogels in removing hexavalent chromium ions was confirmed through a thorough analysis using techniques such as FTIR, TGA, SEM, EDX, VSM, and XPS. Batch experiments revealed that the gelatin-based nanocomposite beads exhibited optimal adsorption efficiency under acidic conditions, lower initial concentrations of chromium ions, extended contact time, and elevated temperature (50-60 °C). The composite achieved a maximum removal efficiency of 99% at pH 1, with an adsorbent dose of 0.5 g at 50 °C, and an initial concentration of 50 mg per liter. The use of 0.7 N NaOH in the regeneration process resulted in a commendable 70.5% desorption efficiency, enabling potential reuse and regeneration. Significantly, the desorption efficiency remained consistently high even after four desorption-readsorption cycles, contributing to the economic and environmental sustainability of chromium removal. Additionally, the study determined that the sorption process was feasible, spontaneous, and endothermic. These collective findings suggest that magnetic gelatin hydrogel beads could serve as a cost-effective alternative adsorbent for the efficient removal of chromium ions from aqueous solutions.
RESUMO
This study introduces a new biosorbent derived from Delonix regia bark-activated carbon to efficiently remove Chromium Cr(VI) metal ions from aqueous systems. The biosorbent was synthesized from the bark powder of the plant species and chemically activated with phosphoric acid. The biosorbent was characterized using FTIR, SEM, and BET to determine its functional properties and structural morphology. The batch adsorption experiments examined the optimal conditions for Cr(VI) metal ion adsorption, identifying that the highest removal efficiency occurred at pH levels of 2. The ideal adsorbent dosage was determined to be 2.5 g/L, with equilibrium achieved at a contact time of 60 min at the optimal temperature of about 303 K for a Cr(VI) metal ion concentration of 20 mg/L. Various isotherm models were applied to the adsorption equilibrium values, revealing that the adsorbent had a maximum removal capacity of approximately 224.8 mg/g for Cr(VI) metal ions. The adsorption process of Cr(VI) on the DAC biosorbent was best described by the Freundlich isotherm, indicating multilayer adsorption. The kinetic data fit well with the pseudo-second-order model. Thermodynamic parameters suggested that the adsorption process was spontaneous, exothermic, and feasible across different temperatures. Furthermore, the desorption studies showed that the DAC biosorbent can easily be rejuvenated and utilized several cycles with high adsorption capacity. These findings indicate that the developed adsorbent is environmentally friendly and effective for removing Cr(VI) from water systems.
Assuntos
Carvão Vegetal , Cromo , Casca de Planta , Poluentes Químicos da Água , Cromo/química , Adsorção , Casca de Planta/química , Poluentes Químicos da Água/química , Carvão Vegetal/química , Concentração de Íons de Hidrogênio , Purificação da Água/métodos , Cinética , Sapotaceae/química , Termodinâmica , Espectroscopia de Infravermelho com Transformada de Fourier , TemperaturaRESUMO
Kinases can be grouped into 20 families which play a vital role as a regulator of neoplasia, metastasis, and cytokine suppression. Human genome sequencing has discovered more than 500 kinases. Mutations of the kinase itself or the pathway regulated by kinases leads to the progression of diseases such as Alzheimer's, viral infections, and cancers. Cancer chemotherapy has made significant leaps in recent years. The utilization of chemotherapeutic agents for treating cancers has become difficult due to their unpredictable nature and their toxicity toward the host cells. Therefore, targeted therapy as a therapeutic option against cancer-specific cells and toward the signaling pathways is a valuable avenue of research. SARS-CoV-2 is a member of the Betacoronavirus genus that is responsible for causing the COVID pandemic. Kinase family provides a valuable source of biological targets against cancers and for recent COVID infections. Kinases such as tyrosine kinases, Rho kinase, Bruton tyrosine kinase, ABL kinases, and NAK kinases play an important role in the modulation of signaling pathways involved in both cancers and viral infections such as COVID. These kinase inhibitors consist of multiple protein targets such as the viral replication machinery and specific molecules targeting signaling pathways for cancer. Thus, kinase inhibitors can be used for their anti-inflammatory, anti-fibrotic activity along with cytokine suppression in cases of COVID. The main goal of this review is to focus on the pharmacology of kinase inhibitors for cancer and COVID, as well as ideas for future development.
