Adsorption of Phosphate Ions on Chicken Feather Hydrochar and Hydrochar-Soil Mixtures

The potential for hydrochar to adsorb phosphate ions (P) is important for understanding the influence of this material when added to soils, as it can amend and prevent nutrient leaching. In this study, the adsorption mechanism of P onto chicken feather hydrochar (CFH) and hydrochar mix alkaline soils was investigated. Batch experiments were conducted to discover the actual P adsorption process parameters of chicken feather hydrochar, incorporating initial P concentration, contact time, pH, and temperature of P solution. All experimental P adsorption data of hydrochar and hydrochar mix soils were better explained when using the Langmuir isotherm model compared to the Freundlich isotherm. The P adsorption capacities of CFH-soil 1, CFH-soil 2, CFH-soil 3, and CFH-soil 4 mixer were 21.93, 20.2, 19.2, and 20.7 mg/g, respectively. Temperature greatly improved P adsorption capacity of the chicken feather hydrochar and its adsorption capacities were 27.10, 29.7, and 33.4 m/g at 30, 40, and 50 °C, respectively. The adsorption kinetic data are best described using the pseudo-second order model. These results strongly suggest that the CFH has a lot of potential as a cost-effective material for adsorbing P and helping remediate environmental pollutants.