预紫外/混凝沉淀控制低浊高藻水三氯乙醛生成潜能

Control of Chloral Hydrate Formation Potential for Low Turbidity and High Algae-laden Water by UV Pretreatment/Coagulation Sedimentation Process

以深圳地区某低浊高藻原水为研究对象,分别考察了单独紫外及预紫外/混凝沉淀组合工艺对三氯乙醛生成潜能(CHFP)的控制效果,以明确预紫外/混凝沉淀工艺控制CHFP的可行性,为水厂控制三氯乙醛(CH)提供参考。在单独紫外及紫外与混凝沉淀工艺联用条件下,对CHFP的去除率均随着紫外剂量的增加而增大,在紫外剂量为1 400 m J/cm^2时,对CHFP的去除率达到最大,分别为33. 61%、81. 56%;该地区原水中的溶解性有机物(DOM)以芳香性蛋白质类物质为主,且CH的前体物含量与芳香性蛋白质类物质和溶解性微生物代谢产物关系密切,单独紫外对DOM有较好的去除效果,对荧光区域Ⅳ所表征的溶解性微生物代谢产物的去除率最高,为40. 64%;相比单独混凝沉淀对CHFP的去除率(55. 37%),紫外与混凝沉淀联用工艺对CHFP的去除率提高了26. 19%,这说明预紫外有很好的助凝效果;预紫外/混凝沉淀工艺对荧光区域Ⅳ物质的去除率最高,为35. 2%。

The removal of chloral hydrate formation potential （CHFP） by UV and UV pretreatment/coagulation sedimentation processes was studied for the low turbidity and high algae-laden water in Shenzhen area in order to provide guidance for controlling CH during water treatment. The experiment resuits showed that for UV or UV pretreatment/coagulation sedimentation processes, the removal rate of CHFP increased with the increase of UV dose. When the UV dose was 1 400 mJ/cm2, the removal effect of CHFP reached the maximum and the removal rates were 33.61% and 81.56%, respectively. Furthermore aromatic protein-like substances were main components of DOM, and the relationship between the content of CH precursors and the contents of soluble microbial product（SMP） or aromatic protein-like substances was best. UV pretreatment achieved better effect on DOM control and the removal rate of SMP-like was highest with 40.64%. Compared with coagulation sedimentation process （55.37%）, the removal rate for CHFP by UV pretreatment/coagulation sedimentation processes increased by 26. 19% , which indicated that UV pretreatment was conducive to coagulation sedimentation. The UV pretreatment/ coagulation sedimentation process also had a good removal effect on the organic matter in fluorescent region IV.