Agus Kuncaka
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281, Indonesia

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Controlled Release Fertilizer Encapsulated by Glutaraldehyde-Crosslinked Chitosan Using Freeze-Drying Method Adhitasari Suratman; Dwi Ratih Purwaningsih; Eko Sri Kunarti; Agus Kuncaka
Indonesian Journal of Chemistry Vol 20, No 6 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55133

Abstract

A new encapsulation of NPK fertilizer hydrogel granules made from glutaraldehyde crosslinked chitosan has been successfully fabricated. This designed fertilizer was aimed to maximize the fertilizing process in the soil, as the environmental pollution affected by the excess release of the nutrients can be prevented. The granule was prepared from biodegradable chitosan crosslinked with glutaraldehyde by applying a method of air and freeze-drying. The release test proved that this designed fertilizer showed a good performance as a Controlled Release Fertilizer (CRF) in which the hydrogel granules could absorb and deposit large amounts of NPK. Later on, they could also release large amounts of NPK as well, unlike several types of CRFs. The release percentage of NPK out of the granules tended to decrease with an increase of pH at a range close to the average pH of the soil, which is neutral to base. Comparing two methods, the freeze-drying technique, which yields a bigger pore size, showed a higher release percentage than air-drying. The release kinetics of the granules followed the Korsmeyer-Peppas model.
Analysis and Characterization of Solid and Liquid Organic Fertilizer from Hydrothermal Carbonization (HTC) of Chicken Feather and Blood Waste Agus Kuncaka; Rizky Ibnufaatih Arvianto; Almas Shafira Ramadhanty Bunga Latifa; Munawir Ramadhan Rambe; Adhitasari Suratman; Sugeng Triono
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.59353

Abstract

Conversion of feather and blood from chicken slaughterhouse waste for producing solid and liquid organic fertilizer excluding composting process with a variation of the mass ratio of feather and blood of a chicken has been conducted. The nitrogen, sulfur, and iron content in the solid and liquid product of the hydrothermal carbonization process were analyzed to identify and characterize the possibility of hydrolysate as a source of nitrogen, sulfur, and iron in soil fertilizer. Feather and blood of chicken waste were introduced to a hydrothermal carbonization reactor with the addition of limestone at a temperature range of 160–170 °C for the preparation of solid and liquid organic fertilizer. According to the FTIR interpretation, the solid product had functional groups such as NH, OH, CH sp3, SH, C=O, C=C, C–O–C, and C–H aromatic. The nitrogen, sulfur, and iron content of the optimal ratio in the solid phase were 4.67%, 1.63%, and 3694.56 ppm, while their contents in the liquid fertilizer were 3.76%, 1.80%, and 221.56 ppm, respectively. The vibration of 478 cm–1 is attributed to Fe–O paramagnetic (Fe2O3) confirmed by TEM images showed the diameter size less than 20 nm indicating the presence of superparamagnetic material.
Fabrication of Alginate-Based Electrospun Nanofibers for Carbon Dioxide Removal Adhitasari Suratman; Desi Nur Astuti; Ryan Jonathan; Agus Kuncaka; Yusril Yusuf
Indonesian Journal of Chemistry Vol 22, No 2 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.67349

Abstract

A fabrication of eco-friendly and low-cost adsorbent materials is reported for CO2 removal. Alginate nanofibers (NFs) adsorbents were prepared by incorporating poly(vinyl alcohol) (PVA) into alginate solutions via electrospinning technique from alginate biopolymers. Smooth-surfaced Alg/PVA NFs were obtained with a specific surface area of 9.197 m2 g–1. Zeolite (Z) was impregnated into polymer solutions to enhance the properties and performances of alginate nanofibers. Alg/PVA/Z NFs appeared to be rougher with a specific surface area of 25.998 m2 g–1. Both adsorbents offered great potential for CO2 adsorbent in the future. The adsorption isotherms of Alg/PVA NFs followed the Langmuir model with optimum CO2 adsorption capacity of 3.286 mmol g–1 and  Alg/PVA/Z NFs followed Dubinin-Radushkevich model with optimum CO2 adsorption capacity of 10.710 mmol g–1.
Enhancing the Amino Acid and Reducing the Metal Ions Contents in the Hydrolysate Resulting from Hydrothermal Carbonization of Chicken Feather Waste by Chemical Phosphorylation Agus Kuncaka; Wahyu Tri Supardi; Winarto Haryadi; Adhitasari Suratman; Priatmoko Priatmoko
Indonesian Journal of Chemistry Vol 23, No 1 (2023)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.73725

