Feasibility and interest of the anammox process as treatment alternative for anaerobic digester supernatants in manure processing--an overview

Abstract

Completely autotrophic nitrogen removal (ANR) is based on the combination of partial nitritation (PN) and anaerobic ammonium oxidation (anammox). It is a promising alternative for the subsequent treatment of biogas digester supernatants in livestock manure processing and nitrogen surplus scenarios. However, as no full-scale experiences in the treatment of manure digestates by ANR have been published to date, future field studies addressing treatment of this kind of effluent would be of great interest. Some topics to be considered in these studies would be coupling anaerobic digestion and ANR, analysis of the factors that affect the process, comparing reactor configurations, microbial ecology, gas emissions, and achieving robust performance. This paper provides an overview of published studies on ANR. Specific issues related to the applicability of the process for treating manure digestates are discussed. The energy requirements of ANR are compared with those of other technological alternatives aimed at recovering nitrogen from digester supernatants. The results of the assessment were shown to depend on the composition of the supernatant. In this regard, the PN-anammox process was shown to be more competitive than other alternatives particularly at concentrations of up to 2 kg NH4(+)-N m(-3).

Keywords: 5-d biological oxygen demand; AD; ANR; AOB; Anaerobic ammonium oxidation (anammox); Autotrophic nitrogen removal (ANR); BOD(5); CHP; COD; CSTR; DEAMOX; DO; Digestate treatment; EGSB; Energy assessment; GHG; HRT; IC; Livestock manure; MABR; MAP; MBR; NLR; NOB; NRR; Nitrogen management; OC; PEG; PN; PVA; RBC; SBR; SHARON; SRT; TN; UASB; VSS; WWTP; ammonium-oxidizing bacteria; anaerobic ammonium oxidation; anaerobic digestion; anammox; autotrophic nitrogen removal; chemical oxygen demand; combined head and power; continuous stirred-tank reactor; denitrifying ammonium oxidation; dissolved oxygen; expanded granular sludge bed; greenhouse gases; hydraulic retention time; inorganic carbon; magnesium ammonium phosphate; membrane bioreactor; membrane-aerated biofilm reactors; nitrite-oxidizing bacteria; nitrogen loading rate; nitrogen removal rate; organic carbon; partial nitritation; polyethylene glycol; polyvinyl alcohol; rotating biological contactor; sequencing batch reactor; single reactor system for high ammonia removal over nitrite; solids retention time; total nitrogen; up-flow anaerobic sludge blanket; volatile suspended solids; wastewater treatment plant.