| Summary: | 碩士 === 大同大學 === 化學工程學系(所) === 106 === This study was to synthesize spinel lithium manganese oxide (LMO) powder which was used as an adsorbent to remove cobalt ions from the aqueous solution. Spinel lithium manganese oxide material was prepared with solid-state method using lithium carbonate and manganese carbonate as the precursors, then the spinel LMO powder was treated with 0.3 N hydrochloric acid to hydrogen manganese oxide (HMO). The LMO powder was also granulated using a water glass binder to form HMO granules in this experiment. Those materials were characterized by X-ray diffraction spectroscopy (XRD), Scanning Electron Microscopy with energy dispersive X-ray microanalysis (SEM) and Thermogravimetric Analysis (TGA).
XRD and TGA patterns show that the spinel LMO powder prepared at a calcination temperature of 800°C has a higher pure phase. The cobalt adsorption capacities of adsorbents were evaluated by ICP-OES to detect the concentration of Co2+ in aqueous solution.
The operating conditions such as sorbent dosages, initial concentrations of cobalt ion, initial pH value (pHo) and temperatures were investigated in batch system. It has been observed that changing the initial pH value does not affect the adsorption capacity during the removal of cobalt using LMO and HMO powders. The process of removing cobalt by LMO powder increases with the increase of reaction temperature and adsorbent dose. The adsorption capacities of LMO and HMO powder in the reaction with an initial cobalt concentration of 500ppm are 99.9 mg/g and 19.02 mg/g, respectively. It is apparent that LMO is a good material to remove highly cobalt contamination in aqueous solution.
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