Jurnal Rekayasa Kimia & Lingkungan
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Synthesis of Hydroxyapatite from Precipitated Calcium Carbonate of Thorny Shells (Murex trapa) with Variable Ca/P Mole Ratio and pH
Full text linkHydroxyapatite, with the chemical formula Ca10(PO4)6(OH)2, is a mineral found in human bones and teeth, providing density and strength to bones as it is a major component of the bone matrix. It is widely used in biomedicine for bone implants, dental fillings, and hard tissue replacement. Hydroxyapatite can be produced from materials high in CaCO3, such as cattle bones, seashells, and fish bones. In this research, thorny clam shells (Murex trapa), with a CaCO3 content of 91.08%, were used. Precipitated Calcium Carbonate (PCC) was formed using the carbonation method, while hydroxyapatite synthesis was performed using the precipitation method. Variables during synthesis included Ca/P molar ratios of 1.47, 1.67, and 1.87, and pH levels of 7, 9, and 11. The best result was achieved at a Ca/P molar ratio of 1.67 and pH 9, with a yield of 96%. The hydroxyapatite was analyzed using Fourier Transform Infra-Red, revealing the core groups PO43-, CO32-, and OH-.Scanning Electron Microscopy-Energy Dispersive X-Ray analysis showed the hydroxyapatite had a crystalline structure, tending to be spherical and agglomerated
Carbon Dioxide (CO2) Separation Study Using Chemically Activated Serpentine as an Adsorbent
No full textThe increase in carbon emissions resulting from industrial activities has become a major concern for environmental and climate conditions. Carbon Capture and Storage (CCS) represents a significant effort to mitigate the CO2 problem. Aceh Province possesses a potential distribution of serpentine, which may serve as an effective material for CCS applications. This study evaluates the effects of gas flow rate, particle size, sorbent weight, and pressure on CO2 adsorption using chemically activated serpentine. The activation process involved hydrochloric acid (HCl) at three concentrations: 8%, 9%, and 10%, with particle sizes of 50 mesh, 100 mesh, and 150 mesh. Activation was conducted at room temperature with an acid-to-serpentine ratio of 10:1 for 30 minutes. Adsorption tests were performed at ambient temperature under pressures of 2, 3, and 4 bar, with adsorption times of 30, 60, and 120 minutes. Results indicate that activated serpentine treated with 9% HCl and a particle size of 150 mesh achieved the highest performance, demonstrating an adsorption efficiency of 33.01% and an adsorption capacity of 82.22% (0.0488 g CO2/g adsorbent) at a pressure of 2 bar. Both the Langmuir and Freundlich isotherm models closely fit the data (R = 1). This study concludes that HCl activation significantly enhances the capacity and efficiency of serpentine as a CO2 adsorbent
Application of Used Cooking Oil Based Emulsion Liquid Membrane for Rhodamine B Extraction
Full text linkUsed cooking oil is utilized as a nontoxic and environmentally friendly organic diluent without the need for complicated pretreatment. Cationic dye rhodamine B was chosen as a sample because of its ability to decolorize water and its use as a base material in toxic, carcinogenic, and mutagenic textile dyes. This study investigates the extraction of rhodamine B from water using cooking oil-based Emulsion Liquid membrane (ELM) methods. This approach addresses issues associated with petroleum-based organic diluents commonly used in ELM processes. The research aimed to evaluate the effect of rhodamine B concentrations ranging from 5 to 20 ppm and D2EHPA concentrations from 0.5 to 2.5% on extraction efficiency. The emulsion was prepared using used cooking oil as the diluent, Span 80 as the surfactant, D2EHPA as the carrier, and HCl as the internal phase. The concentration of rhodamine B in the external phase was determined using a UV-Vis Spectrophotometer. Both rhodamine B concentration and D2EHPA concentration significantly affected extraction efficiency. The highest extraction efficiency of 92.83% was achieved with a rhodamine B concentration of 15 mg/L and a D2EHPA concentration of 2.5% (v/v)
Adsorption of Malachite Green Dye by Magnetic Carboxymethyl Chitosan
