Comparative effectivity of different types of neutral chelating agents for preparing chelated bagasse in solvent-free conditions

Eight different types of reagents containing chelating exchangeable groups were tested to convert sugarcane bagasse into chelating ion exchangers. Urea, melamine, thiourea, dimethylamine, polyethyleneimine, ethylenediamine, diethylenetriamine, iminodiacetic acid and glycine were irradiated with sugarcane bagasse using microwave at different reaction times. It was found that bagasse neutral chelating agents produced from thiourea (BTHI) and urea (BUREA) demonstrated nitrogen contents of 14.6% and 14.9% after 4 and 12 min of reaction, respectively. BTHI demonstrated maximum mercury adsorption capacity of 2.2 meq g−1 followed by BUREA (1.5 meq g−1) and melamine (BMEL) (0.9 mmeq g−1). Among all the reagents tested, BUREA may prove to be the more ecologically benign and inexpensive alternative procedure to prepare chelating ion exchangers. Urea has been classified as a safer reagent than thiourea.