Technical Information Microfiltration/Membrane Filtration Microfiltration is a type of membrane filtration process, where water is filtered through tiny pores in a membrane. The smaller the pores, the more material held by the membrane. Chlorination Chlorine is introduced to wastewater in the form of gas, tablets, solutions, powder or other compounds. The chlorine passes through the organism’s cell wall and attacks the cell, leading to its death. Ozonation Ozone is an unstable gas that can destroy bacteria and viruses. Ozone is formed when oxygen molecules collide with oxygen atoms to produce ozone. Ultraviolet Low dosages may not effectively inactivate some viruses, spores and cysts. If a large amount of suspended solids exist in the wastewater, more difficult to penetrate microorganisms. Detention Lagoons The storage of secondary treated wastewater in pondage systems. This allows natural disinfection via sunlight or microbial die-off to take place. Safety and Ease of Handling Microfiltration/Membrane Filtration No further disinfection is required and as such water quality remains throughout distribution. Chlorination All forms of chlorine are highly corrosive and toxic. Storage, shipping and handling are safety risks. Chlorine can destroy pumps, screws and equipment. Ozonation Ozone is very reactive and corrosive and must be produced on site. Ultraviolet UV disinfection is a physical process, therefore handling or storage is not required. However continual cleaning and maintenance of the light structure is required which can prove dangerous. Detention Lagoons Natural disinfection process, therefore handling is not applicable. Ability to remain effective in water through distribution Microfiltration/Membrane Filtration No further disinfection is required and as such water quality remains throughout distribution. Chlorination The chlorine residual that remains in the wastewater can prolong disinfection. Ozonation The low solubility of ozone in water greatly reduces the disinfection capacity. The ozone residual dissipates quickly as a result of its reactive nature. Ultraviolet In some circumstances photoreactivation can occur, where organisms can repair themselves and undo the effects of UV disinfection. Detention Lagoons Reinfection can occur through birds, and is not a suitable system for sole means of pathogen reduction. By-products and side effects Microfiltration/Membrane Filtration This disinfection process does not require the addition of reactive chemicals and therefore no toxic by-products are produced. Chlorination Chlorine residual, even in low concentrations, is toxic to aquatic life and may require dechlorination. The chlorine oxidizes organic matter in wastewater, sometimes creating compounds that can be harmful to humans and the environment. Ozonation Ozone decomposes rapidly reducing its disinfection capacity, leaving no harmful residual, however it is extremely irritating and possibly toxic. Ultraviolet There is limited data available outlining the possible by-products of UV light. Detention Lagoons There are no toxic residuals that could be harmful to humans or aquatic life.