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1.
Environ Manage ; 73(3): 471-480, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38091027

RESUMEN

The COVID-19 pandemic has caused unprecedented global health and economic crises. The emergence of long COVID-19 has raised concerns about the interplay between SARS-CoV-2 infections, climate change, and the environment. In this context, a concise analysis of the potential long-term effects of the COVID-19 epidemic along with the awareness aboutenvironmental issues are realized. While COVID-19 effects in the short-term have reduced environmental air pollutants and pressures, CO2 emissions are projected to increase as the economy recovers and growth rates return to pre-COVID-19 levels. This review discusses the systematic effects of both the short-term and long-term effects of the pandemic on the clean energy revolution and environmental issues. This article also discusses opportunities to achieve long-term environmental benefits and emphasizes the importance of future policies in promoting global environmental sustainability. Future directions for growth and recovery are presented to cope with long COVID-19 epidemic along with the critical findings focussing on various aspects: waste management, air quality improvement.


Asunto(s)
Contaminación del Aire , COVID-19 , Humanos , Contaminación del Aire/análisis , COVID-19/epidemiología , Pandemias , Síndrome Post Agudo de COVID-19 , SARS-CoV-2
2.
Environ Res ; 231(Pt 1): 115982, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37146934

RESUMEN

Hexavalent chromium (Cr(VI)) is deemed a priority contaminant owing to its carcinogenicity, teratogenicity, and mutagenicity towards flora and fauna. A novel Chitosan-modified Mimosa pigra biochar (CMPBC) was fabricated and the efficiency of Cr(VI) oxyanion removal in aqueous systems was compared with the pristine biochar. The instrumental characterization of X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) confirmed the amino modification of MPBC when treated with chitosan. Characteristic features of the Cr(VI) sorptive process by CMPBC and MPBC were examined by performing batch sorption studies. Experimental data suggested that sorption is heavily dependent on pH and the highest adsorption occurred at pH 3.0. The maximum adsorption capacity of CMPBC was 14.6 ± 1.07 mg g-1. It was further noted that the removal efficiency of CMPBC (92%) was considerably greater than that of MPBC (75%) when the solution pH, biochar dose, and initial concentration of Cr(VI) are 3.0, 1.0 g L-1 and 5.0 mg L-1 respectively. The kinetic data were best interpreted by the power function model (R2 = 0.97) suggesting a homogenous chemisorption process. The isotherm data for the removal of Cr(VI) by CMPBC was inferred well by Redlich Peterson (R2 = 0.96) and Temkin (R2 = 0.96) isotherms. Results of sorption-desorption regeneration cycles indicated that the Cr(VI) uptake by CMPBC is not fully reversible. The coexistence of Cr(VI) and Cr(III) on CMPBC was confirmed through the XPS analysis. The electrostatic attractions between cationic surface functionalities and Cr(VI) oxyanions, the partial reductive transformation of Cr(VI) species to Cr(III), as well as complexation of Cr(III) onto CMPBC were identified as the possible mechanisms of mitigation of Cr(VI) by CMPBC. The results and outcomes of this research suggest the possibility of utilizing the CMPBC as an easily available, environmentally sustainable, and inexpensive sorbent to decontaminate Cr(VI) from aqueous media.


Asunto(s)
Quitosano , Contaminantes Químicos del Agua , Adsorción , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/análisis , Cromo/análisis , Agua , Cinética , Concentración de Iones de Hidrógeno
3.
Int J Phytoremediation ; 25(14): 1988-2000, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37291893

RESUMEN

This research aims to convert pomegranate peel (PP) into microporous activated carbon (PPAC) using a microwave assisted K2CO3 activation method. The optimum activation conditions were carried out with a 1:2 PP/K2CO3 impregnation ratio, radiation power 800 W, and 15 min irradiation time. The statistical Box-Behnken design (BBD) was employed as an effective tool for optimizing the factors that influence the adsorption performance and removal of methylene blue (MB) dye. The output data of BBD with a desirability function indicate a 94.8% removal of 100 mg/L MB at the following experimental conditions: PPAC dose of 0.08 g, solution pH of 7.45, process temperature of 32.1 °C, and a time of 30 min. The pseudo-second order (PSO) kinetic model accounted for the contact time for the adsorption of MB. At equilibrium conditions, the Freundlich adsorption isotherm describes the adsorption results, where the maximum adsorption capacity of PPAC for MB dye was 291.5 mg g-1. This study supports the utilization of biomass waste from pomegranate peels and conversion into renewable and sustainable adsorbent materials. As well, this work contributes to the management of waste biomass and water pollutant sequestration.


