Geopolimer Berpori sebagai Material Enkapsulasi Nutrien Fosfat untuk Slow-Release Fertilizer

Amaliya, Faza (2025) Geopolimer Berpori sebagai Material Enkapsulasi Nutrien Fosfat untuk Slow-Release Fertilizer. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Geopolimer berpori berbahan dasar metakaolin telah digunakan sebagai material enkapsulasi pupuk fosfat untuk Slow-Release fertilizer (SRF). Digunakan variasi rasio solid-to-liquid (S/L) 0,75; 1,00; dan 1,25 w/w serta variasi diameter silinder 2 hingga 6 cm dengan tinggi 6 cm. Agen pembentuk pori yang digunakan adalah hidrogen peroksida (H2O2) sebanyak 3,5% dari total massa pasta geopolimer. Geopolimer disintesis menggunakan metode wet mixing kemudian dianalisis laju release ion fosfat selama periode leaching 3 sampai 24 jam. Untuk mengukur jumlah ion fosfat yanag terlarut dalam air leaching, dilakukan karakterisasi menggunakan spektrofotometer UV-Vis pada panjang gelombang 880nm dan diperloeh release ion fosfat sebesar 1,55% dalam 24 jam. Selain itu, dilakukan uji porositas, open pores, dan daya serap air. Hasil menunjukkan bahwa peningkatan raiso S/L berpengaruh terhadap peningkatan porositas, daya serap air, dan distribusi ukuran pori, dimana hasil uji dari ketiganya nilai tertinggi dicapai oleh rasio S/L 1,00. Pada variasi ketebalan berperan dalam mengatur kecepatan release ion fosfat, semakin tebal dinding geopolimer, maka akan semakin pelan laju releasenya. Release ion fosfat mengikuti kinetika Higuchi, yang menunjukkan bahwa fraksi ion yang dilepaskan berbanding lurus dengan akar kuadrat waktu, mengindikasikan mekanisme release dikendalikan oleh proses difusi melalui matriks geopolimer. Geopolimer dengan diameter lebih besar dan rasio S/L lebih tinggi cenderung memiliki laju release yang lebih lambat. Hal ini menegaskan bahwa geopolimer berpori berbahan dasar metakaolin dapat mengontrol kecepatan release untuk aplikasi pertanian berkelanjutan, dengan efisiensi pemupukan yang lebih baik, serta minim dampak negatif terhadap lingkungan.
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Porous geopolymers based on metakaolin have been utilized as encapsulation materials for phosphate fertilizers in Slow-Release Fertilizer (SRF) applications. Variations in the solid-to liquid (S/L) ratio of 0.75, 1.00, and 1.25 w/w were applied, along with cylinder diameters ranging from 2 to 6 cm, all with a consistent height of 6 cm. Hydrogen peroxide (H₂O₂), amounting to 3.5% of the total geopolymer paste mass, was used as the pore-forming agent. The geopolymer was synthesized using a wet mixing method, followed by analysis of the phosphate ion release rate during a leaching period of 3 to 24 hours. To measure the amount of phosphate ions dissolved in the leachate, characterization was performed using a UV-Vis spectrophotometer at a wavelength of 880 nm, yielding a phosphate ion release of 1.55% over 24 hours. Additionally, tests for porosity, open pores, and water absorption capacity were conducted. The results showed that increasing the S/L ratio influenced an increase in porosity, water absorption, and pore size distribution, with the highest values observed at an S/L ratio of 1.00. Variation in thickness played a role in regulating the phosphate ion release rate; the thicker the geopolymer wall, the slower the release rate. Phosphate ion release followed Higuchi kinetics, indicating that the fraction of ions released is proportional to the square root of time, which suggests that the release mechanism is controlled by diffusion through the geopolymer matrix. Geopolymers with larger diameters and higher S/L ratios tended to have slower release rates. These findings confirm that porous metakaolin-based geopolymers can effectively control release rates for sustainable agricultural applications, enhancing fertilizer efficiency while minimizing negative environmental impacts.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Fosfat, geopolimer berpori, metakaolin, slow-release fertilizer, Phospate, porous geopolymer, metakaolin
Subjects:	Q Science > QD Chemistry > Polymerization
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Chemistry > 47201-(S1) Undergraduate Thesis
Depositing User:	Faza Amaliya
Date Deposited:	05 Aug 2025 04:51
Last Modified:	05 Aug 2025 04:51
URI:	http://repository.its.ac.id/id/eprint/126639

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