Development of an algal treatment system for Se removal: Effects of light regimes, nutrients, sulfate and hypersalinity.
Selenium (Se) exposure poses potential risks to wildlife at the Salton Sea. Our previous research suggests Chlorella sp. be highly efficient at absorbing and volatilizing Se. In developing an algal treatment system for Se removal, this study further evaluated the performance under the conditions to be encountered in the field using Chlorella pyrenoidosa and Chlorella vulgaris. The results show the algal Se removal efficiency was little affected by photoperiod, yet volatilization became relatively greater in dark/light cycles over a longer term. The rates of Se absorption and volatilization by C. vulgaris were 88% and 77% more, respectively, in the DI water, while C. pyrenoidosa acted oppositely, indicating C. vulgaris will perform better in Se removal if nutrient levels are reduced in advance. The presence of sulfate reduced biomass Se, especially through volatilization, by 8% for C. vulgaris, lessening potential ecotoxicity. Finally, C. vulgaris released biomass Se back to the water column under hypersaline conditions, leading to a 6% increase in water Se concentrations. These results suggest C. vulgaris be the best alga for the treatment of Se laden river water in the Salton Sea area, yet a filtering system is required to prevent Se containing algae from entering food chains.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Fang
F
Liu
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China. Electronic address: ecojch@sjtu.edu.cn.
Jung-Chen
JC
Huang
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Chuanqi
C
Zhou
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Shengbing
S
He
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Weili
W
Zhou
D001673:Biodegradation, Environmental; D018533:Biomass; D048408:Chlorella vulgaris / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D005502:Food / Q000009:adverse effects*; D006801:Humans; D017440:Photoperiod; D054712:Salinity; D018036:Selenium Compounds / Q000302:isolation & purification* / Q000378:metabolism; D013431:Sulfates / Q000494:pharmacology*; D014835:Volatilization; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000378:metabolism; D018508:Water Purification / Q000379:methods
D018036:Selenium Compounds; D013431:Sulfates; D014874:Water Pollutants, Chemical
Algae; Bioremediation; Salton Sea; Selenium; Volatilization