Removal of Methyl Red using Adsorbent Produced from Empty Fruit Bunches by Taguchi Approach

Contamination of anionic dye in the water streams may cause harm to human being and aquatic species. The conventional adsorbent used in the adsorption process is normally produced using expensive and unsustainable precursor such as coal. In this work, activated carbon was produced through carbonization and activation of raw oil palm empty fruit bunches (EFBs). Taguchi approach was employed to determine the optimum dye removal parameters. The percentages of contribution of each factor in the removal of Methyl Red (MR) by raw EFB and EFB based activated carbon (AC) were determined using analysis of variance (ANOVA). According to ANOVA, for raw EFB, agitation speed has the highest percentage of contribution. As for EFB based AC, the amount of adsorbent is the most significant factor. The optimum parameters for both adsorbents were obtained from mean and S/N ratio. The optimum operating parameters for raw EFB were 25 ppm of initial dye concentration, 0.01 g of adsorbent and 200 rpm of agitation speed whereas the optimum operating parameters for EFB based AC were 20 ppm of initial dye concentration, 0.06 g of adsorbent and 120 rpm of agitation speed. The predicted percentages of dye removal for raw EFB (55.54%) and EFB based AC (86.72%) were in good agreement with the experimental values for raw EFB (50.5%) and EFB based AC (84.61%), respectively. This study provides a useful insight into the practicability of using the Taguchi method in the removal of anionic dye using raw EFB and EFB based AC as adsorbents.

Recovery of cobalt and molybdenum from consumed catalyst using hydrochloric acid

Cobalt and molybdenum are valuable metals whose presence in nature is very limited. The consumed catalyst, which is abundantly available in the petroleum refinery industry, is a potential source of those metals. A hydrometallurgical process using acid as a leaching agent is usually used to extract and separate the metals more effectively. This method is considered capable of yielding recovery of a higher percentage of metal. In this study, hydrochloric acid solutions at various concentrations of 1.0, 1.5 and 2 M were used. The consumed catalyst was obtained from Pertamina Refinery Unit IV, Cilacap, Indonesia. Leaching experiment was carried out for 300 minutes and sampling was undertaken at 1, 3, 5, 15, 30, 90 and 300 minutes. The particle size and agitation speed were fixed at 200 mesh and 400 rpm. Samples of consumed catalyst were analyzed using EDXRF before the leaching process. Samples of solution were analyzed using ICP-EOS. Experimental results have shown that the recovery of cobalt and molybdenum increases with the increase of either concentration of hydrochloric acid or temperature. The highest recoveries in cobalt and molybdenum were 34.66% and 5.03%, respectively, obtained at a concentration of hydrochloric acid of 2 M and temperature 60°C.

Statistical Optimization of Adsorption Processes for The Removal of Phenol by Activated Carbon Derived from Baobab Fruit Shell

Baobab fruit shell (BFS) biomass was used as an alternative precursor for producing high surface area and microporous baobab fruit shell activated carbon (BFS-AC) by chemical activation using KOH. Scanning electron microscope (SEM) was performed for the characterization of baobab fruit shell activated carbon. The adsorption property of BFS-AC for the removal of phenol from aqueous solution was evaluated. The effect of key adsorption parameters such as the contact time (10-20 min), BFS-AC dose (2.5-3.5 g/L), pH (1-3), and agitation speed (150-250 rpm) were optimized using a response surface methodology (RSM) with faced centered central composite design (FCCCD). Consequently, a maximum adsorption capacity (196.86 mg/g) was achieved at 15 min of contact time, 2 of pH, 3 g/L of adsorbent dosage, and 250 rpm of agitation speed. The results reveal that BFS-AC has an efficient performance for the removal of phenol from aqueous media.

Isothermal and Kinetic Investigation of Exploring the Potential of Citric Acid-Treated Trapa natans and Citrullus lanatus Peels for Biosorptive Removal of Brilliant Green Dye from Water

Trapa natans peels (TNPs) and Citrullus lanatus peels (CLPs) were utilized for the biosorptive removal of brilliant green dye (BGD), after modifying with citric acid. Characterization and surface morphology were studied by Fourier transform infrared spectroscopy and scanning electron microscopy. For the removal of BGD by citric acid-treated Trapa natans peels (CA-TNPs), the optimum conditions were obtained with adsorbent dose 0.8 g, contact time 25 minutes, initial pH 5, temperature 30°C, and agitation speed 100 rpm, while for the citric acid-treated Citrullus lanatus peels (CA-CLPs), adsorbent dose 0.8 g, contact time 20 minutes, pH 5, temperature 30°C, and agitation speed 100 rpm gave optimum results. The qmax values obtained were 108.6, 128, 144.9, and 188.68 mg/g for R-TNP, CA-TNP, R-CLP, and CA-CLP, respectively, while the correlation coefficient (R2) values obtained were 0.985, 0.986, 0.985, and 0.998 for R-TNP, CA-TNP, R-CLP, and CA-CLP, respectively. These favor the Langmuir isotherm and pseudo-second-order kinetics, with negative (ΔG0) values of all adsorbents, determining that the adsorption phenomenon is exothermic and spontaneous in nature. Both citric acid-treated peels of Trapa natans and Citrullus lanatus were found suitable for bulk-scale eradication of hazardous, toxic, and carcinogenic basic cationic dyes.

