Enkapsulasi Urea dengan Material Geopolimer Berpori Berbahan Dasar Metakaolin untuk Slow-Release Fertilizer

Azzahira, Sabira (2025) Enkapsulasi Urea dengan Material Geopolimer Berpori Berbahan Dasar Metakaolin untuk Slow-Release Fertilizer. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Penggunaan pupuk urea secara langsung di lahan pertanian memiliki kelemahan berupa pelepasan nitrogen yang cepat dan tidak terkendali, sehingga menurunkan efisiensi serapan unsur hara oleh tanaman. Dalam penelitian ini, geopolimer berpori berbahan dasar metakaolin disintesis sebagai material pelapis pupuk urea untuk Slow-Release Fertilizer (SRF). Sampel dibuat dalam bentuk silinder dengan tinggi 6 cm dan variasi ketebalan dinding antara 2 hingga 6 cm. Rasio solid-to-liquid yang digunakan adalah 0,75; 1; 1,25. Proses sintesis dilakukan menggunakan metode wet mixing dengan penambahan H2O2 sebanyak 3,5% dari total massa sebagai agen pembentuk pori. Uji pelepasan nitrogen dilakukan selama 24 jam melalui metode leaching dan konsentrasi nitrogen dianalisis menggunakan spektrofotometri UV-Vis. Seluruh variasi geopolimer melepaskan nitrogen dibawah 15% dalam 24 jam pertama. Ketebalan dinding berbanding terbalik dengan laju pelepasan karena memperpanjang difusi. Hasil analisis kinetika menunjukkan bahwa mekanisme pelepasan mengikuti model orde nol dengan nilai rata-rata R2 sebesar 0,934, menandakan bahwa pelepasan berlangsung secara konstan tanpa dipengaruhi konsentrasi pupuk.
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The use of urea fertilizer directly on agricultural land has the drawback of rapid and uncontrolled nitrogen release, thereby reducing the efficiency of nutrient absorption by plants. In this study, porous geopolymer based on metakaolin was synthesized as a coating material for urea fertilizer for Slow-Release Fertilizer (SRF) applications. The samples were shaped into cylinders with a fixed height of 6 cm and varying wall thicknesses ranging from 2 to 6 cm. The solid-to-liquid ratios used were 0.75; 1; and 1.25. The synthesis process was carried out using the wet mixing method with the addition of 3.5% H₂O₂ of the total mass as a foaming agent. The nitrogen release test was carried out over a 24-hour period using the leaching method, with concentrations measured by UV-Vis spectrophotometry. All variations of geopolymer released less than 15% nitrogen within the first 24 hours. Wall thickness was inversely proportional to the release rate due to the extended diffusion path. Kinetic analysis showed that the release mechanism followed a zero-order model with an average R² value of 0.934, indicating that the release occurred at a constant rate regardless of fertilizer concentration.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Geopolimer Berpori, Metakaolin, Nitrogen, Slow-Release Fertilizer, Urea Metakaolin, Nitrogen, Porous Geopolymer, Slow-Release Fertilizer, Urea
Subjects:	Q Science > QD Chemistry > Polymerization
Divisions:	Faculty of Mathematics and Science > Chemistry
Depositing User:	Sabira Azzahira
Date Deposited:	05 Aug 2025 12:13
Last Modified:	05 Aug 2025 12:13
URI:	http://repository.its.ac.id/id/eprint/127565

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