Two Ways to Remove Ammonia That We Will Not Sell You
Both of these work. Both are sold in the Philippines. We do not design compliance around either of them, and I would rather explain the arithmetic than pretend the options do not exist — because you are going to be offered them.
Breakpoint chlorination
You can destroy ammonia with chlorine. It is chemistry, it is reliable, and it works the day you switch it on. That is exactly why it gets sold to a plant that is under pressure from a regulator.
The arithmetic is the problem. It takes roughly 7.6 kg of chlorine for every 1 kg of ammonia nitrogen you want to destroy, and eight to ten in practice once you account for everything else in the water competing for it.
Work that through on a modest plant. Fifty cubic metres a day at 30 mg/L of ammonia is 1.5 kg of nitrogen. At the practical ratio that is somewhere around 12 kg of chlorine every day — not once, not during a crisis, but every day for as long as the plant runs.
And that is before what it does to everything else:
- It forms chloramines, which are their own problem in the receiving water.
- It puts a heavy chloride load into your effluent.
- It creates disinfection by-products.
- The residual kills the biology that was doing your BOD removal — so the parameter that was passing starts wobbling.
What you have done is convert a biological problem into a chemical bill that never ends. It treats the certificate rather than the plant. If your ammonia is failing because the nitrifying bacteria are not surviving, dosing chlorine makes that underlying cause permanently worse, because chlorine is one of the things that kills them.
Zeolite filtration
Zeolite genuinely removes ammonia at low concentrations. As a polishing step on an effluent that is nearly compliant, it has a legitimate place and we would not rule it out.
The question the seller rarely answers is where the regeneration goes.
The media does not destroy ammonia. It holds it. Eventually it fills up, and it has to be washed and regenerated — and every kilogram of ammonia you captured comes back off that media in a concentrated backwash.
If that backwash goes down the same drain you were trying to protect, you have moved the problem thirty metres. Nothing has been treated. The laboratory sample taken after the filter looks excellent; the water body downstream receives the same nitrogen it would have received anyway, in a shorter, sharper dose.
Our position: if you use zeolite, the backwash goes back to the front of your own treatment plant to be dealt with properly. Never to the discharge line. Never onto the ground. If nobody has explained to you where the backwash goes, you are being sold a filter, not a solution.
Why we say this out loud
We sell wastewater treatment plants. Recommending a biological solution over a chemical one is not a neutral position for us — we have written before about the conflict built into designing and building the same plant, and this is another place it applies. So judge the arithmetic rather than us.
The honest summary is that both methods can rescue a specific situation. A plant with a genuine short-term crisis, a deadline and no time to grow biology may reasonably use one as a bridge. What neither of them is, is an answer to a plant that cannot nitrify.
If a supplier proposes either of these as your permanent compliance route, ask two questions. What is the daily chemical consumption at my actual ammonia load, for the life of the plant? And where does the waste stream from this process go?
Both have specific numerical answers. If you do not get them, you have learned something anyway.
Every site is different. A polishing filter on a nearly-compliant effluent and a chemical shortcut on a plant that never worked are two very different decisions, and the arithmetic above is the way to tell them apart.
If you have a proposal in front of you and you want a second opinion on whether the running cost is realistic, send it over. Book a free 15-minute consultation.