| 摘要 |
Automatic or semi-automatic treatment of waste water carrying organic material includes aerating and if necessary fermenting the stored liquid, filtering and then clarifying the liquid before reuse or discharge to the environment. The filtration is controlled in dependence upon the liquid level and degree of pollution of the stored liquid An Independent claim is included for an installation for performing the above includes has a storage container, active filter and a clarifying device. The filters are operative when the liquid level in the container is between two values and the pollution level, e.g. measured as BOD (biological oxygen demand), is below a threshold. Preferred Features: The liquid level values are 10 - 20% full and 25- 40% full. A 90% full level indicator sets off an alarm. Another container can receive an overflow from the first container. The active filter includes a tangential filter unit with micro-porous tubular membranes grouped in modules and with intermittent air injection to form a liquid/gas mixture with the effluent. |
