Abstract:

The combined aerated stripping-adsorption-biological process was used to deal with the high concentration morpholine and N-methylmorpholine organic wastewater in laboratory scale. The results were as follows: after twice aerated stripping, the ammonia nitrogen concentration of the raw wastewater was reduced from 62 500 mg/L to 431 mg/L, meanwhile COD was reduced from 50 840 mg/L to 26 051 mg/L. After the adsorption by activated carbon, COD was reduced from 26 051 mg/L to 2 769 mg/L and the concentration of ammonia nitrogen was reduced from 412 mg/L to 134 mg/L. In the biological treatment process, the combined process of activated sludge reactor and biological aerated filter (BAF) was used. In the activated sludge reactor system, when influent pH was 7.5, DO was 4.3 mg/L and hydraulic retention time (HRT) was 30 h, COD removal rate reached 83.1%. In the BAF process, when DO was 3.3 mg/L, COD removal rate reached 55.8%.Continuous monitoring of the biological process was made in the optimum conditions, when influent COD was 2 769 mg/L, the average effluent COD was 387 mg/L, the removal rate reached 85.9%.The effluent COD of the morpholinecontaining wastewater was reduced to 387 mg/L from 50 840 mg/L through this combined treatment process.

Key words: morpholine, N-methylmorpholine, aerated stripping, adsorption, biodegradation