Experimental study of once-pass ammonia removal from wastewater by membrane contactor

Ammonia is one of the most common pollutants in urban and industrial wastewaters and due to various problems it generates, it is necessary to remove it from wastewaters. In this study, a laboratory scale once-pass membrane contactor system was designed and constructed using PPO hollow fiber membranes and the effect of various operating parameters such as the feed passage side (the lumen-side or the shell-side), feed flow rate and temperature on the efficiency of the process for synthetic wastewater was investigated. Since the petrochemical units are of the main sources of wastewaters containing ammonia at high concentrations, in the second part of this study, the efficiency of the process to remove ammonia from Khorasan Petrochemical wastewater was also investigated. Experimental results showed that low feed flow rate, high feed temperature and feed passage through the lumen side increased the ammonia removal percentage. Also, the ammonia removal percentage variations with the feed velocity and temperature were the same as that of synthetic wastewater. By comparing the ammonia removal percentages of synthetic and real wastewaters, it was obtained that ammonia removal percentages for real petrochemical wastewater at 20 and 40 ºC, were respectively about 25 and 19% lower than that of synthetic wastewater.