Assuntos
COVID-19 , Neoplasias , Humanos , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , SARS-CoV-2 , Neoplasias/tratamento farmacológico , CitocinasRESUMO
Remediation of environmental oil pollution with the usage of fungal organisms has proven to be a successful cleanup bioremediation method for organic contaminants. To investigate the breakdown of oil pollutants in water environments, biosurfactant-producing fungi have been isolated from oil-polluted soil samples. 16s rRNA sequencing technique was performed to identify the fungal organism and phylogenetic tree has been constructed. A variety of biosurfactant screening tests have demonstrated the better biosurfactant producing ability of fungi. The emulsion's stability, which is essential for the biodegradation process, was indicated by the emulsification index of 68.48% and emulsification activity of 1.3. In the isolated biosurfactant, important functional groups such as amino groups, lipids, and sugars were found according to thin layer chromatography analysis with a maximum retention value of 0.85. A maximum oil degradation of around 64% was observed with immobilized beads within 12 days. The half-life, and degradation removal rate constant of 20.21 days and 0.03 day-1, respectively, have been determined by the degradation kinetic analysis. GCMS analysis confirmed the highly degraded hydrocarbons such as nonanoic acid and pyrrolidine. The immobilized fungi exhibit better oil biodegradability in aqueous solutions.
Assuntos
Petróleo , Poluentes do Solo , Biodegradação Ambiental , Ecossistema , Biomassa , Cinética , Filogenia , RNA Ribossômico 16S , Hidrocarbonetos , Água , Fungos/genética , Petróleo/análise , Petróleo/metabolismo , Tensoativos/análise , Poluentes do Solo/análiseRESUMO
The nitrogen-fixing bacterium has great prospects in replacing synthetic fertilizers with biofertilizers for plant growth. It would be a useful tool in eradicating chemical fertilizers from use. Five nitrogen-fixing bacteria were isolated from the Tea and Groundnut rhizosphere soil out of which RSKVG 02 proved to be the best. The optimized condition of RSKVG 02 was found to be pH 7 at 30 °C utilizing 1% glucose and 0.05% ammonium sulfate as the sole carbon and nitrogen source. Plant growth-promoting traits such as IAA and ammonia were estimated to be 82.97 ± 0.01254a µg/ml and 80.49 ± 0.23699a mg/ml respectively. Additionally, their phosphate and potassium solubilization efficiency were evaluated to be 46.69 ± 0.00125 b mg/ml and 50.29 ± 0.000266 mg/ml. Morphological, and biochemical methods characterized the isolated bacterial culture, and molecularly identified by 16 S rRNA sequencing as Rhizobium mayense. The isolate was further tested for its effects on the growth of Finger millet (Eleusine coracana) and Green gram (Vigna radiata) under pot conditions. The pot study experiments indicated that the bacterial isolates used as bio inoculants increased the total plant growth compared to the control and their dry weight showed similar results. The chlorophyll content of Green gram and Finger millet was estimated to be 19.54 ± 0.2784a mg/L and 15.3 ± 0.0035 mg/L which suggested that Rhizobium sp. Possesses high nitrogenase activity. The enzyme activity proved to use this bacterium as a biofertilizer property to enhance soil fertility, efficient farming, and an alternative chemical fertilizer. Therefore, Rhizobium mayense can be potentially used as an efficient biofertilizer for crop production and increase yield and soil fertility.
