A comparative study on the treatment of kitchen grey water using microalgae consortia and microalgae-synthesized silver nanoparticles

Comparative study on the potential of microalgae consortia and green-synthesized silver nanoparticles using microalgae (M-AgNP) consortia for the treatment of kitchen grey water was investigated in this study. The microalgae consortia consisting of four species, viz., Chlorella sp., Scenedesmus sp., Coelastrum sp., and Pediastrum sp. were isolated from a local fish pond and the silver nanoparticles were synthesized with the same. Thus, synthesized silver nanoparticles exhibited a distinctive yellowish-brown colour and spherical morphology. Extensive qualitative and quantitative characterization techniques were employed to determine their size and morphology. Both microalgae consortia and M-AgNP were used separately for the treatment of kitchen grey water under experimental conditions. The synthesized silver nanoparticles demonstrated promising potential for domestic wastewater treatment, leading to substantial reductions in various parameters: total dissolved solids (29.6%), conductivity (49.4%), chemical oxygen demand (64.6%), and heavy metals (arsenic—63.5%, zinc—45.6%, cadmium—88%, copper—60.52%, and lead—80.82%). Notably, microalgae exhibited superior removal efficiency for nitrate (83.1%), sulphate (70.3%), and phosphate (96.5%) compared to microalgae-synthesized silver nanoparticles. This study underscores the effective utilization of both microalgae and microalgae-synthesized silver nanoparticles for wastewater treatment applications.