Mitigation of toxic arsenic (V) from aqueous solution in fixed-bed column using functionally modified bio-polymer

Abstract

The presence of arsenic in groundwater, eventually in drinking water, has been recognized as a serious community health problem due to its highly toxic nature, and therefore, its removal is highly essential. To enhance the adsorption capacity of chitosan for As (V), chitosan which is a natural biopolymer was modified by grafting with 2-Hydroxyethylmethacrylate (HEMA) and Sodium Styrene Sulfonate (SSS). Modified chitosan was characterized by SEM and FTIR spectroscopy. Maximum Removal percentage of As (V) was found to be higher (95%) at inlet concentration of As (V) 60 mg/L, flow rate 1 ml/min, pH 3.5, and bed depth 3 cm. The bed depth service time model and Thomas model are used to analyze the column data in terms of As (V) uptake rate and column capacities. Developed grafted adsorbent could be successfully regenerated using 0.1 M NaOH. Recycle studies suggested that maximum reusability of grafted polymer up to 8 cycles.

Keywords:

• Chitosan
• grafting
• adsorption
• arsenic (V)
• gamma radiation
• desorption

Acknowledgment

The authors would like to express thanks to the Radiation Technology Development Division, BARC, Mumbai, India for providing the facility to synthesize radiation grafted polymers. Authors are also grateful to Sophisticate Analytical Instruments Facility, Cochin, India for FTIR and SEM analysis.