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Impact of Groundwater Salinity on Bioremediation Enhanced by Micro-Nano Bubbles
State Key Laboratory of Hydro-Science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China
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Received: 14 June 2013; in revised form: 16 August 2013 / Accepted: 16 August 2013 / Published: 23 August 2013
Abstract: Micro-nano bubbles (MNBs) technology has shown great potential in groundwater bioremediation because of their large specific surface area, negatively charged surface, long stagnation, high oxygen transfer efficiency, etc. Groundwater salinity, which varies from sites due to different geological and environmental conditions, has a strong impact on the bioremediation effect. However, the groundwater salinity effect on MNBs’ behavior has not been reported. In this study, the size distribution, oxygen transfer efficiency and zeta potential of MNBs was investigated in different salt concentrations. In addition, the permeability of MNBs’ water through sand in different salt concentrations was studied. The results showed that water salinity has no influence on bubble size distribution during MNBs generation. MNBs could greatly enhance the oxygen transfer efficiency from inner bubbles to outer water, which may greatly enhance aerobic bioremediation. However, the enhancement varied depending on salt concentration. 0.7 g/L was found to be the optimal salt concentration to transfer oxygen. Moreover, MNBs in water salinity of 0.7 g/L had the minimum zeta potential. The correlation of zeta potential and mass transfer was discussed. The hydraulic conductivities of sand were similar for MNBs water with different salt concentrations. The results suggested that salinity had a great influence on MNBs performance, and groundwater salinity should be taken into careful consideration in applying MNBs technology to the enhancement of bioremediation.
Keywords: micro-nano bubbles; groundwater bioremediation; salinity; size distribution; oxygen transfer; zeta potential; permeability
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MDPI and ACS Style
Li, H.; Hu, L.; Xia, Z. Impact of Groundwater Salinity on Bioremediation Enhanced by Micro-Nano Bubbles. Materials 2013, 6, 3676-3687.
Li H, Hu L, Xia Z. Impact of Groundwater Salinity on Bioremediation Enhanced by Micro-Nano Bubbles. Materials. 2013; 6(9):3676-3687.
Li, Hengzhen; Hu, Liming; Xia, Zhiran. 2013. "Impact of Groundwater Salinity on Bioremediation Enhanced by Micro-Nano Bubbles." Materials 6, no. 9: 3676-3687.