High surface area acid-treated biochar from pomegranate husk for 2,4-dichlorophenol adsorption from aqueous solution

Abstract

In the present study, zinc chloride (ZnCl2) followed by acid treating was employed for the fabrication of activated biochar from pomegranate husk (APHBC) for 2,4-dichlorophenol (2,4-DCP) adsorption from an aqueous solution. The batch adsorption experiments were carried out as a function of solution pH, APHBC dose, initial 2,4-DCP concentration, contact time, and ionic strength. The APHBC showed a well-developed pore with specific surface areas of 1576 m(2)/g due to explosive characteristics of ZnCl2. In addition, the XRD analysis showed that the diffraction peaks between 15 and 35 degrees corresponded to amorphous carbon. The pore size distribution results showed that APHBC was dominantly mesoporous materials. The pH(pzc) value of APHBC was 6.15 +/- 0.15. According to batch experiments, the optimum adsorption conditions were pH of 3.0, contact time 60 min, APHBC dose of 1.75 g/L and without ionic strengths. The absorption capacity of 2,4-DCP at the initial concentration of 150.0 mg/L promptly decreased from 259.5 +/- 12.9 to 74.5 +/- 3.7 mg/g as the APHBC dose increased from 0.50 to 2.00 g/L. The isotherm and kinetics study of 2,4-DCP adsorption by APHBC revealed that Liu and Avrami fractional-order well fitted with experimental data, respectively.