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A Leak Free Phase Change Materials with Enhanced Thermal Buffering Properties by TiO2/Biochar Ariyanti, Dessy; Huda, Khoirul; Bayu Samudra, Muhammad; Lesdantina, Dina; Adi Saputra, Erwan; Hamzah, Fazlena
Reaktor Volume 23 No.3 December 2023
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.23.3.116-126

Abstract

A leak free organic phase change material of palmitic acid with enhanced thermal buffering properties was synthesized by simple chemical TiO2/biochar encapsulation process. By utilizing the optimum amount of TiO2 as an encapsulation agent the minimalization of leakage phenomena during the phase change process can be achieved with the value 20-25% of weight loss. Furthermore, the additional sugar cane bagasse-based biochar that was introduced to the encapsulation system acts as a support matrix that enhances further the leakage properties into free leak category with the percentage of weight lost 1.1-1.4 %. Moreover, the introduction of sugar cane bagasse-based biochar in the encapsulation system of the palmitic acid PCM can improve the thermal buffering properties by keeping a package box temperature in the range of 2-80C for more than 20 h by means small increment of temperature 0.72oC/h.  Keywords: PCM, encapsulation, palmitic acid, thermal buffering, leakage
Sedimentation Process of TiO2 Nanoparticles in Aqueous Solution Ariyanti, Dessy; Purbasari, Aprilina; Lesdantina, Dina; Saputro, Erwan Adi; Gao, Wei
Reaktor Volume 22 No.2 August 2022
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.22.2.70-76

Abstract

TiO2 nanoparticles, a semiconductor photocatalyst is widely used in various applications especially for water treatment. The common problems for the application are separating the nanoparticles from the water body and recovering it to be reused. This research was conducted to investigate the aggregation and sedimentation properties of TiO2 nanoparticles via chemical addition. The experiment was carried out for 5 hours by varying the pH, ionic strength, and the addition of organic matter such as rhodamine B, methylene orange, and humic acid. The results indicate that pH and ionic strength greatly affect the TiO2 sedimentation process. Sedimentation can be formed properly when the solution is at pH 1 and 14, this happens because pH is close to the isoelectric point. Meanwhile, ionic strength with a concentration of 0.1 M gave the most optimal results in TiO2 sedimentation. In the presence of ionic strength with the appropriate concentration, the thickness of the electrical double layer particles can be reduced so the attractive force increases and sedimentation occur. Meanwhile, in the presence of organic matter, rhodamine B, methylene orange, and humic acid did not significantly affect the formation of TiO2 sedimentation.Keywords: titanium dioxide, sedimentation, ionic strength, isoelectric point, water treatment
Biochar supported photocatalyst (mangrove biochar-TiO2) for organic pollutants removal via synergetic adsorption-photocatalytic process Azizah, Nadya Ummi; Ariyanti, Dessy; Lesdantina, Dina; Saputra, Erwan Adi; Srivastava, Vimal Chandra
Communications in Science and Technology Vol 10 No 1 (2025)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.10.1.2025.1619

Abstract

Access to clean water remains a global challenge, which is made worse by the contamination of chemical dyes. The recent innovations of wastewater treatment have been introduced, such as combined biochar with TiO2 photocatalyst. This study proposed to degrade mainly organic pollutants from dyed wastewater using adsorption-photocatalytic of biochar-supported photocatalyst TiO2 (BSP). Mangroves were converted into biochar via hydrothermal carbonization process and combined with TiO2 by a sol-gel method. The composite was then characterized by SEM-EDX, FTIR, and XRD. The degradation performance of the BSPs was optimized with the addition of Titanium (IV) Isopropoxide (TTIP) solution in biochar for 15-25 mL, solution photocatalyst dosage 0.5–1 g/L, initial dyed water concentration at 10 ppm, pH 5.2, and UV-irradiation time from 30 to 240 min in a photocatalytic reactor. The phenomenon of organic pollutants removal was observed based upon the mechanism and dominance of the process and the degradation reaction rate of organic pollutants in dyed wastewater. Methylene blue used as a model dye was degraded 100% through the adsorption-photocatalysis process using BSP. The highest effective degradation performance was found in BSP 20 that had a functional group area of 4.39923 m²/g, a catalyst loading of 0.5 g/L, and the highest degradation rate at k = 0.021 min?¹. In subsequent development, the synergistic interaction between biochar and TiO2 presents a promising avenue for the development of advanced wastewater treatment systems targeting the removal of organic pollutants, particularly in textile industry.