Optimization of ion exchange process on the removal of heavy metals from cooling tower water and regeneration of ion exchange resins.

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dc.contributor.author Mbedzi, Robert Mbavhalelo
dc.date.accessioned 2022-10-19T00:29:28Z
dc.date.available 2022-10-19T00:29:28Z
dc.date.issued 2020-06
dc.identifier.uri http://hdl.handle.net/10352/524
dc.description M.Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. en_US
dc.description.abstract In the present study, the removal of Ca2+ and Mg2+ from cooling tower water using Amberlite IR120 and Amberjet 1200 was studied by the application of one factor at a time method (OFAT) and response surface modelling (RSM). The effect of operational parameters such as contact time (min), pH, dosage (mL), concentration (mg/L) and temperature (K) were investigated using central composite design. The regeneration of the Amberlite IR120 and Amberjet were also studied. The purpose of the study was to apply OFAT and RSM to investigate and optimize the ion exchange operating parameters. Furthermore, the second-order empirical model that was developed, using the analysis of variance (ANOVA), presented a sufficient correlation to the ion exchange experimental data. The optimal ion exchange operating conditions for Amberlite IR120 and Amberjet 1200 were found to be: contact time was 120 min, dosage of 150mL, initial pH level of 2, concentration of 400mg/L and temperature of 343K. Regeneration of Amberlite IR120 and Amberjet 1200 using 0.5 M NaCl stripping solution initially showed an increase in % Ca2+ and Mg2+ removal, then a decrease in subsequent cycles. The correlation coefficients (R2) of Langmuir, Freudlich and Tempkin isotherms were found to range from 0.92 to 1 and this suggest that experimental data best described the models. However correlation coefficients (R2) for Dubinin–Radushkevich (D-R) model were found to range between 0.5 to 0.8 and this means that experimental data does not fit the model. Thermodynamic functions such as entropy (Δ𝑆𝑜), enthalpy (Δ𝐻𝑜) and change of free energy (Δ𝐺𝑜) were obtained from the gradient and intercepts of straight line graphs. The positive values of ΔG° were found meaning that the adsorption is not spontaneous and positive values of ΔH° were found meaning the endothermic type of adsorption which indicate the chances of physical adsorption.The correlation coefficient (R2) values of pseudo-first-order, pseudo-second-order and intraparticle models were found to range from 0.89 to 1 on both metals as shown in table 4.4. This observation clearly indicates that pseudo-first-order, pseudo-second-order and intraparticle diffusion models best describe the experimental data in the removal Ca2+ and Mg2+ from cooling tower water. en_US
dc.language.iso en en_US
dc.publisher Vaal University of Technology en_US
dc.subject Amberlite IR120 en_US
dc.subject Amberjet 1200 en_US
dc.subject Cooling tower water en_US
dc.subject Response surface modelling en_US
dc.subject Ion exchange en_US
dc.subject Thermodynamics en_US
dc.subject Kinetics, isotherms en_US
dc.subject Ca2+, Mg2+ and regeneration en_US
dc.subject Heavy metals removal en_US
dc.subject.lcsh Dissertations, Academic -- South Africa en_US
dc.subject.lcsh Cooling towers en_US
dc.subject.lcsh Water -- Purification -- Ion exchange process en_US
dc.subject.lcsh Heavy metals -- Environmental aspects en_US
dc.title Optimization of ion exchange process on the removal of heavy metals from cooling tower water and regeneration of ion exchange resins. en_US
dc.type Thesis en_US
dc.contributor.supervisor Rutto, H. L., Prof.

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