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Manganese (Mn) removal is one of the many problems of using ground water since Mn is a common element in ground water. Mn cannot be removed by membrane filtration without being oxidized to manganese dioxide. To find an applicable and clean oxidation method, advanced oxidize processes (AOPs) and Mn sand self-catalytic oxidization were evaluated in this study. Oxidization speed of manganese by hydrogen peroxide was found to be proportional to the concentration of hydrogen peroxide and pH. When pH was adjusted to 9.0 and concentration of H2O2 to 170 mg/L, it took about 100 h of contact hours to obtain a removal of 70%. When pH was adjusted to 9.3, it took no more than 50 h to achieve a 95% removal rate. Mn sand showed a promising effect compared to H2O2. In certain pH and contact time, the removal of Mn is proportional to an increasing in Mn sand contact area, however the effect has limitations, which depend on pH and contact time. As a result of comparing continuous filtration, the Mn sand not only removed over 95% of Mn(II), but also decreased the membrane fouling, and prolonged the operational life of the membrane.

While comparing this study with previous works, several important conclusions can be obtained: 1. Hydrogen peroxide irradiated by UV can oxidize manganese fast enough if the pH is adjusted to alkali. The combination of AOPs and pH control can lower the necessary pH level so as to avoid the membrane fouling caused by calcium and magnesium precipitation. 2. At certain pH and contact time, the removal of manganese increased with an increase in Mn sand contact area, however the effect has limitation which depend on pH and contact time. 3. The total manganese that can be removed by Mn sand can be calculated by Wmax = wm using different w in certain pH. The hypothetical continuous running time (the life of the catalyst Mn sand) can also be predicted by T= 4. The regeneration of manganese sand only by pH adjustment requires too much time and too high a pH, thus is impractical to use in treatment process. It is necessary to regenerate the manganese sand by off-line process. 5. The Mn sand provided a removal of Mn(II) as high as 95%. Moreover, it can be a practical process because it can also decrease the membrane fouling and prolong the operational life of the membrane.