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1.
Waste Manag ; 179: 216-233, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38489980

RESUMEN

Bisphenol A (BPA) accumulates in the environment at lethal concentrations because of its high production rate and utilization. BPA, originating from industrial effluent, plastic production, and consumer products, poses serious risks to both the environment and human health. The widespread aggregation of BPA leads to endocrine disruption, reactive oxygen species-mediated DNA damage, epigenetic modifications and carcinogenicity, which can disturb the normal homeostasis of the body. The living being in a population is subjected to BPA exposure via air, water and food. Globally, urinary analysis reports have shown higher BPA concentrations in all age groups, with children being particularly susceptible due to its occurrence in items such as milk bottles. The conventional methods are costly with a low removal rate. Since there is no proper eco-friendly and cost-effective degradation of BPA reported so far. The phytoremediation, green-biotechnology based method which is a cost-effective and renewable resource can be used to sequestrate BPA. Phytoremediation is observed in numerous plant species with different mechanisms to remove harmful contaminants. Plants normally undergo several improvements in genetic and molecular levels to withstand stress and lower levels of toxicants. But such natural adaptation requires more time and also higher concentration of contaminants may disrupt the normal growth, survival and yield of the plants. Therefore, natural or synthetic amendments and genetic modifications can improve the xenobiotics removal rate by the plants. Also, constructed wetlands technique utilizes the plant's phytoremediation mechanisms to remove industrial effluents and medical residues. In this review, we have discussed the limitations and futuristic advancement strategies for degrading BPA using phytoremediation-associated mechanisms.


Asunto(s)
Disruptores Endocrinos , Contaminantes Ambientales , Fenoles , Niño , Humanos , Contaminantes Ambientales/análisis , Contaminantes Ambientales/metabolismo , Biodegradación Ambiental , Disruptores Endocrinos/análisis , Compuestos de Bencidrilo , Plantas/metabolismo
2.
Heliyon ; 10(4): e26636, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38420369

RESUMEN

In this study, the fabrication of titanium dioxide/reduced graphene oxide (TiO2/rGO) utilising banana peel extracts (Musa paradisiaca L.) as a reducing agent for the photoinactivation of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was explored. The GO synthesis was conducted using a modified Tour method, whereas the production of rGO involved banana peel extracts through a reflux method. The integration of TiO2 into rGO was achieved via a hydrothermal process. The successful synthesis of TiO2/rGO was verified through various analytical techniques, including X-ray diffraction (XRD), gas sorption analysis (GSA), Fourier-transform infrared (FT-IR) spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), scanning electron microscope-energy dispersive X-ray (SEM-EDX) and transmission electron microscopy (TEM) analyses. The results indicated that the hydrothermal-assisted green synthesis effectively produced TiO2/rGO with a particle size of 60.5 nm. Compared with pure TiO2, TiO2/rGO demonstrated a reduced crystallite size (88.505 nm) and an enhanced surface area (22.664 m2/g). Moreover, TiO2/rGO featured a low direct bandgap energy (3.052 eV), leading to elevated electrical conductivity and superior photoconductivity. To evaluate the biological efficacy of TiO2/rGO, photoinactivation experiments targeting E. coli and S. aureus were conducted using the disc method. Sunlight irradiation emerged as the most effective catalyst, achieving optimal inactivation results within 6 and 4 h.

3.
Environ Res ; 243: 117752, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38008202

RESUMEN

Plant leaf litter has a major role in the structure and function of soil ecosystems as it is associated with nutrient release and cycling. The present study is aimed to understand how well the decomposing leaf litter kept soil organic carbon and nitrogen levels stable during an incubation experiment that was carried out in a lab setting under controlled conditions and the results were compared to those from a natural plantation. In natural site soil samples, Anacardium. occidentale showed a higher value of organic carbon at surface (1.14%) and subsurface (0.93%) and Azadirachta. indica exhibited a higher value of total nitrogen at surface (0.28%) and subsurface sample (0.14%). In the incubation experiment, Acacia auriculiformis had the highest organic carbon content initially (5.26%), whereas A. occidentale had the highest nitrogen level on 30th day (0.67%). The overall carbon-nitrogen ratio showed a varied tendency, which may be due to dynamic changes in the complex decomposition cycle. The higher rate of mass loss and decay was observed in A. indica leaf litter, the range of the decay constant is 1.26-2.22. The morphological and chemical changes of soil sample and the vermicast were substantained using scanning electron microscopy (SEM) and Fourier transmission infrared spectroscopy (FT-IR).


