Transport model for the adsorption of chemical oxygen demand from industrial textile effluet: a kinetic study

Abstract

Shea nut shell, an abundant and low cost agricultural waste product was used to prepare activated charcoal by means of two step process using H3PO4 and ZnCl2 as an activating agents. The percentage activation burn off increased with increasing activation dwell time, while the percentage yield decreased. The highest chemical oxygen demand (COD) removal from industrial effluent were reported to be 59.99, 56.64, 51.62, 59.97, 53.32 and 59.99% for the series of adsorbents indicated as SS/H3P04/5, SS/H3P04/10, SS/H3P04/15, SS/ZnCl2/5, SS/ZnCl2/10 and SS/ZnCl2/15 respectively and thus implies that the salt catalyzed shea nut shell adsorbent were more effective than the corresponding acid modified biosorbent. Pseudo-first-order and Pseudosecond- order model were selected to study the adsorption kinetic. The removal of COD could be best described by the Psoudo-second-order model and the result also revealed that the activated charcoal produced from shea nut shell was very effective in removing COD from industrial effluent.

Keywords: Activated carbon, chemical oxygen demand, kinetic model, dye, adsorbent