Tadele Assefa Aragaw

Bahir Dar Institute of Technology, Bahir Dar University Ethiopia
{{numberWithCommas(9)}} Publications

Recovery of Iron Hydroxides from Electro-coagulated Sludge for Adsorption Removals of Dye Wastewater: Adsorption Capacity and Adsorbent Characteristics


The aims of this research work was to investigate the potentials of raw and calcined iron hydroxides/oxides sludge adsorption for DR28 dye removal. The adsorbent is prepared from electro-coagulated (EC) sludge in industrial wastewater treatment plant, as a Nobel adsorbent for decolorizing direct red 28 dye (DR28). The EC sludge adsorbent were prepared with soaking processes and calcination in a range of temperature. The surface properties of raw and calcined EC sludge adsorbent were examined using Zeta Potential, XRD and FTIR. Basic (effect of solution pH, temperature, initial dye concentration) operation parameters were examined for raw and calcined EC sludge adsorbent. The diffraction patter suggests that the crystalline hematite are produced during calcination and increases its intensity as temperature increases. Langmuir and Freundlich Equation were used to model the adsorption equilibrium; and pseudo first and second order Equation were used to model the adsorption kinetics. The results suggested that the adsorption of DR28 dye is chemisorption, the interaction between the adsorbent surfaces with dye is strong. The Langmuir adsorption capacity of DR28 dye with raw and calcined EC sludge adsorbent was calculated as 1.262 mg/g and 1.252 mg/g respectively with experimental conditions: mixing time=20 min, adsorbent dosage=0.5 grams, initial dye concentration= 20 mg/L and solution pH =2 at ambient temperature. The adsorption kinetics model data were consistent with the pseudo-second-order. The removal efficiency of 97% was recorded at pH 2, ambient temperature 20 mg/l concentration and 1g/100ml for 1 hour. High direct red 28 dye uptake capability and cost-effectiveness of sludge utilization from textile wastewater treatment plant make it potentially attractive for dye removal.

Utilization of treated coffee husk as low-cost bio-sorbent for adsorption of methylene blue

Dyes and pigments have been used in many industries for colorization purpose but they pose hazards to the environment and end users of water. Therefore, it is important to remove this pollutant from waste water before their final disposal. This study aimed to investigate the removal of methylene blue by cost effective, ecofriendly, high-efficiency bio-sorbent from activated coffee husk. The process was carried out using chemical activation (H3PO4) process. Fourier transform infrared spectroscopy and surface analyzer (Brunauer-Emmett-Teller) were used to characterize the adsorbent. The specific surface area adsorbent was obtained as 28.54 m2/g. The maximum removal efficiency was obtained as 96.9% at pH of 5, initial dye concentration of 20 mg/L, adsorbent dosage of 0.8 g/50 mL, for contact time of 50 min and 30°C temperature on the activation surface of coffee husk. Langmuir model was found to fit the equilibrium data for methylene blue adsorption with 6.82 mg/g at 30°C. The adsorption process follows the pseudo-second-order model. Thermodynamics analysis showed that the adsorption of methylene blue on to the activated coffee husk was a spontaneous and endothermic process. The experimental data obtained in the present study proved that coffee husk is a suitable bio-sorbent in removal of cationic dyes.

