Abstract

ARIAS-LIZARRAGA, Dulce María  and  MENDEZ-GOMEZ, Evaristo. Removal of Solids from Wastewater from the Fishmeal Industry. Tecnol. cienc. agua [online]. 2014, vol.5, n.3, pp.115-123. ISSN 2007-2422.

The fishmeal company Maz Industrial S.A. de C.V., located in Mazatlan, Sinaloa, Mexico pours its wastewater into the Urías estuary. This effluent has a high organic matter load and contains proteins, fats and oils, resulting in an environmental impact and economic loss from not being reused. As much as 11.44 t d^-1 which could be reused in production is wasted. In order to evaluate the removal of organic matter during the pre-treatment phase of these wastewaters, coagulation, flocculation and sedimentation tests were conducted using natural and innocuous organic polymers, chitosan as a primary coagulant and sodium alginate and tannic acid to assist in anionic coagulation. With 300 mgl^-1 of chitosan and 20 mgl^-1 of sodium alginate, 91.84% of total suspended solids (TSS) was removed and 90.83% of volatile suspended solids (VSS). With 200 mgl^-1 of chitosan and 20 mgl^-1 of tannic acid, 97.78% TSS was removed and 97.79% of volatile suspended solids (VSS). Given the removal efficiencies obtained in this investigation and considering that the precipitate recovered using these biopolymers is not toxic, it is possible to scale the recovery of organic matter to the industry level for reuse in the production of fishmeal, facilitate conventional biological treatment of the organic matter remaining in the pretreated wastewater and reduce the environmental impact of discharges with a high organic load.

Keywords : Removal; fishmeal industry; coagulation; chitosan; tannic acid; sodium alginate.