Implementation of Rotating Biological Contactor for wastewater treatment of Shahid Bahonar port to meet the environmental related standards

There are many domestic wastewater treatment processes in use today. Generally, they are all biological systems and they may be broadly categorized as either fixed film processes or suspended growth processes. A rotating biological contactor or RBC is a biological treatment process used in the treatment of wastewater following primary treatment (1-2). The primary treatment process removes the grit and other solids through a screening process followed by a period of settlement. The RBC process involves allowing the wastewater to come in contact with a biological medium in order to remove pollutants in the wastewater before discharge of the treated wastewater to the environment, usually a body of water (river, lake or ocean). A rotating biological contactor is a type of secondary treatment process (3-4). It consists of a series of closely spaced, parallel discs mounted on a rotating shaft which is supported just above the surface of the waste water. Microorganisms grow on the surface of the discs where biological degradation of the wastewater pollutants takes place. RBCs are a fixed film, aerobic, biological wastewater treatment system. Physically, they consist of parallel, deformed discs mounted perpendicularly on a shaft that is slowly rotated in a tank through which the wastewater to be treated is passed. The shaft is mounted above the water level in the tank. A schematic drawing has been presented in fig.1.