Permeation of fertilizer nutrients through polymer membrane: part I. Effect of P, K, and micronutrient fertilizer on permeability of urea

Abstract

The study aimed at investigating the addition effects of P, K, and micronutrient fertilizers on the permeability of N-nutrient fertilizer urea through a representative polymer membrane, which is of great importance in polymer-coated compound fertilizer. Specifically, the permeability of urea through polystyrene membrane was determined experimentally at the nominal temperature of 298 K using the Ussing chamber method for fertilizer solutions of urea-water, urea-NaH 2 PO 4 -water, urea-Ca(H 2 PO 4 ) 2 -water, urea-KCl-water, and urea-NaCl-water. The experimental data showed that the addition effects of NaH 2 PO 4 , KCl, and NaCl on urea permeability were pronounced and could be promotion or suppression depending on the amounts added. The variation of urea permeability with additive concentration could be explained by the 'solution-diffusion' model, suggesting that the specific intermolecular and interionic interactions in the permeation solution were an important factor determining the permeability. Using the saturated urea-water solution as basis, the addition of saturated KCl increased the urea permeability by 2.5 times, while the addition of saturated Ca(H 2 PO 4 ) 2 and NaH 2 PO 4 decreased the permeability by 41% and 76%, respectively.

Struvite-based composites for slow-release fertilization: a case study in sand

“…Moreover, TPS swelling over time can modify the matrix structure, limiting water and nutrient transportation 21 , 37 . Urea molecules released from the TPS structure can also have a role in lowering phosphate availability, as they tend to form large complexes with ion species in solution 38 , 39 . It is essential to highlight that, even though part of struvite was converted to dittmarite during the preparation of the composites (Fig.…”

Unveiling the Role of Polysulfide Matrices in Phosphate Diffusion for Controlled Release Fertilizers

“…Ion permeability through the PS material was tested using an adapted Ussing Chamber method. − The PS film was positioned at the cell connector of the Ussing Chamber. The receptor and donor cells were then filled with 60 mL of deionized water and saturated salt solution, respectively.…”