二氧化氯消毒工艺优化与安全控制

【作者】 曹大勇；

【导师】 赵大传；

【作者基本信息】 山东大学 ， 环境工程， 2005， 硕士

【摘要】 根据南方微污染源水的特点,研究了二氧化氯、氯混合液及二氧化氯溶液处理微污染源水时,二氧化氯衰减情况及亚氯酸盐的生成情况,并对二氧化氯、氯和亚氯酸盐的消毒能力进行试验研究,从而确定出厂水剩余消毒剂指标及消毒剂的投加量,在提高饮用水安全性的前提下,有效降低成本。 通过静态试验可得出,无论是二氧化氯、氯混合消毒剂,还是二氧化氯消毒剂,二氧化氯和氯的消耗主要发生于和水样接触的初期,当与水中易于反应的物质反应完全后,消毒剂的衰减速率较好地遵循一级反应动力学方程。投加二氧化氯、氯混合消毒剂的试样中,亚氯酸盐的生成量约为二氧化氯消耗量的39.7%～57.9%;投加二氧化氯消毒剂的试样中,亚氯酸盐的生成量约为二氧化氯消耗量的48.0%～70.0%,二氧化氯与氯混合液处理微污染源水时亚氯酸盐生成量较低。 氯酸盐加盐酸法发生的消毒剂是以二氧化氯和氯为主体,同时含有少量亚氯酸盐和氯酸盐的混合液。在此混合液中,亚氯酸盐和氯酸盐氧化性很弱,对细菌和大肠杆菌没有灭活或抑制作用。二氧化氯虽然比氯的氧化性强很多,但是在对细菌和大肠杆菌的灭活和抑制作用上,同等投加量情况下,二氧化氯效果仅比氯略好。因此,出厂水剩余消毒剂指标可用出厂水中残余二氧化氯与氯的质量和来表示。 对采用预氧化工艺,且构筑物运行工况较好,管网中生物活性低的水厂,出厂水消毒剂残余量控制在0.3mg/L以上,消毒剂的投加量为0.50mg/L是比较合适的。而对于未采用预氧化工艺,且源水水质较差时,出厂水消毒剂残余量控制在0.4mg/L以上,消毒剂的投加量在1.0mg/L以上。但是当投加量超过0.5mg/L以上时,亚氯酸盐的生成量有可能达到0.2mg/L,而我国生活饮用水卫生规范要求亚氯酸盐含量不得高于0.2mg/L。此时,则应考虑增加亚氯酸盐的去除工艺。更多还原

【Abstract】 The objectives of this project are to study chlorine dioxide persistence and chlorite formation throughout treatment plants and distribution system and set up relevant criterion of dosage applied on drinking water and residual disinfector of finish water.It was showed that chlorine dioxide and chlorine decayed quickly in the beginning in samples, then the consumption was constant in first order-model. 39.7%~57.9% and 48.0%~70.0% of chlorine dioxide consumption converted to chlorite with the combinations of chlorine dioxide and chlorine and chlorine dioxide respectively. The most common methods for the generation of chlorine dioxide for drinking water treatment in china is that sodium chlorate is reacted with hydrochloric acid. The disinfector includes chlorine dioxide, chlorine, chlorite and chlorate. As the study has showed, chlorite and chlorate have no effect on bacteria and coliform, chlorine dioxide and chlorine have simlar effect on bacteria and coliform. So residual disinfector of finish water should be defined as the sum of residual chlorine dioxide and chlorine.In one water treatment plant which was applied pre-oxidation process, the dosage applied on drinking water should be 0.5mg/L, residual disinfector of finish water should be above 0.3mg/L. In another water treatment plant which was not applied pre-oxidation process, the dosage applied on drinking water should be above 1 .0mg/L, residual disinfector of finish water should be above 0.4mg/L. Forthermoer, if the the dosage applied on drinking water exceeds 0.5mg/L, chlorite concentration may exceed 0.2mg/L which approached the maximum contaminant level (MCL) (0.2mg/L) and some process should be applied to reduce chlorite concentration.更多还原