Abstract

This paper presents experimental results on the implementation of Eichhornia crassipes-based tertiary lagoon to treat effluents generated by a 300 ton d-1 Kraft pulp mill in Chile. Results show that E. crassipes rapidly adapted to the tertiary lagoon conditions. Active growth was maintained even during a cold winter, protected by the wastewater heat content. A 1000 m2 seeding area extended to 2300-6200 m2 after a month of growth, with a monthly harvested biomass and nitrogen uptake were 1.1-5.4 ton (dry wt.), and 18-127 kg N, respectively. E. crassipes growth was adequately described by a first order model, with an estimated rate constant ca. 0.03 d-1 and 0.06 d-1, for winter and summer seasons, respectively. A management strategy based on such model, to account for seasonal variations in growth rate while keeping a constant nitrogen uptake capacity, is proposed here.