Phosphorus removal using novel crystallisation technology.
A soy protein manufacturing facility was faced with the challenge of reducing its effluent phosphorus (P) content from 20-50 mg L(-1) down to <2 mg L(-1) total P without increasing soluble salt levels to comply with discharge and receiving water requirements. A number of biological and chemical P removal technologies previously evaluated either failed to achieve the new standards or would have produced prohibitive amounts of residual sludge and unacceptably high effluent salt concentrations. Lime precipitation, utilising a novel crystallisation technology, was demonstrated through on-site pilot testing to meet the process objectives. It is capable of achieving the required P removal at pH 10 while not increasing soluble salts and producing rapid settling and filterable particles. Also, minimal carbonate removal was observed with residual solids generation being only 40% of a complete lime softening reaction. This paper describes the technical evaluation that led to the full-scale treatment system that was put into operation in late 2005.
Wood
K
K
DuPont Company, 1007 Market Street, Wilmington, DE 19898, USA. kenneth.n.wood@usa.dupont.com
Wood
G
G
Prokop
D
D
Lewyille
F
F
D003460:Crystallization; D004867:Equipment Design; D005525:Food-Processing Industry; D010758:Phosphorus / Q000032:analysis*; D010865:Pilot Projects; D012722:Sewage / Q000737:chemistry*; D013025:Glycine max; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
D012722:Sewage; D014874:Water Pollutants, Chemical; D010758:Phosphorus