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Regeneration of Spent Bleaching Earth by Calcination and Its Morphological Enhancement via KOH Impregnation Nugraheni, Ika Kusuma; Jaya, Jaka Darma; Nuryati, Nuryati; Sunardi, Sunardi; Irawati, Utami; Faiza, Putri Iis; Saputra, Dita Adi
Indonesian Journal of Chemistry Vol 26, No 1 (2026)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.99600

Abstract

Spent bleaching earth (SBE), a waste generated from palm oil bleaching, contains residual oil and organic matter that block its pore structure and pose environmental disposal concerns. Regeneration of SBE is therefore essential to enable its reutilization. In this study, SBE was regenerated by calcination and further modified via KOH impregnation at concentrations of 1.00, 0.10, and 0.01 M. The regenerated materials were characterized using XRF, SEM, TEM, XRD, and BET surface area analysis. Calcination combined with 0.10 M KOH impregnation increased the surface area from 8.70 to 93.81 m2/g, approaching the value of activated bleaching earth (94.29 m2/g), and significantly altered pore volume and pore size distribution. These findings indicate that calcination restores the basic structure of SBE, while subsequent KOH impregnation enhances its morphological properties, highlighting the potential of regenerated SBE as a low-cost adsorbent or catalyst support.
Crystal Phase-Dependence of Ru@TiO2 Catalysts on the Product Selectivity in the Aqueous Phase Hydrogenolysis of Furfuryl Alcohol Bodoi, Thea Seventina Desiani; Rifwanda, Shauqi Aulia; Rodiansono, Rodiansono; Azzahra, Atina Sabila; Irawati, Utami; Oemry, Ferensa; Sunnardianto, Gagus Ketut; Adilina, Indri Badri; Hara, Takayoshi
Bulletin of Chemical Reaction Engineering & Catalysis 2026: BCREC Volume 21 Issue 1 Year 2026 (April 2026)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20547

Abstract

The crystal phase-dependence of ruthenium supported on titania (Ru@TiO2) catalysts on the product selectivity in the aqueous phase hydrogenolysis of furfuryl alcohol (FFalc) was investigated. The supported ruthenium nanoparticles (RuNPs) catalysts on TiO2 with different phases, c.a. rutile (R), anatase (A), and brookite (B) were employed. The Ru@TiO2(R) catalysed the hydrogenation-rearrangement reaction of furan ring to afford cyclopentanone/cyclopentanol (CPO/CPL) as the main product. The presence of high surface acidity in Ru@TiO2(R) catalyst promoted the hydrogenation-rearrangement of furan ring leading to CPO/CPL as the main product as indicated by NH3-TPD and pyridine-ATR-IR results. In contrast, the Ru@TiO2(A) catalyst selectively hydrogenolysed the furan ring to produce 1,5-pentanediol (1,5-PeD). This high selectivity of 1,5-PeD over Ru@TiO2(A) catalyst may be affected by the high dispersion of Ru NPs on TiO2 facets as depicted by the high H2-uptake and small particle sizes. Copyright © 2026 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Effect of Macroporous Chitosan-Tripolyphosphate Beads on COD and Turbidity Values in Sasirangan Wastewater Ariyani, Dahlena; Maulana, Riana; Irawati, Utami; Mujiyanti, Dwi Rasy; Umaningrum, Dewi
Jurnal Presipitasi : Media Komunikasi dan Pengembangan Teknik Lingkungan Article in Press 2026 (For Upcoming Issue)
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/presipitasi.v23i1.38-50

Abstract

A batch system was applied to study the effect of using macroporous cross-linked chitosan–tripolyphosphate (TPP) beads on chemical oxygen demand (COD) values and turbidity in Sasirangan wastewater. The ionic cross-linking reagent, sodium tripolyphosphate, was used to obtain more rigid chitosan beads, and sodium bicarbonate was added as a porogen. COD values were analyzed using the titrimetric method, and turbidity values were analyzed using the turbidimetric method. This analysis was used to study the effect of dose and pH on the performance of beads in Sasirangan wastewater. Scanning electron microscopy (SEM) characterization of the beads showed that NaHCO₃ as a porogen enlarged the pores in the chitosan–TPP beads, and Fourier-transform infrared (FTIR) characterization showed interactions among chitosan, chitosan–TPP beads, and wastewater. The results showed that higher chitosan dosages resulted in increased final COD values in Sasirangan wastewater, and the higher the pH, the higher the COD value. The addition of beads reduced the turbidity value of the Sasirangan wastewater, with higher doses leading to greater turbidity reduction, with the optimum achieved at 400 mL/L. The pH conditions did not affect the reduction in the turbidity value, with less than 1% variation observed.
Modified-ZrO₂ Supported Bimetallic Ruthenium-Tin Catalysts for Selective Hydrogenolysis of Furfuryl Alcohol to 1,5-Pentanediol Bodoi, Thea Seventina Desiani; Mustari, Ikhsan; Nurfitriani, Anggita; Ridhoni, Arif; Almervanka, Firza; Azzahra, Atina Sabila; Irawati, Utami; Rodiansono, Rodiansono
Jurnal Kimia Sains dan Aplikasi Vol 29, No 1 (2026): Volume 29 Issue 1 Year 2026
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.29.1.64-72

