| Summary: | 碩士 === 嘉南藥理科技大學 === 環境工程與科學系碩士班 === 95 === Nitrogen, an essential nutrient for plants, maybe pollutes the groundwater via the transportation from soil with overdosing fertilizer. Nitrate remaining in soil and groundwater could be reduced to form nitrite and N2O, and finally nitrogen gas.
The aim of this study is to observe the reduction of aqueous nitrate by using zero-valent metals, which has some strength of low cost and prompt reaction.
Results of column tests indicate the reduction of nitrate by microscale zero-valent iron could be more efficient under the initial condition of controlled pH (2.5) than uncontrolled pH (6.05-6.17).
Results also reveal that the addition of sodium borohydride is an effective regeneration method for activating the used and oxidized iron particles, especially under the condition of uncontrolled pH (near 9.78). However, the addition of ferrous ion and h ydrochloric acid could not be efficient for the regeneration of irons.
The specific reduction of nitrate by nanoscale zero-valent iron was found little difference under different inflow flux. The available operation time with high reduction efficiency in iron-packed column was found longer in high inflow flux than low flux.
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