Abstract

Microalgae have been the subject of several studies in the wastewater treatment field due to their ability for the removal of various nutrients, organic load and to be a clean and economical way to treat pollutants. The effluents from leather finishing processing steps contain chemical pollutants due to the use of dyes, surfactants, toxic metals, emulsifying agents, retanning agents, oils, pigments, resins, among other chemicals added. In this work, the isolated microalgae Tetraselmis sp. was obtained from a microalgae consortium and evaluated for their ability for the treatment effluents collected from a tannery. The growth of microalgae biomass in these effluents in mixotrophic cultivation was analysed, as well as, the capacity of removal of total nitrogen (TN), total organic carbon (TOC), total carbon (TC), inorganic carbon (IC), ammonia (N-NH3), phosphorus (P-PO4), chemical oxygen demand (COD) and biological oxygen demand (BOD). The removal values observed for the 50R50T (50% raw/50% treated effluent) and 75R25T (75% raw/25% treated effluent) concentrations were 96.59% and 99.81% for phosphorus, 99.90% and 89.2% for ammoniacal nitrogen, 89.06% and 54.78% for TN, 40.46% and 43.54% for COD, 59.24% and 57.90% for TOC, 32.70% and 44.73% for BOD, respectively. The microalgae Tetraselmis sp. showed notable growth in mixotrophic cultivation, and the efficient removal of the controlled parameters indicate an enormous potential for application in tannery wastewater treatment.