碱解工艺预处理DMF废水

N,N-二甲基甲酰胺(DMF)及其分解产物二甲胺(DMA)对生物硝化具有强烈的抑制作用,致使含DMF废水的生物处理系统出水的氨氮质量浓度难以达到排放标准。为此,采用碱解预处理方法去除废水中的DMF和DMA。借助实验室小试装置优化了过程控制参数,再将此预处理方法运用到某DMF废水处理工程。小试结果表明,在加碱量为n(NaOH)∶n(DMF)=1.2∶1、反应压力为0.04MPa、反应温度为76.0℃、反应时间为60min的条件下,模拟废水的DMF质量浓度由10000mg/L降至35mg/L,DMA质量浓度降至28mg/L。DMF实际废水处理工程结果表明,经碱解预处理后,生物处理系统进水中DMF稳定在1.0mg/L以下,DMA稳定在10mg/L以下,出水氨氮质量浓度降至2.0mg/L以下,生物硝化过程得以恢复。

Pretreatment of DMF wastewater by alkaline hydrolysis process

N,N-dimethylformamide （DMF）and its decomposition product dimethylamine （DMA）have strong inhibitory effects on biological nitrification,causing that the concentration of ammonia nitrogen in bio-treated DMF wastewater can not meet the emission standards. To solve this problem,alkaline hydrolysis pretreatment was adopted to remove DMF and DMA from wastewater. The process control parameters were optimized with the help of laboratory testing equipment,and then the pretreatment method was applied to a DMF wastewater treatment project. The testing results showed that under the conditions of n（NaOH）:n（DMF）=1.2:1,reaction pressure 0.04 MPa,reaction temperature 76 ℃ and reaction time 60 min,the mass concentration of DMF in the simulated wastewater was decreased from 10 000 mg/L to 35 mg/L and the mass concentration of DMA was decreased to 28 mg/L. The results of treatment project for actual DMF wastewater showed that after pretreatment by alkaline hydrolysis process,the mass concentration of DMF and DMA in influent of biological treatment system was stably below 1.0 mg/L and 10 mg/L,and the mass concentration of ammonia nitrogen in effluent was decreased below 2.0 mg/L,which indicated that the biological nitrification process was recovered.