摘要
以我国目前广泛采用的常规净水工艺为基础,开展了水源突发性As(Ⅲ)污染的应急处理工艺中试研究,考察了不同的氧化剂种类、投加量、投加点和不同污染物浓度水平对应急处理工艺效果的影响以及As(Ⅲ)的去除机制.结果表明,当原水As(Ⅲ)为150μg/L,常规处理工艺对As(Ⅲ)的去除率仅为71.85%,其中溶解态的砷和总砷在快速混合、一级絮凝、二絮凝、沉淀、过滤各单元去除率分别为36.00%、5.42%、9.30%、14.95%、7.88%以及9.10%、-3.62%、2.74%、55.12%、8.51%,无法将出水中的As控制在10μg/L以下.预氯化-强化混凝工艺能够将初始浓度为100~600μg/L的As(Ⅲ)控制在10μg/L以下.但在低有效氯投加量时,氨氮浓度以及预氯化点的选择会对处理效果产生影响.KMnO4预氧化一强化混凝工艺能够将初始浓度为100~600μg/L的As(Ⅲ)控制在10μg/L以下,且其处理效果明显优于预氯化,预氧化点的选择不会对处理效果产生明显影响.建议有条件的水厂优先选用KMnO4作为As(Ⅲ)的氧化剂.
Based on the conventional water treatment processes widely used in China, a pilot scale study was performed to investigate emergent treatment for arsenite pollution in water source. The results show that As removal efficiency can only reach to 71.85% by conventional water treatment process. The removal efficiencies of dissolved arsenic and total arsenic by mixing, first flocculation, second flocculation, sedimentation, filtration units were 36.00% , 5.42% , 9. 30% , 14. 95% , 7.88% and 9.10% , - 3.62% , 2.74% , 55.12% , 8.51% respectively,when the concentration of As(Ⅲ ) in raw water was 150 μg/L. The arsenic concentration in treated water can not be effectively controlled below 10 μg/L. Hence, the pre-oxidation is necessary. The pre-chlorination-enhanced coagulation process can effectively deal with the sudden As( Ⅲ ) pollution. But for lower chlorine dosage, both ammonia concentration and different pre-chlorination sites have significant effects on arsenic removal, which should be taken into account. Potassium permanganate pre-oxidation-enhanced coagulation process can be more effectively deal with the sudden As( Ⅲ ) pollution than prechlorination. Moreover the different pre-oxidation sites have no obvious effect on arsenic removal. As a result, potassium permanganate is recommended as an oxidant for As(Ⅲ ).
出处
《环境科学》
EI
CAS
CSCD
北大核心
2010年第2期324-330,共7页
Environmental Science
基金
"十一五"国家科技支撑计划项目(2006BAJ08B06)
国家科技重大专项(2008ZX07421-002)
国家高技术研究发展计划(863)项目(2008AA06A412)
关键词
突发性污染
应急处理
亚砷酸盐
强化混凝
预氧化
sudden pollution
emergent treatment
As( Ⅲ )
enhanced coagulation
pre-oxidation