Abstract

Chemical phosphorylation of hydrolysate resulting from hydrothermal carbonization of chicken feather waste was performed to enhance the amino acids and reduce the metal ions content. The aim of this research is to improve the functional properties of chicken feathers hydrolysate without impairing the nutritional availability thereof with the cheapest chemical method by phosphorylation. Phosphorylated hydrolysate can function as animal feed and fertilizer. The hydrolysate of chicken feathers was obtained by hydrothermal carbonization in an alkaline condition using a CaO and KOH catalyst, by the ratio of water:dry matter of chicken feathers is 5:1, at 9–10 atm pressure, and in a temperature of 190–200 °C during 3 h. Phosphorylation has been carried out by reacting the hydrolysate with H3PO4 85% in pH of 5, 6, 7 and using the original hydrolysate as control. The sample that has been prepared was characterized and semi-quantitative analyzed by HPLC and AAS. The phosphorylation results showed that the total maximum protein of soluble protein, their minimum metal ions, and anion in soluble protein was obtained at pH 7, while the higher the pH, the lower the liquid protein that was obtained.
Impregnation of Fe3+ into MCM-41 Pores: Effect of Fe3+ Concentration on the Weight Percent of Fe-Frameworks and Fe-Non-Frameworks Suyanta Suyanta; Agus Kuncaka; Mudasir Mudasir
Indonesian Journal of Chemistry Vol 23, No 4 (2023)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.79468

Abstract

Silica from rice husks (RH) has been used as a starting ingredient in the sonication synthesis of MCM-41 (RH-MCM-41). The impregnation of Fe3+ into RH-MCM-41 pores to produce RH-MCM-41 containing Fe2O3 and Fe (denoted as Fe2O3-Fe-RH-MCM-41) was carried out by examining the effect of various Fe3+ concentrations on the weight percent of Fe-frameworks (Fe3+ that replaces Si4+ in silicate frameworks) and Fe-non-frameworks, i.e., the iron oxide formed outside the silicate frameworks. Fe2O3-Fe-RH-MCM-41 was washed with a 0.01 M HCl solution to remove Fe-non-frameworks from the materials and give Fe-RH-MCM-41 containing Fe-frameworks. The Fe content in Fe2O3-Fe-RH-MCM-41 (Fe-total) and Fe-RH-MCM-41 (Fe-frameworks) for each sample was determined by an AAS (atomic absorption spectrometer), whereas the content of Fe-non-frameworks was calculated from the difference between Fe-total and Fe-frameworks. The XRD (X-ray diffraction) pattern, N2 adsorption-desorption isotherm profile, as well as the TEM (transmission electron microscope) image clearly demonstrate that the RH-MCM-41 exhibits an ordered p6mm hexagonal mesostructure with a large specific surface area and uniform pore size. Based on the weight percents of Fe-frameworks found in each sample, it is clear that the content of Fe-non-frameworks is significantly enhanced compared to that of Fe-frameworks when the more concentrated Fe3+ is used.
Characterization of Synthetic Humin from Solid Hydrolysate and Biochar from Hydrothermal Carbonization Products of Chicken Feather Waste Siti Dewi Fatimah; Agus Kuncaka; Roto Roto
Indonesian Journal of Chemistry Vol 24, No 1 (2024)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.78688

Abstract

Solid hydrolysate and biochar 2:1 are synthetic humus from hydrothermal carbonization of chicken feather waste and contain humin that can be isolated by IHSS method. The recalcitrant humin is obtained in solid form. The yield of isolated humin from biochar 2:1 was 44.5%, and humin from solid hydrolysate was 12.7%. Analysis of humin by FTIR indicated the characteristics of complex functional groups. Based on the XRD and TEM tests, humin is formed from amorphous crystals with <14 nm in size and categorized as a superparamagnetic nanoparticle. The surface morphology of humin from solid hydrolysate is in the form of small spheres attached to larger particles, while humin from biochar 2:1 is smoother and has a larger surface area. This synthetic humin contains the nutrients N, O, Si, Cu, S, Mg, Zn, and K based on the EDX test quantitatively supported by AAS analysis. Characteristics of humin, which contains nutrients, are composed of amorphous crystals with complex functional groups during the hydrothermal carbonization process. Their relatively small heterogeneous molecules are stabilized by hydrophobic interactions and hydrogen bonds to form supramolecular compound associations in hour order. This humin content in synthetic humus is expected to increase its utility as a soil improver.