Transesterification Optimization using Calcium Oxide from Karanja Oil and Results Validation by ANN

Biodiesel is obtained using the transesterification process from renewable oils obtained from vegetable and animal fats. The transesterification process is used to produce biodiesel from Karanja oil with heterogeneous catalyst Calcium Oxide (CaO). In this research work, the Taguchi method has used for the optimization of the transesterification process using five input parameters and five levels for the development of orthogonal arrays. Experiments have conducted as per the L25 orthogonal array developed by Taguchi and yields obtained have been noted. The results obtained by experimentation have been analyzed by Minitab software. The results from Minitab have compared with the results obtained using ANN script analytically as well as graphically. The maximum value of yield has 88% at optimum parametric value namely molar ratio 20% with the addition of 3% Calcium oxide catalyst at process temperature 65ºC for 60 minutes reaction time and agitation speed 600 rpm.

SIMULTANEOUS ADSORPTION OF TETRACYCLINE AND AMOXICILLIN BY CLADOPHORA AND SPIRULINA ALGAE BIOMASS

Adsorption studies were performed at different initial Tetracycline (TC) and Amoxicillin (AMO) concentration, different biomass dosage and type, contact time, agitation speed, and initial pH. In the batch mode were investigated. The optimum pH of solutions is 6.5 for TC and 5 for AMO, agitation speed 200 rpm and concentration 50 ppm. The results in FTIR showed that there were -OH and amides (N-H) and other functional groups on the surface of Cladophora and Spirulina algae. The equilibrium isotherm data were modeled with Freundlich, Temkin, and Langmuir isotherm models. The data best fitted with the Langmuir model. The maximal adsorption capacity from the Langmuir model was (9.86, 20. 5 mg/g) for TC and (7.89, 17.4 mg/g) for AMO on Cladophora and Spirulina algae, respectively. Finally, the pseudo-second-order kinetic model was best fitted the experimental kinetic data of TC and AMO onto Cladophora and Spirulina algae biomass with a high coefficient of determination between 0.97 and 0.99. Cladophora and Spirulina algae, low-cost and eco-friendly adsorbents, can be used to adsorb the TC and AMO from the solution.

Synthesis and Study of Microcapsules with Beeswax Core and Phenol-Formaldehyde Shell Using the Taguchi Method

Phenol-formaldehyde shelled phase change material microcapsules (MPCMs) were fabricated and their processing parameters were analyzed with the Taguchi method. Core to shell ratio, surfactant concentration and speed of mixing are the parameters that were optimized in five levels. The optimized values for the surfactant concentration, core to shell ratio and agitation speed were 3%, 1:1 and 800 rpm, respectively. The obtained microcapsules were spherical in shape. The melting enthalpy of the MPCMs synthesized with optimized processing parameters was 148.93 J/g in 35–62 °C. The obtained temperature range of phase transition temperature can be used for storing different food articles such as chocolate and hot served foods.

Effect of Localized Temperature Difference on Hydrogen Fermentation

In a lab-scale bioreactor system, (20 L of effective volume in our study) controlling a constant temperature inside bioreactor with a total volume 25 L is a simple process, whereas it is a complicated process in the actual full-scale system. There might exist a localized temperature difference inside the reactor, affecting bioenergy yield. In the present work, the temperature at the middle layer of bioreactor was controlled at 35 °C, while the temperature at top and bottom of bioreactor was controlled at 35 ± 0.1, ±1.5, ±3.0, and ±5.0 °C. The H2 yield of 1.50 mol H2/mol hexoseadded was achieved at ±0.1 and ±1.5 °C, while it dropped to 1.27 and 0.98 mol H2/mol hexoseadded at ±3.0 and ±5.0 °C, respectively, with an increased lactate production. Then, the reactor with automatic agitation speed control was operated. The agitation speed was 10 rpm (for 22 h) under small temperature difference (<±1.5 °C), while it increased to 100 rpm (for 2 h) when the temperature difference between top and bottom of reactor became larger than ±1.5 °C. Such an operation strategy helped to save 28% of energy requirement for agitation while producing a similar amount of H2. This work contributes to facilitating the upscaling of the dark fermentation process, where appropriate agitation speed can be controlled based on the temperature difference inside the reactor.

Phragmites australis (Reed) as an Efficient, Eco-Friendly Adsorbent for Brackish Water Pre-Treatment in Reverse Osmosis: A Kinetic Study

A cost-effective adsorbent was prepared by carbonization of pre-treated Phragmites australis reed at 500 °C. Phragmites australis was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) surface analyses. XRD of the as-prepared adsorbent exhibited a partially crystalline structure with a specific surface area of 211.6 m2/g and an average pore diameter of 4.2 nm. The biosorption potential of novel biosorbent Phragmites australis reed was investigated with a batch scale and continuous flow study. The study was conducted at different constraints to obtain optimum pH conditions, adsorbent dose, contact time, agitation speed, and initial TDS concentration. In order to analyze the properties of the procedure and determine the amount of sodium removal, Langmuir, Freundlich, and Dubinin–Radushkevich isotherms were tested. The optimal values of contact time, pH, and adsorbent dose were found to be 150 min, 4, and 10 g/L, respectively, with an agitation speed of 300 rpm at room temperature (27 °C). The three tested isotherms show that the adsorption of Na+ onto the prepared adsorbent is a hybrid process from physi- and chemisorption. For industrial application, the adsorbent was tested using the adsorbent column technique. Pseudo-first-order, pseudo-second-order, and diffusion models were connected, and it was discovered that the information fit best to the pseudo-second-arrange active model. According to the intraparticle diffusion model, the mechanism goes through four stages before reaching equilibrium. The periodicity test shows that the adsorption ability of Phragmites australis can be recovered by washing with 0.1 M HCl.