Development of granular urea-zeolite slow release fertilizer using inclined pan granulator

Slow release fertilizers (SRFs) are so crucial in improvement of agriculture productions. To increase urea fertilizer effectiveness and efficiency, the product could be modified in the form of SRFs. The objective is to conduct slow release urea fertilizer. During granulation, particle sizes of urea and natural zeolite mixture (50, 60 and 80 mesh), binder solution with different percentage (2% to 10%) of starch, and clay additives (5%, 7.5%, and 10%) were used. The obtained granule was further analyzed using percolation reactor to determine the slow release rate. Leachate from reactors was collected, by using UV-visible spectrophotometric method, concentration of dissolved urea was determined. The granule size of 3-4 mm, the urea-zeolite mixture particle size of 60-mesh, the percentage of clay addition in the granulation process of 7.5%, the percentage of starch addition in binder solution of 3% are selected to be the best in term of the roughness of the granules, economic aspects, and slow release rate. In addition, it is proportionally defined the release time of nutrient from experiment and from simulated program is at least for three months which is plenty of time for crops, especially for rice. Key words: Slow Release Fertilizer, Zeolite, Urea, Inclined pan granulatorAbstrakSlow release fertilizers (SRFs) memiliki peranan yang sangat penting dalam peningkatan produksi pertanian. Untuk meningkatkan efisiensi dan efektifitas pupuk urea, produk pupuk bisa dimodifikasi dalam bentuk SFRs. Tujuan dari penelitian ini adalah untuk membuat slow release urea fertilizer. Selama proses granulasi, digunakan ukuran partikel campuran urea dan zeolit alam (50, 60 dan 80 mesh), cairan perekat dengan persentase yang berbeda (2% sampai 10%) starch, dan tambahan tanah liat (5%, 7,5%, dan 10%). Butiran-butiran (granul) yang diperoleh selanjutnya dilakukan analisis menggunakan reaktor perkolasi digunakan untuk menentukan laju slow release. Leachate dari reaktor dikumpulkan, kemudian konsentrasi urea terlarut dapat diketahui dengan menggunakan metode spektrofotometri UV-Vis. Granul 3-4 mm, ukuran 60 mesh campuran antara urea dan zeolit, persentasi penambahan tanah liat dalam proses granulasi sebesar 7,5%, dan persentasi penambahan starch dalam larutan perekat sebesar 3% menunjukkan hasil yang terbaik untuk tingkat kekasaran butiran, aspek ekonomi dan menunjukkan pelepasan nutrisi lambat. Secara proporsional dapat dikatakan bahwa waktu pelepasan nutrisi yang diperoleh dari percobaan dan simulasi program, setidaknya untuk tiga bulan sangat cukup untuk tanaman, khususnya untuk padi.Kata kunci: Slow release fertilizers, Zeolit, Urea, granulator panci miring.

Surface modified nano-zeolite used as carrier for slow release of sulphur

Surface modified nano-zeolite (SMNZ) was used as carrier to develop nano-zeolite based nano-sulphur fertilizer. A laboratory study on sulphur nano-fertilizer and conventional sulphur fertilizer were studied with percolation reactor system to evaluate the slow release of sulphur from both fertilizers in ambient temperature. SMNZ and sulphur nano-fertilizer were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Zeta Analyzer, Raman Spectroscopy, XRD and Scanning Electron Microscope (SEM). Raman spectroscopy confirmed the sulphur attachment at 480 cm-1 in the SMNZ. The FTIR spectra at 1030 cm-1 confirmed the sulphate attachments in the SMNZ spectrum. Zeta analyzer showed the surface charge of sulphur nano-fertilizer had (-) 52.6 mV. SEM imaged the sulphur loaded SMNZ in irregular flake like structure. A comparative study of the release of sulphate (SO4 2-) from fertilizer-loaded SMNZ and (NH4)2 SO4 fertilizers were performed using the percolation reactor. The results showed that the SO42- supply from fertilizer-loaded SMNZ was available even after 912 h of continuous percolation, whereas SO42- from (NH4)2 SO4 was exhausted within 384 h. These properties suggest that SMNZ has a great potential as the fertilizer carrier for slow release of SO42-.