Biorremediação e produção de biomassa por Chlorella sp. isolada da estação de tratamento de efluentes de uma indústria de arroz parboilizado

Resumo

Parboiling rice is a high-water demand process that generates approximately 2 L of effluent per kilogram of processed rice. This effluent is recognized for its high concentrations of phosphorus, organic matter, and nitrogen, and if not treated correctly, it can potentially contaminate the environment. Bioremediation methods offer a sustainable and low-cost alternative to support treatment stations. In this paper, we report on the successful isolation of a microalgae strain from a tertiary treatment station of the rice effluent industry. We also investigate the bioremediation and biomass potential of the strain after cultivating it in parboiled effluent without dilution or supplement. The cultures were carried out in a photobioreactor using parboiled effluent (PE) at 28 ºC, pH 7, a 16:8 light/dark cycle, and 2000 lux for 14 days. The highest concentration of Chlorella sp. biomass was obtained on the 14th day, reaching 2.4 g L^-1 in PE. Additionally, removals ranged from 39 to 95% of total Kjedahl nitrogen (TKN) and 66 to 82% of chemical oxygen demand (COD). These results suggest that treatment stations are a promising source of adapted microorganisms, and that PE can be used as culture medium to produce biomass and obtain bioproducts of high commercial value while simultaneously treating PE.