Impact of surface tension of wastewater on biofilm formation of microalgae Chlorella sp

Xinru Zhang; Hao Yuan; Zeyi Jiang; Dahao Lin; Xinxin Zhang

doi:10.1016/j.biortech.2018.06.082

Impact of surface tension of wastewater on biofilm formation of microalgae Chlorella sp

Bioresour Technol. 2018 Oct:266:498-506. doi: 10.1016/j.biortech.2018.06.082. Epub 2018 Jun 25.

Authors

Xinru Zhang¹, Hao Yuan², Zeyi Jiang³, Dahao Lin², Xinxin Zhang⁴

Affiliations

¹ School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Engineering Research Center of Energy Saving and Environmental Protection, University of Science and Technology Beijing, Beijing 100083, China.
² School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
³ School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory for Energy Saving and Emission Reduction of Metallurgical Industry, University of Science and Technology Beijing, Beijing 100083, China. Electronic address: zyjiang@ustb.edu.cn.
⁴ School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory for Energy Saving and Emission Reduction of Metallurgical Industry, University of Science and Technology Beijing, Beijing 100083, China.

PMID: 29990766
DOI: 10.1016/j.biortech.2018.06.082

Abstract

The organic matter and surfactants in wastewater may cause variations in the surface tension of wastewater (STW) ranging between ∼40 and ∼70 mJ·m^-2. This study focused on the influence of STW on microalgae biofilm formation. A theoretical analysis was first conducted, and then microalgae biofilm formation on hydrophilic and hydrophobic substrata in liquid and real wastewater with different surface tensions was studied. The results demonstrated that STW affected microalgae biofilm formation remarkably. When the surface tension of liquid medium (γ^lv) was approximately equal to the average value of surface free energy of microalgae and substrata, biofilm formation reached the minimum. Microalgae biofilm formation on a hydrophilic surface first decreased (from ∼2200 to ∼1500 cells/mm²) and then increased (from ∼1500 to 3100 cells/mm²) with the decrease in γ^lv (from ∼70 to ∼40 mJ·m^-2), whereas biofilm on a hydrophobic surface continued to decrease (from ∼2500 to 1000 cells/mm²).

Keywords: Adhesion; Microalgae biofilm; Surface free energy; Surface tension; Wastewater treatment.

MeSH terms

Biofilms*
Chlorella*
Microalgae
Surface Tension
Wastewater*

Substances

Waste Water