Asunto(s)
Azadirachta , Suelo , Suelo/química , Árboles , Ecosistema , Carbono/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Nitrógeno/análisis , Hojas de la Planta
4.
Environ Monit Assess ; 195(12): 1467, 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37962670

RESUMEN

The aim of the work was to establish the effect of anthropogenic activities and seasonality on physico-chemical parameters and heavy metal levels of River Yala (RY) within RY Basin of Lake Victoria (LV), as well as the associated ecological risks. Analyses were done on the collected samples in order to establish the levels of EC, pH, DO, temperature, conductivity, turbidity, acidity, alkalinity, BOD, COD, DOC, TOC and heavy metals (Cu, Fe, Pb, Mn, Zn, Cr and Cd) in RY water and sediments adjacent to Agricultural Farms during dry and wet seasons. The levels in terms of µg/mL, µS/cm (EC), NTU (turbidity) of analyzed parameters in the Agricultural Farms in water ranged from 0.01±0.00 to 121.75±15.23 (Upstream pristine sources of RY - S), 0.02±0.01 to 184.83±23.43 (Nandi Tea Estate and Kaimosi Agricultural Farms - N), 0.02±0.01 to 149.67±22.77 (Subsistence Farms - Sub), 0.02±0.01 to 209.33±18.09 (Lake Agro Limited Agricutural Farms and Yala Swamp - D) and 0.01±0.00 to 164.25±30.33 (Terminal of RY - T). The levels in µg/g of analyzed parameters in sediments ranged from 7.2±1.46 to 3342.8±538.7 (S), 9.12±0.2 to 4063.2±90.4 (N), 3.15±1.14 to 5998.5±588.4 (Sub), 2.03±0.76 to 4519.8±194.9 (D) and 2.13±0.75 to 5514.4±201.4 (T). The significant differences in the levels of analyzed parameters in water between dry and wet seasons were computed as; EC (+20.54 µS/cm), alkalinity (-2.85 µg/mL), DOC (+0.24 µg/mL), Fe (+0.58 µg/mL), Pb (+0.11 µg/mL), Zn (+0.07 µg/mL) and Cd (+0.01 µg/mL) while that for Mn in sediment samples was +163.8937 µg/g. The significantly (p ≤ 0.05) positive values indicated that wet season had more impact on the levels than dry season. There was positive correlation of zinc in water and sediments during dry and wet season. Chromium correlated positively in water and sediments during wet season. Copper and cadmium correlated negatively during dry and wet season while Mn only wet season. Results of geostatistical indices (CF, Cd, mCd, PLI, Er and RI) indicated that sediments located at regions N, D and T were highly contaminated with the heavy metals. However, a wetland at the mouth of Lake Victoria cleaned the water before it drained into the lake. Therefore, despite contamination of RY through anthropogenic activities, wetland mitigation protects LV from pollution by the river, indicating the important ecological and restorative functions played by wetlands.


Asunto(s)
Cadmio , Metales Pesados , Lagos , Ríos , Plomo , Monitoreo del Ambiente , Agua
5.
Mol Biotechnol ; 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37907811

