An efficient dye biosorbent was developed for the treatment of textile wastewater by entrapping dead cells of C. tropicalis, within sodium alginate matrix. The biosorbent performance was evaluated in packed bed column with different pH (3 to 6), wastewater strength (25{\%}, 50{\%} 75{\%}), bed height (5cm-15cm) and flow rate (0.5mLmin -1 to 1mLmin -1). pH 5, undiluted wastewater, bed height 15cm and flow rate 0.5mLmin -1 were found to be optimum for dye biosorption. The linearized form of the modified Thomas model equation fitted well with the experimental data and described the dynamic adsorption of synthetic dyes from textile wastewater. The Bed depth service time model was used to express the effect of bed height on breakthrough curves. Dye laden immobilised dead C. tropicalis was regenerated using 0.01molL -1 NaOH at an elutant flow rate of 1mLmin -1. The reusability of the immobilised biomass was tested in consecutive adsorption-desorption cycles. The FT-IR spectral analysis showed the involvement of amine, hydroxyl, carbonyl, amide and phosphoryl groups in biosorption of dyes from wastewater. The analysis of treated samples showed almost zero colour and a significant decrease in Total Dissolved Solids (TDS). {\textcopyright} 2011 Elsevier B.V.

Nilanjana Mitra

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Vellore Campus

Charumathi D

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Desalination

In this study, FeNi nanoparticles were green synthesized using Punica granatum (pomegranate) peel extract, and these nanoparticles were also formed in situ over quartz sand (GS-FeNi) for removal of tetracycline (TC). Under the optimized operating conditions, (GS-FeNi concentration: 1.5% w/v; concentration of TC: 20 mg/L; interaction period: 180 min), 99±0.2% TC removal was achieved in the batch reactor. The removal capacity was 181±1 mg/g. A detailed characterization of the sorbent and the solution before and after the interaction revealed that the removal mechanism(s) involved both the sorption and degradation of TC. The reusability of reactant was assessed for four cycles of operation, and 77±4% of TC removal was obtained in the cycle. To judge the environmental sustainability of the process, residual toxicity assay of the interacted TC solution was performed with indicator bacteria (Bacillus and Pseudomonas) and algae (Chlorella sp.), which confirmed a substantial decrease in the toxicity. The continuous column studies were undertaken in the packed bed reactors using GS-FeNi. Employing the optimized conditions, quite high removal efficiency (978±5 mg/g) was obtained in the columns. The application of GS-FeNi for antibiotic removal was further evaluated in lake water, tap water, and ground water spiked with TC, and the removal capacity achieved was found to be 781±5, 712±5, and 687±3 mg/g, respectively. This work can pave the way for treatment of antibiotics and other pollutants in the reactors using novel green composites prepared from fruit wastes. [Figure not available: see fulltext.]. © 2019, Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature.

Fulltext

Frontiers of Environmental Science & Engineering

In situ formation of bimetallic FeNi nanoparticles on sand through green technology: Application for tetracycline removal

Protein-functionalised aluminium nanosheets (PRS–AlNs) were packed in a continuous fixed-bed column to remove crystal violet (CV) and Congo red (CR) dyes. A group of characterisation techniques, like SEM, TEM, AFM, XRD, BET, DSC and Raman spectroscopy, was performed for PRS–AlNs. The influence of several factors like bed depth (1, 2 and 3 cm), inlet dye concentration (50, 100 and 150 mg/L) and inlet flow rate (1.17, 2.26 and 3.34 mL/min) on the characteristics of the breakthrough profile of the adsorption process was examined at optimum pH 9.8 and 3.5 for CV and CR, respectively. The maximum adsorption capacity was achieved as 38.70 and 57.86 mg/g for CV and CR at 1 cm bed depth, 150 mg/L inlet concentration of the dye and 3.34 mL/min inlet rate of flow. The experimental data were analysed using kinetic models like the Yoon–Nelson, Adams–Bohart and Thomas models. Also, a detailed mechanism behind the CV and CR adsorption using PRS–AlNs was proposed in this research work. [Figure not available: see fulltext.]. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

Environmental Science and Pollution Research

Application of protein-functionalised aluminium nanosheets synthesised from sewage sludge for dye removal in a fixed-bed column: Investigation on design parameters and kinetic models

The occurrence of various antibiotics in natural waters poses an emerging environmental concern. Tetracycline (TC) is a frequently used antibiotic in human therapy, veterinary industry, and agricultural sectors. In the current study, TC removal from aqueous solutions was studied using binary Nickel/nano zero valent iron particles (NiFe nano particles) and in-situ NiFe nanoparticles coated sand (IS-NiFe). Removal of TC using bimetallic NiFe particles was optimized with help of response surface methodology (RSM). Using the optimized parameters (concentration of TC: 20 mg/L; NiFe dose: 120 mg/L; time of interaction: 90 min), 99.43 ± 0.98% removal of TC was noted. Further, IS-NiFe was packed in the column reactors and effects of different parameters like flow rate (1–3 mL/min), bed height (3–10 cm) and inlet TC concentration (20–60 mg/L) on breakthrough characteristics were examined. Under the optimized conditions the removal capacity in the column reactor was 1198 ± 40.2 mg/g using IS-NiFe. The column kinetic data were successfully fitted with Adams- Bohart and Thomas models. TC removal efficiency of IS-NiFe in column reactors was tested with TC (20 mg/L) spiked lake water, ground water, and tap water and the removal capacity was noted to be 698.55 ± 11.21, 764.17 ± 6.78, and 801.7 ± 13.26 mg/g respectively. © 2019 Elsevier Ltd