The novelty of this research work comes from the conversion of the biomass waste, namely; the conversion of pomegranate peel (PP) into microporous activated carbon (PPAC) via a microwave assisted K2CO3 activation process. The applicability of the PPAC toward the removal of methylene blue dye (MB) was statistically optimized using Box Behnken design in the response surface methodology (BBD-RSM).


Asunto(s)
Granada (Fruta) , Contaminantes Químicos del Agua , Azul de Metileno , Carbón Orgánico , Adsorción , Microondas , Biodegradación Ambiental , Cinética , Concentración de Iones de Hidrógeno
4.
Environ Res ; 211: 113073, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35283075

RESUMEN

The objectives of the study were to evaluate and compare the efficacy of hexavalent chromium (Cr(VI)) removal by amino-modified (HDA-MPBC) and pristine biochar (MPBC) derived from an invasive plant Mimosa pigra. Prepared biochars were characterized and batch experiments were conducted to check the performance and the mechanisms of Cr(VI) removal. FTIR spectra revealed that the surface of HDA-MPBC is abundant with amino functional groups which was further confirmed by XPS analysis. The highest Cr(VI) removal for both HDA-MPBC (76%) and MPBC (62%) was observed at pH 3.0. The batch sorption data were well fitted to the Freundlich isotherm model and pseudo-second-order kinetic model, suggesting the involvement of both physisorption and chemisorption mechanisms for Cr(VI) removal. X-ray photoelectron spectroscopy studies showed that both Cr(VI) and Cr(III) were presented at the modified biochar surface after adsorption. These results indicated that the electrostatic attraction of Cr(VI) coupled with reduction of Cr(VI) to Cr(III) and complexation of Cr(III) ions with functional groups on HDA-MPBC as the most plausible mechanism for removal of Cr(VI) by modified biochar. Regeneration experiment concluded that adsorbed Cr(VI) onto the surface of HDA-MPBC had the least tendency of being desorbed in basic conditions. HDA-MPBC showed a high performance in adsorptive removal of Cr(VI) compared to pristine biochar signifying the amino modification to enhance adsorption performance of biochar in Cr(VI) removal from wastewater.


Asunto(s)
Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico/química , Cromo/análisis , Cinética , Agua , Contaminantes Químicos del Agua/análisis
5.
Environ Res ; 214(Pt 3): 113937, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35931193

RESUMEN

In this study the multiple metal(loid) (As, Cd, Cu and Ni) resistant bacterium Serratia sp. KUJM3 was able to grow in both single and multiple metal(loid) contaminated wastewater and removed them by 34.93-48.80% and 22.93-32%, respectively. It reduced As(v) to As(III) by 68.44-85.06% in a concentration dependent manner. The strain's IAA production potential increased significantly under both metal(loid)s regime. The lentil (Lens culinaris) seed germination and seed production were enhanced with the exogenous bacterial inoculation by 20.39 and 16.43%, respectively. Under both multi-metal(loid) regimes the bacterial inoculation promoted shoot length (22.65-51.34%), shoot dry weight (33.89-66.11%) and seed production (13.46-35%). Under bacterial manipulation the metal(loid)s immobilization increased with concomitant curtailment of translocation in lentil plant by 61.89-75.14% and 59.19-71.14% in shoot and seed, respectively. The strain biomineralized struvite (MgNH4 PO4 ·6H2O) from human urine @ 403 ± 6.24 mg L-1. The fertilizer potential of struvite was confirmed with the promotion of cowpea (Vigna unguiculata) growth traits e.g. leaf number (37.04%), pod number (234%), plant wet weight (65.47%) and seed number (134.52%). Thus Serratia sp. KUJM3 offers multiple benefits of metal(loid)s bioremediation, As(V) reduction, plant growth promotion, and struvite biomineralization garnering a suite of appealing environmental applications.