RESUMEN

The present study focused on preparing and characterizing magnetite-polyvinyl alcohol (PVA) hybrid nanoparticles using Acanthophora spicifera marine algae extract as a reducing agent. Various analytical techniques, including UV-Visible spectrometry, Fourier-transform infrared (FTIR) analysis, energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis, were used to characterize the nanoparticles. The results showed the successful synthesis of nanoparticles with a characteristic color change and absorption peak at 400 nm in UV-Visible spectrometry. FTIR analysis indicated an interaction between the carboxyl group and magnetite-polyvinyl alcohol hybrid ions. SEM analysis revealed spherical nanoparticles with sizes ranging from 20 to 100 nm. EDX analysis confirmed the presence of strong magnetite peaks in Acanthophora spicifera, validating successful preparation. XRD analysis indicated the crystalline nature of the nanoparticles. Furthermore, the antimicrobial potential of As-PVA-MNPs was evaluated, demonstrating a significant zone of inhibition against tested bacterial and fungal samples at a concentration of 100 µg. These findings suggest the promising antimicrobial activity of the synthesized nanoparticles for potential applications in combating pathogenic microorganisms.

6.
Int J Biol Macromol ; 253(Pt 6): 127120, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37820902

RESUMEN

The ligand attribute of biomolecules to form coordination bonds with metal ions led to the discovery of a novel class of materials called biomolecule-associated metal-organic frameworks (Bio-MOFs). These biomolecules coordinate in multiple ways and provide versatile applications. Far-spread bio-ligands include nucleobases, amino acids, peptides, cyclodextrins, saccharides, porphyrins/metalloporphyrin, proteins, etc. Low-toxicity, self-assembly, stability, designable and selectable porous size, the existence of rigid and flexible forms, bio-compatibility, and synergistic interactions between metal ions have led Bio-MOFs to be commercialized in industries such as sensors, food, pharma, and eco-sensing. The rapid growth and commercialization are stunted by absolute bio-compatibility issues, bulk morphology that makes it rigid to alter shape/porosity, longer reaction times, and inadequate research. This review elucidates the structural vitality, biocompatibility issues, and vital sensing applications, including challenges for incorporating bio-ligands into MOF. Critical innovations in Bio-MOFs' applicative spectrum, including sustainable food packaging, biosensing, insulin and phosphoprotein detection, gas sensing, CO2 capture, pesticide carriers, toxicant adsorptions, etc., have been elucidated. Emphasis is placed on biosensing and biomedical applications with biomimetic catalysis and sensitive sensor designing.


Asunto(s)
Estructuras Metalorgánicas , Metaloporfirinas , Estructuras Metalorgánicas/química , Metales/química , Metaloporfirinas/química , Aminoácidos , Iones
7.
Bioresour Technol ; 388: 129725, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37683709

RESUMEN

The suitability of biochar as a supplement for environmental restoration varies significantly based on the type of feedstocks used and the parameters of the pyrolysis process. This study comprehensively examines several aspects of biochar's potential benefits, its capacity to enhance crop yields, improve nutrient availability, support the co-composting, water restoration and enhance overall usage efficiency. The supporting mechanistic evidence for these claims is also evaluated. Additionally, the analysis identifies various gaps in research and proposes potential directions for further exploration to enhance the understanding of biochar application. As a mutually advantageous approach, the integration of biochar into agricultural contexts not only contributes to environmental restoration but also advances ecological sustainability. The in-depth review underscores the diverse suitability of biochar as a supplement for environmental restoration, contingent upon the specific feedstock sources and pyrolysis conditions used. However, concerns have been raised regarding potential impacts on human health within agricultural sectors.

