Study On Removal Of Manganese From Water With Manganese Oxide-coated Filter

The content of manganese is widely presented in ground water which needs a technique to remove manganese with instant and steady effect. During the process of catalysis oxidation and biological removal of manganese, the filter maturation period is quite long and the removal efficiency is not steady too. On the basis of exploring the mechanisms of traditional methods removal of manganese from ground water, chemical method was used to coat manganese oxides on filter and the structure of this manganese oxides filter was the same as the filters of traditional. The removal efficiency of Mn2-with manganese oxide-coated filter was studied.1. In determining the manganese oxides was the key factor for filter maturation, and manganese oxide-coated filter was manufactured with chemical method. The colour of this filter was black brown, and electron microscopy analysis indicated they had the same structure with biological manganese oxides, XRD analysis showed this kind of manganese oxides belonged to amorphous form. The load capacity of biological and chemical synthesized manganese oxides were nearly, the latter was4.6mg/g. In acid, alkaline and neutral environment, the intensity of load was much better. In contrast test of manganese sand filter and quartz sand filter, the removal efficiency of manganese oxide-coated filter was more than50%, which was the best.2. In the static experimental conditions, the adsorption property of manganese oxide-coated filter was studied. The adsorption isotherm could be well described with the Langmuir equation, this kind of adsorption was single-module layer adsorption, and this adsorption was a spontaneous and endothermic process. Adsorption process fitted pseudo-second order model. The saturation adsorption quantity of manganese oxide-coated filter was0.1474mg/g for Mn2+, and the desorption quantity was0.042mg/g.3. The experimental results showed that the smaller particle size of filter and the dosing bigger, the removal efficiency of manganese oxide-coated filter was better. When the initial Mn2+concentration is5mg/L and volume is100mL, the best dosage of manganese oxide-coated filter was2.0g. To improve the pH benefited the the adsorption property of manganese oxide-coated filter. The saturation adsorption quantity of Fe2+was bigger than Mn2+, Fe2-could restrain the adsorption process.4. Dynamic experiment of removal manganese by manganese oxide-coated filter indicated original manganese concentration, the filter rate and pH affected the removal efficiency. The saturated manganese oxide-coated filter could be treated with NaClO to regenerate its adsorption ability. When the NaClO was added0.8%for100mL, the capacity of removal manganese for2.0g filter could be fully recovered in40min.Dynamic experiment indicated1L1.0%of the NaClO could regenerate the filter candle in30min. After several cycle, the colour of manganese oxide-coated filter in the filter candle became deep gradually. The load capacity of manganese increased to3.8mg/g from1.0mg/g.