EVALUATION OF AMMONIUM (〖NH〗_4^+) ADSORPTION CAPACITY IN AQUEOUS SOLUTION BY HYDROCHAR DERIVED FROM PAPER SLUDGE
Abstract
The purpose of the study is to recover paper sludge to create adsorbent material used for removing ammonium ( ) from aqueous solution. Paper sludge in Hoang Van Thu paper joint stock company was recycled and used for hydrochar production (HBG) through hydrothermal carbonization with supporting of an HCl solution at a carbonization temperature of 250 oC for ammonium adsorption. Batch adsorption experiments were carried out to investigate and evaluate the effects of some factors on ammonium ( ) adsorption of HBG materials. The results indicate that the optimal conditions for ammonium adsorption onto HBG accurate at pH of 8, contact time of 120 min, initial ammonium concentration of 50 mg/L, and a maximum adsorption capacity calculated based on Langmuir isotherm model of 5.22 mg/g. The experiment data fitted well with the Langmuir model and the pseudo-second-order model with the R2 of 0.98 and 0.99, respectively. Hydrochar derived from paper sludge exhibited a significant adsorption capacity of ammonium in aqueous solution, making it a promising adsorbent for removal of ammonium in wastewater.