Utilization of Biomass Waste at Water Treatment

Abstract

This work presents some preliminary results on the direct use of untreated biomass from agricultural activities as adsorbents for water treatment. Waste was also used to produce activated carbons (ACs) by chemical activation with KOH. The efficacy of agricultural waste such as stubble, sawdust from Teak (Tectona Grandis), fibers from Imbondeiro (Adansonia digitata L.), bamboo flowers, and other regional plants were tested on methylene blue (MB) removal from the aqueous phase. Adsorption studies were conducted in a batch system and the influence of kinetics, pH, and temperature was evaluated. The adsorption performance of the natural adsorbents was significantly high concerning MB. In particular, Imbondeiro presented a maximum removal capacity of 188.3 mg per gram. This amount was similar to or even higher than the values obtained on ACs produced by their predecessors at 873 K. The studies were finished by constructing slow filters containing natural adsorbents or ACs. The maximum amounts of MB removed on a continuous flux were lower than those obtained for a diversity of untreated biomass types on a batch system. However, these amounts were comparable to the published results obtained on a diversity of untreated biomasses in batch mode.