Experimental studies on zeta potential of flocculants for harvesting of algae

Arya Pandey; Vinayak V Pathak; Richa Kothari; Paul N Black; V V Tyagi

doi:10.1016/j.jenvman.2018.09.096

Experimental studies on zeta potential of flocculants for harvesting of algae

J Environ Manage. 2019 Feb 1:231:562-569. doi: 10.1016/j.jenvman.2018.09.096. Epub 2018 Oct 30.

Authors

Arya Pandey¹, Vinayak V Pathak², Richa Kothari³, Paul N Black⁴, V V Tyagi⁵

Affiliations

¹ Department of Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, U.P., India.
² Department of Chemistry, Manav Rachna University, Faridabad, Haryana, India.
³ Department of Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, U.P., India; Robert B. Daugherty Water for Food Institute, University of Nebraska-Lincoln, Lincoln, NE, USA; Department of Environmental Sciences, Central University of Jammu, Raya-Suchani, Bagla, Samba, J&K, India. Electronic address: kothariricha21@gmail.com.
⁴ Department of Biochemistry, Beadle Centre, University of Nebraska-Lincoln, Lincoln, NE, USA.
⁵ School for Energy Management, Shri Mata Vaishno Devi University, Katra, J&K, India.

PMID: 30388653
DOI: 10.1016/j.jenvman.2018.09.096

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.

Keywords: Algal biomass; Bio-flocculant; Harvesting efficiency; Health risks; Zeta potential.

MeSH terms

Biomass
Chlorella*
Flocculation
Microalgae*
Water

Substances

Water