title: Agglomeration of struvite crystals.
abstract: 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.
authors.affiliation: School of Water Sciences, Cranfield University, Cranfield MK43 OAL, UK.
authors.forename: Kristell S
authors.initials: KS
authors.lastname: Le Corre
authors.forename: Eugenia
authors.initials: E
authors.lastname: Valsami-Jones
authors.forename: Phil
authors.initials: P
authors.lastname: Hobbs
authors.forename: Bruce
authors.initials: B
authors.lastname: Jefferson
authors.forename: Simon A
authors.initials: SA
authors.lastname: Parsons
mesh_terms: 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
chemical_list: 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