Wahyudi Budi Sediawan

• Professor at Universitas Gadjah Mada

The recovery of rare earth elements from coal-related materials, primarily fly ash, has become an emerging topic for the past few years. The availability of fly ash as solid waste from coal combustion and its low radionuclide concentrations benefit its utilization as an alternative source of rare earth elements. Using organic substances like citric...

Proanthocyanidin has been extracted from red sorghum seed with Ultrasound-Assisted Extraction using an aqueous-based solvent. Proanthocyanidin concentration in the extract is relatively low mixing with other compounds. The adsorption method was chosen to separate proanthocyanidin compounds due to the relatively simple operation to recover targeted...

Rice straw is a by-product of the production of rice. Most of this material is considered as agricultural waste, used only for fodder, left or burned on the fields after harvest. Rice straw contains 35-50% cellulose, making it promising as raw material for microcrystalline cellulose production. The production of microcrystalline cellulose consists...

The production of fly ash as a solid waste of coal combustion increases with electricity demand growth in Indonesia. Fly ash is usually discarded in landfills due to its lack of utilization. Poor handling of the material can cause pollution and harm to human health. One potential of fly ash that can be further explored is as an alternative source o...

Rice husk as a by-product of the rice milling process is a material that can still be processed to be a product that can be used in various applications. The potential for the commercialization ofrice husks is still hampered by its low economic value. By using the heating method using an inert gas,rice husk can be converted into a composite whichco...

Proanthocyanidin extraction for antioxidant material from intact red sorghum grains in agitated vessel had been investigated. The optimization and the appropriate kinetic evaluation were useful to conduct the engineering design of the developed process. Concentrations of the proanthocyanidin compounds in the aqueous extract were affected by the agi...

Production of fly ash as a solid waste of coal combustion rises as the need of electricity in Indonesia increases. In 2020, the amount of fly ash produced is estimated to reach 9.72 million tons. Utilization of coal fly ash is still limited while poor handling on abundant amount of this material can cause air, soil and water pollution. This researc...

Sulfur-oxidizing bacterias were isolated then grown on salak fruit seeds forming bio-film. Their performances in sulfide removal were experimentally observed. The salak fruit seeds were then used as packing material in a cylinder. Liquid containing 83 ppm of sodium sulfide was flown through the bed. Then the sulfide concentrations in the outlet at...

Chitosan is known as an antibacterial agent. The effective surface area ratio of chitosan can be increased by modification into nanoparticles. Nano-chitosan can be prepared with several simple methods, i.e. precipitation, ionic gelation, or the polyelectrolyte complex method. This study compared these three methods in terms of the targeted product...

Antibacterial properties of nano-chitosan used for fish preservation would achieve optimum effect when combined with cooling. Applying nano-chitosan incorporated in ice can reduce the cooling cost of conventional fish industry. On the other hand, during fish handling, nano-chitosan has a high probability to be contaminated by salt in seawater. This...

The Dayak's Tribes in West Kalimantan of Indonesia uses the leaves of san-sangk (Albertisia papuana Becc.) as one of the seasoning ingredients. The leaves are known to contain gallic and glutamic acid, which are important chemical compounds for human health. Various extraction methods using solvents have been used to produce gallic and glutamic aci...

The purpose of this review is to examine the use of Albertisia papuana Becc. for food and its therapeutic effects as anticancer, antimalarial, antimicrobial. The method used is various articles that are relevant to the topic of electronic data. Results show Albertisia papuana Becc. containing umami compounds (glutamic, aspartic, IMP, GMP, AMP) whic...

The aim of this work is to evaluate the influence of the pore structure of Fe-supported carbon catalysts in heterogeneous Fenton oxidation. For such goal, two types of porous carbons i.e. biomass-derived carbon (BDC) and polymer-derived carbon (PDC) were employed as catalytic supports. Both solids present the same specific surface area (ca. 1300m²/...