Adsorption of Basic Yellow Dye Dataset Using Ethiopian Kaolin as an Adsorbent

Publication date: Available online 13 September 2019

Source: Data in Brief

Author(s): Tadele Assefa Aragaw, Fikiru Temesgen Angerasa


This article presents batch experimental data describing the main batch adsorption operation parameters. Also the adsorption models (adsorption isotherm, adsorption kinetics and thermodynamic studies) of basic yellow dye on to the raw and treated kaolin adsorbents. Besides, instrumental analyses were recorded to characterize kaolin adsorbent. Such as, thermogravimetric analyzer, Fourier transformation infrared and scanning electroscope with energy dispersion spectroscopy were used. UV-Visible spectrometer was used throughout the experimental study for the determination of absorbance. The effect of adsorption temperature (30°C, 50°C 70°C), PH (3, 7, 9), initial dye concentration (20 mg/l, 40 mg/l, 60 mg/l), contact time (20 min, 40 min, 60 min, 80 min, 100 min) and adsorbent dosage (0.1, 0.5, 1, 1.5, 2 g/100ml) have been well determined. For adsorbent characteristics, we provide dataset regarding (i) thermogravimetery with differential scanning calorimetery, (ii) Fourier transform infrared spectral data before and after basic yellow dye adsorption process, (iii) scanning electroscope with energy dispersion spectroscopy image at x500 resolution, (iv) X-ray diffraction and, (v) batch adsorption experimental parameters records. Regarding scanning electroscope with energy dispersion spectroscopy image, we provide data of three surface morphology image and three elemental distribution spectra for raw and treated kaolin adsorbent.

Water Practice and Technology

Phycoremediation of textile wastewater using indigenous microalgae

Abstract The recognition that environmental pollution is a worldwide threat to public health and environmental degradation has given rise to new initiatives for environmental restoration for both economic and ecological reasons. There are several methods to treat the dye contaminated industrial wastewater; of which biological treatment methods are economical and environmentally friendly. The bacteria and fungi remediation of dye pollutants has been well characterized over a period of more than 30 years. So, finding other biological methods in addition to bacteria and fungi is great important in the world. As a result, investigating and evaluating Phycoremediation techniques of dye wastewater (bioremediation using Microalgae) have gained a great deal of attention because of their versatility and capacity than bacteria and fungi. The aim of the research is to study Phycoremediation of Textile Wastewater Using indigenous Microalgae. Physico-chemical parameters such as color, pH, total dissolved solid (TDS), biochemical oxygen demand (BOD) and chemical oxygen demand of the waste were determined with ASTM standard methods before and after bioremediation. Photo bioreactor systems were used for Phycoremediation treatment techniques. PH, incubation time and temperature effects were determined on a photo bioreactor treatment and optimal experimental condition was ascertained. Instrumental analytical techniques (UV-Vis, FTIR) were used to determine percent decolorizations of dye wastewater before and after bioremediation; and the actual break down of the dye functional groups. The maximum reductions of the basic parameters; COD, BOD and TDS were obtained 91.50%, 91.90% and 89.10% respectively. The optimum operating conditions in the photo bioreactor system were found incubation time 20 days, 30°C; with 10% of inoculums at a pH of 8. Under these conditions, a maximum of 82.6% decolorization was achieved in 20 days. The experimental investigations evidently tell us algae undoubtedly have the potential to rapidly, efficiently and effectively remove dyes wastewater.

Water Practice and Technology

Removal of water hardness using zeolite synthesized from Ethiopian kaolin by hydrothermal method

Abstract The use of low cost materials in zeolite synthesis becomes an area of important interest in water softening. This research is aimed to utilize kaolin for zeolite synthesis with hydrothermal method. Mechanical, thermal chemical treatments of raw kaolin were used for zeolite synthesis. Fourier Transform Infrared Spectrometry (FTIR), AAS, XRD, surface area (BET), differential scanning calorimetry and TGA were used to characterize kaolin and zeolite and UV–VIS/spectrometer were used for adsorption capacity of ion exchange. Effect of contact time, pH solution and temperature of the solution were studied for batch experiments. XRD values indicated that the prepared material is showed as fully crystalline and primarily amorphous. Before and after hardness removal sample transmittance percentage intensity showed a wide range of difference. From this study, it can be deduced that Zeolite can be used as a low cost water softening agent. At room temperature, the residue is well with calcium and badly with magnesium, whereas affinity toward Mg ions increases to acceptable levels at 60 °C. The cation exchange capacity of zeolite was found to be dependent on contact time. The batch experiments of removing Ca2+ and Mg2+ show that the adsorption capacity of zeolite in calcium ion is higher affinity than magnesium ion.

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