化学氧化法应急处理甲醛污染饮用水源的工艺研究

Technical studies on the emergency treatment of formaldehyde polluted drinking water by chemical oxidation method

采用化学氧化法应急处理甲醛污染饮用水源,探讨H_2O_2、NaClO、Ca(ClO)_2、KMnO_4、K_2FeO_4这5种氧化剂在典型浓度下投加量、pH、时间、温度等反应条件对甲醛废水的去除效果并找出最佳工艺条件。结果表明,H_2O_2、NaClO、Ca(ClO)_2可作为应急处理甲醛污染饮用水源的药剂,典型浓度下处理的最佳工艺条件:常规pH条件下反应30 min,当水中甲醛浓度依次超标10、20、50、100、200、500、1 000倍时,0~20℃时分别投加20 g/L Ca(ClO)_2、100 mL/L NaClO(8%)、25g/L Ca(ClO)2、200 mL/L NaClO、100 g/L Ca(ClO)_2、300 mL/L NaClO、400 mL/L NaClO;20~35℃时适宜投加H2O2(30%),分别投加60、100、120、250、400、600、800 mL/L。经处理后甲醛浓度基本能降到标限以内,甲醛去除率可达到99%以上。

The chemical oxidation method has been used for the emergency treatment of formaldehyde polluted drinking water sources.The removing effects of five kinds of oxidants,including H2O2,NaClO,Ca(ClO)2,KMnO4 and K2FeO4,on formaldehyde wastewater,under the following reaction conditions,such as dosages with typical concentrations,pH value,reaction time,temperature,initial concentration of pollutants,etc.,as well as the optimal process conditions,have been investigated.The results show that H2O2,NaClO and Ca(ClO)2 can be used as the best chemical agents for emergency treatment of formaldehyde polluted drinking water sources.Under typical concentrations,the optimal treatment process conditions are as follows:the reaction time is 30 min,under conventional pH conditions.When the concentrations of formaldehyde in water exceed the standard in sequence of 10,20,50,100,200,500,1 000 times,and the temperature is 0-20℃,Ca(ClO)2 20 g/L,NaClO(8%)100 mL/L,Ca(ClO)2 25 g/L,NaClO 200 mL/L,Ca(ClO)2 100 g/L,NaClO 300 mL/L,and NaClO 400 mL/L ought to be added.When the temperature is 20-35℃,it is suitable to add H2O2(30%),adding 60,100,120,250,400,600,800 mL/L respectively.After the treatment,the formaldehyde concentration can basically be reduced below the standard limit value,and the removing rate can be above 99%.