Assuntos
Bactérias Fixadoras de Nitrogênio , Rhizobium , Solo/química , Bactérias Fixadoras de Nitrogênio/genética , Rizosfera , Fertilizantes , Raízes de Plantas/microbiologia , Rhizobium/genética , Bactérias , Nitrogênio , Microbiologia do SoloRESUMO
An electrochemical sensor detection of sulfamethoxazole was performed using a copper oxide Molybdenum sulfide modified glassy carbon electrode using Molybdenum sulfide (CuO/MoS2) functionalization. As part of the characterization process, materials were characterized via cyclic voltammetry (CV), Square wave voltammetry (SWV), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). To optimize the performance of the experiment, parameters like the scan rate and pH, the electrolytes study, the stability, the comparative study and repeatability were optimized. In comparison to CuO, MoS2 and bare Glassy carbon electrode (GCE), an electrochemical sensor that incorporated CuO/MoS2 exhibited exceptional electrochemical performance. CuO/MoS2 modified electrodes showed a higher peak current for oxidation compared with bare, CuO and MoS2 modified electrodes, which demonstrated enhanced electrochemical conductivity for detection of SMX by minimizing oxidation potential from +0.18 V to +0.10 V. In the range of 100-800 µl SMX concentrations, the peak current linearly correlated with the concentration of SMX. In the calibration plot, the modified electrode showed linearity under ideal circumstances for SMX concentrations starting at 0.3 µM. This study investigated the presence of SMX with a detection limit of 0.34 Pg/L. CuO/MoS2 based electrochemical sensor, according to our analysis, are potentially useful in applications requiring the detection of trace amounts of SMX.
Assuntos
Cobre , Nanocompostos , Cobre/química , Molibdênio/química , Carbono/química , Sulfametoxazol , Técnicas Eletroquímicas/métodos , Nanocompostos/química , Eletrodos , Óxidos , Limite de DetecçãoRESUMO
Accidents involving diesel oil spills are prevalent in sea- and coastal regions. Polycyclic aromatic hydrocarbons (PAHs) can be adsorbed in soil and constitute a persistent contaminant due to their poor water solubility and complex breakdown. PAHs pollution is a pervasive environmental concern that poses serious risks to human life and ecosystems. Thus, it is the need of the hour to degrade and decontaminate the toxic pollutant to save the environment. Among all the available techniques, microbial degradation of the PAHs is proving to be greatly beneficial and effective. Bioremediation overcomes the drawbacks of most physicochemical procedures by eliminating numerous organic pollutants at a lower cost in ambient circumstances and has therefore become a prominent remedial option for pollutant removal, including PAHs. In the present study, we have studied the degradation of Low molecular Weight and High Molecular Weight PAH in combination by bacterial strains isolated from a marine environment. Optimum pH, temperature, carbon, and nitrogen sources, NaCl concentrations were found for efficient degradation using the isolated bacterial strains. At 250 mg/L concentration of the PAH mixture an 89.5% degradation was observed. Vibrio algiolytcus strains were found to be potent halotolerant bacteria to degrade complex PAH into less toxic simple molecules. GC-MS and FTIR data were used to probe the pathway of degradation of PAH.
Assuntos
Poluentes Ambientais , Hidrocarbonetos Aromáticos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Humanos , Ecossistema , Biodegradação Ambiental , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Bactérias , Hidrocarbonetos Aromáticos/metabolismo , Redes e Vias Metabólicas , Poluentes Ambientais/metabolismo , Poluentes do Solo/metabolismoRESUMO
The environment worldwide has been contaminated by toxic pollutants and chemicals through anthropogenic activities, industrial growth, and urbanization. Microbial remediation is seen to be superior compared to conventional remediation due to its low cost, selectivity towards particular metal ions, and high efficiency. One key strategy in enhancing microbial remediation is employing an immobilization technique with biochar as a carrier. This review provides a comprehensive summary of sources and toxic health effects of hazardous water pollutants on human health and the environment. Biochar enhances the growth and proliferation of contaminant-degrading microbes. The combined activity of biochar and microbes in eliminating the contaminants has gained the researcher's interest. Biochar demonstrates its biocompatibility by fostering microbial populations, the release of enzymes, and protecting the microbes from the acute toxicity of surrounding contaminants. The current review complies with the immobilization technique and remediation mechanisms of microbes in pollutant removal. This review also emphasizes the combined utilization, environmental adaptability, and the potential of the combined effect of immobilized microbes and biochar in the remediation of contaminants. Challenges and future outlooks are urged to commercialize the immobilized microbes-biochar interaction mechanism for environmental remediation.
