Enhancement performance of CO2 on the organic toxicity removal of sludge by Scenedesmus obliquus with proteomics analysis. (July 2022)

• Record Type: Journal Article
• Authors: Hu, Xueyang; Wei, Xiao; Yang, Yingying; Zhang, Xinyu; Chen, Xiurong; Tian, Jinyi; Zhao, Jiamin; Yu, Xiao
• Is Part Of: Journal of CO₂ utilization. Volume 61(2022)
• Publication Date: 2022-07
• Subjects: Sludge extract -- Toxicity removal -- Carbon dioxide -- Scenedesmus obliquus -- Proteomics; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2022.102038
• Languages: English
• ISSNs: 2212-9820

Abstract

Abstract: Microalgae have strong adaptability to toxic environments. The accumulation of toxic organic matter and secondary metabolites during the biologically treatment of wastewater can cause sludge toxicity. Scenedesmus obliquus was cultivated in the sludge extract from coal-gasification synthetic wastewater contained 100 mg/L hydroquinone, with 15% CO2, to investigate the removal of sludge toxicity together with CO2 fixation. Results showed that S. obliquus could utilize the organic matter and CO2 in the mixed cultivation mode. On the 30th day, the dry cell weight was 1.46 ± 0.07 g/L, and chlorophyll-a was 24.76 ± 0.21 mg/L. S. obliquus reduced the sludge toxicity by heterotrophically utilizing the organic matter of sludge extract. TOC decreased from 393.52 ± 0.65 mg/L to 113.78 ± 0.43 mg/L, and organic matter with molecular weights of < 500 Da and 500–5KDa was significantly consumed, reducing the sludge toxicity from 83.46 ± 0.27% to 29.37 ± 0.19% in terms of inhibition rate of luminescent bacteria. S. obliquus mainly utilized HCO3 - for autotrophic growth and the CO2 removal (%) was up to the maximum 35.08 ± 0.19% on the 10th day. Proteomics analysis results showed that 15% CO2 improved autotrophic ability of S. obliquus and the activity of the functional protein, thereby improving its antioxidant capacity against toxicity stress. By increasing its protein kinase and ATPase activity, S. obliquus enhanced the oxidative phosphorylation process to heterotrophically utilize organic matter to reduce the sludge toxicity. Graphical Abstract: ga1 Highlights: S. obliquus has strong adaptability and tolerance to toxic environments and CO2 . Heterotrophic-autotrophic culture strategy can improve growth of S. obliquus . Organics of < 500 Da and 500–5KDa were utilized, thereby reducing sludge toxicity. 15% CO2 improved functional protein activity against toxicity stress. Protein kinase and ATPase activity increased enhancing oxidative phosphorylation.