method for continuous removal of ammonia from ammonia containing and rueckgewinnung abfallwasser.

摘要

A process is developed for continuously removing and recovering respectively ammonia from aqueous ammonia waste water by stripping the waste water in a column, using heat absorption from already stripped waste water and by using a gas flow, e.g. an air flow, flowing in counter current with the waste water through the column. Especially in view to the presently desired control of environmental pollution a know process involves such high investments that an economic solution often automatically fails. The invention eliminates such serious disadvantages whereas moreover an economically more valuable product can be obtained, e.g. water with a high concentration of aqueous ammonia. This is achieved according to the invention in that the heat transfer is effected by a gas flow which, by direct contact in a packed bed, absorbs heat from the effluent liquid whereafter this absorbed heat is again transferred to the influent liquid. Preferably the gas flow consists of a recirculating air flow having a high temperature, said air flow transferring heat in a part of the column which is provided with a packed bed, to the waste water to be stripped, flowing in counter current to the low temperature waste water, whereafter the same air flow, now having a low temperature, recuperates in another part of the column, likewise provided with a packed bed, heat from the stripped liquid, now having a high temperature, also in counter current.