Abstract

Biomass-derived platform C5-furanic compounds such as furfural (FFald) and furfuryl alcohol (FFalc) can be converted into 1,5-pentanediol (1,5-PeD), an important intermediate for textiles and plastics, via catalytic hydrogenolysis reaction. However, catalyst selectivity for the hydrogenolysis reaction of FFalc to 1,5-PeD remains a challenge. In this study, modification of ZrO2 with metal oxides such as TiO2(R), TiO2(A), g-Al2O3, and active carbon (C) as the supports of bimetallic ruthenium-tin (Ru-Sn) catalysts for the selective hydrogenolysis of furfuryl alcohol (FFalc) to 1,5-pentanediol (1,5-PeD) has been investigated systematically. The modified-ZrO2 supports were prepared by physical mixing using oxalic acid as a binder at room temperature, followed by calcination under N2 at 300°C (ramping 2.5°C min−1) for 2 h. The supported Ru-Sn catalysts were synthesised by using the coprecipitation-hydrothermal method at 150°C for 24 h and reduced with H2 at 400°C (ramping 3.3°C min−1) for 2 h. The synthesised catalysts were characterised by means of XRD, H2-TPR, and NH3-TPD. The pristine structures of ZrO2, TiO2, and g-Al2O3 were maintained during the preparation of catalysts. Ru-Sn/ZrO2-TiO2(A) catalyst (Ru = 4 wt%, Sn = 1.30 wt%, ZrO2 = 67 wt%, and TiO2 (A) = 33 wt%) with calcination temperature of 300°C gave the highest yield of 1,5-PeD (72%) at 140°C, H2 10 bar for 3 h.
Characteristics of Chitosan from Chitin Deacetylation Using Different NaOH Concentration and Evaluation of Its Solubility in Liquid Smoke Ahmad Budi Junaidi; Nurul Hikmah; Utami Irawati; Nawwal Hikmah; Taufiqur Rohman
Jurnal Sains dan Terapan Kimia Vol 20, No 1 (2026)
Publisher : Jurnal Ilmiah Berkala Sains dan Terapan Kimia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/jstk.v20i1.25118

Abstract

This research aimed to determine the effect of chitosan characteristics produced from the deacetylation of chitin with various concentrations of NaOH on its solubility in liquid smoke. Chitin produced from rajungan shell raw materials was deacetylated using 40% NaOH (K40%), 50% (K50%), and 60% (K60%). The resulting chitosan was then measured of its degree of deacetylation (DD), molecular weight (BM), and solubility in liquid smoke. The results showed that K40% had a DD of 56.99%, K50% had a DD of 72.86% and a BM of 149.1 kDa, also K60% had a DD of 82.87% and a BM of 102.6 kDa. The solubility of chitosan in 10% liquid smoke indicated that K40% was not dissolved, K50% was almost completely dissolved, and K60% was completely dissolved.
Photocatalytic Degradation of Phenol Red Using Titanium Dioxide (TiO₂)–Chitosan Composite Catalyst Assisted By Solar Energy Taufiqur Rohman; Muhammad Ridwan Baidhowi; Utami Irawati
Jurnal Sains dan Terapan Kimia Vol 19, No 2 (2025)
Publisher : Jurnal Ilmiah Berkala Sains dan Terapan Kimia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/jstk.v19i2.23475

Abstract

Phenol Red is a very water-soluble textile dye that belongs to the triphenylmethane dye class. In this study, a photocatalyst composite was synthesized by combining TiO2 as photocatalyst with chitosan as a solid support material. The aim of this research is to study what ratio of TiO2: Chitosan would yield the best-performing composites in catalysing the photodegradation of phenol red. This research also studied, the optimum dose of TiO2-chitosan for photodegradation of phenol red, and the effect of solar radiation time towards the photodegradation of phenol red. Into 100 mL of phenol red solution with an initial concentration of 25 ppm, chitosan beads and TiO2-Chitosan composites were added with various doses, i.e:  0.5:100, 1:100, 2:100, and 5:100 gram/mL. The mixtures were put into solar radiaton exposure for 6 hours, where the concentration of phenol red in the solution was analysed every 20 minutes. The highest degradation level of phenol red (72.84%) was achieved by using TiO2-Chitosan 5:10 composites, where the dose added was 5 grams of composite for in 100 mL sample along with a 6-hour of solar radiation exposure.
Photocatalytic Degradation of Naphthol Blue Black Using TiO2-Chitosan Catalyst Under Solar Energy Utami Irawati; Taufiqur Rohman; Khairun Nisa
Jurnal Sains dan Terapan Kimia Vol 18, No 2 (2024)
Publisher : Jurnal Ilmiah Berkala Sains dan Terapan Kimia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/jstk.v18i2.21809

