二氧化氯处理中药废水的氧化特性研究

采用稳定性二氧化氯溶液氧化降解中药废水,运用正交设计方法考察了常温、常压(291～298 K,1.013×10~5Pa)下ClO_2起始浓度(ClO_2]:COD)、pH、氧化反应时间等因素对中药废水处理效果的影响。研究表明,(1)当ClO_2]:COD在1.0～0.4范围时,COD的平均去除率42%;当ClO_2]:COD大于1.0或小于0.4时,COD平均去除率仅为27%～35%;(2)pH=2～4时,COD去除率可以达到40%以上,且pH≥10时,COD去除率高达59%;(3)COD去除率随着反应时间的延长而升高,氧化反应30 min左右,COD去除率能达到40%以上,105 min后处理效率达到63%;(4)ClO_2处理中药废水的最佳工艺条件是ClO_2]:COD为0.7:1,反应pH值6,反应时间75 min。

Oxidation characteristics of treating Chinese traditional medicine wastewater with chlorine dioxide

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.