Abstract
Carbon fibers, to which large amounts of aquatic microorganisms adhere, may have a capability of decomposing the pollutants in water. Thus, we investigated the purification of polluted reservoir water using carbon fibers in a concrete circulating waterway. The circulating waterway was made from a reinforced concrete U-form gutter (30cm in depth, 30cm in width). This waterway was 10m in circumference and its capacity was 0.9m3. The water pumped up from the reservoir was circulated in the waterway and then aerated. In this work, we used 50-cm-long PAN-based carbon fibers (Toray T-300 12K). The carbon fibers were attached at one end to a frame, and the other end was free to move in the circulating water. A large amount of sludge adhered to the carbon fibers that were allowed to move freely in the waterway. The clarity of the treated water increased to above 100°. In an artificial circulating waterway, the addition of carbon fibers could reduce the concentrations of Ammonium-nitrogen and Phosphate-phosphorus throughout the duration of the experiment. Carbon fibers with high modulus and small diameter could effectively come into contact with polluted water by being free to move in the water.