RESUMO
Disposal of biodegradable waste of seashells leads to an environmental imbalance. A tremendous amount of wastes produced from flourishing shell fish industries while preparing crustaceans for human consumption can be directed towards proper utilization. The review of the present study focuses on these polysaccharides from crustaceans and a few important industrial applications. This review aimed to emphasize the current research on structural analyses and extraction of polysaccharides. The article summarises the properties of chitin, chitosan, and chitooligosaccharides and their derivatives that make them non-toxic, biodegradable, and biocompatible. Different extraction methods of chitin, chitosan, and chitooligosaccharides have been discussed in detail. Additionally, this information outlines possible uses for derivatives of chitin, chitosan, and chitooligosaccharides in the environmental, pharmaceutical, agricultural, and food industries. Additionally, it is essential to the textile, cosmetic, and enzyme-immobilization industries. This review focuses on new, insightful suggestions for raising the value of crustacean shell waste by repurposing a highly valuable material.
Assuntos
Quitosana , Animais , Humanos , Quitosana/química , Quitina/química , Alimentos Marinhos , AgriculturaRESUMO
In recent periods, a broad assortment of continual organic contaminants has been released into our natural water resources. Indeed, it is exceedingly poisonous and perilous to living things; thus, the elimination of these organic pollutants before release into the water bodies is vital. A variety of techniques have been utilized to remove these organic pollutants with advanced oxidation photocatalytic methods with zinc oxide (ZnO) nanoparticles being commonly used as a capable catalyst for contaminated water treatment. Nevertheless, its broad energy gap, which can be only stimulated under an ultraviolet (UV) light source, and high recombination pairs of electrons and holes limit their photocatalytic behaviors. However, numerous methods have been suggested to decrease its energy gap for visible regions. Including, the doping ZnO with metal ions (dopant) can be considered as an effectual route not only the reason for a movement of the absorption edges toward the higher (visible light) region but also to lower the electron-hole pair (e--h+) recombination. This review concentrated on the impact of dissimilar types of metal ions (dopants) on the advancement in the degradation performance of ZnO. So, this work demonstrates a vital review of contemporary attainments in the alteration of ZnO nanoparticles for organic pollutants eliminations. Besides, the effect of doping ions including transition metals, rare earth metals, and metal ions (substitutional and interstitial) concerning numerous types of altered ZnO are summarized. The photodegradation mechanisms for pristine and metal-modified ZnO nanoparticles are also conferred.
Assuntos
Poluentes Ambientais , Nanopartículas Metálicas , Óxido de Zinco , Zinco , Metais , Compostos Orgânicos , Corantes , Preparações Farmacêuticas , Íons , CatáliseRESUMO
Biochar is the solid material produced from the carbonization of organic feedstock biomass. This material has several unique characteristics such as greater carbon content, good electrical conductivity, high stability and large surface area, which can be applied in several research areas such as generation of power and wastewater treatment. In connection with this, recently, the investigations on biochar significantly focus on the removal of toxic heavy metals since the biochar material is easily available and environmentally friendly. According to an environmental analytical device, biochar-derived carbonaceous material has been additionally applied to the synthesis of an effective, sensitive, and low-cost electrochemical sensor. Biochar with an assessment of electrochemical properties has engaged with different redox reactions in water. In this survey, electrochemical ways of behaving of biochar in light of the electrochemical structures were analytically compiled as well as the impact from biomass sources and manufacturing process including carbonization strategies, pre-treatment/changed techniques. This review emphasizes the various synthesis methods of biochar form organic feedstock, properties and different modulations of biochar for the bioremediation of heavy metals. This review study emphasizes the utilization of biochar as sensing platform and supercapacitor for electrode fabrication in electrochemical biosensor to enhance the remediation of toxic contaminants from water streams and by switching the less ecological traditional materials. Brief information on the techniques employed for packaging biochar as carbon electrode is summarized. Scope in the aspect of environmental concern of biochar, future challenges and prospects are proposed in detail.
