Growth of Picochlorum celeri in produced water from the Permian Basin (US)

Abstract

Produced water generated from hydraulic fracking is a waste stream that, on one hand, demands remediation, and, on the other hand, can be used as a water source to support a circular economy. In this study, we aimed to assess the ability of Picochlorum celeri to grow in two different sources of raw, untreated produced water collected in New Mexico, USA. The produced water had initial salinities of 110 and 140 PPT. Picochlorum was screened, with additional algae, on two different sources of produced water supplemented with nitrogen and phosphorus. The strain was able to grow on 25 % and 50 % produced water and achieve biomass densities between ∼40 and 100 % of those demonstrated by control cultures. To separate the effects of high salinity stress from toxicity of the produced water samples, we conducted a bioassay with produced water under isotonic conditions of 60 PPT. When controlling for salinity, the contaminants associated with the two sources of produced water did not affect growth of the algae. This study provides justification to consider P. celeri as a candidate for remediation of and biomass production on produced water. Foundational studies are necessary to assess remediation potential and characterize the growth, biomass accumulation, and biomass composition of P. celeri grown on a variety of produced water streams.