Study of struvite precipitation in anaerobic digesters

Study of Struvite Precipitation in Anaerobic Digesters

-In this paper struvite formation and crystal forms in anaerobic digesters under differing feed types and support media have been studied. Struvite appears when the medium contains magnesium, ammonium and phosphate ions. NH + can be supplied from protein degradation, phosphate from bacterial exudation and Mg 2+ by the supports. The precipitation of struvite has also been checked with real feedi...

Hydrodynamics Study of Sludge in Anaerobic Digesters

Inadequate design and improper mixing operation in anaerobic digesters often lead to poor mixing and digester failures due to the presence of dead zones formed in the digester. More research is required to understand the mixing phenomena in anaerobic digesters and thus improve their efficiency. This paper investigates the efficiency of mixing of digester sludge in a mechanically agitated vessel...

Application of Struvite Process for Nutrient Recovery from Anaerobic Digesters of Livestock Wastewater

Process of struvite (MgNH4PO4·6H2O) precipitation is a promising method for phosphorus recycling. The use of cheap magnesium ore for precipitation struvite as phosphate recovery has been examined. The optimal conditions for precipitation are pH 9.0 and Mg: 4 NH  : 4 PO  molar ratio 1.1:30.7:1. Linear correlation of experimental data is in qualitative agreement with modelling calculation. Surf...

Dairy Manure Anaerobic Digesters

Modeling of ammonia speciation in anaerobic digesters.

Anaerobic digestion of high-nitrogen wastes such as animal manure can be inhibited by high concentrations of un-ionized ammonia, NH(3) (aq). Understanding the toxicity of NH(3) (aq) to anaerobic digestion requires a method for determining its concentration. Previous work on ammonia toxicity in anaerobic digesters has utilized a simple equilibrium calculation for estimating NH(3) (aq) concentrat...