Assuntos
Carvão Vegetal , Metais Pesados , Biodegradação Ambiental , ÁguaRESUMO
BACKGROUND: Textile industries produce fabricated colored products using toxic dyes and other harsh chemicals. It is the responsibility of the textile industries to treat and eliminate these hazardous pollutants. However, due to the growing population demand, the treatment of these hazardous effluents is ineffective and imposes the treatment cost over the end users. The release of partially treated effluents in the environment may cause a severe threat to the ecology and its biota. The critical objective is to treat textile effluents efficiently using agricultural natural fiber waste. Generation of agricultural lignocellulosic fibrous waste increases every year due to growing population demand. Its use in the modern world is limited due to synthetic products. An alternative has enumerated to avoid wastage of fibrous resources and its clean disposal. OBJECTIVE: The main objective of this review paper discussed the feasibility of lignocellulosic fibers and other lignocellulosic materials as natural low-cost adsorbent. METHODS: The literature study was performed using Web of Science and Scopus indexed journals. The main factors considered to increase the adsorption ability, including the types of lignocellulosic surface modification techniques were searched with utmost importance for quality results. Intending to summarize the literature survey and provide persuasive content, systematic review process was considered for this novel article. RESULTS: Out of 230 valuable publications, 159 published articles were considered for the present study until March 2022. The articles surplus with factors affecting adsorption (pH, adsorption dosage, surface area, temperature, initial concentration, contact time, physical and chemical properties of pollutants) and surface modification techniques (physical, chemical, and biological) were considered for this manuscript. CONCLUSION: Overall, the physical and chemical modification methods are widely used instead of biological methods due to various factors as discussed briefly. Furthermore, the finding of this article supports the fact that the fibrous by-product resources are wasted in various occasions due to the modern lifestyle. Even though there is evidential possibility to implement the low-cost adsorbents, the industries limit their application prospects due to existing technology and financial compromises.
Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Adsorção , Corantes/química , Resíduos Industriais/análise , Lignina , Indústria Têxtil , Têxteis , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análiseRESUMO
In this study, pristine ß-Cu2V2O7, CTAB-ß-Cu2V2O7 and PVP-Cu3V2O8 were synthesized via hydrothermal method. The synthesized brown powder samples were exemplified using XRD, UV, PL, Raman and SEM studies. Further with XRD, we confirmed that the impurities were eradicated in addition of surfactant PVP. The bandgap obtained were 3.09 eV, 2.97 eV and 2.28 eV for ß-Cu2V2O7, CTAB-ß-Cu2V2O7 and PVP-Cu3V2O8. The morphology of ß-Cu2V2O7 was found to be cluster of nanoparticles with high level of agglomeration. While adding the surfactants (CTAB, PVP) the nano platelets were grown and uniformly arranged. The PVP-Cu3V2O8 sample exhibited 96%, 77% and 96% efficiency on reducing Methylene Blue, Rhodamine B and Malachite Green dyes. The enhancement of attaining complete efficiency by the PVP-Cu3V2O8 photocatalyst is attributed by the appropriate phase of host material and the PVP itself acted as a trapper for electron and hole which induced the rate of degrading toxic pollutants. The PVP-Cu3V2O8 photocatalyst will be enthusiastic and optimized aspirant for reducing organic pollutants and for wastewater management in future days.
Assuntos
Cobre , Poluentes Ambientais , Catálise , Cetrimônio , Corantes/toxicidade , Tensoativos , Têxteis , VanadatosRESUMO
Anthropogenic activities resulted in the deposition of huge quantities of contaminants such as heavy metals, dyes, hydrocarbons, etc into an ecosystem. The serious ill effects caused by these pollutants to all living organisms forced in advancement of technology for degrading or removing these pollutants. This degrading activity is mostly depending on microorganisms owing to their ability to survive in harsh adverse conditions. Though native strains possess the capability to degrade these pollutants the development of genetic engineering and molecular biology resulted in engineering approaches that enhanced the efficiency of microbes in degrading pollutants at faster rate. Many bioinformatics tools have been developed for altering/modifying genetic content in microbes to increase their degrading potency. This review provides a detailed note on engineered microbes - their significant importance in degrading environmental contaminants and the approaches utilized for modifying microbes. The genes responsible for degrading the pollutants have been identified and modified fir increasing the potential for quick degradation. The methods for increasing the tolerance in engineered microbes have also been discussed. Thus engineered microbes prove to be effective alternate compared to native strains for degrading pollutants.
