Oxidation characteristics of treating Chinese traditional medicine wastewater with chlorine dioxide
二氧化氯处理中药废水的氧化特性研究

Chinese traditional medicine wastewater was oxidized and decomposed by using stabilized chlorine dioxide solution. The influences of the original concentration of ClO_2(expressed by C1O_2 ]:COD) , pH value and reaction time on the disposal effect of the wastewater were investigated by the orthogonal design method under the normal condition of 291-298 K and 1.013×10~5 Pa. The results show that; (1) the average removal rate of COD (expressed by ARR_(COD)) exceeds 42% when ClO_2 ]: COD is in the range of 1.0 ~0.4, and ARR_(COD) is only 27%～35% when ClO_2 ]: COD is greater than 1.0 or smaller than 0.4; (2) when pH equals 2～4, ARR_(COD) exceeds 40% , and when pH is equal to or greater than 10, the rate reaches 59% ; (3) ARR_(COD) increases with increasing the reaction time, and when the time is about 30 min, ARR_(COD) can arrive at 40% , besides, when the time is 105 min the corresponding value reaches 63% ; (4) the best technological conditions are that the ratio of ClO_2 to COD is 0.7, the pH value is 6 and the reaction time is 75 min.