Abstract: A fuel cell system and a method of controlling the system are provided. The fuel cell system includes: a fuel cell having a plurality of cells to generate power through a reaction between hydrogen supplied to an anode space and oxygen supplied to a cathode space; a power storage device to be charged with power generated by the fuel cell or discharged to supply power; and a controller. The controller recirculates hydrogen, diffused from the anode space to the cathode space, into the anode space by supplying power charged in the power storage device to the fuel cell when the power generation of the fuel cell is stopped. The controller is configured to control whether to supply the power to the fuel cell based on a pressure measured in the anode space and voltages of the cells that constitute the fuel cell.

Abstract: The present invention relates to an apparatus and a system for treating acid mine drainage. The apparatus includes first and second reaction baths for receiving acid mine drainage, wherein the first and second reaction baths are provided with inlets and outlets and are separated from each other to prevent communication between acid mine drainages, an electrically connected anode and a cathode installed in each of the first and second reaction baths, and an electron transport medium for connecting the first reaction bath receiving the anode and the second reaction bath receiving the cathode. The electron transport medium blocks the transport of metal cations and allows the transport of electrons between acid mine drainages in the first and second reaction baths. Ferrous ions are oxidized to ferric ions in the acid mine drainage to precipitate hydroxides in the first reaction bath, and hydroxide ions are produced in the second reaction bath.

Abstract: Provided is an oxidation pond for treating acid mine drainage discharged from an abandoned mine. The oxidation pond comprises: an inlet into which mine drainage is introduced; a retention pond in which the mine drainage introduced into the inlet resides; and an outlet through which the mine drainage is discharged from the retention pond, so that iron in the mine drainage is oxidized and precipitated during residence of the mine drainage in the retention pond, wherein a neutralizing agent that increases the pH of the mine drainage to accelerate the iron precipitation reaction is placed in the retention pond.

Abstract: Provided is an oxidation pond for treating acid mine drainage discharged from an abandoned mine. The oxidation pond comprises: an inlet into which mine drainage is introduced; a retention pond in which the mine drainage introduced into the inlet resides; and an outlet through which the mine drainage is discharged from the retention pond, so that iron in the mine drainage is oxidized and precipitated during residence of the mine drainage in the retention pond, wherein a neutralizing agent that increases the pH of the mine drainage to accelerate the iron precipitation reaction is placed in the retention pond.