Impact of salinities, metals and organic compounds found in saline oil & gas produced water on microalgae and cyanobacteria

Ecotoxicol Environ Saf. 2022 Apr 1:234:113351. doi: 10.1016/j.ecoenv.2022.113351. Epub 2022 Mar 4.


This work evaluates the impact of salinity and the toxicity of some metals and organic compounds commonly found in produced waters on the growth of model photosynthetic organisms. Five strains of marine microalgae and one cyanobacteria (i.e. Dunaliella salina, Nannochloropsis oceanica, Tetraselmis suecica, Picochlorum costavermella, Coccomyxa simplex and Synechococcus rubescens) were tested in microplates as well as the freshwater Chlorella vulgaris selected as reference. Results revealed that D.salina was able to growth at high salinity (up to 135 g·L-1). Copper was the most toxic metal for all strains (half maximal effective concentration between 0.1 and 10 mg·L-1) except for D.salina and C.simplex. These two strains were the most resistant to all metals tested. All organic compounds presented half maximal effective concentration above 10 mg·L-1, none of them being very toxic for the studied microorganisms. P.costavermella and C.simplex were the most resistant strains to organic compounds. Looking at tolerance to salinity, metals and organic compounds, D.salina appeared to be the best choice for biomass production in produced waters. In addition, growths in 80% artificial produced water supplemented with f medium confirm the feasibility to use this medium to produce biomass.

Keywords: Metal toxicity; Microalgae; Organic compound toxicity; Produced waters; Salinity.