Dissolved organic nitrogen (DON) constitutes a significant portion of the nitrogen in treated wastewater effluent. Owing to stringent effluent nitrogen limits, removal of DON is becoming increasingly important. In addition to being potentially recalcitrant within biological treatment systems, DON also has the potential to form disinfection byproducts (DBPs) and to cause membrane fouling. Enhanced coagulation is effective in removing DON from wastewater. Most of the previous studies on DON removal by coagulation are primarily based on employing commonly used metal coagulants. The removal of DON by metal coagulants is believed to be governed by charge neutralization or sweep coagulation and is influenced by various factors such as type and the dose of the coagulant, DON chemical properties, water pH, and temperature. The focus of this presentation is to highlight laboratory and pilot-scale research aimed at identifying the effectiveness of aluminum and iron-based coagulants on DON removal Experiments were also conducted to investigate the removal mechanism and influencing factors during coagulation. It is well established that metal-based coagulants are effective in removing high molecular weight (MW) organic compounds which are relatively hydrophobic. This study investigated the mechanism of DON removal whilst hypothesizing that Fe (III) could be preventing the removal of DON by forming organo-Fe complexes which could eventually influence the hydrophilic/hydrophobic ratio.

Dissolved organic nitrogen removal from wastewater by enhanced coagulation

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.