Biotreatment of Un-/Pre-treatment Simulated Produced Water (SPW) Using Chlorella vulgaris

There have been increasing environmental concerns surrounding industrial wastewater especially from oil and gas industries, which call for the need for sustainable and effective treatment strategies. This study aims to investigate the biotreatment of Chlorella vulgaris for simulated produced water (SPW), looking at both untreated and pretreated water. This research used a laboratory bioreactor system where Chlorella vulgaris was nurtured and then introduced into SPW and 3,5-dimethylphenol (DMP) based produced water. Fenton oxidation was performed on the pretreatment of SPW to assess the effects with algal treatment. The parameters like pH, chemical oxygen demand (COD), volatile organic acids (VOAs), and UV-Visible spectrometer were observed for five weeks to evaluate treatment efficiency. The results obtained showed that Chlorella vulgaris developed substantial growth and adaptability in various treatments with notable changes occurring in colour, pH, and biomass. COD levels were significantly reduced across all treated samples, particularly in TSPW (884 to 315.5 mg/L) and SPW (2224.5 to 199.25 mg/L), which demonstrated strong pollutant removal capacity. The levels in VOA dropped to non-detectable limits in the TSPW CV sample, and it showed a major reduction in other treatments. UV spectrometry revealed changes in absorbance patterns at 272 nm and 687 nm, indicating organic matter transformation and algal activity. In conclusion, Chlorella vulgaris revealed it can be effectively used in the biotreatment of simulated produced water with commendable results obtained.