Producing Superphosphate with Sewage Sludge Ash: Assessment of Phosphorus Availability and Potential Toxic Element Contamination

Recovering and recycling phosphorus (P) from sewage sludge ash (SSA) for the purpose of P fertilizer production contributes to reducing input mined phosphate-minerals closing cycle. However, direct use SSA as is often a questionable strategy due its low nutrient efficiency. In addition, environmental risk potential utilizing in agriculture still unclear, particular toxic element (PTE) contamination. this study, mixture rock phosphate was used at lab-scale superphosphate (SP) production. availability final product PTE contamination (Cd, Cr, Cu, Zn, Pb, Ni) soil crop investigated through maize (Zea mays L.) cultivation. Results showed that application SP produced by 25% replacement did not affect growth, uptake, content aboveground compared without replacement. significant inputs with may decrease solid-soil solution partitioning Ni Pb long-term. Separation municipal/industrial removal technology are necessary be implemented prior secondary raw material P-fertilizer