Asunto(s)
Lens (Planta) , Metales Pesados , Contaminantes del Suelo , Biodegradación Ambiental , Humanos , Metales , Metales Pesados/análisis , Desarrollo de la Planta , Serratia , Contaminantes del Suelo/análisis , Estruvita
6.
J Environ Manage ; 308: 114617, 2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-35121465

RESUMEN

Nanotechnology holds huge potential for the prevention of various viral outbreaks that have increased at a disquieting rate over the past decades. Metal oxide nanomaterials with oxidative capability are the effective materials that provide platforms as well as tools for the well understanding of the mechanism, its detection, and treatment of various viral diseases like measles, influenza, herpes, ebola, current COVID-19 etc. In this inclusive review, we survey various previous research articles on different notable photoactive transition metal oxides that possess enough potential to act as antiviral agents for the deactivation of harmful viruses. We investigated and highlighted the plausible photocatalytic oxidative mechanism of photoactive transition metal oxides in degrading viral coatings, genomic RNA using suitable free radical generation. The key finding of the present review article including the discovery of a vision on the suitable photocatalytic transition metal oxides that have been proven to be excellent against harmful viruses and consequently combatting deadly CoV-2 in the environment. This review intends to provide conclusive remarks and a realistic outlook on other advanced photocatalytic metal oxides as a potential solution in battling other similar upcoming pandemics.


Asunto(s)
COVID-19 , Virus , Desinfección , Humanos , Óxidos , SARS-CoV-2
7.
Molecules ; 27(15)2022 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-35956849

RESUMEN

Within the frame of this article, briefly but comprehensively, we present the existing knowledge, perspectives, and challenges for the utilization of Layered Double Hydroxides (LDHs) as adsorbents against a plethora of pollutants in aquatic matrixes. The use of LDHs as adsorbents was established by considering their significant physicochemical features, including their textural, structural, morphological, and chemical composition, as well as their method of synthesis, followed by their advantages and disadvantages as remediation media. The utilization of LDHs towards the adsorptive removal of dyes, metals, oxyanions, and emerging pollutants is critically reviewed, while all the reported kinds of interactions that gather the removal are collectively presented. Finally, future perspectives on the topic are discussed. It is expected that this discussion will encourage researchers in the area to seek new ideas for the design, development, and applications of novel LDHs-based nanomaterials as selective adsorbents, and hence to further explore the potential of their utilization also for analytic approaches to detect and monitor various pollutants.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Hidróxidos/química , Contaminantes Químicos del Agua/química
8.
Environ Chem Lett ; 20(2): 1275-1294, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35069060

RESUMEN

The outbreak of the human coronavirus disease 2019 (COVID-19) has induced an unprecedented increase in the use of several old and repurposed therapeutic drugs such as veterinary medicines, e.g. ivermectin, nonsteroidal anti-inflammatory drugs, protein and peptide therapeutics, disease-modifying anti-rheumatic drugs and antimalarial drugs, antiretrovirals, analgesics, and supporting agents, e.g. azithromycin and corticosteroids. Excretion of drugs and their metabolites in stools and urine release these drugs into wastewater, and ultimately into surface waters and groundwater systems. Here, we review the sources, behaviour, environmental fate, risks, and remediation of those drugs. We discuss drug transformation in aquatic environments and in wastewater treatment systems. Degradation mechanisms and metabolite toxicity are poorly known. Potential risks include endocrine disruption, acute and chronic toxicity, disruption of ecosystem functions and trophic interactions in aquatic organisms, and the emergence of antimicrobial resistance.

