Avaliação da eficiência do sistema Algae Turf Scrubber (ATS®) no tratamento de águas eutrofizadas e na produção de biomassa perifítica.

Abstract

EVALUATION OF THE EFFICIENCY OF THE ALGAE TURF SCRUBBER SYSTEM (ATS) IN THE TREATMENT OF EUTROPHICED WATERS AND THE OF PERIPHYTIC BIOMASS PRODUCTION - Eutrophication is recognized as one of the most important water quality problems nowadays, and there is a strong need to develop strategies that reduce nutrient loading in water. The objective of this study was to evaluate the efficiency of the Algae Turf Scrubber system (ATS®) in the treatment of eutrophic waters and in the production of periphytic biomass. The system was drained from the freshwater reservoir for human supply in the city of Santa Cruz do Sul (Lago Dourado). A pilot-scale ATS system (0.9 m wide, 5 m long, 1.0% slope) was constructed and received continuous flow of approximately 2 L min-1 of pumped water from Lago Dourado, during a period of 7 months. On average, the system produced 4.46 g m-2 d-1 (range: 1.33 - 7.64 g m-2 d-1) of periphyton (dry weight). The collected periphyton contained an average composition of 27.97% carbon, 3.73% nitrogen, 17.81% protein and 65% carbohydrates. The periphyton harvest reached a mean removal index of 0.10 g m-2 d-1 and 0.008 g m-2 d-1 for nitrogen and phosphorus respectively. The average ash level was 36.90%, the lipids had low concentrations, with an average of 5.90%. The fatty acids have a general average higher concentrations of saturated fatty acids (53.72%) than unsaturated (45.59%). The observed nutrient removal suggests a potential for the use of ATS® systems as an effective means of treating eutrophic waters while producing periphyton with potential market value, so this study was able to provide information for future optimization experiments ATS® system.