Biosorption of lead and cadmium ions from aqueous solution by tea and coffee wastes

摘要

Due to toxicity and non-biodegradable nature of lead and cadmium, they are reported as most detrimental metal. In this paper aptness of tea and coffee wastes is examined to treat lead and cadmium ions. FTIR study of tea and coffee wastes confirmed theexistence of various functional groups that have adequate tendency to attract positively charged heavy metals ions and form complex with the electrostatic interaction. The tendency of heavy metal is highly dependent on pH, adsorbent dosage, contact time, metal ion concentration and temperature. Maximum percent adsorption was found at pH 5 for both ions. Temperature effect was examined in the range of 25 to 65 oC for both lead and cadmium ions on tea and coffee wastes respectively, that reveals the exothermic nature of adsorption process.