Pembuatan Beads Alginat-NPK dengan Metode Freeze-Drying sebagai Controlled Release Fertilizer

PRADIVA NADYA AGASTA, Dr. rer. nat Adhitasari Suratman., S.Si., M.Si ; Prof. Drs. Mudasir., M.Eng., Ph.D

2020 | Skripsi | S1 KIMIA

Pembuatan beads alginat-NPK dengan metode freeze-drying sebagai controlled release fertilizer telah dilakukan. Penelitian ini bertujuan untuk mempelajari pelepasan NPK dari beads berdasarkan variasi konsentrasi pupuk dan membandingkan pengaruh metode freeze-drying dengan air-drying untuk efektivitas controlled release fertilizer. Beads dibuat menggunakan alginat, larutan pupuk NPK, dan larutan Kalsium Klorida (CaCl2) 0,5 Molar. Konsentrasi nitrogen, fosfor dan kalium yang dilepaskan masing-masing dianalisis menggunakan metode Kjeldahl, spektrofotometer UV-Vis, dan AAS (Atomic Absorption Spectrophotometer). Karakterisasi beads dilakukan dengan spektrometer FTIR (Fourier Transform Infrared) dan SEM (Scanning Electron Microscope). Kinetika pelepasan NPK dikaji menggunakan model orde satu, dua, dan Korsmeyer-Peppas. Hasil penelitian menunjukkan bahwa pelepasan nutrisi dipengaruhi oleh konsentrasi, yakni semakin tinggi konsentrasi pupuk maka semakin besar konsentrasi nutrisi yang lepas. Pelepasan nutrisi dari beads Alginat-NPK pada pengeringan freeze-drying lebih besar dibandingkan air-drying. Laju reaksi pelepasan N, P, dan K mengikuti model kinetika Korsmeyer-Peppas.

Synthesis of alginate-NPK beads using freeze-drying method as controlled release fertilizer had been conducted. This research aims to study the release of N, P, K from beads with variation of NPK concentration and to compare effectiveness of controlled release fertilizer between freeze-drying method and air-drying method. Beads were prepared by mixing alginate, liquid fertilizer NPK and liquid Calcium Chlorida (CaCl2) 0.5 Molar. Concentration of nitrogen, phosphor and potassium released were analyzed using Kjeldahl method, UV-Vis spectrophotometer, and AAS (Atomic Absorption Spectrophotometer). The beads then were characterized using FTIR (Fourier Transform Infrared) and SEM (Scanning Electron Microscope). Kinetics study of releasing NPK evaluated using first, second, and Korsmeyer-Peppas equation order. Results of the study showed that releasing of NPK is affected by NPK concentration which higher concentration NPK causes an increase of releasing rate of NPK. Nutrition released from beads with freeze-drying method was relatively higher than air-drying. Releasing rate of NPK followed Korsmeyer-Peppas equation.

Kata Kunci : controlled release fertilizer, fosfor, freeze-drying, kalium, nitrogen.