Cultivation of Chlorella vulgaris in sludge extracts: Nutrient removal and algal utilization

Lu Wang; Min Addy; Qian Lu; Kirk Cobb; Paul Chen; Xiurong Chen; Yuhuan Liu; Hualin Wang; Roger Ruan

doi:10.1016/j.biortech.2019.02.017

Cultivation of Chlorella vulgaris in sludge extracts: Nutrient removal and algal utilization

Bioresour Technol. 2019 May:280:505-510. doi: 10.1016/j.biortech.2019.02.017. Epub 2019 Feb 4.

Authors

Lu Wang¹, Min Addy², Qian Lu³, Kirk Cobb², Paul Chen², Xiurong Chen⁴, Yuhuan Liu³, Hualin Wang⁵, Roger Ruan⁶

Affiliations

¹ State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai 200237, PR China; Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, MN 55108, USA.
² Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, MN 55108, USA.
³ The Engineering Research Center for Biomass Conversion, Ministry of Education, People's Republic of China, Nanchang University, Nanchang, Jiangxi 330047, PR China.
⁴ State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai 200237, PR China.
⁵ State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai 200237, PR China. Electronic address: wanghl@ecust.edu.cn.
⁶ Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, MN 55108, USA; The Engineering Research Center for Biomass Conversion, Ministry of Education, People's Republic of China, Nanchang University, Nanchang, Jiangxi 330047, PR China.

PMID: 30777700
DOI: 10.1016/j.biortech.2019.02.017

Abstract

In order to utilize the excess sludge and reduce the cost of algal cultivation, Chlorella vulgaris was cultivated in increasing proportions of sludge extracts for simultaneous nutrients removal and algal utilization. Results showed that C. vulgaris cultivated in the 100% sludge extract gained the highest total biomass (33.98 ± 0.30 × 10⁶ cells/mL) and showed good results in TOC (absolute value 175 mg/L) and nutrients (TN: 77.1%; TP: 95.0%) removals. According to the Excitation-emission matrix spectra (EEMs) analysis, the 8th day was suggested as the optimal time for biomass harvesting. Although the lipid contents showed a negative correlation with the proportion of sludge extract, the FAME analysis showed that the saturated fatty acids (SFA) contents decreased and the unsaturated fatty acids (UFA) content increased as the concentration of sludge extract increased. The 100% sludge extract could be a desirable alternative medium for the algae cultivation.

Keywords: Algal utilization; Chlorella vulgaris; Low-cost cultivation; Nutrient removal; Sludge extracts.

MeSH terms

Biomass
Chlorella vulgaris / metabolism*
Fatty Acids / metabolism
Lipid Metabolism
Lipids
Nutrients*
Sewage*

Substances

Fatty Acids
Lipids
Sewage