Preparation and testing of a tetra-amine copper(II) chitosan bead system for enhanced phosphate remediation

• Published in: Carbohydrate polymers 2018-03, Vol.183, p.173-182
• Main Authors: Kumar, Ilango Aswin, Viswanathan, Natrayasamy
• Format: Article
• Language: English
• Subjects: Biocomposite beads; Chitosan; Field trial; Phosphate sorption; Tetra-amine copper
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2017.11.087

•Tetra amine copper(II) salt grafted chitosan (TAC@CS) composite beads were prepared & tested for enhanced phosphate adsorption.•The TAC@CS beads demonstrate higher phosphate sorption capacity than either TAC or chitosan individually.•Adsorption modeling indicates a complexation and electrostatic phosphate sorption mechanism.•Use of TAC@CS composite beads improved other water quality parameters in the field study. A tetra-amine copper(II) chitosan bead system (TAC@CS composite beads) was developed by grafting tetra-amine copper(II) (TAC) with chitosan (CS) and utilized for phosphate removal. The prepared TAC@CS composite beads possess enhanced phosphate sorption capacity (SC) of 41.42 ± 0.071 mg/g than copper grafted chitosan (Cu@CS) composite, TAC and chitosan which were found to be 37.01 ± 0.803, 33.20 ± 0.650 and 7.24 ± 0.059 mg/g respectively. In batch mode, various adsorption influencing parameters like contact time, initial phosphate concentration, solution pH, co-anions and temperature were optimized for maximum phosphate sorption. The prepared adsorbents were characterized by FTIR, XRD, UV–Visible, SEM and EDAX analysis. The adsorption isotherms and thermodynamic parameters of the adsorbent were studied. The feasible phosphate uptake mechanism of TAC@CS biocomposite beads was reported. The reusability studies of TAC@CS composite beads were carried out using NaOH as elutant. The suitability of TAC@CS composite beads at field conditions was tested with phosphate contaminated field water samples collected from nearby areas of Dindigul district.