VALOURISATION OF COTTON HULL FOR THE DECONTAMINATION OF KAGARA MINING WASTEWATER

Abstract

In this work, a fixed bed adsorption column was used in the decontamination of Pb (II) ions from illegal gold mining wastewater of Kagara mines, Niger State, North Central Nigeria. Flame Atomic Absorption Spectrometer analysis of the waste solution showed a high concentration of Pb (II) ion of 85 mg/L. Fourier Transform Infra-Red (FT-IR) spectroscopy revealed the presence of OH, C-O, C=O, C-O-H and CH2 functional groups in cotton hull. Brauneur-Emmet Teller (BET) test results indicated surface area of 139.8 m2/g and micropores size and radius of <2 nm and 9.237 Ǻ respectively, while the Scanning Electron Microscope micrographs revealed the presence of pores on the raw adsorbent. Column adsorption scale-up data for the 120 L/hr of Kagara mining wastewater shows that 607.2 L of the effluent can be treated of Pb (II) in 5.06 hours using 4.75 kg of the cotton hull adsorbent. The maximum adsorption capacity of 27.65 mg/g, with correlation coefficients within 0.7674 and 0.9551 has an average experimental value of 23.09 mg/g and theoretical of 21.60 mg/g adsorption capacities of the cotton hull adsorbent (CHA) which signify that Thomas kinetics model fit the experimental data