生物滴滤塔好氧脱氮过程ORP和pH值的变化规律

Change regulations of ORP and pH value during nitrogen removal process in bio-trickling filter under aerobic condition

采用一套内部填充多孔蜂窝陶瓷填料的生物滴滤塔,研究了不同硝酸盐浓度和不同起始pH值条件下pH值、氧化还原电位(ORP)在一个反应周期内的变化规律。结果表明:改变起始pH值、初始硝酸盐的浓度,ORP、pH值的变化规律并没有改变,特征点并没有因为硝酸盐浓度和pH值的改变而消失,而是依然存在。当pH值为7.4,ORP特征点出现的时间是90min,ORP为219mV;而当pH值为6.4、5.9时,ORP特征点出现的时间同为120min,ORP分别为226、228mV。当硝酸盐氮的质量浓度分别为78.23、125.63、384.26mg/L时,pH值对应出现特征点的时间依次为62、73、115min;pH值分别是8.11、8.76、9.27。而ORP出现特征点的时间依次是65、70、120min,对应的特征点ORP值分别为251、221、186mV。利用ORP、pH值特征点可以判定反硝化进程。

The change regulations of pH value and oxidation-reduction potential（ORP） during one reaction period in a bio-trickling filter filled with porous honeycomb ceramic under different nitrate concentrations and initial pH values were studied. The results showed that： the change regulations of ORP and pH value didn＇t change with the variation of pH value and initial concentration of nitrate and the feature point still appeared. When the pH value was 7.4, the feature point appeared after 90 min, and the ORP was 219 mV; when the pH value was 6.4 and 5.9, the feature points both appeared after 120 min, the ORP were 226 and 228 mV respectively. When the mass concentration of nitrate nitrogen were 78.23, 125.63 and 384.26 mg/L, the feature points of pH value appeared after 62, 73, 115 min respectively, and the pH values were 8.11, 8.76 and 9.27 respectively; while, the feature points of ORP appeared after 65, 70 and 120 min respectively, and the ORP values were 251,221 and 186 mV respectively. Therefore, the feature points of pH value and ORP could be used to study the process of denitrification.