Now a day's biosorbents with magnetic properties have been applied for water and wastewater treatment process, because of its magnetic nature it can be easily separated and can be reused more than ...one time. In the present study, two magnetic biosorbents were synthesized from waste biomass of Citrus limetta (peel and pulp) at 500 °C temperature represented as PAC-500 and PPAC-500. These biosorbents were effectively used for the removal of As(III) and As(V) from an aqueous solution and groundwater samples. The prepared biosorbents were characterized by using Brunauer Emmett Teller (BET), Zeta potential, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Disperssive X-ray (EDS), X-ray Diffraction (XRD) and Particle Size Analyzer (PSA). Isotherms, kinetics and thermodynamics were also applied to the obtained experimental data. The regeneration study revealed that the biosorbent can be recycled up to four cycles. The adsorbent capacity of PAC-500 and PPAC-500 for the sorption of As(III) was 714.28 μg/g and 526.31 μg/g, respectively, whereas the qmax value for As(V) sorption was 2000 μg/g for both the biosorbents (PAC-500 and PPAC-500). The effect of competitive ions was also studied that shows that the presence of H2PO4− and CO32 have negative effects on the sorption of As(III) and As(V). Arsenic is very toxic and it is a more important subject for consideration, therefore it is necessary to develop a low cost material that is very efficient in removing As from ground water contaminated with As water.
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•Activated carbon was prepared from Citrus limmeta waste (Peel and Pulp) at 500 °C.•PAC-500 removed As(III) and As(V) up to 100% at concentration of 0.5 mg/L.•The Maximum adsorption capacities of As(III and V) were found 0.714 and 0.2 mg/g.•Removal of As(III) from ground water by PAC-500 was found under permissible limit.•Phosphate and carbonate ions have negatively impact on removal of Arsenic (III and V).
In the growing polymer industry, the interest of researchers is captivated by bioplastics production with biodegradable and biocompatible properties. This study examines the polyhydroxyalkanoates ...(PHA) production performance of individual
sp. RGS and
ATCC 17699 and their co-culture by utilizing sugarcane bagasse (SCB) hydrolysates. Initially, acidic (H
SO
) and acidified sodium chlorite pretreatment was employed for the hydrolysis of SCB. The effects of chemical pretreatment on the SCB biomass assembly and its chemical constituents were studied by employing numerous analytical methods. Acidic pretreatment under optimal conditions showed effective delignification (60%) of the SCB biomass, leading to a maximum hydrolysis yield of 74.9 ± 1.65% and a saccharification yield of 569.0 ± 5.65 mg/g of SCB after enzymatic hydrolysis. The resulting SCB enzymatic hydrolysates were harnessed for PHA synthesis using individual microbial culture and their defined co-culture. Co-culture strategy was found to be effective in sugar assimilation, bacterial growth, and PHA production kinetic parameters relative to the individual strains. Furthermore, the effects of increasing acid pretreated SCB hydrolysates (20, 30, and 40 g/L) on cell density and PHA synthesis were studied. The effects of different cost-effective nutrient supplements and volatile fatty acids (VFAs) with acid pretreated SCB hydrolysates on cell growth and PHA production were studied. By employing optimal conditions and supplementation of corn steep liquor (CSL) and spent coffee waste extracted oil (SCGO), the co-culture produced maximum cell growth (DCW: 11.68 and 11.0 g/L), PHA accumulation (76% and 76%), and PHA titer (8.87 and 8.36 g/L), respectively. The findings collectively suggest that the development of a microbial co-culture strategy is a promising route for the efficient production of high-value bioplastics using different agricultural waste biomass.
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•Green synthesis of TiO2 NPs in a one-step using leaf extract of Jatropha curcas.•Characterization of TiO2 NPs by UV–Vis, SEM-EDS, XRD, FTIR, DLS and BET analysis.•Spherical shaped ...anatase TiO2 NPs with various structural and optical properties.•TiO2 NPs first applied in TWW treatment with COD (82.26%) and Cr (76.48%) removal.•TiO2 NPs demonstrated the astounding potential for the in-situ remediation of TWW.
