Jurnal Rekayasa Kimia & Lingkungan
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Applied of Synthesis Furfural Based on Cassava Stems (Manihot utilissima) As Fuel Additive to Gasoline
Full text linkBiofuel is an option to reduce CO2 generated by vehicles. In this study, synthetic crude furfural from cassava stems was blended as fuel additive to gasoline (Pertalite) and then induced by electromagnetic field. Analysis were carried out on engine performance and exhaust emissions produced by Kohler engines. Variations formed by samples crude furfural and commercial furfural (C5H4O2), then time variations of electromagnetic induction for 0 and 30 minutes. The blending composition of gasoline and furfural in a mixture of 1,500 ml fuel is 96% : 4%. The best results from increasing torque, cranking power and saving fuel consumption were obtained from variations in the use of crude furfural additives induced by electromagnetic fields (CFE). Exhaust emissions produced by pure Pertalite are still lower than fuels with furfural additives. The content of water and impurities in crude furfural causes the additive unmixed with Pertalite which is non-polar and hydrophobic
Synthesis of Lactic Acid from Molasses by Lactobacillus acidophilus Using a Batch Fermentation Process
Full text linkLactic acid is a chemical with widespread applications, mainly in pharmaceutical, cosmetic, chemical as well as food industries. One of the major uses of lactic acid is the polylactic acid (PLA) feedstock which is biodegradable and biocompatible as an alternative to plastic derived from fossil fuels. Efforts continue to be made to reduce the cost of producing PLA in order to compete with the conventional petrochemical-based plastics. This include the use of molasses as a raw material because it is cheap and contains high glucose. The purpose of this study was to obtain cell concentrations through the addition of starter volume that produces high concentrations of lactic acid and to obtain the growth kinetics of Lactobacillus acidophilus during the fermentation process. This study was conducted in several stages; the design of bioreactors, inoculation of Lactobacillus acidophilus, and fermentation of molasses. In a batch system, molasses substrate was directly inserted as much as 500 ml in the fermentor and the addition of starter volume of Lactobacillus acidophilus was 1; 3; 5 dan 10% v/v. The fermentation of molasses for 72 hours and the product was analysed every 8 hours. The highest concentration of lactic acid produced in batch fermented molasses was added to 5% (v/v) starter volume with 72 hours of fermentation time, which was 23.1 mg/L, with value the carrying-capacity coefficient (k) and the maximum net specific growth rate (net) were 0.2379 h-1 and 0.0160 h-1 respectively
The Heat Resistant Capabilities of Bioplastic Composites on Sago Hampas Starch-Al2O3
Full text linkSago hampas are a waste with a high starch content. The starch from sago hampas can be used as a raw material for bioplastics. However, because bioplastics have a lower heat resistance than conventional plastics, additives are required to increase heat resistance. Aluminum oxide can be used as a metal compound that acts as an additive to increase heat resistance. Bioplastics were created using a weight percentage of 0, 1, 3, and 5% Al2O3. DTA was used to determine the melting point of bioplastics, as well as their mechanical properties, density, and water resistance. The best results were identified using FTIR and SEM. The results showed that adding Al2O3 at 1, 3, and 5% increased the heat resistance of bioplastics with melting points of 270, 274, and 280 oC. Except for mechanical properties, the best results were obtained with a melting point of 280 oC, tensile strength of 3.41 Mpa, elongation of 38.66%, density of 5.52 g cm-3, and 80.28% water resistance for bioplastics with 5% Al2O3 that suitable on Indonesian National Standard 7188.7:2016. The FTIR analysis revealed that bioplastics containing Al2O3 experienced physical interactions. Morphological analysis revealed that Al2O3 was evenly distributed on the bioplastic's surface
Analysing Pan Evaporation to Understand Wastewater Treatment Plant Performance, A Case Study in A Manufacturing Industry
