The Removal of Phosphorus in Solution by the Magnesium Modified Biochar from Bamboo

The eutrophication of water would cause the quality of the water to deteriorate and the algae to grow in large quantities. The recovery of phosphorus from sewage can not only purify the water quality, but also achieve the recycling of phosphorus. Its environmental and economic benefits are considerable. In this study, bamboo was used as raw material and modified with MgCl2 solution to prepare Mg-loaded biochar from bamboo (Mg@B). The adsorption experiments of phosphorus in solution by Mg@B were carried out. The adsorption kinetics of phosphorus by Mg@B was depicted by pseudo-first order kinetic and pseudo-second order kinetic models. The results showed that the surface of Mg@B is covered with the compound of Mg(OH)2. The adsorption process fits well with the pseudo-second order kinetics equation. The predominant process is chemisorption, which involves a sharing of electrons between the adsorbate and the surface of the adsorbent. The factor limiting the rate of reaction is primarily the number of surface-active sites of the adsorbent. The mechanism of Mg@B adsorbing phosphate ions in solution has physical adsorption, electrostatic adsorption and chemical precipitation.