Abstract

Contact time, starting concentration, and pH change were used to demonstrate how Cd, Cu, Pb, and Zn sorption reactions occurred when a biopolymer based on xanthan gum was present. The biopolymer has three major functional groups and has a negative surface charge in the pH range of 1-8.5. (i.e., OH, C-H, and C double bond C bonds). The biopolymer’s concentrations of Cd, Cu, Pb, and Zn reached equilibrium after 10 min, and a pseudo-secondorder kinetic process ensued. Cd, Cu, Pb, and Zn each had maximal sorption capacities of 16.0 mg/g, 8.5 mg/g, 38.3 mg/L, and 7.2 mg/L, respectively. It was discovered that the Langmuir sorption isotherm was more suitable than the Freundlich model. Additionally, HCl and NaH2PO4 extraction were used to evaluate the immobilisation of heavy metals in the soil that had been amended with biopolymers. Cu was found to be immobilised in soil between 20% and 90% of the time, and the immobilisation rate rose with the biopolymer mixing ratios. According to this study, Cd, Cu, Pb, and Zn may be removed from solutions using a biopolymer, and the biopolymer could also be used as an addition to immobilise heavy metals in soil.

Keywords: Xanthan; Biopolymer; Heavy metal