Bio-composite of nipa palm husk derived activated carbon/poly(butylene succinate): an effective agricultural waste based adsorbent for ammonia removal

Abstract

In this work, activated materials were successfully prepared by pyrolyzing various ratios of Nipa palm husk powder to potassium hydroxide  (1:1, 1:2, and 1:3) at predetermined temperatures (500℃, 600℃, and 700℃). The surface area was obtained from nitrogen isotherms using the Brunauer-Emmett-Teller (BET) equation. The surface area of the prepared activated carbon was increased with decreasing potassium hydroxide impregnation ratio and increasing pyrolyzing temperature. The highest surface area was 1,211 m2×g-1. In contrast, acidic surface functional groups investigated by Boehm’s titration were increased with decreasing pyrolyzing temperature and impregnation ratio. Ammonia removal capacity was increased with an increase in the acidic surface functional groups on prepared activated carbon. Therefore, the activated sample with the highest acidic surface functional groups contents provided the greatest ammonia adsorption of around 95% (from 100 ppm to 5 ppm), implying that ammonia removal capacity was closely related to the acidic surface functional groups on the activated carbon. Adsorptive poly(butylene succinate) was carried out by incorporating activated carbon into the poly(butylene succinate) matrix for ammonia adsorption. This adsorption increased with increasing activated carbon content so that it was found that 12 wt% activated carbon provided the highest ammonia adsorption by reducing ammonia from 108 ppm to 26 ppm.