Desempenho energético e tratamento de água residuária em fotobiorreator contínuo iluminado artificialmente.

Abstract

The use of Light Emitting Diodes (LEDs) as a light source has several advantages: high efficiency, long lifetime and low energy consumption. LEDs can be obtained in the lighting of photobioreactors for the treatment of wastewater. Cleaning removing organic matter, nutrients and pathogens. Most of the researches found in the literature make use of laboratory scale photobioreactors (1L) generally and operated in batch. Despite the low energy consumption of LEDs, its use for continuous photobioreactors is questioned, since the energy performance for these systems has not yet been evaluated. Microalgae are cultivated in photobioreactors and, in addition to promoting wastewater treatment, their biomass can be reused to generate different bioproducts. This research evaluated the efficiency of an open LED-illuminated photobioreactor, simulating the operation of a High Rate Lagoon (LAT) in the treatment of synthetic wastewater and also evaluated the energy aspect as a function of artificial lighting. The system was operated in continuous regime under hydraulic detention time (TDH) of 7 days and luminous intensity of 815 μE.m-2.s-1. The microalgae biomass productivity was 6.80 ± 1.9 g.d-1.m-2 and the net oxygen production was 0.83 g.L-1. The stability and efficiency system in the removal of organic matter, represented by the Chemical Oxygen Demand (COD), with 90.3 ± 1.7% of removal. However, high values of energy consumption indicators for wastewater treatment were obtained, with 368.8 kWh / kg COD removed, 287 kWh.m-3 and 51.66 kWh (hab.d) -1.