Surface Modified Low Cost Adsorbent in Malachite Green Scavenging, Malachite Green/Rhodamine B and Malachite Green/Rhodamine B/[Cu.sup.2+] Composite Treatment

Modified Irvingia gabonensis nut waste (MIg) was used for malachite green (MG) removal from aqueous solution. Adsorption operational parameters such as pH, adsorbent load, concentration with contact time were investigated to establish the behavior of MIg for subsequent applications in a complex media. The potency of MIg in the effective treatment of binary and ternary mixture of MG/rhodamine B (RhB) dyes and MG/RhB/[Cu.sup.2+] solution was also studied. Optimum MG adsorption was obtained at pH of 6.0. MG-MIg kinetics adsorption data was best described by the Pseudo second order kinetic model. MG adsorption onto MIg was predominantly onto a uniform site and the maximum monolayer adsorption capacity was obtained to be 250 mg/g. MG and RhB synergistically aided the removal of each other both in binary and ternary solutions hence 99.99% removal was observed for the two dyes after treatment with MIg. [Cu.sup.2+] showed no change in concentration after treatment with MIg. Keywords: adsorption; malachite green; binary; kinetics; isotherms