Parameter Biokinetika dari Degradasi Limbah Kol dan Tomat Menggunakan Sistem Bioreaktor Anaerobik

The world's energy supply is very dependent on non-renewable energy in the form of fossil fuels. This causes fossil fuels depletion and the need for alternative energy sources such as biogas. Biogas is produced from the fermentation process of organic matter with the help of anaerobic bacteria in free oxygen absence. This study aims to produce biogas from cabbage and tomato waste separately. Biogas production was carried out by varying feed concentrations of 100 g/L, 200 g/L, and 300 g/L for cabbage waste and 81.6 g/L; 215 g/L; and 237 g/L for tomato waste. This study consisted of 10 days seeding and acclimatization process, followed by a start-up stage using insulated anaerobic bioreactors. The largest methane from cabbage and tomato waste was 60% at a feed concentration of 200 g/L and 50% at a feed concentration of 237 g/L, respectively. The maximum growth rates (µm) for biogas from cabbage and tomato waste were 0.122 day-1 and 0.121 day-1, respectively.

Stabilitas Zeolit HY Hidrofobik terhadap Uji Hot Liquid Water (HLW)

Initially, zeolite catalysts cannot be used for reactions involving hot liquid water, so it is necessary to modify the zeolite to be stable under these conditions. The synthesis of HY and hydrophobic zeolites aimed to determine the stability of zeolite in hot liquid water (HLW). The stability of zeolite in HLW is related to zeolite hydrophobicity. In this study, the main raw materials for the synthesis of HY zeolite were sodium aluminate (NaAlO2) and Ludox HS-40 by calcining the product at 350 oC for 1 hour. Furthermore, increasing the hydrophobicity of HY zeolite was carried out by modifying the external zeolite surface using organosilanes (aminopropyltriethoxysilane). The stability of two zeolites in HLW was set at 200 oC. Zeolite analysis used physical test and Fourier Transform-Infra Red (FTIR) Spectrometer. The results of the zeolite distribution in two phases confirmed that HY zeolite was completely dispersed in the water phase, while the zeolite one was dispersed in the organic phase. Moreover, the IR spectra of HY zeolite showed that the wide peak detection at wave number 720 cm-1 for beginning to disappear. This means that the HLW condition could be damaged to the d6r unit. Another result was shown by hydrophobic zeolite spectra with a stable peak for 72 hours. This indicates that the hydrophobic zeolite has thermal stability in HLW so that it can be used in chemical reaction catalytic applications that use on phase.

Pengaruh Waktu Ekstraksi, Rasio Bahan/Pelarut, dan Daya Microwave Terhadap Hasil Ekstraksi Minyak Serai Dapur dengan Bantuan Gelombang Mikro

Lemongrass, one type of source of essential oils, is widely cultivated in Indonesia. There are several methods for extracting the essential oils from lemongrasses, such as hydro-distillation, steam distillation, soxhlet extraction, extraction with supercritical fluids, ultrasonic extraction, and microwave-assisted hydro-distillation. In this study, microwave-assisted hydro-distillation was used as the extraction method. The purpose of this study was to determine the effect of extraction time (60 minutes, 75 minutes, and 90 minutes), lemongrass/solvent ratio (1:4 g/mL and 1:5 g/mL), and microwave power (500 watt and 600 watt) on quantity and quality of lemongrass essential oil. The essential oils obtained were analyzed in the form of calculation of the essential oil density, yield, and GC-MS analysis. The results of the analysis showed that the density of the extracted lemongrass oil ranged from 0.880 g/mL – 0.920 g/mL at a temperature of 30 oC, with the highest yield ranging from 0.0044% – 0.0046% in samples with a material/solvent ratio of 1:5 g/mL. The components found in lemongrass oil were Z-citral, geranyl acetate, geraniol.

