Biological waste water clarifier with inert gas recirculation - in which gas is circulated through vessel so that oxygen@ content is reduced and water is agitated without introducing oxygen@

摘要

In a new treatment unit for waste water, a gas, and esp. atmospheric air, which has been passed through the waste water, is passed through it again once or more than once. At each passage, a part of the oxygen in the gas is biochemically consumed so that eventually the hydromechanical effect of the rising bubbles becomes preponderant over the aerobic biochemical effect of the remaining oxygen content of the gas. The treatment takes place in a sealed vessel so that the gas leaving the water can easily be collected and recirculated. A device for replacing that part of the gas which is lost in the biochemical process or by absorption is provided, and may consist of a weight- or spring-loaded valve, or a simple opening. A similar device may be used for reducing the volume of the gas being recirculated. The gas is recirculated via a duct and a fan from above the surface of the water to a distribution pipe system near the floor of the vessel. A regulatable and/or adjustable gas make-up pipe, which may also be provided with a fan, is connected to the recirculation pipe. This make-up pipe may be supplied with air, or for example an inert gas, an aerosol or another substance. USE/ADVANTAGE - Used in clarifying domestic or industrial waste water, and esp. for nitrification and/or denitrification stages. Intended partic. for clarifying water in fish farm