High-efficiency remediation of cadmium (Cd2+) from aqueous solution using poultry manure- and farmyard manure-derived biochars

Farmyard manure (FYM-BC) and poultry manure (PM-BC) derived biochars were applied as adsorbents to remove Cd2+ from water. Results indicated that PM-BC was a more efficient adsorbent than FYM-BC at all experimental conditions. Maximum Cd2+ adsorption was observed at pH 4, temperature 318 K and contact time 1 h, regardless of biochar type. The Langmuir model predicted maximum adsorption capacity of 90.09 mg g(-1) for PM-BC. The data fitting to pseudo-second-order model proposed chemisorption of Cd2+ onto biochars. Thermodynamics indicated that adsorption was spontaneous and endothermic. Post-adsorption analysis provided evidences of strong chemical interactions between biochars' functional groups and Cd2+ ions.