9.
Environ Monit Assess ; 193(12): 855, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34853926

RESUMEN

Guar gum blended soil (GGBS) offers potentially advantageous engineering characteristics of hydraulic conductivity and strength for a soil to be used as a liner material. Characterization techniques such as X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy and scanning electron microscope were used to examine the mineral composition, functional groups and morphological changes in the unblended soil (UBS) and GGBS. These characterization approaches are used to understand adsorption-associated mechanisms of Pb(II) removal. Batch adsorption tests were performed to evaluate the adsorption capacity of UBS and the GGBS with various proportions (0.5%, 1.0%, 1.5% and 2.0%) of guar gum (GG) towards the removal of Pb(II) ions. Batch adsorption experiments were conducted by varying the pH, dosage of adsorbent, concentration of metal ions and contact time. The experimental results showed that the optimum removal of Pb(II) ions was high at a pH of 3.0 for all blends, and adsorption tests beyond 3.0 pH demonstrated a decline in adsorption performance. The maximum Pb(II) removal efficiency of 95% was obtained using the 2.0% GGBS. The isotherm model assessment for adsorption experimental data of Pb(II) showed the best fit for the Langmuir model on using GG. The present research demonstrated that the guar gum-treated blends exhibited potential Pb(II) ion adsorption properties and therefore can be used as sustainable liner material in sanitary landfills.


Asunto(s)
Suelo , Contaminantes Químicos del Agua , Adsorción , Monitoreo del Ambiente , Galactanos , Concentración de Iones de Hidrógeno , Cinética , Mananos , Gomas de Plantas , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/análisis
10.
Environ Res ; 181: 108920, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31776017

RESUMEN

In the present study, green nanoceria (gNC) was synthesized and surface-functionalized (sf-gNC) with amine moieties through chemical means and used as an adsorbent for the removal of Fenalan Yellow G (FYG) from the aqueous solution. Prior to the adsorption process, the optical, structural and textural characteristics of the nanomaterial ensured the presence of highly crystalline and monodisperse nanoceria with the functionalized amine group on their surfaces. The effects of the independent variables of the FYG removal process including initial solution pH, adsorbent dose, initial adsorbate concentration and time were examined for the percent removal. The maximum removal of 93.62% was observed at the pH of 2.0 with the adsorbent dose of 0.1 g for 10 mg/L of FYG dye concentration in 210 min. The equilibrium studies revealed that the maximum adsorption capacity was 25.58 mg/g by monolayer Langmuir model at 303 K and the chemical kinetics results followed pseudo-second-order and chemisorptive Elovich model. The magnitude of the energy variables from the thermodynamic analysis exposed the feasibility and spontaneity of endothermic adsorption. Furthermore, the interactive effects of the screened process variables investigated and optimized through response surface methodology (RSM). Besides, the FYG adsorption behavior was well predicted using artificial neural network (ANN) model with good accuracy (Mean Squared Error < 0.5; Coefficient of determination > 0.99) using 3 input layers, 3 hidden layers and 1 output layer. The study proposed the intrinsic mechanism of adsorbent-adsorbate interactions as either of electrostatic interaction or through surface complexation. Moreover, the prepared amine-modified nanoceria was found to have a minimum of 75% regenerative potential for five adsorption-desorption cycles.


Asunto(s)
Gentiana/química , Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Cerio/química , Concentración de Iones de Hidrógeno , Cinética , Termodinámica
11.
Int J Phytoremediation ; 20(6): 624-633, 2018 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-29688057

RESUMEN

Biosorption potential of novel lignocellulosic biosorbents Musa sp. peel (MSP) and Aegle marmelos shell (AMS) was investigated for the removal of toxic triphenylmethane dye malachite green (MG), from aqueous solution. Batch experiments were performed to study the biosorption characteristics of malachite green onto lignocellulosic biosorbents as a function of initial solution pH, initial malachite green concentration, biosorbents dosage, and temperature. Biosorption equilibrium data were fitted to two and three parameters isotherm models. Three-parameter isotherm models better described the equilibrium data. The maximum monolayer biosorption capacities obtained using the Langmuir model for MG removal using MSP and AMS was 47.61 and 18.86 mg/g, respectively. The biosorption kinetic data were analyzed using pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models. The pseudo-second-order kinetic model best fitted the experimental data, indicated the MG biosorption using MSP and AMS as chemisorption process. The removal of MG using AMS was found as highly dependent on the process temperature. The removal efficiency of MG showed declined effect at the higher concentrations of NaCl and CaCl2. The regeneration test of the biosorbents toward MG removal was successful up to three cycles.


