废水中高浓度甲醛的预处理工艺实验研究

Experimental Study on Pretreatment Technology of High Concentration Formaldehyde in Wastewater

本论文以南京某化工企业生产过程产生的高浓度甲醛工艺废水为研究对象,通过小试实验考察尿素缩合法对废水中甲醛的去除效果。论文通过单因素优化法对尿素缩合法的反应条件pH值、尿素投加量、缩合温度、反应时间等四个主要影响因素进行了操作参数优化。实验结果表明:当初始反应pH值为2~3、投加的尿素与甲醛的摩尔比为1.5∶1、温度为75℃、水浴加热时间为2 h时,废水中甲醛的降解率高达99%以上。

In this paper,the process wastewater with high concentration of formaldehyde produced in the production process of a chemical enterprise in Nanjing is studied.The removal efficiency of Formaldehyde from wastewaterand Urea condensation processes was investigated in a small scale experiment.Firstly,the operation parameters of urea condensation were optimized by means of single factor optimization,which included pH value,urea dosage,condensation temperature and reaction time.The results showed that the degradation rate of Formaldehyde in wastewater was over 99%when the initial pH value was 2~3,the molar ratio of urea to formaldehyde was 1.5∶1,the temperature was 75℃and the heating time was 2 hours.