Full text linkMalachite green dye is widely used in the textile industry. Wastewater contaminated with malachite green dye threatens aquatic life and human health. Therefore, adsorption is needed in the dye waste treatment process. This research aims to synthesize magnetic carboxymethyl chitosan as an adsorbent for malachite green dye. Magnetic carboxymethyl chitosan was synthesized via a coprecipitation method and analyzed using FTIR. Batch experiments were used to study the adsorption of malachite green dye under adsorption parameters, such as the effects of pH and time, adsorption kinetics, isotherms, and reusability. The research results show that at pH 4, malachite green adsorbed most effectively into magnetic carboxymethyl chitosan. The pseudo-second-order kinetic model and the Langmuir adsorption isotherm model describe the adsorption process. Reduction for malachite green chitosan, carboxymethyl chitosan, and magnetic carboxymethyl chitosan were 34.19, 83.24, and 91.34%, respectively
Enhancing Diatomaceous Earth Characteristics for Adsorption of Heavy Metals from Acid Mine Drainage: The Impact of Dual Activation Process
Full text linkThis study investigates the effects of dual activation methods, including physical and chemical processes, on the characteristics of diatomaceous earth (DE) for the purpose of controlling heavy metal concentration in acid mine drainage. The DE is subjected to physical activation through calcination at 750 oC for 60 minutes, followed by chemical activation using 1N HCl at 80 oC for 24 hours under magnetic stirring. The resulting adsorbent is then characterized using XRD, SEM-EDX, and BET instruments. The analysis reveals that the dual activation methods increase the silica content and eliminate impurities in the DE, leading to a more amorphous structure with decreased crystallinity. The physical activation increases the surface area, while the dual activation process reduces the surface area and increases pore size. These findings provide valuable insights into the adsorption capacity of DE for reducing heavy metals in acid mine drainage
Activation of Sugarcane Bagasse Biosorbent with Potassium Hydroxide and Hydrogen Chloride to Reduce Color of Batik Wastewater
Full text linkThe textile industry, particularly the batik sector, significantly contributes to the Gross Domestic Product (GDP) of East Java Province. However, the batik dyeing process, which uses synthetic dyes like remazol, rapid, and naphthol, causes environmental issues due to the non-biodegradable nature of these dyes, leading to environmental pollution such as an increase in color levels in water bodies. This research investigated using activated sugarcane bagasse with KOH and HCl in batch adsorption systems as an alternative method. It compared the color efficiency removal in batik wastewater with variation biosorbent mass, contact time, and activator type. The study found that the highest percentage removal of dye substances was achieved with the KOH-activated biosorbent, reaching 69.46%, and the HCl-activated biosorbent demonstrated a 60.98% removal efficiency with a mass variation of 0.4 grams and a contact time of 30 minutes. Statistical analysis using multiple linear regression showed that independent variables (biosorbent mass, contact time, and activator) significantly affect the dependent variable (color removal efficiency) simultaneously. In the partial test, the independent variables of biosorbent mass and type of activator significantly affect color removal efficiency, but contact time does not significantly affect color removal efficiency
Tar Removal of Palm Kernel Shell Syngas using Wet Scrubber
Full text linkIn the current situation, biomass gasification has become a major interest in producing clean energy and green chemicals. By gasification, the biomass can be converted to synthetic gas (syngas) for many purposes. However, syngas with high tar content can cause pipeline fouling and disturb the operation of downstream equipment. To reduce tar content, a two-series wet scrubber was installed for syngas cleaning produced by palm kernel shell gasification. Firstly, the gasification is operated at a temperature range of 500 600oC and 700 800oC to determine the conditions where the lowest tar syngas is produced. After that, the wet scrubber is installed with a variety of solvents including isopropyl alcohol, water, used cooking oil, and used lubricating oil. The results show that the lowest tar syngas was produced at a temperature of 800oC with a tar yield of 0.165 g/kg biomass. Meanwhile, in the same condition, isopropyl alcohol delivers the most substantial impact on tar removal efficiency, whereas used lubricating oil results in less impact. The use of isopropyl alcohol resulted in 99.25% tar removal effectiveness while lubricating oil yielded just 50.32%
Production of Rubber Seed Oil: Study of Parameters and some Food Oil Properties