8.
Chemosphere ; 341: 139822, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37598950

RESUMEN

The dehydration of ethanol into diethyl ether over a SO4/SiO2 catalyst was investigated. The SO4/SiO2 catalysts were prepared by the sulfation method using 1, 2, and 3 M of sulfuric acid (SS1, SS2, and SS3) via hydrothermal treatment. This study is focused on the synthesis of a SO4/SiO2 catalyst with high total acidity that can be subsequently utilized to convert ethanol into diethyl ether. The total acidity test revealed that the sulfation process increased the total acidity of SiO2. The SS2 catalyst (with 2 M sulfuric acid) displayed the highest total acidity of 7.77 mmol/g, whereas the SiO2 total acidity was only 0.11 mmol/g. Meanwhile, the SS3 catalyst (with 3 M sulfuric acid) has a lower total acidity of 7.09 mmol/g due to the distribution of sulfate groups on the surface having reached its optimum condition. The crystallinity and structure of the SS2 catalyst were not affected by the hydrothermal treatment or the sulfate process on silica. Furthermore, The SS2 catalyst characteristics in the presence of sulfate lead to a flaky surface in the morphology and non-uniform particle size. In addition, the surface area and pore volume of the SS2 catalyst decreased (482.56-172.26 m2/g) and (0.297-0.253 cc/g), respectively, because of the presence of sulfate on the silica surface. The SS2 catalyst's pore shape information explains the formation of non-uniform pore sizes and shapes. Finally, the activity and selectivity of SO4/SiO2 catalysts in the conversion of ethanol to diethyl ether yielded the highest ethanol conversion of 70.01% and diethyl ether product of 9.05% from the SS2 catalyst (the catalyst with the highest total acidity). Variations in temperature reaction conditions (175-225 °C) show an optimum reaction temperature to produce diethyl ether at 200 °C (11.36%).


Asunto(s)
Éter , Dióxido de Silicio , Humanos , Dióxido de Silicio/química , Éter/química , Deshidratación , Sulfatos , Etanol/química
9.
Chemosphere ; 339: 139699, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37532206

RESUMEN

Sustainable energy transition has brought the attention towards microalgae utilization as potential feedstock due to its tremendous capabilities over its predecessors for generating more energy with reduced carbon footprint. However, the commercialization of microalgae feedstock remains debatable due to the various factors and considerations taken into scaling-up the conventional microalgal upstream processes. This review provides a state-of-the-art assessment over the recent developments of available and existing microalgal upstream cultivation systems catered for maximum biomass production. The key growth parameters and main cultivation modes necessary for optimized microalgal growth conditions along with the fundamental aspects were also reviewed and evaluated comprehensively. In addition, the advancements and strategies towards potential scale-up of the microalgal cultivation technologies were highlighted to provide insights for further development into the upstream processes aimed at sustainable circular bioeconomy.


Asunto(s)
Microalgas , Biocombustibles , Biotecnología , Bioingeniería , Biomasa
10.
Environ Res ; 236(Pt 2): 116810, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37532209

RESUMEN

Gestagens are common pollutants accumulated in the aquatic ecosystem. Gestagens are comprised of natural gestagens (i.e. progesterone) and synthetic gestagens (i.e. progestins). The major contributors of gestagens in the environment are paper plant mill effluent, wastewater treatment plants, discharge from pharmaceutical manufacturing, and livestock farming. Gestagens present in the aquatic environment interact with progesterone receptors and other steroid hormone receptors, negatively influencing fish reproduction, development, and behavior. In fish, the gonadotropin induces 17α, 20ß-dihydroxy-4-pregnen-3-one (DHP) production, an important steroid hormone involved in gametogenesis. DHP interacts with the membrane progestin receptor (mPR), which regulates sperm motility and oocyte maturation. Gestagens also interfere with the hypothalamic-pituitary-gonadal (HPG) axis, which results in altered hormone levels in fish. Moreover, recent studies showed that even at low concentrations exposure to gestagens can have detrimental effects on fish reproduction, including reduced egg production, masculinization, feminization in males, and altered sex ratio, raising concerns about their impact on the fish population. This review highlights the hormonal regulation of sperm motility, oocyte maturation, the concentration of environmental gestagens in the aquatic environment, and their detrimental effects on fish reproduction. However, the long-term and combined impacts of multiple gestagens, including their interactions with other pollutants on fish populations and ecosystems are not well understood. The lack of standardized regulations and monitoring protocols for gestagens pollution in wastewater effluent hampers effective control and management. Nonetheless, advancements in analytical techniques and biomonitoring methods provide potential solutions by enabling better detection and quantification of gestagens in aquatic ecosystems.


