The Utilization of Boiler Fly Ash for Treatment of Wastewater Color by Adsorption Process: Case Study for Pulp and Paper Industry

This research aimed to investigate the possibility of utilizing coal fly ash and eucalyptus fly ash from boilers in pulp and paper industry as adsorbents for color removal of biological treated wastewater. The physical properties of fly ash such as pore properties (surface area, pore volume and average pore size), thermal degradation and functional group were analyzed. The results showed that both types of fly ash were mesopore adsorbents. The percentage of color removal increased with the increasing of amount of adsorbent. The maximum percentage of color removal for amount of adsorbent at 0.5, 1, 1.5 and 2 g are 76%, 86%, 90% and 94%, respectively. The adsorption reaches equilibrium at 48 hours for all experiments. The adsorbents were reused and the experiments showed that the adsorbent can be reused twice without any regeneration before the percentage of color removal went below the target number of industry at 58%. The scale up of adsorption process was also studied. The experimental results showed that increasing amount of adsorbent and adsorbate 2 to 10 times do not have any significant effect on the percentage of color removal. The coal fly ash yielded higher percentage of color removal (90%) than eucalyptus fly ash (82%).