Asunto(s)
Contaminantes Químicos del Agua , Adsorción , Biodegradación Ambiental , Biomasa , Concentración de Iones de Hidrógeno , Cinética , Lignina , Colorantes de Rosanilina , Termodinámica , Compuestos de Tritilo
13.
Chemosphere ; : 142774, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38969231

RESUMEN

Extraction of coal through opencast mining leads to the buildup of heaps of overburden (OB) material, which poses a significant risk to production safety and environmental stability. A systematic bibliometric analysis to identify research trends and gaps, and evaluate the impact of studies and authors in the field related to coal OB phytostabilization was conducted. Key issues associated with coal extraction include land degradation, surface and groundwater contamination, slope instability, erosion and biodiversity loss. Handling coal OB material intensifies such issues, initiating additional environmental and physical challenges. The conventional approach such as topsoiling for OB restoration fails to restore essential soil properties crucial for sustainable vegetation cover. Phytostabilization approach involves establishing a self-sustaining plant cover over OB dump surfaces emerges as a viable strategy for OB restoration. This method enhanced by the supplement of organic amendments boosts the restoration of OB dumps by improving rhizosphere properties conducive to plant growth and contaminant uptake. Criteria essential for plant selection in phytostabilization are critically evaluated. Native plant species adapted to local climatic and ecological conditions are identified as key agents in stabilizing contaminants, reducing soil erosion, and enhancing ecosystem functions. Applicable case studies of successful phytostabilization of coal mines using native plants, offering practical recommendations for species selection in coal mine reclamation projects are provided. This review contributes to sustainable approaches for mitigating the environmental consequences of coal mining and facilitates the ecological recovery of degraded landscapes.

14.
Chemosphere ; 352: 141480, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38401866

RESUMEN

Food waste is a lucrative source of complex nutrients, which can be transformed into a multitude of bioproducts by the aid of microbial cell factories. The current study emphasizes isolating Glucoamylase enzyme (GA) producing strains that can effectively break down mixed food waste (MW), which serves as a substrate for biomanufacturing. The screening procedure relied heavily on the growth of isolated fungi on starch agar media, to specifically identify the microbes with the highest starch hydrolysis potential. A strain displayed the highest GA activity of 2.9 ± 0.14 U/ml which was selected and identified as Aspergillus fumigatus via molecular methods of identification. Exposure of the A. fumigatus with 200 mM Ethyl methanesulphonate (EMS) led to a 23.79% increase compared to the wild-type GA. The growth conditions like cultivation temperature or the number of spores in the inoculum were investigated. Further, maximum GA activity was exhibited at pH 5, 55 °C, and at 5 mM Ca2+ concentration. The GA showed thermostability, retaining activity even after long periods of exposure to temperatures as high as 95 °C. The improvement of hydrolysis of MW was achieved by Taguchi design where a maximum yield of 0.57 g g-1 glucose was obtained in the hydrolysate. This study puts forth the possibility that mixed food waste, despite containing spices and other microbial growth-inhibitory substances, can be efficiently hydrolyzed to release glucose units, by robust fungal cell factories. The glucose released can then be utilized as a carbon source for the production of value-added products.


Asunto(s)
Glucano 1,4-alfa-Glucosidasa , Eliminación de Residuos , Glucano 1,4-alfa-Glucosidasa/química , Alimento Perdido y Desperdiciado , Alimentos , Hongos , Hidrólisis , Almidón , Glucosa
15.
Sci Total Environ ; 925: 171116, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38382596