Asunto(s)
Contaminantes Ambientales , Progestinas , Animales , Masculino , Progestinas/farmacología , Aguas Residuales/toxicidad , Ecosistema , Motilidad Espermática , Peces , Reproducción , Receptores de Progesterona , Esteroides/farmacología
11.
Bioresour Technol ; 387: 129660, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37573978

RESUMEN

This review article critically evaluates the significance of adopting advanced biofuel production techniques that employ lignocellulosic materials, waste biomass, and cutting-edge technology, to achieve sustainable environmental stewardship. Through the analysis of conducted research and development initiatives, the study highlights the potential of these techniques in addressing the challenges of feedstock supply and environmental impact and implementation policies that have historically plagued the conventional biofuel industry. The integration of state-of-the-art technologies, such as nanotechnology, pre-treatments and enzymatic processes, has shown considerable promise in enhancing the productivity, quality, and environmental performance of biofuel production. These developments have improved conversion methods, feedstock efficiency, and reduced environmental impacts. They aid in creating a greener and sustainable future by encouraging the adoption of sustainable feedstocks, mitigating greenhouse gas emissions, and accelerating the shift to cleaner energy sources. To realize the full potential of these techniques, continued collaboration between academia, industry representatives, and policymakers remains essential.


Asunto(s)
Biocombustibles , Conservación de los Recursos Naturales , Biotecnología/métodos , Biomasa , Políticas
12.
Int J Biol Macromol ; 253(Pt 2): 126492, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37634772

RESUMEN

The unscientific disposal of the most abundant crustacean wastes, especially those derived from marine sources, affects both the economy and the environment. Strategic waste collection and management is the need of the hour. Sustainable valorization approaches have played a crucial role in solving those issues as well as generating wealth from waste. The shellfishery wastes are rich in valuable bioactive compounds such as chitin, chitosan, minerals, carotenoids, lipids, and other amino acid derivatives. These value-added components possessed pleiotropic applications in different sectors viz., food, nutraceutical, cosmeceutical, agro-industrial, healthcare, and pharmaceutical sectors. The manuscript covers the recent status, scope of shellfishery management, and different bioactive compounds obtained from crustacean wastes. In addition, both sustainable and conventional routes of valorization approaches were discussed with their merits and demerits along with their combinations. The utilization of nano and microtechnology was also included in the discussion, as they have become prominent research areas in recent years. More importantly, the future perspectives of crustacean waste management and other potential valorization approaches that can be implemented on a large scale.


Asunto(s)
Quitosano , Administración de Residuos , Animales , Quitina/química , Crustáceos/metabolismo , Alimentos Marinos
13.
Environ Res ; 235: 116611, 2023 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-37437863

RESUMEN

The current study aims to investigate the influence of seasonal changes on the pollution loads of the sediment of a coastal area in terms of its physicochemical features. The research will focus on analyzing the nutrients, organic carbon and particle size of the sediment samples collected from 12 different sampling stations in 3 different seasons along the coastal area. Additionally, the study discusses about the impact of anthropogenic activities such as agriculture and urbanization and natural activities such as monsoon on the sediment quality of the coastal area. The nutrient changes in the sediment were found to be: pH (7.96-9.45), EC (2.89-5.23 dS/m), nitrogen (23.98-57.23 mg/kg), phosphorus (7.75-11.36 mg/kg), potassium (217-398 mg/kg), overall organic carbon (0.35-0.99%), and sediment proportions (8.91-9.3%). Several statistical methods were used to investigate changes in sediment quality. According to the three-way ANOVA test, the mean value of the sediments differs significantly with each season. It correlates significantly with principal factor analysis and cluster analysis across seasons, implying contamination from both natural and man-made sources. This study will contribute to developing effective management strategies for the protection and restoration of degraded coastal ecosystem.


