Harvesting environmental microalgal blooms for remediation and resource recovery: A laboratory scale investigation with economic and microbial community impact assessment

Research output: Contribution to journalArticlepeer-review

Authors

  • Jagroop Pandhal
  • Wai L. Choon
  • Rahul V. Kapoore
  • David A. Russo
  • James Hanotu
  • Pratik Desai
  • Malcolm Bailey
  • William J. Zimmerman
  • Andrew S. Ferguson

Colleges, School and Institutes

External organisations

  • University of Sheffield
  • University of Copenhagen
  • Link2Energy

Abstract

A laboratory based microflotation rig termed efficient FLOtation of Algae Technology (eFLOAT) was used to optimise parameters for harvesting microalgal biomass from eutrophic water systems. This was performed for the dual objectives of remediation (nutrient removal) and resource recovery. Preliminary experiments demonstrated that chitosan was more efficient than alum for flocculation of biomass and the presence of bacteria could play a positive role and reduce flocculant application rates under the natural conditions tested. Maximum biomass removal from a hyper-eutrophic water retention pond sample was achieved with 5 mg_L-1 chitosan (90% Chlorophyll a removal). Harvesting at maximum rates showed that after 10 days, the bacterial diversity is significantly increased with reduced cyanobacteria, indicating improved ecosystem functioning. The resource potential within the biomass was characterized by 9.02 μg phosphate, 0.36 mg protein, and 103.7 μg lipid per mg of biomass. Fatty acid methyl ester composition was comparable to pure cultures of microalgae, dominated by C16 and C18 chain lengths with saturated, monounsaturated, and polyunsaturated fatty acids. Finally, the laboratory data was translated into a full-size and modular eFLOAT system, with estimated costs as a novel eco-technology for efficient algal bloom harvesting.

Details

Original languageEnglish
Article number4
JournalBiology
Volume7
Issue number1
Publication statusPublished - 29 Dec 2017

Keywords

  • Algal bloom, Environmental microalgae, Eutrophication, Microflotation, Resource recovery