RESUMEN

Traditional and emerging contaminants pose significant human and environmental health risks. Conventional physical, chemical, and bioremediation techniques have been extensively studied for contaminant remediation. However, entomo- or insect-driven remediation has received limited research and public attention. Entomo-remediation refers to the use of insects, their associated gut microbiota, and enzymes to remove or mitigate organic contaminants. This novel approach shows potential as an eco-friendly method for mitigating contaminated media. However, a comprehensive review of the status, applications, and challenges of entomo-remediation is lacking. This paper addresses this research gap by examining and discussing the evidence on entomo-remediation of various legacy and emerging organic contaminants. The results demonstrate the successful application of entomo-remediation to remove legacy organic contaminants such as persistent organic pollutants. Moreover, entomo-remediation shows promise in removing various groups of emerging contaminants, including microplastics, persistent and emerging organic micropollutants (e.g., antibiotics, pesticides), and nanomaterials. Entomo-remediation involves several insect-mediated processes, including bio-uptake, biotransfer, bioaccumulation, and biotransformation of contaminants. The mechanisms underlying the biotransformation of contaminants are complex and rely on the insect gut microbiota and associated enzymes. Notably, while insects facilitate the remediation of contaminants, they may also be exposed to the ecotoxicological effects of these substances, which is often overlooked in research. As an emerging field of research, entomo-remediation has several knowledge gaps. Therefore, this review proposes ten key research questions to guide future perspectives and advance the field. These questions address areas such as process optimization, assessment of ecotoxicological effects on insects, and evaluation of potential human exposure and health risks.


Asunto(s)
Contaminantes Ambientales , Plásticos , Humanos , Animales , Biodegradación Ambiental , Insectos
16.
Chemosphere ; 352: 141419, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38360410

RESUMEN

The survival of humanity is severely threatened by the massive accumulation of waste in the ecosystem. One plausible solution for the management and upcycling of waste is conversing waste at the molecular level and deriving carbon-based nanomaterial. The field of carbon nanomaterials with distinctive properties, such as exceptionally large surface areas, good thermal and chemical stability, and improved propagation of charge carriers, remains a significant area of research. The study demonstrates recent developments in high-value carbon-based photocatalysts synthesis from various waste precursors, including zoonotic, phytogenic, polyolefinic, electronic, and biomedical, highlighting the progression as photocatalysts and adsorbents for wastewater treatment and water splitting applications. This review highpoints the benefits of using waste as a precursor to support sustainability and circular economy and the risks associated with their use. Finally, we support that a sustainable society will eventually be realized by exploring present obstacles and potential steps for creating superior carbon-based nanomaterials in the future.


Asunto(s)
Nanoestructuras , Contaminantes Químicos del Agua , Purificación del Agua , Carbono , Ecosistema
17.
Bioresour Technol ; 369: 128395, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36442602

RESUMEN

Microalgae are a promising source of raw material (i.e., proteins, carbohydrates, lipids, pigments, and micronutrients) for various value-added products and act as a carbon sink for atmospheric CO2. The rigidity of the microalgal cell wall makes it difficult to extract different cellular components for its applications, including biofuel production, food and feed supplements, and pharmaceuticals. To improve the recovery of products from microalgae, pretreatment strategies such as biological, physical, chemical, and combined methods have been explored to improve whole-cell disruption and product recovery efficiency. However, the diversity and uniqueness of the microalgal cell wall make the pretreatment process more species-specific and limit its large-scale application. Therefore, advancing the currently available technologies is required from an economic, technological, and environmental perspective. Thus, this paper provides a state-of-art review of the current trends, challenges, and prospects of sustainable microalgal pretreatment technologies from a microalgae-based biorefinery concept.


Asunto(s)
Microalgas , Microalgas/metabolismo , Biomasa , Carbohidratos , Biotecnología , Biocombustibles
18.
Int J Biol Macromol ; 226: 1284-1308, 2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36574582

RESUMEN

In recent times, green chemistry or "green world" is a new and effective approach for sustainable environmental remediation. Among all biomaterials, cellulose is a vital material in research and green chemistry. Cellulose is the most commonly used natural biopolymer because of its distinctive and exceptional properties such as reproducibility, cost-effectiveness, biocompatibility, biodegradability, and universality. Generally, coupling cellulose with other nanocomposite materials enhances the properties like porosity and specific surface area. The polymer is environment-friendly, bioresorbable, and sustainable which not only justifies the requirements of a good photocatalyst but boosts the adsorption ability and degradation efficiency of the nanocomposite. Hence, knowing the role of cellulose to enhance photocatalytic activity, the present review is focused on the properties of cellulose and its application in antibiotics, textile dyes, phenol and Cr(VI) reduction, and degradation. The work also highlighted the degradation mechanism of cellulose-based photocatalysts, confirming cellulose's role as a support material to act as a sink and electron mediator, suppressing the charge carrier's recombination rate and enhancing the charge migration ability. The review also covers the latest progressions, leanings, and challenges of cellulose biomaterials-based nanocomposites in the photocatalysis field.


