Use of calcite mud from paper factories in phosphorus treatment

Abstract

To use calcite mud waste generated from the paper production process, calcite mud was treated by calcination and then applied as a sorbent agent to remove phosphorus from an aqueous solution. The pre-treatment muds were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The effects of calcite mud with different calcination temperatures on phosphorus removal were investigated. Different sorbent dosages, contact times, and initial phosphorus concentration conditions were also studied to understand the phosphorus removal mechanism. The results show that phosphorus removal efficiency was increased by increasing the calcination temperature of the mud. The phosphorus removal efficiency over 10 min increased by 35%, 82%, 98%, and 100% with 4.5, 6.75, 9.0, and 11.25 mg, respectively, of calcite mud calcined at 1000 °C. However, the efficiency decreased as initial phosphorus concentration increased. To study the phosphorus removal trend, the pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetic models were used. The Langmuir and Freundlich isotherm models were also used to further investigate the phosphorus adsorption mechanism characteristics of the calcite mud.