Asunto(s)
Sedimentos Geológicos , Contaminantes Químicos del Agua , Humanos , Sedimentos Geológicos/análisis , Estaciones del Año , Ecosistema , Monitoreo del Ambiente/métodos , Bahías , Carbono/análisis , Contaminantes Químicos del Agua/análisis
14.
Chemosphere ; 337: 139224, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37336442

RESUMEN

This work provides a first-time comparative study examining the photocatalytic activity of functionalized TiO2-based composites to eliminate naphthol blue in Batik wastewater. Reduced graphene oxide (RGO) was synthesized by oxidizing solid graphite using the Hummers' method followed by sonication and reduction. N-doped TiO2 (N-TiO2) was synthesized from titanium tetrachloride (TiCl4) and urea (CH4N2O) precursors by the sol-gel method. N-TiO2 modified RGO (RGO/NT) was synthesized using a hydrothermal method from N-TiO2 and RGO. Prepared TiO2-based composites and commercial TiO2, for comparison were characterized using Fourier transform infrared spectrometer (FTIR), X-Ray diffractometer (XRD), scanning electron microscope-energy dispersive X-ray (SEM-EDX), and UV-Vis diffuse reflectance spectrometer (UV-Vis DRS). FTIR characterization indicated Ti-N bonding in N-TiO2 and RGO/NT. XRD patterns showed that commercial TiO2 had a rutile phase, while N-TiO2 and RGO/NT had an anatase phase with crystal sizes of 30.09, 16.28, and 12.02 nm, respectively. SEM results displayed the presence of small and glossy white N-TiO2 dispersed on the surface of RGO. Characterization using UV-Vis DRS showed that the band gap energy values for TiO2, N-TiO2, and RGO/NT were 3.25, 3.12, and 3.08 eV with absorption regions at the wavelengths of 382, 398, and 403 nm, respectively. The highest photocatalytic activity for RGO/NT for degrading naphthol blue was obtained at pH 5, with a photocatalyst mass of 60 mg, and an irradiation of 15 min. Photocatalytic degradation by RGO/NT on Batik wastewater under visible light showed higher effectivity than under UV light.


Asunto(s)
Óxidos , Aguas Residuales , Óxidos/química , Naftoles , Titanio/química , Luz , Catálisis
15.
Bioresour Technol ; 384: 129358, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37336449

RESUMEN

Bacterial communities were dynamically tracked at four stages of biochar-driven sheep manure pile composting, and the co-occurrence networks with keystone taxa were established. The succession of bacterial community obvious varied during the composting process, Proteobacteria predominant in initial stage (39%) then shifted into Firmicutes in thermophilic (41%) and mesophilic (27%) stages, finally the maturation stage dominant by Bacteroidota (26%). Visualizations of bacterial co-occurrence networks demonstrate more cooperative mutualism and complex interactions in the thermophilic and mesophilic phases. Noticeably, the 7.5 and 10% biochar amended composts shown highest connections (736 and 663 total links) and positive cooperation (97.37 and 97.13% positive link) as well as higher closeness centrality and betweenness centrality of keystone taxa. Overall, appropriate biochar addition alters bacterial community succession and strengthens connection between keystone taxa and other bacteria, with 7.5 and 10% biochar amended composts has intense mutualistic symbiosis among bacterial communities.


Asunto(s)
Compostaje , Animales , Ovinos , Bacterias , Carbón Orgánico , Estiércol/microbiología , Suelo
16.
Chemosphere ; 332: 138882, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37164194

RESUMEN

Methylene blue (MB) and hexavalent chromium(Cr(VI)) are hazardous pollutants in textile waste and cannot be completely removed using conventional methods. So far, there have been no specific studies examining the synthesis and activity of N-TiO2/rGO as a photocatalyst for removing MB and Cr(VI) from textile wastewater. This work especially highlights the synthesis of N-TiO2/rGO as a photocatalyst which exhibits a wider range of light absorption and is highly effective for simultaneous removal of MB-Cr(VI) under visible light. Titanium tetrachloride (TiCl4) was used as the precursor for N-TiO2 synthesis using the sol-gel method. Graphite was oxidized using Hummer's method and reduced with hydrazine to produce rGO. N-TiO2/rGO was synthesized using a hydrothermal process and then analyzed using several characterization instruments. The X-ray diffraction pattern (XRD) showed that the anatase N-TiO2/rGO phase was detected at the diffraction peak of 2θ = 25.61. Scanning electron microscopy and transmission electron microscopy (SEM-EDS and TEM) dispersive X-ray spectrometry images show that N-TiO2 particles adhere to the surface of rGO with uniform size and N and Ti elements are present in the N-TiO2/rGO combined investigated. Gas absorption analysis data (GSA) shows that N-TiO2/rGO had a surface area of 77.449 m2/g, a pore volume of 0.335 cc/g, and a pore size of 8.655 nm. The thermogravimetric differential thermal analysis (TG-DTA) curve showed the anatase phase at 500-780 °C with a weight loss of 0.85%. The N-TiO2/rGO composite showed a good photocatalyst application. The photocatalytic activity of N-TiO2/rGO for textile wastewater treatment under visible light showed higher effectiveness than ultraviolet light, with 97.92% for MB and 97.48% for Cr(VI). Combining N-TiO2 with rGO is proven to increase the light coverage in the visible light region. Removal of MB and Cr(VI) can be carried out simultaneously and results in a removal efficiency of 95.96%.


