Seminar Nasional Teknik Kimia Kejuangan
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Penjerapan Natrium pada Hasil Ekstraksi Silika dari Lumpur Panas Bumi
Geothermal sludge contains silica which can be used as plant fertilizer. Extraction of silica from geothermal sludge can be carried out by the extraction method using sodium hydroxide solution to form sodium silicate. This extraction was conducted by varying the extraction time of 10, 20, 30, 40, 50, 60, 70 and 80 minutes; NaOH concentration of 1,5N; and extraction temperature of 80oC. Extracted silica concentration was analyzed using UV-Vis Spectrophotometry. The best extracted silica content was 158673 ppm under 60 minutes of extraction time, 80oC of extraction temperature, and 1.5N of NaOH concentration. The results of this extraction still contain sodium at a concentration and need to be reduced so that it can be used as fertilizer. The process of reducing sodium concentration using the ion exchange method in a batch system. This process uses variations of initial sodium concentration with a resin mass of 20 grams and temperature of 45oC. From the Atomic Adsorption Spectroscopy (AAS) analysis, the adsorption capacity (qe) increases with increasing the initial sodium concentration. Langmuir\u27s equilibrium provide a match to the adsorption equilibrium experimental data
Batik Industry Wastewater Treatment using Constructed Wetland in Sidoarjo Regency
Batik is one of the industrial potentials of Indonesia, which is experiencing rapid growth in various regions. Besides providing economic benefits, the batik industry also harms the environment. One of the processing methods that can be used as a solution is the Constructed Wetland (CW) method. This method is appropriate because it doesn\u27t require high processing and maintenance costs and the process is simple and uses local resources. The purpose of this study was to measure the efficiency of batik industry wastewater treatment in reducing the pollutant load with the CW system so that the waste discharged into the environment can be declared safe. The parameters studied were COD, and TSS with the Hydraulic Retention Time for 10, 20, and 30 days. The results of the analysis of the initial content obtained a COD value of 1832,02 mg/L and a TSS value of 300 mg/L. Based on the results of the research that has been done, the results obtained for the removal of COD and TSS at 10 days HRT were 92.698% and 83.33%, then HRT 20 days of 94.603% and 86.67%. and then HRT 30 days of 96.138 % and 93.33%
Pengaruh Lapisan Kalsium pada Devais Sel Surya Organik Berbasis Bahan Polimer
Organic solar cells (OSC) as an emerging photovoltaics devices have potential clean energy source due to their advantages properties, including low-cost production, light weight, and promising for flexible devices. In this study, we investigated the effect of calcium as buffer layer on top photoactive layer of the polymer based solar cell device. Poly-3-hexylthiophene (P3HT) as donor material combining with phenyl-C61-butyric acid methyl ester (PC61BM) were blended to form bulk heterojunction. Calcium was deposited on top of polymer (P3HT) and fullerene derivative (PC61BM) photoactive layer using thermal evaporation inside ultrahigh vacuum chamber. Calcium was selected as buffer layer because of its low-work -function in order to improve performance of polymer solar cells. Our study presented that calcium buffer layer enhanced the performance of solar cells mainly in open circuit voltage, VOC, (0.45 V to 0.61 V) and fill factor, FF, (44% to 65%), increasing power conversion efficiency (PCE) from 1.79% to 3.79%. This result suggested that the improvement of polymer solar cells performance because of the recombination suppression and more efficient charge transfer in cathode. The energy level alignment and work function properties of calcium form an ideal ohmic contact between the active layer and the cathode, thus ensuring effective electron injection from the active layer to the cathode. We also demonstrated the fabrication of polymer solar cells device under ambient atmosphere. However, the devices fabricated under ambient atmosphere have lower performances than fabricated inside nitrogen filled glovebox, because polymer photoactive material and calcium are easily degraded by moisture
Penentuan Kadar Sulfat pada Air Sumur di Wilayah Surabaya Menggunakan Spektrofotometer
