Experimental studies on zeta potential of flocculants for harvesting of algae. (1st February 2019)

• Record Type: Journal Article
• Authors: Pandey, Arya; Pathak, Vinayak V.; Kothari, Richa; Black, Paul N.; Tyagi, V.V.
• Is Part Of: Journal of environmental management. Volume 231(2019)
• Page Start: 562
• Page End: 569
• Publication Date: 2019-02-01
• Subjects: Bio-flocculant -- Zeta potential -- Algal biomass -- Harvesting efficiency -- Health risks; LACC Laboratory Available Calcium Carbonate -- NCIM National Collection of Industrial Microorganism -- OD Optical Density -- HE Harvesting Efficiency -- SEM Scanning Electron Microscopy -- EDS Energy Dispersive X-Ray spectroscopy -- AOM Algal Organic Matter; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2018.09.096
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: An experimental study was performed to evaluate the comparative efficiency of bio-flocculant (waste egg shell), laboratory available calcium carbonate (LACC) and alum (Al2 (SO4 )3 ) for harvesting of unicellular microalga, Chlorella pyrenoidosa . The influence of pH on zeta potential ( ζ ) was also studied to explain the chemistry of flocculation process. The maximum harvesting efficiency (99%) was obtained with alum with deformities in algal cell surfaces. Waste egg-shell material is developed as a low-cost bio-flocculant for harvesting of Chlorella pyrenoidosa using 100 mg egg-shell bio-flocculant/L and 100 mg LACC/L, zeta potential analysis was completed to further understand the chemistry of harvesting efficiency over the different ranges of pH (2.0, 4.0, 6.0, 8.0, and 10.0). The optimized range for harvesting efficiency (HE) of pH is 4.0–8.0 for both flocculants. Maximal harvesting efficiency was achieved at pH 4.0 (99%) and pH 8.0 (95%) with bio-flocculant and LACC respectively. Hence, bio-flocculant based harvesting method is found as the best way to dewatering the algal biomass from aqueous medium with entire and intact algal cell surface with environment friendly and cost-effective approach. Graphical abstract: Image Highlights: Harvesting of C. pyrenoidosa at optimized pH with flocculants at 100 mg/L Impact of zeta potential & pH investigated on harvesting efficiency (HE). Comparative analysis for HE with different flocculants at pH (2, 4, 6, 8, 10). ζ is pH dependent, decrease in zeta value as the pH increases. Sustainable chemistry between ζ & pH for harvesting of algae with bioflocculant.