Experiences in Using MBBR and Denitrification Filters for Nitrogen Removal from Saline Wastewater

As water recycling becomes more widespread, brine disposal and the removal of nitrogen and phosphorus from a wastewater that is relatively high in chlorides have emerged as important areas of study and development. This paper discusses the use of biofilm processes for both nitrification and denitrification of saline wastewaters. Testing results from parallel pilot-scale submerged aerated filter (SAF) and moving bed bioreactors (MBBR) for nitrification followed by deep-bed denitrification filters on a municipal wastewater with an average chloride concentration of 6,000 mg/L are summarized. The lessons learned were applied to the full-scale design of a nitrification MBBR and of denitrification filters for treatment of reverse osmosis concentrate from a water recycling plant. The paper will discuss design considerations and the first year of full-scale operating data.