Green synthesis is a simple, eco-friendly and emerging approach of synthesizing nanoparticles (NPs) and currently, attracting scientific community from around the world. The objective of the present study was to synthesize green titanium dioxide (TiO2) NPs and evaluate its performance for the photocatalytic treatment of TWW after the secondary (biological) treatment process. TiO2 NPs was synthesized using leaf extract of the biodiesel plant, Jatropha curcas L. in a one-step at room temperature to examine its treatability for tannery wastewater (TWW). Moreover, the green synthesized TiO2 NPs was further characterized by UV–Visible spectrophotometer, Field Emission Scanning Electron Microscopy (FESEM), X-ray Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), Dynamic Light Scattering (DLS), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) analysis. Results confirmed the synthesis and anatase phase of the spherical TiO2 NPs and also unfold the presence of phytochemicals in leaf extract, which might involve in the capping/stabilization of NPs. Further, the green synthesized TiO2 NPs was applied for the first time to testify its potential for the simultaneous removal of chemical oxygen demand (COD) and chromium (Cr) from secondary treated TWW. During the photocatalytic treatment of wastewater in a self-designed and fabricated Parabolic Trough Reactor (PTR), 82.26% removal of COD and 76.48% removal of Cr from TWW was achieved upon the treatment with green synthesize TiO2 NPs, and thus, successfully employed for the wastewater treatment. Overall, the green synthesized TiO2 NPs demonstrated the astounding potential for the in-situ treatment of TWW as an alternative clean-green treatment solution.
This study explored the potential of abundantly available sodium lignosulfonate (LS) as a reducer and fabricating agent in preparing silver nanoparticles (LS-Ag NPs). The operational conditions were ...optimized to make the synthesis process simpler, rapid, and eco-friendly. The prepared LS-Ag NPs were analyzed via UV-Vis spectroscopy, X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, and high-resolution transmission electron microscopy. Results demonstrated that LS-Ag NPs were of crystalline structure, capped with LS constituents, and spherical in shape with a size of approximately 20 nm. Under optimized conditions, LS-Ag NPs exhibited significant photocatalytic activity in Reactive Yellow 4G degradation. The effects of photocatalyst (LS-Ag NPs) dosage, dye concentration, and its reusability for dye degradation were studied to make the process practically applicable in textile wastewater treatment. Additionally, the synthesized LS-Ag NPs displayed significant free radical scavenging against 2-diphenyl-1-picrylhydrazyl (DPPH) with an IC
value of (50.2 ± 0.70 µg/mL) and also exhibited antidiabetic activity in terms of inhibition in the activity of carbohydrate-degrading marker enzyme α-glucosidase with an IC
value of (58.1 ± 0.65 µg/mL). LS-Ag NPs showed substantial antibacterial potential against pathogenic strains, namely
and
. In conclusion, LS-Ag NPs can be a reliable and eco-friendly material for their possible application in the treatment of dye-containing wastewater and have a great perspective in the biomedical and pharmaceutical sectors.
Leather industries are key contributors in the economy of many developing countries, but unfortunately they are facing serious challenges from the public and governments due to the associated ...environmental pollution. There is a public outcry against the industry due to the discharge of potentially toxic wastewater having alkaline pH, dark brown colour, unpleasant odour, high biological and chemical oxygen demand, total dissolved solids and a mixture of organic and inorganic pollutants. Various environment protection agencies have prioritized several chemicals as hazardous and restricted their use in leather processing however; many of these chemicals are used and discharged in wastewater. Therefore, it is imperative to adequately treat/detoxify the tannery wastewater for environmental safety. This paper provides a detail review on the environmental pollution and toxicity profile of tannery wastewater and chemicals. Furthermore, the status and advances in the existing treatment approaches used for the treatment and/or detoxification of tannery wastewater at both laboratory and pilot/industrial scale have been reviewed. In addition, the emerging treatment approaches alone or in combination with biological treatment approaches have also been considered. Moreover, the limitations of existing and emerging treatment approaches have been summarized and potential areas for further investigations have been discussed. In addition, the clean technologies for waste minimization, control and management are also discussed. Finally, the international legislation scenario on discharge limits for tannery wastewater and chemicals has also been discussed country wise with discharge standards for pollution prevention due to tannery wastewater.
Global energy consumption has been increasing in tandem with economic growth motivating researchers to focus on renewable energy sources. Dark fermentative hydrogen synthesis utilizing various ...biomass resources is a promising, less costly, and less energy-intensive bioprocess relative to other biohydrogen production routes. The generated acidogenic dark fermentative effluent e.g., volatile fatty acids (VFAs) has potential as a reliable and sustainable carbon substrate for polyhydroxyalkanoate (PHA) synthesis. PHA, an important alternative to petrochemical based polymers has attracted interest recently, owing to its biodegradability and biocompatibility. This review illustrates methods for the conversion of acidogenic effluents (VFAs), such as acetate, butyrate, propionate, lactate, valerate, and mixtures of VFAs, into the value-added compound PHA. In addition, the review provides a comprehensive update on research progress of VFAs to PHA conversion and related enhancement techniques including optimization of operational parameters, fermentation strategies, and genetic engineering approaches. Finally, potential bottlenecks and future directions for the conversion of VFAs to PHA are outlined. This review offers insights to researchers on an integrated biorefinery route for sustainable and cost-effective bioplastics production.
