Phosphorus Adsorption Capacity of Biochar Obtain From Pyrolysis of Sesame Waste Under Different Temperatures and Activation Methods.

The use of biochar to remove phosphate from wastewater, however, is still a relatively less explored, though promising concept. But little research has been conducted to explore the phosphate removal potential of biochar. The objective was to determine the effect of pyrolysis temperature and activation method on the adsorption of phosphorus onto the sesame waste biochar. The adsorption characteristics of phosphorus by sesame waste biochar were determined at 500 and 600°C with or without ZnCl₂-activation for 4 hr using the Freundlich and Langmuir adsorption isotherm equations. The adsorption capacities of phosphorus by Freundlich isotherm for the tested sesame waste biochar were high in the order of 600°C+ZnCl₂ > 500°C+ZnCl₂ > 500°C à 600°C. The maximum adsorption capacities of the phosphorus by sesame waste biochar determined by Langmuir isotherms were high in the order of 600°C+ZnCl₂ > 500°C+ZnCl₂ >  500°C à 600°C. Sesame waste biochar with ZnCl₂-activation is a promising alternative adsorbent for treating phosphate from wastewater. Biochar with ZnCl₂-activation can be used to reclaim phosphate from water or reduce phosphate leaching from fertilized soils.