Copper ion (Cu 2+) and zinc ion (Zn 2+) are widely co-existent in anaerobic digestion effluent as typical contaminants. This work aims to explore how Cu 2+-Zn 2+ association affects physiological properties of S. platensis using Schlösser medium (SM) and sterilized anaerobic digestion effluent (SADE). Microalgae cells viability, biochemical properties, uptake of Cu 2+ and Zn 2+, and risk assessment associated with the biomass reuse as additives to pigs were comprehensively assessed. Biomass production ranged from 0.03 to 0.28 g/L in SM and 0.63 to 0.79 g/L in SADE due to the presence of Cu 2+ and Zn 2+. Peak value of chlorophyll-a and carotenoid content during the experiment decreased by 70-100% and 40-100% in SM, and by 70-77% and 30-55% in SADE. Crude protein level reduced by 4-41% in SM and by 65-75% in SADE. The reduction ratio of these compounds was positively related to the Cu 2+ and Zn 2+ concentrations. Maximum value of saturated and unsaturated fatty acids was both obtained at 0.3 Cu + 2.0 Zn (50.8% and 22.8%, respectively) and 25% SADE reactors (33.8% and 27.7%, respectively). Uptake of Cu in biomass was facilitated by Zn 2+ concentration (> 4.0 mg/L). Risk of S. platensis biomass associated with Cu 2+ was higher than Zn 2+. S. platensis from SM (Cu 2+ ≤ 0.3 mg/L and Zn 2+ ≤ 4.0 mg/L) and diluted SADE (25% and 50% SADE) reactors could be used as feed additives without any risk (hazard index <1), which provides sufficient protein and fatty acids for pig consumption. These results revealed the promising application of using S. platensis for bioremediation of Cu 2+ and Zn 2+ in anaerobic digestion effluent and harvesting biomass for animal feed additives.
|Original language||English (US)|
|Journal||Science of the Total Environment|
|State||Published - Sep 1 2022|
Bibliographical noteFunding Information:
This work was supported by Australian Research Council Future Fellowship ( FT200100264 ); Research Project of State Key Laboratory of Food Science and Technology , Nanchang University ( SKLF-ZZB-202122 ); The Key Project of Jiangxi Provincial Department of Science and Technology ( 20181BAB206030 , 20181BBF60026 , GCXZ2014-124 , 20161BBF60057 ); National Natural Science Foundation of China (No. 21878139 , 21878237 , 21706087 , 21466022 , 21766019 , 51708308 ) and the Post-doctoral Innovative Talents Support Program of China ( BX20190147 ).
- Ecotoxicological response
- Heavy metal
- Risk assessment
- S. platensis
- Sterilized anaerobic digestion effluent
PubMed: MeSH publication types
- Journal Article