Photocatalytic Removal Of As（Ⅲ） From Polluted Water By Cellulase Templated TiO2and Treatment Of Landfill Leachate Using Fresh MnO₂

Removal of arsenic (As) and high concentration fluorion (F-) from polluted water have been studied in this work. Treatment of landfill leachate using fresh manganese dioxide (MnO2) has also been investigated.Firstly, itanium dioxide templated by enzyme (E-MTiO2) was synthesized by a facile hydrothermal method and characterized using a combination of physicochemical techniques. The effects of catalysts amount, pH and reaction time on the removal rate, as well as transition between As(â…¢) and As(V) were investigated. The results show that E-MTiO2act as photocatalyst and absorbent in the removal process. As(III) was oxidized to As(V) and As(V) was adsorbed by E-MTiO2in situ. The removal rate of total As from a175ppb arsenic solution was up to90.3%under optimum condition.F-was removed using a absorbent which synthesize by our laboratory with high efficiency. The effects of calcinate temperature, amount and reaction time on removal rate of F-also studied. The removal rate of F-from a163mg/L F-solution was up to99.5%under the optimum condition. In addition, lanthanum nitrate (La(NO3)3) modified absorbent could be used in removal of As3+and Pb2+. The results show that removal rate of As3+(15.6mg/L) and Pb2+(5.1mg/L) were85.7%and91.7%respectively and the mesoporous absorbent could also be recycled.Finally, Kinds of fresh MnO2were prepared using different methods and used for landfill leachate treatment. The results show that a KMnO4-activated carbon-high temperature method was the best to prepare fresh MnO?. The effects of amount of catalyst, reaction time, pH, and temperature on removal of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) over the as-prepared fresh MnO2were investigated. The removal rate of COD and NH3-N was67.5%and66.3%respectively. A remarkable results of decolorization as achieved.