Abstract: This disclosure relates to physical selection, deselection or outselection for smaller, less dense, sheared or compressed particles in sludge, wherein the first deselection step occurs at the reactor or at a clarification step, by separately deselecting for such particles and then a second deselection step occurs in an external selector. This double deselection promotes the more efficient removal of slow settling particles, while simultaneously allowing for maintenance of multiple solids residence times for fast and slow growing organisms. The deselection in a clarifier occurs typically at the periphery of the tank or at the surface of a blanket using a positive or negative pressure device. Structures such as slotted or perforated plates, pipes or manifolds can be used to assist in such deselection. Baffles can also be used for such deselection.

Abstract: A methodology, system and apparatus are provided that include anoxic biofilms to perform partial denitrification and anammox (PdNA) reactions. The PdNA reactions can facilitate process intensification and carbon efficient biological nitrogen removal. The anoxic biofilms can be placed in a pre-anoxic zone or a downstream anoxic zone, where the biofilm and reactions are managed, including using storage compounds, to overcome mass transfer limitations in the biofilm. The methodology, system and apparatus can, when compared to state-of-the art technologies, improve the concentration gradient or reduce mass transfer limitations to facilitate PdNA reactions.

Abstract: An apparatus and a method for removing constituents from an influent. The apparatus includes a biological processor that receives a water mixture as influent and outputs a liquor, a solid-liquid separator that receives the liquor and separates the liquor into a liquid and a solid; and a biofilm media that includes at least one media surface. The biofilm media may have a biofilm mass, biofilm volume, biofilm density, biofilm thickness, hydraulic retention time or solids residence time. The at least one media surface grows a biofilm that removes one or more constituents contained in the influent. The biofilm mass, biofilm volume, biofilm density, biofilm thickness, hydraulic retention time or solids residence time can be controlled by at least one of a physical process, a biological process or a chemical process.

Abstract: This disclosure relates to nitrogen removal with carbon addition, including for wastewater treatment. The denitrification reaction may be terminated at an intermediate nitrite product which is supplied to the anammox reaction. Nitrogen may be removed by use of an electron donor source including, but not limited to, acetate or glycerol at a specific zone. The electron donor may be used to convert nitrate to nitrite through appropriate dosing, anoxic SRT and/or maintenance of a nitrate residual in isolation or in combination. The subsequent supply of nitrite and ammonia for anammox reactions is also proposed. The slower growing anammox may be selectively retained on media or using other physical approaches. The overall intent of the present disclosure is to minimize the use of electron donor by maximizing denitratation and anammox reactions. Test results for selective retention of anammox in biofilm, granular or suspended growth system or nitrate residual control are provided.