Assuntos
Poluentes Ambientais , Metais Pesados , Biodegradação Ambiental , Ecossistema , Biologia SintéticaRESUMO
In this study, indium-gallium-zinc oxide (IGZO)-decorated ZnO thin films were investigated through the change in IGZO deposition time for the detection of NO2 gas. The atomic layer deposited ZnO on interdigitated Au electrode alumina substrates are decorated with IGZO by controlling the deposition time. The IGZO (ZnO:Ga2O3:In2O3 = 1:1:1 mol. %) polycrystalline target was used for deposition and effect of deposition time was investigated. The sensor responses (Rgas/Rair) of 20.6, 39.3, and 57.1 and 45.2, 102.5, and 243.5 were obtained at 150 °C, 200 °C, and 250 °C and 25-ppm NO2 concentration for ZnO (Z1) and IGZO-decorated ZnO (Z3) films, respectively. The sensor response (Rgas/Rair) increased from â¼27 to 243.5 by decorating the ZnO film with IGZO for a 60-s sputtering time. The sensor recovery and response times of the IGZO-decorated ZnO/ZnO sensor increased, and the sensor selectivity to different gases was also evaluated.
Assuntos
Gálio , Óxido de Zinco , Gases , Índio , Dióxido de Nitrogênio , Compostos Orgânicos , ZincoRESUMO
To ensure safe drinking water, it is necessary to have a simple method by which the probable pollutants are detected at the point of distribution. Nitrite contamination in water near agricultural locations could be an environmental concern due to its deleterious effects on the human population. The development of a frugal paper-based microfluidic sensor could be desirable to achieve the societal objective of providing safe drinking water. This work describes the development of a facile and cost-effective microfluidic paper-based sensor for quantitative estimation of nitrite in aquatic environments. A simple punching machine was used for fabrication and rapid prototyping of paper-based sensors without the need of any specialized equipment or patterning techniques. A reusable 3D printed platform served as the support for simultaneous testing of multiple samples. The nitrite estimation was carried out with smartphone-assisted digital image acquisition and colorimetric analysis. Under optimized experimental conditions, the variation in average grayscale intensity with concentration of nitrite was linear in the range from 0.1 to 10 ppm. The limits of detection and quantitation were 0.12 ppm and 0.35 ppm respectively. The reproducibility, expressed as relative standard deviation was 1.31%. The selectivity of nitrite detection method was determined by performing interference studies with commonly existing co-ions in water, such as bicarbonates, chloride and sulphate. The paper-based sensor was successfully applied for estimation of nitrite in actual water samples and showed high recoveries in the range of 83.5-109%. The results were in good agreement with those obtained using spectrophotometry. The developed paper-based sensor method, by virtue of its simplicity, ease of fabrication and use, could be readily extended for detection of multiple analytes in resource-limited settings.
Assuntos
Água Potável , Nitritos , Colorimetria/métodos , Água Potável/análise , Humanos , Microfluídica , Papel , Impressão Tridimensional , Reprodutibilidade dos TestesRESUMO
1,4-dioxane is a heterocyclic ether used as a polar industrial solvent and are released as waste discharges. 1,4-dioxane deteriorates health and quality, thereby attracts concern by the environment technologists. The need of attaining sustainable development goals have resulted in search of an eco-friendly and technically viable treatment strategy. This extensive review is aimed to emphasis on the (a) characteristics of 1,4-dioxane and their occurrence in the environment as well as their toxicity, (b) remedial strategies, such as physico-chemical treatment and advanced oxidation techniques. Special reference to bioremediation that involves diverse microbial strains and their mechanism are highlighted in this review. The role of macronutrients, stimulants and other abiotic cofactors in the biodegradation of 1,4-dioxane is discussed lucidly. We have critically discussed the inducible enzymes, enzyme-based remediation, distinct instrumental method of analyses to know the fate of intermediates produced from 1,4-dioxane biotransformation. This comprehensive survey also tries to put forth the different toxicity assessment tools used in evaluating the extent of detoxification of 1,4-dioxane achieved through biotransforming mechanism. Conclusively, the challenges, opportunities, techno-economic feasibility and future prospects of implementing 1,4-dioxane through biotechnological interventions are also discussed.
