Agglomeration of struvite crystals.
Struvite crystallisation is widely studied as a way to remove phosphorus from wastewater effluents and simultaneously generates a valuable product for the fertiliser industry. However, to date, some crystallisation processes experimented at either pilot/or full scale face problems linked to the formation of fines. This paper presents results on the investigation of struvite agglomerative properties and the possible application of coagulants and/or flocculants to remove fines. Coagulants investigated were hydrolysing metals salts (Al(3+) and Fe(3+)), calcium compounds and a cationic polymer, polydiallyldimethylammoniumchloride (polyDADMAC). The effects of a natural flocculant (alginate) have also been tested. Results demonstrated that destabilisation of struvite particles by chemical addition was feasible and identified polyDADMAC as a good option for the agglomeration of struvite particles. However, optimisation of its dosage under typical pH conditions for struvite formation showed floc formation to be very pH sensitive.
Le Corre
Kristell S
KS
School of Water Sciences, Cranfield University, Cranfield MK43 OAL, UK.
Valsami-Jones
Eugenia
E
Hobbs
Phil
P
Jefferson
Bruce
B
Parsons
Simon A
SA
D000464:Alginates / Q000737:chemistry; D004563:Electrochemistry; D005427:Flocculation; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D017616:Magnesium Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010316:Particle Size; D010710:Phosphates / Q000138:chemical synthesis* / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D000069877:Struvite; D014865:Waste Disposal, Fluid / Q000379:methods
D000464:Alginates; D006603:Hexuronic Acids; D017616:Magnesium Compounds; D010710:Phosphates; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D020723:Glucuronic Acid; D000069877:Struvite