The quality of drinking water can be assessed based on three aspects: physical, chemical, and microbiological aspects. One of the chemical aspects in determining water quality is the sulfate content. UV-Vis spectrophotometry method has been widely used to analyze sulfate content. UV-Vis spectrophotometry is a spectroscopic analysis technique that uses an electromagnetic wave source with ultraviolet (UV) for wavelength (190-380 nm) and visible light with wavelength (380-780 nm). The purpose of this study is to determine the absorbance and concentration of samples using spectrophotometric analysis, calculate the sulfate content in the samples, and compare it with the Indonesian Ministry of Health Regulation Permenkes RI No. 32//2017. The research stages include calibration, calibration curve creation, making standard H2SO4 solutions, measuring the absorbance of the standard solutions, and analyzing the sulfate content in water samples. The research results showed that the sulfate concentration in the Bangkalan, Nginden, Sidoarjo, Keputih, and Kapas Madya well water samples were 14.0817, 27.551, 29.1837, 49.0817, 54.6939 ppm, respectively. Based on the Indonesian Ministry of Health Regulation Permenkes RI No. 32//2017, the maximum sulfate content in water is 400 mg/L, thus it can be concluded that the water samples in those areas have met the clean water standards
Catalytic Pyrolysis of Corn Cob Using Fe-Ni/Char Catalyst
There is a growing interest to convert biomass waste such as corn cob to biofuel. Thermal conversion such as pyrolisis may play an important role to produce bio-oil. The objective of this research was to develop a kinetic study of catalytic pyrolysis of corn cob over Fe-Ni/Char catalyst using Thermogravimetric Analysis (TGA). The solid catalyst was prepared by impregnation method. The ratio of the percentages of Fe and Ni metals in the X-Ray Fluorescence (XRF) analysis of the catalyst was close to 1:1, resulting in metal loading values of 2.5% (1.062% and 1.013%), 5% (2.291% and 2.794%), and 10% (4.947% and 5.417%) for the catalyst. The pyrolysis experiments were performed using various catalyst loadings of 0, 2.5, 5, and 10%. In addition, the present study also investigated the influence of heating rates of 5, 10, and 20 K min-1. Two isoconversion models, Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) were utilized to determine the activation energies. The activation energies calculated using the KAS and OFW models revealed a consistent trend, with values of activation energy of corn cob pyrolysis around 124 - 303 kJ/mol and 133 - 313 kJ/mol, respectively
Karakter Lumpur Pemboran Berbahan Dasar Bentonite Lokal Tulungagung dan Boyolali Mengacu Standar API 13A dengan Variasi Additive Polyamine
This study examined the feasibility of using locally sourced bentonite as drilling mud, with the aim of reducing the cost of imported drilling mud. Bentonite, a soil type containing a high concentration of smectite or montmorillonite, is widely used in drilling mud. The physical properties of drilling mud made from bentonite from Boyolali and Tulungagung were compared, with the addition of various additives to meet the API 13A standard. The research found that drilling mud made from Boyolali bentonite showed physical properties that were closer to the API 13A standard compared to Tulungagung bentonite. Specifically, adding 7 grams (12%) of polyamine to Boyolali bentonite mud produced a volume of filtrate loss and mud cake thickness closest to the API 13A standard, namely 10.8 ml (maximum 15 ml) and 0.14 cm (maximum 0.28 cm), respectively. Adding 2.3 grams (5.04%) of KOH resulted in the highest pH value of 13, while adding 2.5 grams (1.17%) of Na2CO3 produced the least amount of filtrate loss, namely 7.2 ml (maximum 15 ml), with a mud cake thickness of 0.27 cm (maximum 0.28 cm
Preparasi Katalisator Berbasis Biochar dari Ampas Buah Merah untuk Reaksi Transesterifikasi Minyak Jelantah
Biodiesel can be produced from plant and animal oils by transesterification reaction using homogeneous or heterogeneous catalysts. In this study, we prepare a biochar-based catalyst, as a heterogeneous catalyst, for transesterification of used cooking oil. The biochar was made by the pyrolysis of the solid waste from the oil extraction of Papuan red fruit (Pandanus conoideus). After the pyrolysis, the solid was immersed in KOH solution to provide the kalium in the produced biochar. The biochar was then sulfonated by H2SO4 5M for 15h at 120°C. Afterwards, the catalysts were characterized by BET for surface area measurement, FTIR for functional groups on the catalyst surface determination and XRD for successive crystallography characterization. The catalytic performance was studied by conducting transesterification of used cooking oil using methanol with the prepared biochar-based catalysts. The transesterification optimum conditions were found to be oil to methanol molar ratio of 1:15, temperature of 60°C, reaction time of 2 hours and the catalyst amount of 3% of the oil weight. Furthermore, the highest biodiesel yield was obtained by the catalyst prepared from biochar that was sulfonated with 5M H2SO4 solutio
