| Abstrakt: |
The presence of toxic selenium species in aquatic streams is on the rise because of increased anthropogenic activities. The most dominant forms in which selenium is found in the environment are the inorganic selenite and selenate species. This study investigated the removal of selenite and selenate from binary system using novel MgCuAl-layered triple hydroxide (MgCuAl-LTH) along with response surface methodology (RSM)-based process optimization under a varying set of process conditions i.e., selenite concentration, selenate concentration, and adsorbent dosage. The characterization of synthesized MgCuAl-LTH indicated the formation of highly crystalline hydrotalcite mass that has a mesoporous structure. Quadratic models, yielding selenite and selenate removal responses, were also developed, and the factors that most significantly affected the responses were the adsorbent dose followed by the concentration of selenite and selenate. The process also indicated that an increase in selenite over selenate and vice versa also favors the selenium adsorption, hence emphasizing the effect of competitive adsorption. Multiple response optimizer feature in the RSM was also used to obtain the most suitable conditions for the optimal removal of both selenium species. Furthermore, an additional experiment with a higher MgCuAl-LTH dose showed greater than 99% and 95% selenite and selenate removal, respectively. The results obtained in this study demonstrated that the novel MgCuAl-LTH can be used for the treatment of selenite and selenate in combined waste streams. |
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