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Ammoniacal Nitrogen Removal in Semiconductor Waste Stream

My plant have a waste stream (negligible metal content) of normal 30-55 mg/L NH3-N, at a continuous flow of 150 m3/hr. Recently the government has introduce a discharge specification of <20 mg/L, and our neutralization waste water plant was not design with such capability.

I was just wondering does anybody have any idea or suggestion on what is the best industrial solution?

SL Kong
engineer - Malaysia
August 8, 2010

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August 12, 2010

I am assuming that you cannot change the chemistry used at your facility and substitute a chemical that does not contain ammonia, however this would be the simplest solution to eliminate excess ammonia

The best solution is probably to find the source or sources of the ammonia nitrogen and to address them in a smaller flow and more concentrated form. It may be that there are concentrated dumps that can be hauled away, and this would resolve your problem with the new discharge limit.

If not, it would still be less expensive to treat a smaller flow. Biological treatment, aerobic first can convert the ammonia to nitrate, then anaerobic to denitrify the water to nitrogen gas, may be your easiest and least expensive solution.

Lyle Kirman
consultant - Cleveland Heights, Ohio