Full text linkWater loss has become a problem with the balance of a water system, including one in the industry. General opinion has considered evaporation as one of the main justifications for explaining the water loss, especially in the area with a higher daily temperature. A study was conducted on a wastewater treatment system owned by a manufacturing industry consisting of semi-open-air sedimentation and aeration ponds, which suddenly experienced a significant deficit in its water balance. Problem-solving was performed by 8-Step Problem Solving approach and root causes were confirmed by estimating water evaporation. The actual water evaporation rate (E) was approached by pan evaporation (Epan) using the partial pressure of the water vapour and the pan evaporation coefficient (Kpan). The study revealed that evaporation (1.670.59mm.d-1 and 1.720.62mm.d-1, for sedimentation pond and aeration pond, respectively) was not the main cause of sudden significant water loss (R2 = .490, p-value .05) and confirmed another root cause. In parallel, a water balance model was constructed and fitted the actual condition (R = .987). A countermeasure was performed against the confirmed root cause followed by a monthly evaluation of water loss using the constructed model with a 3 threshold value (UCL = 9.55%) which showed the elimination of the problem
Mapping the Spread of Mercury from Artisanal Mining Activities in Aceh Jaya through Geochemical Surveys
No full textIllegal gold mining carried out using amalgamation techniques produce mercury waste which can then damage the environment and damage the health of residents. The negative impact due to the use of mercury is dead fish, contaminated river water, water quality below environmental standard quality and spreading in the food chain. This has caused environmental damage, one of which is in terms of land and water. This condition is the basis for conducting deeper research on environmental damage by mercury waste, especially in terms of soil and water. The sampling method used is the Geochemical Method and Geoelectric Method. Geoelectric samples were taken using the superstring R8 tool. Geochemical samples used were soil and water samples which were subsequently tested by the Atomic Absorption Spectrophotometry (AAS) and X-ray Fluorescence (XRF) methods to see the mercury levels that had been scattered in the research location. The study aims to determine the distribution of mercury waste and its levels. This research includes sampling, sample testing, data processing and analysis, and making maps of the distribution of mercury waste through QGis software. From the study, it was found that the distance from the traditional gold mining processing location determines the concentration level (Hg). Analysis using AAS shows that there were 13 samples had mercury concentrations above the critical threshold. From the analysis, it is also known that AAS could not detect mercury levels in soil samples which is different from the results obtained using XRF
Fish-scale inspired superoleophobic membrane from cellulose: A Review
Full text linkNature-inspired technology has been investigated widely. Anti biofouling properties of fish scale has inpired to improve membrane performance. Biofouling affects an oil-water separation membrane. The bacterial, coagulant, and hydrophobic oils attach to the membrane surface, demanding periodic cleaning. To overcome the problems, surface modification materials are introduced namely superoleophobic surface. The superoleophobic surface promises antifouling, high flux, and high separation efficiency. Superoleophobic surfaces are inspired by the scales on fish that form a hydrogel-like layer on their surface. The hydrogel repels oil and any organic materials, keeping the surface clean. The hydrogel of fish scales can be mimicked by cellulose-based materials. A dense layer of hydroxyl groups absorbs a lot of water and forms a hydrogel bond. The membrane with the cellulose hydrogel-like structure will perform a superoleophobic characteristic surface. The characteristic can be utilized as a functional membrane for oil-water separation. This article reviews the principle, mechanism, current development, and future challenges of bioinspired superoleophobic surfaces from cellulose-based materials for membrane applications
Synthesis of Biofoam Based on Starch Mixture of Cassava Peel and Kepok Banana Peel with Chitosan Additive to Improve Mechanical and Physical Characteristics