Asunto(s)
Grafito , Grafito/química , Aguas Residuales , Óxidos/química , Titanio/química , Cromo/química , Catálisis
17.
Chemosphere ; 335: 138931, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37245596

RESUMEN

The current study evaluated the effectiveness of Tamarindus indica L. seed polysaccharides in removing fluoride from potable water collected from Sivakasi,Viruthunagar district, Tamil Nadu, India. The physiochemical properties of the water samples were examined, and each parameter was compared to the standard prescribed by Bureau of Indian standards. Most of the parameters were within the permissible limit except for fluoride levels in the Sivakasi water sample. Polysaccharides were isolated from Tamarindus indica L. seeds and the fluoride removal efficacy of the polysaccharides was evaluated. The optimum treatment dosage of the isolated seed polysaccharides was determined using aqueous fluoride solutions of various ppm concentrations (1, 2, 3, 4, and 5 ppm). Tamarindus polysaccharides were added to the aqueous solutions in varying doses (0.02, 0.04, 0.06, 0.08, 1.0, and 1.2 g), and 0.04 g was observed to be the most effective at removing fluoride (by 60%). It was selected as the optimum dose for treating the fluoride-contaminated water sample. Following the treatment, fluoride concentration in the water sample dropped from 1.8 mg/L to 0.91 mg/L, falling below the BIS standard limit. The findings from the study demonstrated the use of T. indica L. seed polysaccharides as an effective natural coagulant for removing fluoride from potable water. GC-MS and FTIR analysis of the isolated polysaccharide samples were performed. The FTIR results revealed the functional groups that might attribute to the fluoride removal activity of the isolated polysaccharides. The observations from the study suggested that Tamarindus polysaccharides might be used as an alternative to chemical agent used for fluoride removal in order to preserve the environment and human welfare.


Asunto(s)
Agua Potable , Tamarindus , Humanos , Fluoruros , India , Polisacáridos
18.
Int J Biol Macromol ; 239: 124467, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37068536

RESUMEN

Nanocellulose, a subset of nanomaterials made from cellulose, one of the world's most plentiful natural resources, has the potential to offer environmentally friendly, renewable, and sustainable building blocks with enhanced properties for a variety of applications in the nanotechnology field. This article describes the impact of glutaraldehyde (GA) on glycerol plasticized nanocellulose derived from I. coccinea L. plant root. Using a variety of characterization techniques, including Fourier Transform Infrared Spectroscopy (FTIR), X-ray Powder Diffraction (XRD), Scanning Electron Microscopy (SEM), AFM, tensile and Brunauer-Emmett-Teller (BET) analysis, the effect of GA on glycerol plasticized nano-cellulose was investigated. The tensile modulus of the GA-crosslinked, 2 % glycerol-plasticized nanocellulose scaffolds is higher (88.82 MPa) than that of the regular nanocellulose scaffolds (78.8 MPa). The scaffold Young's modulus has been increased to 86.3 MPa. The results of the BET study proved that the surface area of the GA crosslinked nano-cellulose scaffold improved to129.703 m2/g. The larger surface area in turn results in a greater number of contact sites between consecutive fibers. This enhances the utility of the scaffold as a bio-adsorbent for waste water treatment. The absorbance of textile black dye and methylene blue dye in sunlight using nanocellulose composites as photocatalyst revealed a significant decrease in dye concentration after each hour, demonstrating the composites' bio-adsorbent property. The non-toxic nature, inertness, increased crystallinity index values, and good mechanical qualities are other characteristics of the GA-treated nanocellulose encourages its uses as product packaging, bioengineering materials, tissue engineering, and insulation coatings.