Assuntos
Poluentes Químicos da Água , Biodegradação Ambiental , Dioxanos/análise , Dioxanos/metabolismo , Poluentes Químicos da Água/análiseRESUMO
Recently, halides (silver halides, AgX; perosvkite halides, ABX3) and oxyhalides (bismuth oxyhalides, BiOX) based nanomaterials are noticeable photocatalysts in the degradation of organic water pollutants. Therefore, we review the recent reports to explore improvement strategies adopted in AgX, ABX3 and BiOX (X = Cl, Br and I)-based photocatalysts in water pollution remediation. Herein, the photocatalytic degradation performances of each type of these photocatalysts were discussed. Strategies such as tailoring the morphology, crystallographic facet exposure, surface area, band structure, and creation of surface defects to improve photocatalytic activities of pure halides and BiOCl photocatalysts are emphasized. Other strategies like metal ion and/or non-metal doping and construction of composites, adopted in these photocatalysts were also reviewed. Furthermore, the way of production of active radicals by these photocatalysts under ultraviolet/visible light source is highlighted. The deciding factors such as structure of pollutant, light sources and other parameters on the photocatalytic performances of these materials were also explored. Based on this literature survey, the need of further research on AgX, ABX3 and BiOX-based photocatalysts were suggested. This review might be beneficial for researchers who are working in halides and oxyhalides-based photocatalysis for water treatment.
Assuntos
Bismuto , Nanoestruturas , Bismuto/química , Catálise , Luz , Nanoestruturas/química , Prata/químicaRESUMO
A microbial fuel cell (MFC) is a sustainable device that produces electricity. The main components of MFC are electrodes (anode & cathode) and separators. The MFC's performance is ascertained by measuring its power density. Its components and other parameters, such as cell design and configuration, operation parameters (pH, salinity, and temperature), substrate characteristics, and microbes present in the substrate, all influence its performance. MFC can be scaled up and commercialized using low-cost materials without affecting its performance. Hence the choice of materials plays a significant role. In the past, precious and non-precious metals were mostly used. These were replaced by a variety of low-cost carbonaceous and non-carbonaceous materials. Nano materials, activated compounds, composite materials, have also found their way as components of MFC materials. This review describes the recently reported modified electrodes (anode and cathode), their improvisation, their merits, pollutant removal efficiency, and associated power density.
Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Águas ResiduáriasRESUMO
In the current research work, the activated carbon synthesized from the plant species Delonix regia is doped with iron oxide nanoparticles and enforced as a nanosorbent for the effective extermination of Tartrazine (TAR) and Methylene blue (MB) dyes. This nanosorbent is prepared from the bark powder of the Delonix regia and subjected to chemical activation; Furthermore, the synthesized biosorbent were characterized using FTIR, SEM, TGA, and XRD to understand their functional properties and structural morphology. The optimum effectiveness adsorption of Tartrazine and Methylene blue has been investigated by using different key parameters. The conclusions have shown the highest removal percentage at a pH of 3 and 6 for Tartrazine and Methylene blue, respectively. For the various initial concentrations, the adsorption percentage reached equilibrium after 60 min and 90 min for TAR and MB. The adsorption equilibrium values were applied to various isotherms models. The adsorbent showed a higher removal capacity of 357.142 mg g-1 and 147.058 mg g-1 and for MB and TAR respectively. The kinetic data were best fits to pseudo second order model. The thermodynamic parameters indicated that this adsorption process was found to be spontaneous, exothermic and feasible at different temperatures. These results have shown that the prepared adsorbent is an environmentally friendly and suitable material for the elimination of TAR and MB from water systems.