Abstract

Naphthol blue black (NBB) is an aromatic azo compound that is potentially carcinogenic and mutagenic. An alternative method of dealing with dye waste is photocatalysis. Photocatalysis is a combination of photochemical processes with the use of catalysts. The purpose of this study is to obtain data on the ratio of TiO2: Chitosan, which produces composites with the best ability, irradiation time and optimum dose of TiO2, which is effective in the process of photodegradation of NBB. The process of NBB photodegradation by chitosan beads and composites and chitosan irradiated with the best irradiation time on reducing NBB levels is for 360 minutes with a decrease in concentration of NBB more than 80%. Beads composite TiO2: Chitosan ratio of 5: 10 produces optimal ability. The optimum dose of composite beads in the NBB photodegradation process is 1 g composite / 100 mL solution.
Efficiency of Chitosan and Alum as Coagulants for Peat Water Treatment Dahlena Ariyani; Utami Irawati; Taufiqur Rohman
Jurnal Sains dan Terapan Kimia Vol 20, No 1 (2026)
Publisher : Jurnal Ilmiah Berkala Sains dan Terapan Kimia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/jstk.v20i1.25697

Abstract

Penelitian ini mengkaji efisiensi dari kitosan dan tawas sebagai koagulan untuk pengolahan air gambut. Dosis dan pH optimum koagulasi ditentukan berdasarkan penurunan turbiditas dan kadar senyawa organik dalam air gambut setelah dikoagulasi dengan kitosan dan tawas. Hasil penelitian menunjukkan bahwa dosis optimum untuk kitosan sebesar 5 mg/L dan tawas sebesar 15 mg/L dengan penurunan turbiditas sebesar 81,91% dan 76,28%. Koagulasi oleh kitosan dan tawas dipengaruhi oleh pH, dimana koagulasi oleh kitosan berlangsung optimum pada pH 8 dengan penurunan turbiditas sebesar 83,36%. Untuk tawas, pH optimum koagulasi adalah pada pH 7 dengan penurunan turbiditas sebesar 88,02%. Hasil penelitian menunjukkan bahwa tawas lebih efektif dibandingkan dengan kitosan dalam menurunkan kadar senyawa organik pada air gambut.
Co-Authors Adilina, Indri Badri Ahmad Budi Junaidi Alfanaar, Rokiy Almervanka, Firza Arfan, Aulia Rhamdani Arif Sholahuddin Azzahra, Atina Sabila Bodoi, Thea Seventina Desiani Chatimatun Nisa Dahlena Ariyani Dahlena Ariyani Desmalina Safitri Dewi Umaningrum Dewi Umaningrum Dirgahayu, Daniel Dwi Rasy Mujiyanti Dwi Rasy Mujiyanti Dwi Rasy Mujiyanti Edi Mikrianto Etty Novita Faiza, Putri Iis Fathul Jannah Ferensa Oemry Fitriani, Rizky Aulia Gea, Temani Hamidah . Hanifa Muslima Hanna Habibah Hikmah, Nawwal Indah, Rahma Iriansyah Iriansyah Iriansyah Iriansyah, Iriansyah Jaka Darma Jaya Khairun Nisa Laksono Trisnantoro Lilik Nofianti Manurung, Tety Wahyuningih Marvin Horale Pasaribu Maulana, Riana Messy Risna Mokhamat Ariefin Muhammad Ridwan Baidhowi Mustari, Ikhsan Nafia Fitrawati Nafisah Nafisah Nainggolan, Yuni Natania Gracia, Amanda Nawwal Hikmah Ningsih, Rima Oktavia Noer Komari Nor Pana Yupa Nora Rotua Sybianti Nugi Maulana Nugraheni, Ika Kusuma Nugravita, Annisa Nurfadilla Nur Firda Trianda Nurfitriani, Anggita NURUL HIKMAH Nuryati Nuryati Puspita Jamilah Rahimah Radna Nurmasari Rahmi Wulandari, Oktavia Retno Elya Rohmah Riana Maulana Ricky Kurniawan Ridhoni, Arif Rifwanda, Shauqi Aulia Rinne Nintasari Risaldi Ridwan Risaldi Ridwan Rizki Fitria Rodiansono Rodiansono Ryu Pratiwi, Djihan Saputra, Dita Adi Sunardi Sunardi sunardi sunardi Sunardi, Ph.D., Sunardi Sunnardianto, Gagus Ketut Suraida Suraida Sutarno Sutarno Takayoshi Hara Taufiqur Rohman Taufiqur Rohman Tety Wahyuningsih Manurung Totok Wianto Umi Baroroh Lili Utami Uripto T Santoso Uripto T Santoso, Uripto T Uripto Trisno Santoso Wahyuningsih Manurung, Tety Yateman Arryanto