Asunto(s)
Celulosa , Contaminantes Ambientales , Celulosa/química , Reproducibilidad de los Resultados , Polímeros/química , Materiales Biocompatibles
19.
Chemosphere ; 319: 138003, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36731678

RESUMEN

Biodiesel is an alternative to fossil-derived diesel with similar properties and several environmental benefits. Biodiesel production using conventional catalysts such as homogeneous, heterogeneous, or enzymatic catalysts faces a problem regarding catalysts deactivation after repeated reaction cycles. Heterogeneous nanocatalysts and nanobiocatalysts (enzymes) have shown better advantages due to higher activity, recyclability, larger surface area, and improved active sites. Despite a large number of studies on this subject, there are still challenges regarding its stability, recyclability, and scale-up processes for biodiesel production. Therefore, the purpose of this study is to review current modifications and role of nanocatalysts and nanobiocatalysts and also to observe effect of various parameters on biodiesel production. Nanocatalysts and nanobiocatalysts demonstrate long-term stability due to strong Brønsted-Lewis acidity, larger active spots and better accessibility leading to enhancethe biodiesel production. Incorporation of metal supporting positively contributes to shorten the reaction time and enhance the longer reusability. Furthermore, proper operating parameters play a vital role to optimize the biodiesel productivity in the commercial scale process due to higher conversion, yield and selectivity with the lower process cost. This article also analyses the relationship between different types of feedstocks towards the quality and quantity of biodiesel production. Crude palm oil is convinced as the most prospective and promising feedstock due to massive production, low cost, and easily available. It also evaluates key factors and technologies for biodiesel production in Indonesia, Malaysia, Brazil, and the USA as the biggest biodiesel production supply.


Asunto(s)
Petróleo , Aceites de Plantas , Esterificación , Aceites de Plantas/química , Biocombustibles , Brasil , Indonesia , Malasia
20.
Chemosphere ; 333: 138873, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37164195

RESUMEN

Over the past several decades, the increase in industrialization provoked the discharge of harmful pollutants into the environment, affecting human beings and ecosystems. ZnO-based photocatalysts seem to be the most promising photocatalysts for treating harmful pollutants. However, fast charge carrier recombination, photo corrosion, and long reaction time are the significant factors that reduce the photoactivity of ZnO-based photocatalysts. In order to enhance the photoactivity of such photocatalysts, a combined process i.e., sonocatalysis + photocatalysis = sonophotocatalysis was used. Sonophotocatalysis is one of several different AOP methods that have recently drawn considerable interest, as it produces high reactive oxygen species (ROS) which helps in the oxidation of pollutants by acoustic cavitation. This combined technique enhanced the overall efficiency of the individual method by overcoming its limiting factors. The current review aims to present the theoretical and fundamental aspects of sonocatalysis and photocatalysis along with a detailed discussion on the benefits that can be obtained by the combined process i.e., US + UV (sonophotocatalysis). Also, we have provided a comparison of the excellent performance of ZnO to that of the other metal oxides. The purpose of this study is to discuss the literature concerning the potential applications of ZnO-based sonophotocatalysts for the degradation of pollutants i.e., dyes, antibiotics, pesticides, phenols, etc. That are carried out for future developments. The role of the produced ROS under light and ultrasound stimulation and the degradation mechanisms that are based on published literature are also discussed. In the end, future perspectives are suggested, that are helpful in the development of the sonophotocatalysis process for the remediation of wastewater containing various pollutants.


Asunto(s)
Contaminantes Ambientales , Óxido de Zinc , Humanos , Especies Reactivas de Oxígeno , Ecosistema , Catálisis , Agua
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