The current study presents a novel approach for the removal of Ni(II) from aqueous environments using plant gum-based (PG) and clay-based (CL) nanobiocomposite (NBC) composed of ZnO nanoparticles and chitosan. Parameters like pH, contact time, temperature, initial metal concentration and adsorbent dosage were optimized. Under optimized conditions, maximum removal of Ni(II) was noted as 90.1{\%} and 95.5{\%} in the case of PG-NBC and CL-NBC, respectively. Equilibrium studies suggested a homogeneous mode of adsorption. Good linearity was observed for the pseudo-first order kinetic model, suggesting a physical mode of adsorption. Thermodynamic studies showed an endothermic and spontaneous nature of adsorption. The mechanism was further elucidated using SEM, EDX, AFM and FT-IR analysis. Ex-situ studies showed a maximum Ni(II) removal of 87.34{\%} from electroplating wastewater using CL-NBC in column mode. Regeneration studies suggested that CL-NBC could be consistently reused up to 4 cycles.

Nilanjana Mitra

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Vellore Campus

Varghese L.R

Das 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

Korean Journal of Chemical Engineering

The present study investigates the enhanced removal of total dissolved solids (TDS) from tap water in Vellore using bead and membrane form of nanobiocomposite (CNTs, gum Arabic and chitosan), previously cyclodextrinated, sulfonated and aminated. The potential of beads and membranes was individually exploited in terms of pH, dosage, dilutions and time. Among various pretreated materials, the aminated form of both bead and membrane exhibited the maximum TDS removal efficiency followed by the sulfonated and cyclodextrinated form at pH6.0, dosage value 6.0g/L and time 6h under optimum condition. The materials were characterized in terms of their BET surface area (aminated (198cm2/g){\textgreater}sulfonated (145.6cm2/g){\textgreater}cyclodextrinated (102.3cm2/g){\textgreater}control (78.0cm2/g)). Packed bed column studies were conducted at varying dosages of bead, membrane and sophorolipid and flow rates. A 3-level Box-Behnken design was used to validate the model significance. Equilibrium and kinetic studies were conducted to determine the mode of adsorption and rate of the process. To elucidate the mechanism of the process, spectroscopic analysis using SEM-EDX and FT-IR was done. Regeneration cycles were performed which showed that the novel duo could be successfully regenerated up to 10cycles/day with an effective treatment of 8L of tap water.

Desalination

Enhanced TDS removal using cyclodextrinated, sulfonated and aminated forms of bead–membrane duo nanobiocomposite via sophorolipid mediated complexation

The present investigation attempts to recover lanthanum(III) from aqueous environments using biosorbents of animal (fish scales) and plant origin (neem saw dust). Optimization experiments were carried out using a log transformed 5-level Box-Behnken design. Maximum La(III) uptake was noted to be 200.0 mg/g in the case of fish scales (FS) and 160.2 mg/g in the case of neem sawdust (NS) under optimum conditions (pH: 6.0, biomass dosage: 0.3 g/L; 0.2 g/L, initial metal concentration: 300 mg/L; 250 mg/L, temperature: 50 °C, time: 4 h; 3 h). A low p-value of {\textless}0.0001 validated the significance of the model. The process was found to follow a homogeneous chemical mode in the case of FS whereas heterogeneity and physisorption was noted in the case of NS. This was further confirmed by scanning electron microscopy (SEM). High uptake values in the case of FS could be attributed to the involvement of both intraparticle and film diffusion. Thermodynamic studies showed that the process is endothermic and spontaneous in the case of both the adsorbents. FTIR analysis confirmed a major involvement of the participation of amide, amines, alkines, aliphatic compounds and alkyl groups during La(III) biosorption. Maximum adsorption efficiency and recovery of La(II) from ceramic industrial effluent using FS were noted as 88.5{\%} and 84.6{\%} which were obtained in column mode at a flow rate of 1 ml/min, bed height of 12 cm and 0{\%} dilution. Regeneration studies suggested that the biosorbent FS could be consistently reused up to 6 cycles. {\textcopyright} 2014 Elsevier Ltd. All rights reserved.

Minerals Engineering

Recovery of lanthanum(III) from aqueous solution using biosorbents of plant and animal origin: Batch and column studies

The present study was carried out using dead biomass of isolated yeast species viz. Candida rugosa and Candida laurentii as biosorbents for the removal of Zn(II) from aqueous environment. C. rugosa and C. laurentii exhibited 65.4{\%} and 54.8{\%} removal of zinc at pH 6.0 in presence of 90mgL -1 Zn(II) at 30°C in batch system. Remarkable increase in Zn(II) removal was noted using dead yeast biomass treated with anionic surfactant sodium dodecyl sulphate (SDS) which was confirmed through SEM analysis. Kinetic studies based on various models were carried out and the results showed a very good compliance with the fractional power model. The experimental data were analyzed using two, three and four parameter isotherm models. The most appropriate equation for describing the isotherm profile was Freundlich model. The biosorbent performance was evaluated in column mode packed with SDS treated dead biomass of C. rugosa entrapped in sodium alginate beads. FT-IR analysis showed the involvement of -NH, -CO and -COOH functional groups in the binding of Zn(II) by yeast. The present study confirmed that immobilized SDS treated dead biomass of C. rugosa may serve as potential and eco-friendly biosorbent for removal of Zn(II) ions from aqueous solution. {\textcopyright} 2012 Elsevier B.V.

Biochemical Engineering Journal

Kinetics and equilibrium studies on removal of zinc(II) by untreated and anionic surfactant treated dead biomass of yeast: Batch and column mode

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.

Packed bed column studies for the removal of synthetic dyes from textile wastewater using immobilised dead C. tropicalis

The removal of Cr (VI) from tannery wastewater by neem sawdust was investigated in a fixed bed column. The experiments were conducted to study the effect of important parameters such as bed depth (5-15 cm) and flow rate (5-15 ml min-1). The bed depth service time model (BDST) fit well with the experimental data. The adsorption capacity estimated from the BDST model was 33,009.9 mg g-1. The column was regenerated by eluting chromium (VI) using 2 N NaOH after adsorption studies. The desorption of Cr (VI) failed to reach 100{\%} in each cycle because some amount of adsorbed Cr (VI) got reduced to Cr (III) in the biosorbent surface and released into the aqueous phase. The effect of co-ions on adsorption of Cr (VI) was studied in column mode, where the breakthrough and the exhaustion time of the column decreased in the presence of co-ions. In the three cycles of biosorption, about 3.75 L of tannery effluent were treated to reach the chromium (VI) standard (0.1 mg L-1) established by the Central Pollution Control Board (CPCB). Neem sawdust proved to be the potential biosorbent for the removal of Cr (VI) from tannery effluents. {\textcopyright} 2010 Elsevier B.V.

Journal	Data powered by TypesetKorean Journal of Chemical Engineering
Publisher	Data powered by TypesetSpringer Science and Business Media LLC
ISSN	0256-1115
Open Access	0