Geochemical equilibrium speciation modeling was used to determine optimum conditions for precipitation of magnesium ammonium phosphate, or struvite, for the recovery of nutrients from anaerobically digested wastes. Despite a wide range of pH values with the potential to precipitate struvite, the optimum pH was determined to be 9.0. Bench experiments conducted on effluent from an anaerobic seque...

Infectious urolithiasis is a result of recurrent and chronic urinary tract infections caused by urease-positive bacteria, especially Proteus mirabilis. The main role in the development of this kind of stones is played by bacterial factors such as urease and extracellular polysaccharides, but urinary tract environment also contributes to this process. We used an in vitro model to establish how t...

10 P recovery from wastewater treatment plants (WWTPs) as struvite fertiliser is a recognised method of 11 improving P use efficiency and reducing P losses into the environment. The main driver for P recovery from the 12 water industry viewpoint is the reduction in the nuisance of struvite clogging inside pumps and pipes. Struvite 13 recovery leads to an average P recovery rate of 72±7% from ce...

Urethral catheters often become encrusted with crystals of magnesium struvite and calcium phosphate. The encrustation can block the catheter, which can cause urine retention in the bladder and reflux into the kidneys. We develop a mathematical model to investigate crystal deposition on the catheter surface, modelling the bladder as a reservoir of fluid and the urethral catheter as a rigid chann...

Phosphorus (P) in wastes from piggeries may contribute to the eutrophication of waterways if not disposed of appropriately. Phosphorus leaching, from three soils with different P sorption characteristics (two with low P retention and one with moderate P retention) when treated with piggery effluent (with or without struvite), was investigated using batch and leaching experiments. The leaching o...

Background: Mature landfill leachate is a complicated mixture which is resistant to biological treatment processes. The treatment of mature landfill leachate by struvite precipitation and Fenton oxidation was the main objective of the current research. Methods: Struvite with the phosphate/ammonia/magnesium molar ratio of 1/1/1.05 was considered during all experiments. Five initial pHs of 3, 4,...

Forced precipitation of struvite (MgNH4PO4 . 6H2O) can reduce dissolved reactive phosphorus (DRP) in swine manure slurries. Optimization of this process requires that the swine manure slurry pH be increased, that magnesium be added, and that sufficient reaction time be allowed for struvite precipitation. To gather data that could be used for a full-scale continuous-flow struvite precipitation r...

Forced precipitation of struvite (MgNH4PO4*6H2O) has been demonstrated to be an effective method to reduce dissolved reactive phosphorus (DRP) from swine manure. The development of a robust and flexible continuous flow struvite precipitation reactor is essential to the application of this method to modern livestock operations. Swine manure generally requires pH adjustment, magnesium amendment a...