Uptake of Cu2+ by unicellular microalga Chlorella vulgaris from synthetic wastewaters is attenuated by polystyrene microspheres

Aquatic and terrestrial ecosystems are receiving micro-and macro-plastic pollutants alarmingly from various anthropogenic activities. The complications caused by microplastics are largely unexplored and need substantial studies. In the current study, we investigated the repressive effects of negatively and positively charged polystyrene microspheres of two variable sizes (0.05 and 0.5 mu m) on functioning of unicellular green microalgae. For the purpose, a pollution-resistant microalgal species was isolated and identified by 18 S rRNA gene sequencing as Chlorella vulgaris. The functioning of the pure-cultured microalgal cells was then assessed in terms of their better metal (Cu2+) uptake potential with and without the provision of PS microspheres. The algal cells up took Cu2+ significantly (90% at 75 mg/L) after 15 days of aerobic incubation. However, positively charged polystyrene microspheres remarkably affected the uptake of Cu2+ and it was comparatively reduced to almost 50%, while negatively charged microspheres couldn't influence the Cu2+ uptake potential of C. vulgaris. In addition, size of the microspheres insignificantly affected the metal uptake potential of the microalgae. Unveiled facts of this investigation will be helpful for designing economical and efficient remedial systems based on the in-situ implication of microalgae.

Automated summary

This study investigated the repressive effects of polystyrene microspheres on the functioning of unicellular green microalgae. The results showed that positively charged microspheres significantly affected the uptake of Cu2+ by the microalgae, while negatively charged microspheres did not. The size of the microspheres had little impact on the uptake potential. The findings of this study provide guidance for the design of cost-effective remediation systems.