Full text linkRubber seeds are one of the plantation commodities that are underutilized by the Indonesian people, apart from being the generative seeds of rubber trees. Rubber seeds have a reasonably high vegetable oil content of 68.53% with a carbohydrate content of 6.99%, protein content of 17.41%, and ash content of 3.08%. This study aimed to obtain food oil from rubber seeds with fewer chemicals and more affordable production costs. This study investigates the properties of food oil from rubber seeds and analyzes the cyanide content. The oil extracted using the traditional method yielded an 8.48% oil content. The rubber seeds were soaked for four days with rice husk charcoal (1:1) to reduce cyanide levels, followed by cooking to obtain the oil and bleaching with bentonite for purification. The oil was characterized according to Indonesian National Standards (SNI), assessing cyanide content, organoleptic properties, water content, acid values, and peroxide numbers. The resulting oil had a density of 0.87 g/cm and a cyanide content of 0.54 ppm. The tests showed a water content of 0.04%, an acid value of 0.4 mg NaOH/g, and organoleptic properties that met SNI standards. However, the peroxide value of 13.5 meq O2/kg was slightly above the standard, making the oil non-edible
Kinetic of Aerobic Decomposition Process of Linear Alkylbenzene Sulfonate (LAS) in a Well-Shaped Bioreactor Using Commercial Inoculum
Full text linkLinear alkylbenzene sulfonate (LAS) belongs to a class of surfactants claimed as an environmentally friendly detergent due to its biodegradability. However, the disposal of LAS waste into the waters without prior treatment causes a risk to the ecosystem. These experiments aimed to study the effects of commercial inoculum size EM-4 on the aerobic decomposition process of LAS in a well-shaped bioreactor. These experiments of LAS decomposition were carried out in a batch system aerated by 2.5 L/min for the low and high initial LAS concentrations. The effects of inoculum acclimation were also investigated for the high LAS concentration. The effects of inoculum size were explored at sizes ranging from 5 to 20% v/v, and samples were taken on a regular basis for residual LAS assessment. The first-order kinetic model gave the best fit to the rate of LAS decomposition, with the highest rate coefficient of 10.44 x 10-2 hour-1. This was achieved by using a 20% v/v inoculum for the initial low concentration of LAS, resulting in the highest decomposition efficiency of 89.4% after 24 hours of incubation. The decomposition rate was slower at the high LAS concentrations than at the low concentrations. The inoculum acclimation increased the decomposition rate for the high LAS concentrations. The results of this study show great potential for the bioremediation of LAS detergent waste using commercial inoculum in a well-shaped batch bioreactor
Extraction of Natural Dyes from Cocoa Pod Husk (Theobroma cacao L.) using Ultrasound Assisted Extraction as a Natural Fabric Dye
Full text linkNatural dyes are one of the popular choices for textile dyes today. One part of the plant that has the potential to produce natural dyes is cocoa pod husk (Theobroma cacao L.) because it contains several secondary metabolite compounds, such as tannin which produces a brown color. The extraction method used in this research is Ultrasonic Assisted Extraction (UAE). This study aims to obtain the highest yield of natural dye extracts from cocoa pod husk by varying solvent types, extraction time, and material-to-solvent ratios using the UAE method. In addition, the types of compounds contained in extracts of natural dyes and color results on cotton fabrics were also obtained. The extraction process was carried out using several types of solvents, namely methanol, ethanol, acetone, and distilled water with varying extraction times of 30, 60, and 90 minutes. The research results show that the solvent that can extract the best natural dyes was ethanol with a yield of 11.43% and an extraction time of 90 minutes. Variable ratios of material to 96% ethanol solvent were also observed, namely at ratios of 1:5, 1:6, 1:7, and 1:8 for extraction times of 30, 60, 90, and 120 minutes. The research results were obtained for the ratio of material to ethanol solvent; 1:8 (w/v) and extraction time 120 minutes with a dye yield of 12.29%. The results of the UV-visible spectrophotometry analysis were obtained that the maximum wavelength of cocoa pod husk extract was 656.5 nm with an absorbance of 0.532. The results of the Gas Chromatography-Mass Spectrometry (GC-MS) analysis were obtained that the dye compound in the cocoa pod husk was tannin. Tannin compounds are natural dyes that can be applied to fabrics and will reduce the use of synthetic dyes. The application of dye extracts to cotton fabrics produced a brown color