A review on the adsorption of heavy metals by clay minerals, with special focus on the past decade

The biosorption process has been established as characteristics of dead biomasses of both cellulosic and microbial origin to bind metal ion pollutants from aqueous suspension. The high effectiveness of this process even at low metal concentration, similarity to ion exchange treatment process, but cheaper and greener alternative to conventional techniques have resulted in a mature biosorption technology. Yet its adoption to large scale industrial wastewaters treatment has still been a distant reality. The purpose of this review is to make in-depth analyses of the various aspects of the biosorption technology, staring from the various biosorbents used till date and the various factors affecting the process. The design of better biosorbents for improving their physico-chemical features as well as enhancing their biosorption characteristics has been discussed. Better economic value of the biosorption technology is related to the repeated reuse of the biosorbent with minimum loss of efficiency. In this context desorption of the metal pollutants as well as regeneration of the biosorbent has been discussed in detail. Various inhibitions including the multi mechanistic role of the biosorption technology has been identified which have played a contributory role to its non-commercialization.

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Bioadsorbents for remediation of heavy metals: Current status and their future prospects

Microorganism remediation strategies towards heavy metals.

Preparation of amine functionalized carbon nanotubes via a bioinspired strategy and their application in Cu2+ removal

Mussel-inspired fabrication of functional materials and their environmental applications: Progress and prospects

Adsorption of heavy metal ions from aqueous solutions by amine and carboxylate functionalised bentonites

An investigation into the adsorption of thorium(IV) from aqueous solutions by a carboxylate-functionalised graft copolymer derived from titanium dioxide-densified cellulose.

This paper describes the adsorption properties of Cu(II) ions from aqueous media by 4-ethyl thiosemicarbazide (ETSC) intercalated organophilic calcined hydrotalcite (OHTC). Elemental analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric–differential thermogravimetric (TG/DTG) studies have helped in characterizing the adsorbent. The effects of various factors like adsorbent dose, pH, initial concentration, and contact time were studied. The pH study indicated that Cu(II) has a good adsorption potential at pH 5.5. The adsorption of metal ion remained constant after 4 h. The pseudo-second-order model was the best fit to describe the adsorption kinetics. The FTIR spectroscopy revealed that both amino and thiocarbonyl groups in ETSC–OHTC are responsible for Cu(II) removal. The Freundlich model described the adsorption results very well, and the KF value was found to be 21.38 at 303 K. Electroplating industry wastewater was u...

Adsorptive Removal of Cu(II) Ions from Aqueous Media onto 4-Ethyl Thiosemicarbazide Intercalated Organophilic Calcined Hydrotalcite

The aim of this work is to evaluate the adsorption performance of a carboxylate-functionalized graft copolymer of TiO2-densified cellulose (PGTDC-COOH) for copper ions removal from aqueous solutions and industrial effluents. The chemical modification was confirmed by infrared spectroscopy and X-ray diffraction. The adsorption experiments were conducted in a batch adsorption technique. The influence of different experimental parameters such as pH, contact time, adsorbent dose, and Cu(II) concentration was investigated. The optimum pH for Cu(II) adsorption was observed at pH 5.0 and the equilibrium was reached in 1 h. Kinetic data was analyzed using pseudo-first-order and pseudo-second-order equations and showed better fit with pseudo-second-order equation. The equilibrium isotherm data correspond to the Langmuir model. The maximum binding capacity, Q 0 was found to be 75.82 mg L−1 with binding constant, b = 0.036 L mg−1 at 30°C and pH 5.0. Utility of the adsorbent was tested by removing Cu(II) from electro...

Preparation of poly(methacrylic acid)-grafted TiO2-densified cellulose as an adsorbent for the removal of copper(II) ions from aqueous solutions and industrial effluents

S.S. Sreekumari

Papers

Adsorption of heavy metal ions from aqueous solutions by amine and carboxylate functionalised bentonites

An investigation into the adsorption of thorium(IV) from aqueous solutions by a carboxylate-functionalised graft copolymer derived from titanium dioxide-densified cellulose.

Adsorptive Removal of Cu(II) Ions from Aqueous Media onto 4-Ethyl Thiosemicarbazide Intercalated Organophilic Calcined Hydrotalcite

Preparation of poly(methacrylic acid)-grafted TiO2-densified cellulose as an adsorbent for the removal of copper(II) ions from aqueous solutions and industrial effluents