Microalgal wastewater recycling: Suitability of harvesting methods and influence on growth mechanisms

Jingjing Sun; Shuhong Jiang; Libin Yang; Huaqiang Chu; Bo-Yu Peng; Shaoze Xiao; Yayi Wang; Xuefei Zhou; Yalei Zhang

doi:10.1016/j.scitotenv.2022.160237

Microalgal wastewater recycling: Suitability of harvesting methods and influence on growth mechanisms

Sci Total Environ. 2023 Feb 10;859(Pt 2):160237. doi: 10.1016/j.scitotenv.2022.160237. Epub 2022 Nov 17.

Authors

Jingjing Sun¹, Shuhong Jiang¹, Libin Yang², Huaqiang Chu³, Bo-Yu Peng¹, Shaoze Xiao¹, Yayi Wang⁴, Xuefei Zhou⁴, Yalei Zhang⁴

Affiliations

¹ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
² State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China. Electronic address: neuqyanglibin@126.com.
³ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China. Electronic address: chuhuaqiang@tongji.edu.cn.
⁴ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.

PMID: 36402329
DOI: 10.1016/j.scitotenv.2022.160237

Abstract

Wastewater recycling helps address the challenge of microalgae biomass commercialization by allowing for efficient resource recovery. In this study, three conventional harvesting methods, including centrifugation, microfiltration, and flocculation sedimentation, were investigated to explore the effects of harvesting methods on the characteristics of recycled wastewater and the growth of microalgae to select a suitable harvesting method for the microalgal wastewater recycling system. During the wastewater recycling process, the least amount of accumulated substances was exhibited in the wastewater recycled by microfiltration, followed by centrifugation, and the most by flocculation sedimentation. After 4 batches of cultivation, microalgal biomass harvested from centrifugation wastewater and microfiltration wastewater was 21.26 % and 13.54 % higher than that from flocculation wastewater, respectively. Lipids, carbohydrates and pigments were all increased by varying degrees. Additionally, flocculation sedimentation was not suitable for the microalgal wastewater recycling process since the low residual nutrients, high salinity, and excessive algal organic matter severely inhibited the growth of microalgae. Under the regulation of phytohormones, microalgae increased their energy reserves, enhanced photosynthesis, and improved their defense capability to resist the increasing abiotic stress. This study provides scientific support for the selection of suitable harvesting technology during the microalgal wastewater recycling process.

Keywords: Centrifugation; Flocculation sedimentation; Microalgae harvesting; Microfiltration; Phytohormone; Wastewater recycling.

MeSH terms

Biomass
Flocculation
Microalgae*
Recycling
Wastewater

Substances

Wastewater