Waste-water process

A process for separating acid gas and ammonia from waste water having an appreciable content thereof and for the production of recycle water, comprising the steps:

• 1. producing a first recycle water stream and an effluent gas stream comprising acid gas, ammonia and water vapor by passing said waste water into an acid gas-ammonia stripping column, said column being maintained at a bottoms temperature in the range from about 93.degree. to 149.degree. C and at a pressure in the range from about 1 to 5 atmospheres absolute, said first stream having an acid gas and ammonia content which is less than 15 percent of the content thereof for said waste water;
• 2. separately withdrawing said first recycle water stream and said effluent gas stream from said acid-gas ammonia stripping column;
• 3. Producing a liquid aqueous concentrate of ammonia and acid gas by decreasing the temperature of said effluent gas stream, said temperature decrease being an amount in the range from about 55.degree. to 110.degree. C.
• 4. producing an effluent acid-gas stream and an aqueous bottoms stream by passing said concentrate into a primary acid-gas stripping column, said column being maintained at superatmospheric pressure acid-gas stripping conditions;
• 5. separately withdrawing said acid-gas stream and said bottoms stream from said acid-gas stripping column;
• and
• 6. producing an effluent gas stream comprising ammonia and a second recycle water stream by passing said bottoms stream into an ammonia stripping column, said column being maintained at superatmospheric pressure ammonia stripping conditions, said second stream having an acid gas and ammonia content which is less than 15 percent of the content thereof for said bottoms stream from said acid-gas stripping column.