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Treatment of Fish Farm Wastewater Using Sand Filtration
Author(s) -
Kristiansen Rolv,
Cripps Simon J.
Publication year - 1996
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1996.00472425002500030020x
Subject(s) - effluent , clogging , environmental science , wastewater , sand filter , filtration (mathematics) , pulp and paper industry , settling , environmental engineering , sewage treatment , nitrate , suspended solids , chemistry , environmental chemistry , statistics , mathematics , archaeology , organic chemistry , engineering , history
The treatment of aquaculture wastewaters typically consists of screening suspended particles from the primary flow, producing a sludge that must be disposed of. Two experiments were conducted to determine the feasibility of using sand to renovate, stabilize, and dry salmon farm sludge. Data from a preliminary laboratory experiment were used to quantify and design a pilot‐scale study facility linked to a salmon farm. The pilot study comprised coarse sand‐filled infiltration beds loaded with either an artificial fish farm wastewater (AFW), backwash water from a microsieve (BW), or sedimented microsieve backwash water (SBW) collected daily from a settling chamber. A large reduction in hydraulic capacity was caused by the establishment of a clogging mat on the sand filter surface. About 60% of the sludge total organic C was removed by the filters. Nitrogen in the effluent from the SBW loaded filters was predominately organic, and nitrate concentrations were insignificant (<0.03 mg NO 3 ‐N L −1 ). Effluent ammonium concentration decreased from 97% of the effluent total nitrogen (TN) after 1 mo of loading, to 10% after 2 to 3 mo, with an attendant increase in nitrate to about 65% of the TN. The P binding capacity of the test sand volume was exceeded after 1 to 2 mo of SBW loading. This capacity was not exceeded during the experiment, using the two other effluent types (BW and AFW). Filter effluent P concentrations were about 1.4 mg L −1 . At a SBW loading of 1 cm d −1 , to a coarse sand, with a hydraulic head of >10 cm, it is expected that 2 to 3 mo loading can be conducted before maintenance or change of filter surface sand is required, as a result of hydraulic malfunction. The use of sand infiltration for treating salmon farm sludge was therefore shown to be feasible.