Ammonia removal from ammonia-rich wastewater by air stripping using a rotating packed bed

作者：Yuan Min Hao; Chen Yi Hung; Tsai Jhih Ying; Chang Ching Yuan

来源：Process Safety and Environmental Protection, 2016, 102: 777-785.

DOI：10.1016/j.psep.2016.06.021

• Air stripping
• Ammonia removal
• Rotating packed bed
• Continuous flow
• Mass transfer coefficient

Air stripping of ammonia from an ammonia-rich stream (1000 mg/L) was performed in a continuous-flow rotating packed bed (RPB) at temperatures from 25 to 40 degrees C. The effects of the major operating variables (rotational speed (omega), liquid flow rate (Q(L)), gas flow rate (Q(G)), and stripping temperature (T)) on the volumetric liquid mass-transfer coefficient (K(L)a) and stripping efficiency (eta) were elucidated. The results indicate that the RPB exhibits higher mass-transfer performance (12.3-18.41/h) compared with those of stripping tanks, packed towers, and other advanced gas-liquid contactors (0.42-1.2 1/h). At Q(L), = 0.05 L/min, Q(G)/Q(L) =1600, and omega =1200 rpm, eta values for the RPB at 30 and 40 degrees C respectively reached 69% and 81% within 13.3 s. In contrast, conventional ammonia stripping processes with liquid recirculation in larger towers usually take hours to achieve the same values. The proposed dimensionless models describe the relationship between KLa and the major parameters for ammonia stripping in the RPB. KLa showed the greatest increase with increasing QG followed by the increase in Q(L), omega, and T. However, the operating conditions that would make the technology economically viable and the optimal conditions for efficient ammonia removal must be further studied.

• 出版日期2016-7