关键词: 红色粘土, 磷, 吸附, 水体

Abstract: Physical and chemical properties of 11 different types of red clays collected from the sub-layer (20 – 40 cm) of wastelands in Yingtan of Jiangxi and Yixing of Jiangsu were analyzed and their performances of phosphorus adsorption in 2 solutions different in concentration (35 and 50 mg•L^-1) were compared. Results show that the phosphorus adsorption capacities of the samples in the two solutions varied in the range of 0.52 – 0.86 and 0.52 -1.18 mg•L^-1, separately. Of the samples, S9 which was collected from Jiangsu demonstrated the highest P removal rate, being over 90% in both solutions. It was also found that iron and aluminum oxides in the red clays were the dominant controlling factors. They combined most of the phosphorus in the solutions, forming insoluble Fe-P and Al-P. the content of aluminum oxides was significantly and positively related to phosphorus removal rate. Therefore, it is advisable to add a proper amount of iron and aluminum oxides into red clay or some other adsorbents to improve their phosphorus adsorption capacity.

Key words: red clay, phosphorus, adsorption, water body