Optimization of process using carboxymethyl chitosan for the removal of mixed heavy metals from aqueous streams

• Published in: International journal of biological macromolecules 2020-04, Vol.149, p.404-416
• Main Authors: Kavitha, Edward, Kedia, Ritika, Babaria, Nikhil, Prabhakar, Sivaraman, Rajesh, Mathur P.
• Format: Article
• Language: English
• Subjects: Cadmium - chemistry; Cadmium - isolation & purification; Chitosan; Chitosan - analogs & derivatives; Chitosan - chemistry; Copper - chemistry; Copper - isolation & purification; Heavy metals; Humans; Metals, Heavy - chemistry; Metals, Heavy - isolation & purification; Nickel - chemistry; Nickel - isolation & purification; Recovery of heavy metals; Response surface methodology; Ultrafiltration; Waste Disposal, Fluid; Waste Water; Water - chemistry; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; Water Purification - methods; Zinc - chemistry; Zinc - isolation & purification
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.01.066

This paper highlights the efficacy of carboxymethyl chitosan (CMCh), a bio-degradable water-soluble derivative of chitosan for the separation of a mixture of heavy metal ions such as copper, nickel, zinc and lead from aqueous streams, as they constitute, the major industrial pollutants present in wastewater. The experimental studies are conducted using commercially available ultrafiltration module using synthetic solutions of the contaminants. The design of experiments was performed by Response Surface Methodology (RSM) with split-plot D-optimal design. Parametric studies were carried out using initial pH of the feed solution, loading ratio (P/M) and initial metal ion concentration to assess the percentage rejection and recovery of metal ions. The maximum percentage rejection of Cu(II), Ni(II), Zn(II) and Pb(II) with CMCh were found to be 100%, 100%, 95%, and 98% respectively under optimum conditions. Subsequently the metal ions were recovered collectively by reversing the pH to 2. The results show that CMCh could be an effective size enhancing species for the removal and recovery of mixture of metals by SEUF. •Carboxymethyl chitosan (CMCh) was selected as a size enhancing species.•It was used for the removal of mixture of heavy metals such as Cu(II), Ni(II), Zn(II), and Pb(II) by SEUF•RSM was adopted for the experimental design.•Recovery of heavy metals by altering the initial pH.