3. Gaseous (air) stage First, organic matter and liquid components are drawn into the biofilm, usually through a biodegradation process. Biofiltration methods are generally aerobic. This means that microbes need oxygen for their metabolism. Either simultaneously or counter-currently, oxygen is supplied to the biofilter with a flow of water. During the process, aeration occurs inactively through normal air flow and forced air supply. In process performance, the activity of microorganisms is a key factor. The compositions of the water, the hydraulic packing of the biofilter, the type of mass media, the nourishing plan, the duration of the biofilm, the temperature, the aeration are the main influencing factors.9-Capacitive deionization system: By applying an electric potential change across two absorbent carbon electrodes, we can deionize water. The anions detach from the water and are deposited in the positively differentiated electrode. Likewise, cations are deposited in the cathode (the negatively differentiated electrode). Currently, capacitive deionization system is used for salt water purification. Salt water has a low or reasonable salt concentration. Distillation, reverse osmosis and electrodialysis are the other skills used for water deionization. It is an energy-saving technology for salt water purification. It is considered a better technology than all other technologies. It removes salt ions from water, while other tools remove water from saline solution. Generally, it is called electrochemical demineralization, also called electrosorption of salt ions. It also goes by the names of capacitive purification. Method: In the two-stage capacitive deionization system process...... middle of paper ...... other wastewater flows out and causes a contagious layer of slime called biofilm. This layer grows and covers the media bed. Aerobic conditions are maintained by beating, dispersing and forced airflow. Manure trickle filters are used in areas not controlled by community sewage treatment plants. They are naturally installed in areas where the old-fashioned poison tank system is failing. Because improved levels of handling are necessary for ecological benefits, such as preventing infection of groundwater or surface water. All selections of wastewater trickle filters are low consumption and sometimes have irregular power consumption. They are more expensive than old-fashioned septic tanks such as drain field systems; nevertheless, they are used for better management, decrease in removal area size, less excavation and expansion of high density land..