Development of ELN/COL- LA/CA matrix for urea encapsulation and study of its nitrogen release kinetics

Abstract

Direct Administration Of Chemical Fertilizers On Soil Was Shown To Have Low Utilization Efficiency Of The Nutrients Absorbed. The High Solubility Of Chemicals Like Urea As A Fertilizer Has Higher Chances Of Leaching Resulting In Losses Of Nutrients. In This Research, A New Type Of Least Water Soluble Eln/Col-La/Ca Matrix Was Synthesized To Reduce The Release Of Nutrients From Urea Fertilizer. Eln/Col-Mixture Was Extracted From Waste Broiler Skin And Modified With Lactic And Citric Acids For Urea Encapsulation. The Urea Powder Was Also Dispersed On La/Ca Modified Eln/Col Matrix With A Matrix To Urea Ratio Of 1:1.5,1:1,1:2,And 1:3. The Effect Of Reaction Time, Temperature, And Lactic Acid To Citric Acid Ratio On The Water Solubility Of The Eln/Col-La/Ca Matrix Was Studied. The Extracted Eln/Col From Broiler Skin Was Characterized By Ftir. 1h Nmr And 13c-Nmr Were Also Applied To Further Characterize The Eln/Col-La/Ca Matrixes For The Reaction Mechanism And The Type Of Bonds Formed During The Condensation Reaction Between Eln/Col And La/Ca. The Solubility Test For The Synthesized Eln/Col-La/Ca Matrix Was Investigated Following The Kjeldahl Method For Its Release Kinetics. The Ftir And Nmr Results Show That The Eln/Col-La/Ca Matrix Synthesized Was Formed Due To The Reaction Between The Primary Structure Of Eln/Col And That Of La/Ca With A Formation Of Amide As Well As Ester Bonds. Further Results From The Solubility Test, As Well As The Ftir Analysis, Shows That The Matrix Which Was Synthesized At A Reaction Time Of 4 Hours, Reaction Temperature Of 70 Oc, And Lactic Acid To Citric Acid Ratio Of 1:1.5 Was Found To Be The Least Water Soluble Matrix. The Nitrogen Release Data Were Fitted And Compared With Two Empirical Models Namely Higuchi And The Korsmeyer-Peppas To Evaluate The Release Kinetics. The Nitrogen Release Kinetics For Urea Dispersed Eln/Col?�?La/Ca Matrix Was Found To Have A Good Korsmeyer-Peppas Model Fitting At An R2 Value Of More Than 0.98. The Diffusion Exponent (N) For The Three Samples (1:0.5, 1:1, And 1:2) Matrix To Urea Ratio Was (N ??? 0.85) Showing A Non-Fickian Diffusion, Case Ii Transport Mechanism. But For The Fourth Sample Which Is A (1:3) Ratio The Value Of The Diffusion Exponent Was (N=0.75) Representing Anomalous Transport