Mobile organic biofilm process for ammonia removal under low solids retention time and low operating temperature conditions

This study aimed to evaluate the effectiveness of mobile organic biofilm (MOB) technology for removing ammonia (NH₃/NH₄⁺, referred to as NH₄⁺) from wastewater in low solids retention time (SRT) and low operating temperature conditions. The MOB technology is based on process intensification using a plant-based media (milled kenaf) to develop a mobile organic biofilm. In the MOB process, media is added to the aeration tanks of an activated sludge process. Two bench-scale sequencing batch reactors (SBRs) with 1.5 L volume were used to assess MOB technology, a control, and a MOB-added reactor, hereafter the MOB reactor. The NH₄⁺ concentration in the influent ranged from 5.5 to 14.9 mg N/L, with an average of 10.1 mg N/L over the study period. The COD level varied from 66.0 to 94.0 mg/L, with an average of 78.8 mg/L. The results showed that the MOB process effectively removes NH₄⁺ and COD with a three-day SRT at 12 °C. The MOB reactor achieved an average of 93.1% NH₄⁺ and over 47% COD removal throughout the stable operation period. MOB represents a promising wastewater treatment technology for the removal of nitrogen in activated sludge facilities.