An efficient sorbent for phosphate removal from wastewater: a new application of phosphate mine wastes from Ruseifa City-Jordan

摘要

Jordanian phosphate mine wastes (PMW) at Ruseifa City was fully characterized and tested for its PO4 removal capacity by batch experiments using prepared phosphate solutions and domestic wastewater. PMW particles are positively charged with median particle size of 0.625 mu m. Mineralogical and chemical analyses of PMW showed that it is mainly composed of calcite, fluorapatite, and quartz with high concentrations of calcium and phosphorous. The phosphate concentrations in PMW range from 11 to 24% expressed as P2O5. PMW as a sorbent has a very high PO4 removal efficiency from wastewater and prepared solutions. PO4 solutions with concentrations ranging from 5 to 5,000mgL(-1) were prepared and utilized in batch experiments in the presence of PMW as a sorbent. The concentration of PO4 in the solution phase and pH were the main parameters influencing the PMW sorption capacity of PO4. The PO4 removal efficiency from prepared solutions was up to 99%. Moreover, Langmuir sorption model was able to describe the observed data for PO4 sorption by PMW. The sorption data at PO4 concentrations >50mgL(-1) were highly fitted to Langmuir model. The estimated sorption maximum capacity (b(max)) of PMW was 46,620mgkg(-1). On the other hand, domestic wastewater samples obtained from six Jordanian wastewater treatment plants were subjected to PO4 removal by PMW, and the results showed that the PO4 removal efficiency exceeded 97%. The adverse environmental impacts and human health risks associated with PMW presence are briefly discussed.