As the result of increasing environmental concern, new technologies for bleaching pulps have been developed. Chlorine containing bleaching agents has been replaced by more environmentally benign chemical, such as H2O2. This paper proposes mechanism of alkaline peroxide bleaching in order to get better understanding of the process mechanism. Bleachi...

This paper presents an experimental investigation on using mixed culture for immobilization and co-immobilization for hydrogen production. The shape and diameter of the beads were investigated. Hydrogen was produced from 10 g.L-1 glucose in anaerobic batch using immobilized mixed culture with extrusion dripping method. The alginate concentrations a...

Ethanol can be used as fuel if it has a purity of 99.5%, while ethanol distillation will stop at its azeotrop point, ie at 95.6%. Adsorption of molecular sieve is one of the methods to obtain ethanol with level above the azeotropic point. Adsorbent that serves as molecular sieve is synthetic zeolite 4A. The adsorbent has a pore diameter of 3.9 Ǻ, t...

This study tried to explore the quantitative description of removal of hydroden sulphide (H2S) by bio-filtration. H2S is degraded by bacteria immobilized on the packing materials of Salak fruit seeds inside a column. Two kinetics models are proposed. In both models, the biofilm formed on the packing material is assumed to be thin, so intra-film gra...

Mathematical modelling of batch adsorption of Oryzanol separation from Rice Bran Oil (RBO) has been set-up and tested by generated experimental data. The proposed model takes into account mass transfer and equilibrium phenomena. The effects of intra-particle gradient were considered, so the adsorption rate is controlled by the rate of solute mass t...

PREDIKSI KESETIMBANGAN ADSORPSI URANIUM PADA AIR DAN BERBAGAI SEDIMEN. Kegiatan penelitian, pengembangan, penambangan, dan pemurnian uranium berpotensi menimbulkan pencemaran lingkungan. Uranium merupakan salah satu logam berat berbahaya karena bersifat racun dan radioaktif sehingga perlu diketahui sampai sejauh mana sebaran uranium di lingkungan....

The objective of this research was to get the mechanism of nano size chitosan particle growth during storage by observing the effect of temperature and initial concentration of chitosan. The products were analyzed using PSA to have the average of particle radius. Nanochitosan solution was prepared by ionic gelation method. This method is described...

This time, the natural resources of zircon sand is processed into several zirconium products which is utilized for various industries, such as ceramics,glass industry, metal industry and nuclear industry. The process of zircon sand into zirconium products through several stages, one of them is leaching process of Na2ZrO3 with HCl. In this research,...

Utilization of valuable trace components in agriculture by product such as rice bran oil is interesting to be explored. Among the valuables, oryzanol, a healthy nutrition for cardiovascular prevention, is the most promising one. Literature studies suggest that adsorption-desorption is a prospective method for oryzanol isolation. Design of commercia...

ABSTRAK Oryzanol merupakan senyawa fitokimia yang penting dalam bidang farmasi, kosmetika, dan pangan fungsional. Oryzanol diperoleh sebagai produk samping pertanian padi. Isolasi dan purifikasi diperlukan untuk meningkatkan konsentrasi oryzanol. Salah satu metode pemungutan oryzanol adalah proses adsorpsi berkonsep kromatografi. Pengembangan konse...

Reduction of U3O8 by H2 gas is among the important steps in manufacturing coated UO2 fuel kernels used in High Temperature Reactor (HTR). Most of previous studies in this area focus on finding operating conditions, such as temperature and reaction time, which can be used in producing high quality UO2 kernel. The present work deals with experimental...

Mathematical modeling on kinetics of batch adsorption of vitamin E separation from palm fatty acid distillate (PFAD) has been setup and then applied for literature experimental data. Since the sizes of adsorbent particles used are usually relatively small, the concentration in the particles is assumed to be uniform. Hence, the adsorption rate is co...

Mathematical modeling on kinetics of batch adsorption of vitamin E separation from palm fatty acid distillate (PFAD) has been setup and then applied for literature experimental data. Since the sizes of adsorbent particles used are usually relatively small, the concentration in the particles is assumed to be uniform. Hence, the adsorption rate is co...