Riani Ayu Lestari
Department Of Chemical Engineering, Faculty Of Engineering, Lambung Mangkurat University, South Kalimantan, Indonesia

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ANALYSIS OF ENCAPSULATED YEAST IN COMPUTATIONAL FLUID DYNAMICS APPROACH Riani Ayu Lestari; Rianti Indah Lestari
Konversi Vol 8, No 2 (2019): Oktober 2019
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v8i2.7203

Abstract

Abstract - Computational fluid dynamics of encapsulated yeast has been developed to determine characterization of encapsulated yeast applied for ethanol production from lignocellulose waste. Encapsulated yeast as biologically activate materials enclosed in a semipermeable membrane to protect cell from inhibitor attack. Encapsulated yeast system relates to mass transfer of substrate (glucose) into capsule and out of capsule and fermentation reaction. Modelling of mass transfer was developed to understand capsule performance consisting of 3 parts, cell aggregate, liquid space and thin membrane. Finite element method has been applied to solve partial differential equation of glucose concentration profile against x, y position and t -time in Comsol multhiphysics 3.5a. Capsule geometry was showed in half part capsule, 2D and axis symmetries. Trend line of glucose distribution was effected by thickness membrane that 0.1 mm controlling in mass transfer and cell aggregate of 50%-v of membrane.Keywords: computational fluid dynamics, encapsulated yeast system, glucose mass transfer
INVESTIGATION OF THE INFLUENCE OF PARTICLE SIZE OF RICE HUSK ASH AS ADSORBENT FOR MERCURY IN COLUMN ADSORPTION SYSTEM Desi Nurandini; Riani Ayu Lestari; Isna Syauqiah; Ahmad Rizalli; Ryan Rahmatullah
Konversi Vol 10, No 2 (2021): Oktober 2021
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v10i2.11726

Abstract

The presence of heavy metal mercury (Hg2+) in liquid waste has caused serious problems to environmental pollution. One of the most effective method to reduce the levels of heavy metals mercury (Hg2+) in liquid waste is adsorption. Rice husk ash is highly potential to adsorb heavy metals in water because it is a porous material with a high silica content. Therefore, rice husk ash can be used as an adsorbent for heavy metals in liquid waste. The purpose of this study was to determine the level of mercury (Hg2+) that can be adsorbed from the column adsorption process using adsorbent of rice husk ash and to determine the optimum mass of rice husk ash as an adsorbent. The research was conducted using a series of simple adsorption column tools with a circulation time of 120 minutes. While the independent variables were adsorbent particle size of 50, 100, and 200 mesh. Measurement of mercury (Hg2+) levels was carried out on samples before and after treatment with Atomic Absorption Spectrophotometer (AAS). The results showed a significant decrease in Hg2+ levels with the optimum adsorbent particle size of 200 mesh. The value of the adsorbed Hg2+ ion content reached 101.670 mg/L in the adsorption process using adsorbent with 200 mesh particle size . 
CHARACTERISTICS ANALYSIS OF ADSORBENT FROM RUBBER TREE TRUNK AND RUBBER SEED SHELLS Desi Nurandini; Riani Ayu Lestari; Muhammad Zeva Prayitno; Isna Syauqiah
Konversi Vol 11, No 2 (2022): OKTOBER 2022
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v11i2.14600

Abstract

The efforts to control heavy metal waste are developingg to obtain an economical, effective, and efficient method. One method that is widely used in industry is adsorption. In general, the use of conventional adsorbents requires relatively more expensive operational and regeneration costs, thus it is necessary to investigate alternative adsorbents derived from nature. Local commodities that can be taken as the basic material for adsorbents are rubber plants. In the rubber seed shell there are fibers containing cellulose, hemicellulose, lignin, and waxes. The rubber tree trunk at the base has a relatively high cellulose content (67.38%), the middle part has a cellulose content of (59.37%) and the end part has a cellulose content of (45.73%). Therefore, this study was conducted to determine the potential of rubber stems and rubber seed shell waste to be processed into adsorbents. The making of the adsorbent is preceded by the delignification stage and then followed by the activation process. Based on the characterization tests that have been carried out, it is known that the moisture content in the biosorbent of the rubber seed and shell is 10% and 11%, while the ash content is 1.23% and 2.33%, respectively. The volatile matter levels for the adsorbents from the stems and shells were 6.43% and 6.18%, respectively.The efforts to control heavy metal waste are developingg to obtain an economical, effective, and efficient method. One method that is widely used in industry is adsorption. In general, the use of conventional adsorbents requires relatively more expensive operational and regeneration costs, thus it is necessary to investigate alternative adsorbents derived from nature. Local commodities that can be taken as the basic material for adsorbents are rubber plants. In the rubber seed shell there are fibers containing cellulose, hemicellulose, lignin, and waxes. The rubber tree trunk at the base has a relatively high cellulose content (67.38%), the middle part has a cellulose content of (59.37%) and the end part has a cellulose content of (45.73%). Therefore, this study was conducted to determine the potential of rubber stems and rubber seed shell waste to be processed into adsorbents. The making of the adsorbent is preceded by the delignification stage and then followed by the activation process. Based on the characterization tests that have been carried out, it is known that the moisture content in the biosorbent of the rubber seed and shell is 10% and 11%, while the ash content is 1.23% and 2.33%, respectively. The volatile matter levels for the adsorbents from the stems and shells were 6.43% and 6.18%, respectively.
Step-by-Step Fabrication of PVDF-TiO2 Hollow Fiber Membrane and Its Application Desalination of Wetland Saline Water via Pervaporation M. Mahmud; Muthia Elma; Aulia Rahma; Nurul Huda; Riani Ayu Lestari; Awali S. K. Harivram; Erdina L. A. Rampun; Mohd H. D. Othman; Muhammad Roil Bilad
Indonesian Journal of Science and Technology Vol 8, No 3 (2023): (ONLINE FIRST) IJOST: December 2023
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v8i3.63433

Abstract

Wetland water is opted as the source of domestic water supply when the availability of clean fresh water is scarce. Wetland water requires proper treatment due to the high concentration of organic matter and high salinity, particularly in the dry season. This research aims to synthesize, characterize, and investigate the performance of polyvinylidene fluoride (PVDF)-TiO2 hollow fiber membrane for wetland saline water desalination via pervaporation. The PVDF-TiO2 hollow fiber membranes were fabricated through the dry wet spinning method under various air gaps (10, 15, and 20 cm). Then, the resulting membranes were tested in a pervaporation process at temperatures of 25, 40, and 60°C. Results show that the incorporation of TiO2 into the PVDF matrix imparted hydrophilicity properties into the resultant membranes. The presence of TiO2 was confirmed by the TiO2 stretching vibration at 1640 cm-1 (FTIR) and the TiO2 phase at diffraction peaks at 25.5 and 37°. The membranes exhibited the highest water flux (7.48 kg/m2.h) and salt rejection ( 99.5%) at 40°C. Overall, the developed PVDF-TiO2 hollow fiber membranes showed encouraging results and demonstrated their effectiveness for the desalination of wetland saline water.