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Application of Chemical Coagulation Aids for the Removal of Suspended Solids (TSS) and Phosphorus from the Microscreen Effluent Discharge of an Intensive Recirculating Aquaculture System
Author(s) -
Ebeling James M.,
Ogden Sarah R.,
Sibrell Philip L.,
Rishel Kata L.
Publication year - 2004
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/a03-056.1
Subject(s) - alum , flocculation , turbidity , settling , suspended solids , ferric , effluent , coagulation , total suspended solids , chloride , pulp and paper industry , phosphorus , sedimentation , aluminium sulfate , recirculating aquaculture system , environmental engineering , chemistry , sewage treatment , wastewater , environmental science , aquaculture , chemical oxygen demand , biology , fishery , inorganic chemistry , ecology , sediment , psychiatry , engineering , psychology , paleontology , fish <actinopterygii> , organic chemistry
An evaluation of two commonly used coagulation–flocculation aids (alum and ferric chloride) was conducted to determine optimum conditions for treating the backwash effluent from microscreen filters in an intensive recirculating aquaculture system. Tests were carried out to evaluate the dosages and conditions (mixing and flocculation stirring speeds, durations, and settling times) required to achieve optimum waste capture. The orthophosphate removal efficiency for alum and ferric chloride were greater than 90% at a dosage of 60 mg/L. Optimum turbidity removal was achieved with a 60‐mg/L dosage for both alum and ferric chloride. Both alum and ferric chloride demonstrated excellent removal of suspended solids from initial total suspended solid values of approximately 320 mg/L to approximately 10 mg/L at a dosage of 60 mg/L. Flocculation and mixing speed and duration played only a minor role in the removal efficiencies for both orthophosphates and suspended solids. Both coagulation–flocculation aids also exhibited excellent settling characteristics, with the majority of the floc quickly settling out in the first 5 min.