Sintesis Asil Gliserol Melalui Reaksi Esterifikasi Asam Oleat dengan Gliserol
Acyl glycerol derivatives from oleic acid, especially monoacylglycerol (MAG) and diacylglycerol (DAG), are products that is widely used in the food, lubricant, and cosmetic industries. Acyl glycerol can be obtained through esterification reaction of glycerol with fatty acids. This study aims to determine the effect of temperature on the conversion and amount of acyl glycerol produced. This research was conducted using a batch system with temperature variations of 80°C, 100°C, and 120°C with HCl 1%wt as catalyst and 1:1 reactant mole ratio (glycerol: oleic acid) for 2 hours reaction time. Samples were taken every 10 minutes, then the samples were analyzed using Thin Layer Chromatography (TLC) to determine the fraction of the product produced. The experimental results showed that increasing the temperature will produce higher conversions and acyl glycerols. The highest conversion of oleic acid occurred at 120°C (43.016%), with mole percentage of 1,796% monoacylglycerol (MAG), 3,820% diacylglycerol (DAG), and 5,813% triacylglycerol (TAG)
Effect of Cycling and Washing in Fouling Level from Theaflavin Filtration on Ultrafiltration Membrane
Ultrafiltration membranes, characterized by their molecular weight cutoff ranging from 50 to 100 kDa, are extensively employed for the filtration of macromolecules including suspended solids, carbohydrates, proteins, and various other components. However, the prolonged usage of these membranes leads to a notable decline in their performance due to fouling. Membrane fouling entails the accumulation of filtered foulant media and the formation of deposits, adversely impacting the filtration efficiency. This study focuses on evaluating the impact of repeated filtration cycles on membrane fouling and investigates the effectiveness of membrane washing in restoring membrane performance. The ultrafiltration membrane was subjected to five consecutive repetition cycles using theaflavin as the filtration media. The observed flux exhibited a substantial decline of 87%, decreasing from an initial value of 0.0574 L/m2.hr to 0.0073 L/m2.hr. To mitigate fouling and enhance membrane performance, a thorough washing process was carried out. Following the washing procedure, the flux was found to increase to 0.034 L/m2.hr, indicating a significant improvement in the membrane\u27s performance. These findings are further supported by the morphological analysis of the membrane using Scanning Electron Microscope (SEM) photographs, which reveal the distinct differences between the membrane\u27s morphology before and after washing
Optimalisasi Regenerasi Dan Pemakaian Kembali Karbon Aktif Untuk Pemungutan Krom Dari Limbah Penyamakan Kulit
In the wastewater treatment of leather tanning processes, commercial activated carbon from palm shells is usually used as an adsorbent. Therefore, a study is needed to evaluate the effectiveness of activated carbon that has been repeatedly regenerated and used as a total chromium adsorbent medium in wastewater. This study aims to examine the leaching process that uses acids and bases to analyze the adsorption and regeneration processes of activated carbon. Adsorption time variations of 30 minutes, 60 minutes, 90 minutes, and 120 minutes were used to evaluate how activated carbon interacts with wastewater. Then, the effluent was analyzed by Atomic Absorption Spectrophotometry (AAS) to determine the amount of total chromium remaining in the sample. The activated carbon which had been used as an adsorbent was contacted with 0.1 M H2S04 solution for 4 hours and stirred at 400 rpm using a magnetic stirrer to regenerate the surface of the activated carbon. It is neutralized with an alkaline solution. The Freundlich model is used to determine the value of the adsorption equilibrium constant. After testing 5 times, commercial activated carbon can still be used effectively as a adsorbent medium for total chromium (total Cr) repeatedly. Optimum adsorption contact time was 90 minutes. The optimum absorption efficiency during the fifth stage of the adsorption process was 43.93%