Abstract
We have been developing a method of establishing a phosphate ion removal, recovery and recycle system using a synthesized Mg-Al-Cl form of hydrotalcite (HT). The powder form of the HT, however, is not ideal for wastewater treatment because of its poor solid-liquid separating efficiency; thus, we have developed a hydrotalcite-carrying fiber (HTCF). The HTCF is made of a porous polymer that carries HT at weight percents of 80-90. The internal structure of the HTCF is composed of a pore structure with continuous holes, so the HTCF is a carrier with a high permeability and exhibits the characteristics of HT sufficiently. In this study, we investigated the characteristics of the HTCF, such as adsorption capacity, desorption rate, regeneration rate and change in regeneration rate with regenerating time by applying the "two- liquid regeneration system". As a result, the HTCF showed a high adsorption rate, a high adsorption capacity, a high desorption rate for phosphate ions and a high regeneration rate, equal to that of HT powder. In addition, the HTCF can be reused more than 10 times, maintaining a regeneration ratio of 80% higher. From these results, it was confirmed that the HTCF is a suitable carrier that exhibits characteristics comparable to those of HT powder and can contribute to the establishment of a zero-emission-formula phosphate removal and recovery system for wastewater.