Pemanfaatan Asap Cair Hasil Pirolisis Batubara sebagai Pestisida Organik pada Rayap (Coptotermes curvignathus Holmgren)

Pyrolysis is a process of chemical decomposition of materials through a heating method in the absence of oxygen or a little oxygen. The utilizing coal as a raw material for making liquid smoke, it is hoped that it will be able to produce pesticides that have economic value and can be used as a termite exterminator. The use of coal as a raw material for making liquid smoke is expected to produce pesticides that have economic value and can be used as a termite repellent. This research aimed to determine the optimum concentration and time of liquid coal smoke as a pesticide against termite insect mortality (Coptotermes curvignathus Holmgren). The method used is the coal pyrolysis process at a temperature of 300 0C. The process of testing the mortality of termites with time and concentration variables. The determination of the liquid smoke content of coal is carried out by qualitative and quantitative analysis. The results showed that the optimum time for termite mortality was 25 minutes with an optimum concentration of 80%, where the termite mortality was obtained by 100%. Based on the results of UV/VIS Spectrophotometer Analysis, the sulfur content of liquid coal smoke was 46.92 mg/kg, and the degree of acidity (pH) was 3.00. The acidity content is high enough to allow pesticides from liquid coal smoke to be widely used in agriculture.

Pengaruh Oleamida Terhadap Karakteristik Pematangan Karet Alam Terisi Silika

The purpose of this study was as a feasibility study of the utilization of oleamide as a new additive for natural rubber (NR) filled with silica using the semi-efficient vulcanization system. Silica fillers used as much as 30 parts per hundred parts rubber (phr). Oleamide was obtained from the synthesis of oleic acid with urea. Oleamide was inserted into the silica filled NR compounds with the varied composition of 0.0 phr; 2.0 phr; 4.0 phr; 6.0 phr, and 8.0 phr. The influence of oleamide on the curing characteristic of the silica filled NR compounds was observed. It was obtained that the oleamide functions as a curative and also a plasticizer. The greater the levels of oleamide added, the shorter the scorch time and optimum curing time were. Oleamide also decreased the minimum torque with addition up to 8.0 phr. The greater the levels of oleamide was, the lower the minimum torque was. Oleamide also increased the maximum torque and torque difference of the silica-filled NR composites at the addition of 2.0 phr. The 2.0 phr was the optimum composition of the oleamide.

Kinerja Aktivasi dan Impregnasi Fly Ash sebagai Adsorben Fenol

The purpose of this study was to determine the response and performance of fly ash as an adsorbent activated by HCl and impregnated with FeCl3 to absorb phenol. In this study, the fly ash activation process was carried out using 8 M HCl for 2 hours and impregnated with 2% FeCl3 for 2 hours. Activated and impregnated fly ash was analyzed using a Scanning Electron Microscope-Energy Dispersive Spectrophotometer (SEM-EDX). The results of the activated and impregnated fly ash surface using SEM-EDX showed that there were changes in morphology and functional groups. Then activated and impregnated fly ash was used to absorb phenol at a time variation of 60 minutes, 120 minutes, 180 minutes, 240 minutes and 300 minutes. At 180 minutes of contact time, the equilibrium point is obtained with an absorption efficiency of 90.5%. Second-order pseudo kinetics were used for phenol adsorption by Fe+ impregnated fly ash (R2 = 0.9916). The isotherm models used in the phenol adsorption process by fly ash impregnated with Fe+ are Langmuir Isotherm (R2 = 0.9927) and Freundlich Isotherm (R2 = 0.9984), which means that the adsorption process occurs in multi-layer and mono-layers.

Pengaruh Beda Potensial dan Waktu Kontak terhadap Penurunan Kadar COD dan TSS pada Limbah Batik menggunakan Metode Elektrokagulasi

Batik is one of Indonesia's original cultural heritage that must be preserved. However, the resulting liquid waste has a negative impact on the environment because it contains high levels of phosphate, surfactant, TSS, TDS, turbidity, BOD5 and COD contaminants. An effective method for dealing with batik waste is electrocoagulation, which is coagulation in the presence of an electric current using electrodes. This study treats batik waste by electrocoagulation using aluminum electrodes, which are operated at a current of 5 Ampere, electrode distance is 2 cm, electrode thickness is 0.1 cm, electrode cross-sectional area is 7x10 cm with a waste volume of 500 mL. The effect of potential difference treatment (3 volts, 4.5 volts, 7.5 volts, 9 volts, and 12 volts) and contact time (15 minutes, 20 minutes, 25 minutes, 30 minutes, and 35 minutes) on changes in COD and TSS levels were studied. Optimal conditions were obtained at a potential difference of 12 volts for 35 minutes with a COD reduction efficiency of 84.84% and 91% for TSS.