•Review of brewery wastewater treatment for biogas generation and energy production.•Production of sustainable energy from anaerobic digestion.•Biogas is a promising technology as a substitute for ...fossil fuels.•Brazil has a high potential for biogas production.
Brazil is the third largest beer producer in the world and has several brewing industries. These industries cover a range of production processes due to their wide variety of beverages, which leads to the generation of effluents with different physicochemical characteristics. Furthermore, these residues are usually disposed of without any treatment despite having enormous potential for biogas and bioenergy production. Biorefinery is a relevant alternative to the transition from a linear economy to a Circular Economy (CE). The Biorefinery exploits all available resources in the production of goods and contributes to sustainable development in the face of industrial production. In this context, as an alternative solution, anaerobic digestion (AD) has been commonly used as it uses different biomass sources to satisfy current energy demands. AD can be implemented to treat brewing effluent, promote its energy recovery, reduce environmental pollution, and produce environmentally friendly biological products: biogas and biofertilizer. Thus, this review explored the potential of AD for brewery waste management in association with the bio-based CE. Overall, the current manuscript emphasized the potential of brewery waste for biogas generation and energy production, discussing its adoption and challenges.
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•Vinasse degradation and laccase production by Pleurotus sajor-caju were performed;•Laccase activity induction by copper sulfate and ethanol in raw vinasse as substrate was ...confirmed;•Fermentation time to maximum laccase activity was reduced to just 3 days when cooper sulfate was used as inducer;•The use of laccase inducers does not interfere with decolorization and turbidity removal;•Aqueous two-phase systems reached 2.88-fold in laccase purification, with recovery of ∼ 99.9% to upper phase (PEG-rich phase).
This study evaluated simultaneously the raw vinasse degradation, an effluent from the sugar-alcohol industry, the laccase production by Pleurotus sajor-caju and its purification using aqueous two-phase systems (ATPS). To improve laccase production, different concentrations of inducers (ethanol and CuSO4) were added. The higher laccase production promoted an increase of 4-fold using 0.4 mM of CuSO4 as inducer, with maximum enzymatic activity of 539.3 U/L on the 3rd day of fermentation. The final treated vinasse had a decolorization of 92% and turbidity removal of 99% using CuSO4. Moreover, the produced laccase was then purified by ATPS in a single purification step, reaching 2.9-fold and recovered ≈ 99,9 %, in the top phase (PEG-rich phase) using 12 wt% of PEG 1500 + 20 wt% of citrate buffer + enzyme broth + water, at 25 °C. Thus, an integrated process of vinasse degradation, laccase production and purification with potential industrial application was proposed.
In this study, the efficiency of free and immobilized cells of newly isolated hexavalent chromium Cr(VI) reducing Bacillus cereus strain Cr1 (accession no. KJ162160) was studied in the treatment of ...tannery effluent. The analysis of effluents revealed high chemical oxygen demand (COD-1260 mg/L), biological oxygen demand (BOD5-660 mg/L), total dissolved solids (TDS-14000 mg/L), electrical conductivity (EC-21.5 mS/cm) and total chromium (TC-2.4 mg/L). The effluents also showed genotoxic effects to Allium cepa. Treatment of tannery effluent with isolated B. cereus strain led to considerable reduction of pollutant load. The pollutant load reduction was studied with both immobilized and free cells and immobilized cells were more effective in reducing COD (65%), BOD (80%), TDS (67%), EC (65%) and TC (92%) after 48 h. GC-MS analysis of pre and post-treatment tannery effluent samples revealed reduction of organic load after treatment with free and immobilized cells. An improvement in mitotic index and reduction in chromosomal aberrations was also observed in A. cepa grown with post-treatement effluent samples compared to untreated sample. Results demonstrate that both methods of bacterial treatment (free and immobilized) were efficient in reducing the pollutant load of tannery effluent as well as in reducing genotoxic effects, however, treatment with immobilized cells was more effective.
•Novel chromium (VI)-reducing Bacillus cereus strain Cr1was isolated.•Bacterial treatment of effluent led to noticeable reduction in pollutant load.•Allium cepa bioassay showed reduced genotoxicity of treated effluent.
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