Surfactant-Modified Zeolite as a Slow Release Fertilizer for Phosphorus

The feasibility of using surfactant-modified zeolite(SMZ)as a carrier for fertilizer and for slow release of phosphorus (P)was investigated. Zeolite-A was modified by using hexadecytrimethylammonium bromide, a cationic surfactant, to modify its surface to increase its capacity to retainanion, namely, infrared, and scanning electron microscopy to study the effect of surfactant modification. Zeolite-A and SMZ were then subjected to P loading by treating them with fertilizer(KH2PO4). It was observed that the P loading on SMZ increased by a factor of 4.9 as compared to the unmodified Zeolite-A. A comparative study of the release of P from fertilizer-loaded unmodified zeolite-A and SMZ and from solid KH2PO4 was performed using the conatant flow percolation reactor. The result show that the P supply from fertilizer-loaded SMZ was available even after 1080 h of continuous percolation, whwreas P from KH2PO4 was exhausted within 264 h. The result indicate that SMZ is a good sorbent for PO4, and a slow release of P was achievable. These properties suggest that SMZ has a great potential as the fertilizer carrier for slow relese of P