Kajian Pembuatan Bioetanol dari Limbah Kulit Nanas (Ananas comosus. L)

Ethanol is a fuel with a high octane number and is environmentally friendly. Bioethanol which can be made from biomass materials such as pineapple peel, is considered not to interfere with food security. With a fairly high carbohydrate and glucose content, pineapple can be converted into reducing sugars that can be fermented to produce ethanol. This study was conducted using the journal review method and aims to determine the mechanism, the variables that play the role, and the optimum conditions of fermentation in the manufacture of bioethanol from pineapple peel. The focus of the analysis was on hydrolysis, namely the type, concentration of the hydrolyzing agent, pH, temperature, and concentration of yeast in fermentation. The analysis from previous studies, the best hydrolysis was obtained by enzymatic hydrolysis using cellulase enzymes with a concentration of 1%-2%. The optimum pH of fermentation was found at pH 5 to pH 6, the fermentation temperature was 30 oC with a Saccharomyces cerevisiae concentration of 1.5% – 2%, and the optimum fermentation time occurred in the range of 48 to 96 hours. The high amount of reducing sugar produces a high amount of ethanol as well.

Metode Menentukan Klor dalam Sludge Oil: Perbandingan Metode Wet dan Metode Jena

Currently, the use of alternative fuels and raw materials (AFR) in the cement industry is very attractive. This is driven by demands for environmental sustainability and the efficiency of fuel and raw material costs. One of the materials that can be used as AFR is sludge oil. However, it needs to be ensured that the chlorine content in the sludge oil does not exceed the threshold so that it does not have a negative impact during the cement production process. It is known that if the chlorine content is more than the threshold, it can cause blocking or clogging of the separator and the kiln. This study aims to determine the performance of the Jena Multi EA 4000 instrument in determining the chlorine content in sludge oil quickly and accurately. Analytic Jena Multi EA 4000 is an Atomic Absorption Spectrometers (AAS) instrument that can be used for analysis of samples in the form of solids or slurries containing chlorine. As validation of the resulting analysis, the wet method is used, which as usual, to determine chlorine levels. From the statistic analysis, namely the F-test and T-test, We found that F-count equal to 0.0080 and F-table equal to 4.2839. it shows that F-count < F-table, indicating the difference in the variance of the two methods H0: s12 = s22 is accepted because there is no difference to the variability of these two tests and the value of T-count = -3.9717 and T-table = 2.1788 so that T-count <T-table is accepted because there is no difference in the average accuracy of the two methods H0: M1 = M2.

Ekstraksi Tanin dari Buah Balakka (Phyllanthus emblica L.) dengan Bantuan Microwave: Pengaruh Daya Microwave, Perbandingan Massa Kering Terhadap Jumlah Pelarut Etil Asetat

Tannins are phenolic compounds with considerable abundance in nature. In this study, the extraction of Indian gooseberry fruit was performed using Microwave Assisted Extraction (MAE) method with ethyl acetate as solvent. Two grams of Indian gooseberry fruit were extracted for 1 minute with variable microwave power operation (100, 180, 300, 450 and 600) W. The experiment is continued at the power that gave the highest yield of tannin with variable ratio sample to solvent (1/10, 1/20, 1/30, 1/40 and 1/50) g/mL. Total tannins in the extract were analyzed using UV-Vis Spectroscopy method to find the yield of tannin. Functional groups that were contained in the extract were analyzed using Fourier-Transform Infrared Spectroscopy (FTIR) method. The results of this study indicate that the extract contains tannins in qualitative tests with gelatin and FeCl3 as well as in FTIR analysis. The highest yield of tannin was 36.86 mg/g which was obtained under conditions of power 100 W and ratio sample with ethyl acetate 1/50 g/mL.