Elimination of Cadmium from Wastewater Using Modified and Unmodified Tea Waste in Kisii County, Kenya

International audience Heavy metals are a major source of water pollution in developing countries. One inexpensive technique for removing heavy metal ions from aqueous solutions is adsorption with a cheap adsorbent. This study focused into sulfuric acid-modified tea waste as a low-cost alternative adsorbent for removing Cd (II) ions from aqueous solution. The tea waste was modified using 1M H2SO4 at a temperature of 150°C for 24 hours. Tea factory wastewater was taken from Nyamache in Kisii County.The findings from the study show the optimum values for initial ions concentration as 70 mg/l, adsorbent dosage as 0.7 grams pH as 6 and contact time as 95 minutes. It was discovered that adsorption isotherms suited well in Langmuir model (R2=0.9961) than Freundlich model (R2=0.9954). the adsorption capacities for modified tea waste were relatively higher compared to unmodified tea waste, 6.7159 and 5.359 respectively. FT-IR analysis of the biomass tea waste showed the presence of O-H at a maximum of 3395 cm-1, COO- at a maximum of 2448 cm-1, C=O at a maximum of 1594 cm-1, and P-OOH at a maximum of 1216 cm-1. The existence of these functional groups on modified tea waste improved the removal of Cadmium (II) ions. SEM analysis showed the development of distinct pores on modified tea waste following treatment with sulfuric acid which also enhanced the efficacy of modified tea waste. The result reveal that modified tea waste can be applied to eliminate Cadmium from waste water in our homes.