Process Engineering

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Browsing Process Engineering by Subject "adsorption"

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    Production and Characterization of Silica Gel For Textile Wastewater Treatment (Methylene Blue Dye)
    (AAU, 2017-10) Temechachew, Tigabu; Zebene, Kiflie (PhD)
    In the world, different pollutants from industries released every day to the soil and ground water without treatment. This will lead to different health problems to both human beings and animals. According to pure earth non-profit environmental organization, because of pollution more than 200 million peoples was affected. In some of the world’s most polluted places babies are born with birth defects, children have lost 30 to 40 IQ points, and life expectance may be as low as 45 because of cancer and other diseases. In Ethiopia most textile factories are located nearby water bodies and they discharge their colour effluent to canals, rivers, lakes and streams without treatment. Those effluents have the capacity to cause an adverse effect on all forms of livings. Among those dyes discharging MB dye without treatment can affect human life and aquatic life. To protect human life as well as aquatic life the product silica gel (SiO 2 ) was successfully prepared from sodium silicate solution and sulphuric acid by sol-gel process to treat dye house waste. The obtained dry silica gel is characterized by using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The variables pH of silicic acid sol and pH of quenching water was studied by using design expert 7.0.0 software. A 2 Factorial model was adopted in order to represent the results in the form of three-dimensional surfaces. The results showed that the pH of silicic acid sol effect is more significant than pH of quenching water. We obtained gels with a good adsorption capacity of MB dye 48.84 mg/g at pH of silicic acid sol 3 and pH of quenching water is acidic (4). The adsorption experiments were conducted at different particle size, wide range of pH, adsorbent dosage, temperature, initial concentration, and contact time to adsorb MB dye efficiently. It was observed that around 78.8 % removal efficiency of MB day was achieved after 15 min, at solution pH around 10.06 and 25 O C temperature using 0.02 g weight of dose of silica gel with particle size ≤ 100 μm and intial concentration of 20 mg/L of 50 ml dye solution. Different adsorption isotherm models, adsorption kinetics and adsorption thermodynamics are carried out to determine the maximum adsorption capacity, to identify feasibility and favourability of using silica gel for adsorption of MB dye. Langmuir maximum adsorption capacity Q m is 58.45 mg/g, at 25 O C and pH 10.06 and 0.02 weight of adsorbent dose. The R L value (0.185 at 25 O C) indicates that the adsorption of MB dye on silica gel is favourable. From Freundlich isotherm model parameters, value of 1/n = 0.6452 while 1/n = 1.55 indicating that the sorption of MB dye on silica gel is favourable. The negative ∆G O values (-1067.82 to -1959.0 J/mol) indicates that the adsorption is favourable and spontaneous at these temperatures. The positive value of ∆S O (39.45 J/mol.K)
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    Statical Process Optimization on Adsorption of Phenol from Water Using Activated Carbon Prepared from False Banana (Enseteventricosum) Leaf
    (Addis Ababa University, 2023-10) Mohammed Keder; Anteneh Wodaje (PhD)
    The reason for this current study was to examine the potential of an adsorbent produced from EL to recover phenol from wastewater. Using agricultural wastes as valuable resources to create ACs from biomass wastes is one of the greenest resolutions. The main objective of this study was to use a chemical activation technique to produce ACs from readily available waste EL. An essential property for the synthesis of AC is the EL's cellulose concentration (18.4%), lignin level (10.3%), MC of 8.35%, VM of 71.09%, AC of 3.28%, FCC of 17.28%, and yield of 49.30% at 400°C. With a nitrogen flow rate of 150ml/min, the process of carbonization was conducted for 30, 60, and 90minutes at 400, 500, and 600°C. The char product was treated with 37% phosphoric acid (H3PO4) at diverse impregnation ratios (0.5, 1 and 1.5). It was found that 500°C, a 60-minute contact period, and an impregnation ratio of 1 in AC5 were ideal for the production of AC. With respect to surface area (1023m2/g), iodine number (984mg/g), and total pore volume (0.45cm3/g), AC5 was the largest. Scanning electron microscopy (SEM) analysis showed that the samples' uneven surface structure. Several functional groups that aid in adsorption was found when Fourier Transform Infrared Spectroscopy (FTIR) was examined. Using phenol as a separate adsorbate and the ideal conditions (PH=6, adsorbent dosage=0.4g, initial concentration=10mg/l, and contact time=120min) at room temperature, the adsorption capacity of generated activated carbon (AC5) was investigated. It was demonstrated that as initial concentration increased, the capacity of adsorption increased. The maximal phenol elimination capability of the AC5 adsorbent is 95%. With the aid of the model, a relationship between the three experimental variables and the percentage of elimination was constructed. It looked into the phenol adsorption equilibrium isotherms utilizing the Freundlich, Temkin, and Langmuir isotherm models. For the concentration range of 10-150 mg/L, the monolayer adsorption capacity was 5.80mg/g, according to equilibrium data that followed the Langmuir model. There were kinetic analyses done. It was discovered that the data fit a pseudo-second order model. The best phenol elimination was obtained with an initial phenol PH of 6 and contact duration of 80 minutes. The study concluded that phenol could be effectively removed from aqueous solutions using activated carbon obtained from discarded Enset leaves.
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    Synthesis and characterization of Iron nano particle using Eucalyptus (Eucalyptus globulus) for the removal of lead from aqueous solution
    (AAU, 2018-12) Yemane, Gebremedihn; Anuradha, Jabasingh (PhD)
    The application of greenly synthesized ironl nano particle for the removal of lead from aqueous solution is what was studied in this thesis research. The FT-IR and X-RD results reveal that a greenly synthesized iron-polyphenol nano particle complex (GInP) with 80nm size was synthesized using eucalyptus leaf extract the specific surface area was found to be 59m By: Yemane G. Page vi 2 /g. The deployment of GInP in the removal of lead was studied after this diminutive GInP had been procreated by reduction of ferric iron in presence of Eucalyptus globulus leaf extract. The lead removal capability of GInP was investigated for lead concentration ranging from 50ppm250ppm. Batch experiments were performed to investigate the influence of lead concentration, contact time, dosage of GInP and pH on the removal process. A maximum lead removal percentage of 96.75 was observed at pH 4 for 100 ppm lead concentration in 45min using 0.8g dosage. Minitab response optimize technic was used to optimize the amount of lead concentration which has shown there was around 86% removal probability at 150 ppm lead concentration. The adsorption kinetics data were well fitted by the pseudo-first-order rate model with high regression coefficient (0.975). The intra particle diffusion of pb (II) on GInP represents the rate-limiting step. The lead removal process was found to be well fitted into the Langimure isotherm model with determination coefficient of 0.965. Desorption was observed to increase with time. The adsorption capacity was decreased with the increase of temperature, and thermodynamic calculations suggested that the adsorption of lead (II) ions onto GInP is an endothermic process. It has been found that GInPs show high selectivity’s and adsorption capacities to removal of Pb 2+ from aqueous solution