Bulk Disposal of Unserviceable Toxic Cresylic Acid Waste Using Polymerisation Technique

摘要

A bulk amount of unserviceable toxic cresylic acid waste has been disposed off in a safe and environmentally benign manner. A process to immobilize this waste into non-toXic solid cresol formaldehyde polymer has been developed. Initial study was performed for 1.0 kg batch size for optimising the process parameters and conditions, and on the basis of this data, process was scaled-up for bulk disposal (100 kg/batch). The effect of ratio of reactants, type of catalyst [H2_SO_4, NaOH, and Ca(OH)_2], catalyst concentration, reaction temperature and reaction time have been studied in a batch process. Maximum immobilization in the 1.0 kg batch studies was obtained when cresylic acid and formaldehyde were taken in a molar ratio 1:1.5 using NaOH as a catalyst. For bulk polymerisation, a ratio of 1.0 : 1.2 (cresylic acid : formaldehyde) with NaOH [0.7 per cent (wt/wt of total charge)] was found optimum. The final polymerised product has been buried as per standard procedure in two brick lined pits. Finally, the site has been declared as free from the toxic waste.