Synthesis of activated biochar from cowdung and its application in removal of methylene blue from textile wastewater.

Abstract

This research focused on the removal of methylene blue dye from wastewater using adsorption method through application of activated biochar. Activated biochar was synthesized from pyrolysis of cow dung at 500C for 2 hours to form biochar which was then activated using 3M phosphoric acid. The optimization of a range of factors of adsorption was investigated by using the activated biochar as the adsorbent of methylene blue solutions. The residual solutions’ dye concentration was then measured using an ultraviolet-visible spectrophotometer at 664 nm. The results showed that the optimum conditions for the adsorption of methylene blue dye using activated biochar were 0.1 g of adsorbent dose in 20ml of solution, at an initial concentration of 10 mg/L, a contact time of 20 minutes, and the adsorbent removed upto 94.5% of methylene blue dye. The Langmuir isotherm model emerged as the best-fit for the experimental data. A pseudosecond-order was also reported as the kinetic model of best-fit for the study. Finally, the study identified some knowledge gaps that could aid future investigation in this research field. Summarily, it can be deduced that cow dung-based adsorbent exhibited good potential as an adsorbent for the mitigation of dyes from wastewater.