Adsorption of Formaldehyde on Treated Activated Carbon and Activated Alumina

Formaldehyde is extensively used for disinfection and antisepsis in medical facilities and especially in textile and paint industries as a solvent. Owing to the higher concentration of formaldehyde, both in waste effluents and local environment of medical facilities and industries, it has been reported to cause cancer and as an irritant to eyes and skin. The removal efficiency and the adsorption mechanism of formaldehyde onto the treated activated carbons and activated alumina were studied to analyze the effect of modified surface chemistry of adsorbents. The adsorption capacities of all the selected adsorbents were investigated in batch study at varying contact time and initial concentration of formaldehyde at STP. It was found that commercially implemented activated alumina, treated with effective nucleophile, showed significant formaldehyde adsorption with less variation in adsorption capacity even with decrease in initial concentration of adsorbate. These set of experiments indicate that acidity of formaldehyde can be exploited for its removal from waste effluent and air. The optimization studies were carried out to find out the optimum conditions for this adsorption process with adsorption model fitting and kinetic studies. The investigation results were evaluated on per gram of adsorbent basis to predict feasibility of scaling up at commercial level.