二氧化氯预氧化除锰副产物亚氯酸根作用的影响

Action of Chlorite in Manganese Removal of Ground Water by ClO_2 Preoxidation

通过向含锰地下水中投加ClO_2,主要考察C1O2预氧化除锰过程中亚氯酸根浓度变化及其发挥氧化性能除锰效果的影响因素。采用模拟试验,选用强氧化剂Cl02对水中Mn2+去除。试验过程通过分别改变ClO_2投加量,p H值,原水Mn2+含量来考察该工艺的最佳的运行条件。p H值和二氧化氯投加量是影响亚氯酸根生成量及其发挥氧化性能的重要因素,适当提高p H值有利于亚氯酸根与锰的反应;ClO_2-的生成量随着二氧化氯投加量增加而增加。因此,控制投加二氧化氯的量是控制水中剩余ClO_2-浓度首要条件。当初始锰浓度为1~7 mg·L-1,0.5≤[C1O2]/[Mn2+]≤1.25,p H=6.9,能有效将水中的锰离子降到0.1 mg·L-1以下,此时亚氯酸根能充分发挥其氧化的效能,最大量地减少了亚氯酸根的累积。

The removal effect of manganese from high manganese groundwater using chlorine dioxide and its oxidizing performance in the pre-oxidization process of manganese removal were investigated. The strong oxidant chlorine dioxide was used to remove the divalent manganese by static simulation experiment. By controlling the dosage of oxidant, p H value, and initial concentration of Mn2＋during the test, the optimal operation conditions were determined. The results showed that the value of p H and the dosage of chlorine dioxide（ClO_2） played an important role in the formation of chlorite ion and its oxidizing performance. Increasing the p H value properly was beneficial to the reaction between chlorite ion and Mn2＋. In addition, the more the dosage of ClO_2, the more the chlorite ion was formed. Therefore, the chlorite ion concentration can be controlled by controlling the amount of ClO_2. The results indicated that when the initial concentration of manganese, the [ClO_2]/[Mn2＋] ratio and the p H were 1~7 mg·L-1, 0.5~1.25 and 6.9 respectively, the Mn2＋concentration was reduced to less than 0.1 mg·L-1 effectively. Meanwhile, the chlorite ion gave full play to its oxidizing performance, which minimized the accumulation of chlorite ion.