关键词:
Northern regions
Zinc removal
Freezing technology
MFC
ELECTRICITY-GENERATION
FREEZE DESALINATION
HEAVY-METALS
REMOVAL
ZINC
POWER
摘要:
A water treatment approach integrating freezing technology, also referred to as cryopurification, and a microbial fuel cell (MFC) process was tested for Zn removal in laboratory experiments. The water samples used were from the Faro Mine site, in Yukon, Canada. The effect of freezing temperature, mixing, and the direction of the ice front propagation on Zn removal from the Faro Mine water was investigated and quantitively analyzed. The MFC was used to treat the post-cryopurification brine. When the coolant temperature ranged from -5 to -1 degrees C and 180 rpm solution mixing was used, up to 80-95% of the Zn was removed after a single freezing cycle. The results of laboratory experiments demonstrated that Zn concentrations in mine water can be reduced by cryopurification to 0.5 mg/L (the effluent quality standard) under optimal experimental conditions. The MFC process was run for 120 h to test the capacity of the microorganism (Shewanella oneidensis) for Zn removal from the brine concentrated by freezing. In these laboratory experiments, MFC showed a reliable and high Zn removal up to 90-93% with S. oneidensis incubated in the anode chamber. The MFC generated a maximum power density and open-circuit voltage of 8.8 mW/m(2) and 168.5 mV, respectively.