Influence of pH on Chemical Forms of Phosphate Adsorbed on Goethite Surfaces

摘要

Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinate groups which exchange with P on goethite surfaces in solutions with different pll values were investigated. Results showed that the chemical forms of Pon goethite surfaces changed from the dominance of mouodentate corrdination to that of bidentate one with increasing pH of the solution. By influencing types of phosphate ions in solutions, pH affected the chemical forms of P on goethite surfaces. The amount of OH~- displaced by phosphate on goethite surfaces was the most at pH 7.0, the second at pH 9.0, and the least at pH 4.5.