Fixed growth treatment systems attach microorganisms to a surface that is exposed to water. In a fixed growth treatment system, aerobic microorganisms attach and grow on an inert media. Wastewater flows across a slime layer created by the attached microorganisms, which extract soluble organic matter from the wastewater as a source of carbon and energy. Fixed growth technologies for fixed growth treatment systems may include the biology of fixed-growth reactors, trickling filter process, and rotating or dual biological processes.
A water treatment system is used to reduce common contaminates in water, such as sediment, calcium, iron, magnesium, sulfate, nitrates, arsenic, or lead. Water treatment for fixed growth treatment systems can produce clearer, safer, better tasting, and better smelling water that is better suited for residential, commercial, and industrial use. A wastewater treatment system is used to remove large objects, grit, and sedimentation from water that has been used for domestic or industrial purposes. The wastewater treatment process follows primary and then secondary treatments. The primary treatment removes settleable and floatable materials. The secondary treatment uses biological or chemical treatment to accomplish substantial removal of dissolved organics and colloidal materials. Wastewater treatment equipment may include centrifuges, vacuum filters, and belt presses or plate-and-frame presses for dewatering sludge. Other types of fixed growth treatment systems will use grinders (comminuters), bar screens, and grit channels. Computers may also be used in fixed growth treatment systems to provide stream model software to predict the effects of pollutants entering the waterways.
Industrial water treatment is used to treat processed and non-process wastewater from manufacturing, commercial, mining, and silvicultural facilities. Biological treatment of wastewater and sewage water is used to lower the organic load of soluted organic compounds for fixed growth treatment systems. Wastewater biological treatment provides two major types of biological treatment processes: attached growth and suspended growth. In an attached growth process, the microorganisms grow on a surface, such as rock or plastic. In suspended growth process, microorganisms are responsible for the conversion of the organic matter or other constituents in the wastewater to gases and cell tissue.