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| dc.contributor.author | Girma, Anteneh | |
| dc.date.accessioned | 2020-06-05T05:31:08Z | |
| dc.date.available | 2020-06-05T05:31:08Z | |
| dc.date.issued | 2019-11-19 | |
| dc.identifier.uri | http://hdl.handle.net/123456789/10903 | |
| dc.description.abstract | Wastewater from industry can lead to water pollution if untreated, especially due to its high concentration of heavy metals. The discharge of untreated wastewater contaminates with heavy metals such as Cr(VI) and Cd2+ are a major concern for ecosystems, leading to carcinogenic to the human and hinder development of plants. The adsorption of Cr (VI) and Cd2+ from synthetic wastewater by activated bentonite natural clay was investigated. This work was focused on Activated Bentonite Natural Clay for Removal of Heavy Metals from Metallurgic Wastewater in batch mode experiments. To achieve this aim, the research study was carried out in two stages; (1) activation of natural bentonite clay and (2) characterization, adsorption performance evaluation, isotherm and kinetics study of the natural bentonite clay for removal of Cr(VI) and Cd2+. Characterization of both the untreated and acid activated natural bentonite clay was done for bulk density, moisture content, porosity, texture, point of zero charge and cation exchange capacity, surface functional groups (FTIR), x-ray diffraction (XRD). The moisture content of the natural bentonite clay was 10.37 % for raw bentonite laid in the standard range. The influences of various process parameters such as initial concentration, solution pH, adsorbent dose and contact time on the adsorption performance of natural clay were investigated. A total of 30 sorption experimental runs were carried out employing the detailed conditions designed by response surface methodology based on the Central Composite Design. From the experimental result, maximum Cr(VI) and Cd2+ removal of 99.23 and 77.54 %, respectively was obtained at the operating condition of initial Cr (VI) and Cd2+ concentration (80 and 150 mg/L), pH (1.5 and 4), adsorbent dose (1 g) and contact time (106.79 and 90 min). The adsorption data were well fitted to the Freudlich isotherm model and pseudo-second order kinetic model for chromium (VI) and Cd2+ metal ion. Moreover, the analysis of variance (ANOVA) depicted that the quadratic model was suitable to explain the parametric interaction of the responses. Based on the results obtained activated bentonite natural clay is attractive sorbent material because of its rapid uptake and high sorption capacity of Cr (VI) and Cd2+ metal ions. | en_US |
| dc.language.iso | en | en_US |
| dc.subject | Environmental Engineering | en_US |
| dc.title | Activated Bentonite Natural Clay for Removal of Heavy Metals from Metallurgic Wastewater | en_US |
| dc.type | Thesis | en_US |