No full textBiodegradable foam(biofoam) is a type of bioplastic that is used as an alternative packaging to replace styrofoam which is safe and environmentally friendly. This study aims to determine the characteristics of biofoam made from cassava peel starch (A) and banana peel starch (B), as well as the effect of adding chitosan to the physical, mechanical, and biodegradation properties of the resulting biofoam. In the manufacture of biofoam, the variation of the A:B ratio used is 1:0; 3:2; 1:1 (%w/w). While the chitosan content added was 0%, 15%, and 30% by weight of starch and blowing agent NaHCO3 with a content of 12% by weight of starch. The production of biofoam was carried out using the thermopressing method with a printing temperature of 125C and a printing time of 7 minutes. The results of biofoam were characterized by density, water absorption, compressive strength, biodegradation, and FTIR functional groups. Based on the research results, it is known that biofoam is close to commercial biofoam standards, namely biofoam with an A:B ratio of 3:2 and the addition of 15% chitosan with a density value of 0.560 g/cm3, the water absorption capacity of 33.68%, compressive strength value of 5, 05 MPa, and the decomposition power of 17.44%. These variations have functional groups NH, OH, CH, C=O, CN, and CO
Molten Salt Synthesis of Photocatalyst Material SrBi4Ti4O15 for Methylene Blue Degradation
Full text linkThe four-layered Aurivillius SrBi4Ti4O15 compound has been reported to be potentially used as a photocatalyst material. In this research, SrBi4Ti4O15 was prepared by the molten salt method using NaCl/KCl and then used to degrade methylene blue. The analysis of sample diffractogram indicated that the SrBi4Ti4O15 was obtained but there was still the impurities of Bi4Ti3O12. The micrograph showed that particle shape of SrBi4Ti4O15 is plate-like (sheets) with a lot of agglomeration. The band gap energy of SrBi4Ti4O15 is 3.14 eV (394.85 nm), according to the Kubelka-Munk calculation from the spectrum of reflectance. The photocatalytic test results showed that SrBi4Ti4O15 degraded methylene blue to 47.8% in 120 minutes
Gasification of Coffee Parchment as Potential Method for Coffee Agro-Industry Waste Utilization
Full text linkCoffee parchment is a lignocellulosic waste material which has a potential to transform into synthesis gas. This research aims to study the feasibility of coffee parchment conversion under downdraft gasification with auto-heating supply method. The temperature profile in each zone of the reactor was investigated as the effect of different equivalence ratio (ER) as well as the producer gas characteristics such as ignition time, flame duration, colour and temperature, carbon conversion and producer gas composition. Initially, coffee parchment collected from dehulling process was sun-dried three to four days. The gasification was ignited by firing ca. 300 g of wood charcoal inside the reactor before the coffee parchment loaded, then the reactor was tighly closed. Once the combustible gas was produced, the gasification time was measured. The result shows that the highest operational temperature inside the reactor was 715.66 C within the combustion zone. The biomass conversion tends to increase by the increasing of ER, but the producer gas might dilute by more carbon dioxide production, and nitrogen input into the producer gas which indicated by the flame duration, colour, and temperature. Introducing an ER of 0.3 into the gasification reactor has provided adequate amount of oxygen to convert the coffee parchment into producer gas. This investigation suggests that coffee parchment is feasible to be converted into syngas. However, providing an advance process integrated to cleaning system would be required in the future to obtain a fuel grade syngas
Degradation of Ciprofloxacin Antibiotic Waste Using TiO2 Nanotube with Addition of Anthocyanin Dye-Sensitizer In Photocatalysis Process: Review
Full text linkAn antibiotic-containing waste entering the water bodies is very dangerous because it can disturb the balance of the ecosystem and can modify the genetic information of natural bacteria so that resistance occurs. One type of antibiotic is ciprofloxacin (CIP) which can pollute aquatic ecosystems. One potential method that can be used to degrade the CIP is photocatalysis since it is low cost, highly effective, and environmentally friendly. To improve the performance of TiO photocatalyst, morphological engineering is carried out to form TiO nanotube arrays and then coated with natural anthocyanin sensitizer. The morphological engineering of TiO can be done through the anodization process. It is an electrochemical coating process that can convert metals to porous metal oxide layers. The effectiveness of the TiO2 photocatalyst in degrading pollutants can be increased by a dye-sensitizer addition. Commonly, natural anthocyanin dyes are chosen as sensitizers on the TiO2 semiconductor surfaces. Visible light is absorbed by the dye-sensitizer substances to speed up the electron excitation mechanism. The dye-sensitizer addition causes the TiO2 photocatalyst to be more responsive to visible light. The addition of the dye-sensitizer on the surface of TiO2 nanotubes has the potential to increase the degradation of ciprofloxacin waste using a photocatalytic process