Relationship between selenium removal efficiency and production of lipid and hydrogen by Chlorella vulgaris

• Published in: Chemosphere (Oxford) Vol. 217; pp. 825 - 832
• Main Authors: Gan, Xinyu, Huang, Jung-Chen, Zhou, Chuanqi, He, Shengbing, Zhou, Weili
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2019
• Subjects: Biomass; Chlorella vulgaris; Chlorella vulgaris - metabolism; Hydrogen; Hydrogen - metabolism; Lipid; Lipids - biosynthesis; Photoproduction; Selenic Acid - pharmacology; Selenious Acid - pharmacology; Selenium; Selenium - pharmacokinetics; Sulfur; Volatilization; Water Pollutants, Chemical - isolation & purification; Water Pollutants, Chemical - metabolism; Selenium; Photoproduction; Hydrogen; Chlorella vulgaris; Lipid
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2018.11.075

In our previous studies, Chlorella vulgaris had proven highly efficient in removing selenium (Se) from water, while the disposal of Se containing in algal biomass was still an issue of concern. Firstly, this research suggests algal Se could be released back to water, posing risks to aquatic wildlife. Thus, we further explored the possibility of using C. vulgaris to remove Se and produce lipid and hydrogen simultaneously. Our results show the higher percentage of saturated fatty acids, especially palmitic acid, was found in the sulfur (S) deprived algae exposed to either selenate or selenite, although the highest lipid content (21.9%) was found in the selenite treated algae in full BG11 medium. In addition, compared with the Se free algae, hydrogen production rate was 2.1- and 4.3-fold higher for the selenate and selenite treated algae, respectively. Se removal efficiency achieved by the selenite treated algae through accumulation and volatilization was 2.3-fold higher than the selenate treatment under hypoxic condition with S deprived, which is in contrast to the results obtained under aerobic conditions. [Display omitted] •Se-containing C. vulgaris releases Se back to water after treatment.•S deficiency enhances Se removal by C. vulgaris for both selenite and selenate.•S deprived and selenite treated algae yield the highest saturated fatty acids.•Photoproduction of hydrogen is significantly enhanced in the presence of Se.•Selenite removal efficiency is significantly enhanced under hypoxic conditions.