Journal of Environmental Management

Enhanced tetracycline removal by in-situ NiFe nanoparticles coated sand in column reactor

Sixty days of continuous flow column study was carried out to investigate the removal of Cr(VI) using NZVI immobilized in alginate beads (NZVI beads) and bacterial consortium immobilized alginate beads (bio beads) in a sequence process. Initially continuous flow study in glass column was done to set the parameter for the pilot scale studies. Under the optimized conditions, Cr(VI) removal by NZVI beads, bio beads and sequential removal process showed 79 ± 6.22%, 51 ± 4.23 and 96 ± 3.9% removal percentage and 177 ± 5.0, 224 ± 8.16, and 421 ± 10.14 mg/g removal capacity respectively. The current study determines the influences of NZVI immobilized beads and bio beads for the Cr(VI) removal in contaminated groundwater. The process applicability using both the NZVI beads and bio beads was successfully analysed with Cr(VI) spiked groundwater sample. The process of Cr(VI) removal was determined using SEM–EDX, FTIR and mathematical models.

Environmental Technology & Innovation

Removal of hexavalent chromium using nano zero valent iron and bacterial consortium immobilized alginate beads in a continuous flow reactor

Increasing pesticide application and improper wastewater disposal methods contaminate water resources and severely affect the ecology as well as environment. The present study is focused on the adsorption coupled photocatalytic degradation of dichlorvos using UV light in presence of LaNiMnO6perovskite nanoparticles (Prv) supported on polypropylene filter cloth (PPPrv) and carboxymethyl cellulose (CMCPrv) microspheres. The synthesized LaNiMnO6perovskite nanoparticles were characterized by XRD, FT-IR, SEM and EDX. The adsorption percentage of DCV followed the order: CMCPrv (62.7{\%}) {\textgreater} PPPrv (46.1{\%}) {\textgreater} Prv (32.6{\%}). Equilibrium studies suggested the heterogenous mode of adsorption. Pseudo-first order exhibited the good linearity indicating the involvement of physical forces. Thermodynamics showed an endothermic and spontaneous nature of adsorption. The influences of various photocatalytic parameters viz., pH, irradiation time, initial DCV concentration, Prv loading and catalyst dosage on DCV degradation were investigated. Ex situ studies conducted for 8 h of sunlight exposure showed complete degradation of DCV present in industrial wastewater which was confirmed by GC-MS analysis. The advantage of CMCPrv as supported catalyst is the easy separation and reuse for four cycles. The present work is the first report that signifies the potential efficacy of CMCPrv to serve as an effective remedial agent for DCV removal from contaminated water. {\textcopyright} 2016 American Institute of Chemical Engineers Environ Prog, 36: 180–191, 2017.

Environmental Progress & Sustainable Energy

Adsorption coupled photocatalytic degradation of dichlorvos using LaNiMnO6perovskite nanoparticles supported on polypropylene filter cloth and carboxymethyl cellulose microspheres

Single and binary effects of dye Basic Violet 3 and heavy metals, 'namely', Pb(II) and Cd(II), were investigated for their role in dye and heavy metal bioaccumulation by Candida tropicalis that was grown in a sugarcane bagasse extract medium containing 8g/L, 16g/L or 24g/L of sugar. The optimum pH was found to be 4.0 in the single system and 5.0 in the binary system. A central composite design was successfully used to analyse the experimental results. Four numerical correlations that were fitted to a second order quadratic equation were used to estimate optimum combinations predicted by response surface methodology. In the dye-Pb(II) binary system, C. tropicalis was capable of bioaccumulating 49.5{\%} of the dye and 49.6{\%} of the Pb(II), in comparison to 15.9{\%} of the dye and 55.5{\%} of the Cd(II) in the dye-Cd(II) binary system. In these two systems, the pollutants were dispersed at minimum working concentration levels. Competitive inhibition was observed in both the single and binary systems, which was suggested by an increase in the saturation constant, Ks and a simultaneous decrease in the specific growth rate that was calculated from Lineweaver-Burk plots. Atomic force microscopy images demonstrated changes in yeast cell morphology by exposure to these contaminants in the dye-Pb(II) binary system grown in a bioaccumulation medium. {\textcopyright} 2010 Elsevier B.V.

Journal of Hazardous Materials

Bioaccumulation of the synthetic dye Basic Violet 3 and heavy metals in single and binary systems by Candida tropicalis grown in a sugarcane bagasse extract medium: Modelling optimal conditions using response surface methodology (RSM) and inhibition kinetics

Journal	Data powered by TypesetDesalination
Publisher	Data powered by TypesetElsevier BV
ISSN	0011-9164
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