Asunto(s)
Glicerol , Nanoestructuras , Nanoestructuras/química , Nanotecnología , Ingeniería de Tejidos , Difracción de Rayos X , Celulosa/química
19.
Mar Pollut Bull ; 189: 114766, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36870138

RESUMEN

The distribution of heavy metals in the seafood intake by various age group representatives around the Kalpakkam coastal region was part of the baseline study. Totally 40 different types of fish species were estimated on heavy metals (Cu, Cr, Co, Cd, Pb, Ni, Zn, and Mn) in the coastal zone; the average concentration of heavy metals were 0.71, 0.06, 0, 0, 0.07, 0.02, 1.06 and 0.36 ppm, respectively. Individual mean bioaccumulation index (IMBI) and Metal pollution index (MPI) with heavy metals distributed around the coastal zone were compared with fish tissue and were found to be higher for Zn and Cu. The human health risk was calculated using uncertainty modeling of risk assessment of Estimated daily intake (EDI), Maximum allowable consumption rate (CRlim), Target hazard quotient (THQ), and Hazard index (HI) were estimated for different age groups. Our present values were suggestively high (>1) for both kids and adults. The cumulative cancer risk assessment based on heavy metals and the Hospital-Based Cancer Registry (HBCR) compared to the region did not exceed the recommended threshold risk limit around the Kalpakkam coastal zone. Statistical analyses such as correlation, Principal component, and Cluster investigation ensure that heavy metal concentrations do not pose a major risk to occupants.


Asunto(s)
Metales Pesados , Neoplasias , Adulto , Animales , Humanos , Bahías , Metales Pesados/análisis , Peces , Medición de Riesgo , Alimentos Marinos/análisis , Monitoreo del Ambiente
20.
Environ Res ; 227: 115716, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-36940816

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) are considered a major class of organic contaminants or pollutants, which are poisonous, mutagenic, genotoxic, and/or carcinogenic. Due to their ubiquitous occurrence and recalcitrance, PAHs-related pollution possesses significant public health and environmental concerns. Increasing the understanding of PAHs' negative impacts on ecosystems and human health has encouraged more researchers to focus on eliminating these pollutants from the environment. Nutrients available in the aqueous phase, the amount and type of microbes in the culture, and the PAHs' nature and molecular characteristics are the common factors influencing the microbial breakdown of PAHs. In recent decades, microbial community analyses, biochemical pathways, enzyme systems, gene organization, and genetic regulation related to PAH degradation have been intensively researched. Although xenobiotic-degrading microbes have a lot of potential for restoring the damaged ecosystems in a cost-effective and efficient manner, their role and strength to eliminate the refractory PAH compounds using innovative technologies are still to be explored. Recent analytical biochemistry and genetically engineered technologies have aided in improving the effectiveness of PAHs' breakdown by microorganisms, creating and developing advanced bioremediation techniques. Optimizing the key characteristics like the adsorption, bioavailability, and mass transfer of PAH boosts the microorganisms' bioremediation performance, especially in the natural aquatic water bodies. This review's primary goal is to provide an understanding of recent information about how PAHs are degraded and/or transformed in the aquatic environment by halophilic archaea, bacteria, algae, and fungi. Furthermore, the removal mechanisms of PAH in the marine/aquatic environment are discussed in terms of the recent systemic advancements in microbial degradation methodologies. The review outputs would assist in facilitating the development of new insights into PAH bioremediation.


Asunto(s)
Contaminantes Ambientales , Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , Humanos , Biodegradación Ambiental , Ecosistema , Agua , Contaminantes Ambientales/metabolismo , Hidrocarburos Policíclicos Aromáticos/metabolismo , Contaminantes del Suelo/análisis
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