What the water can still do.
Every consent you hold governs what left your outfall. None of them ask whether the receiving water can still support anything. Sterilisation takes something out; the ventilator puts something back, and it is the half of this system nobody is legally obliged to buy.
A water body has a budget it never publishes. Oxygen goes in from the atmosphere and from photosynthesis; oxygen comes out through respiration, decomposition and the chemistry of whatever has recently been added. Most of the time the budget balances and nobody thinks about it.
Then a basin gets warm, and stops mixing, and receives a summer's worth of organic material at once. Or a spill is worked through. Or a treatment stage does its job and the by-product of doing that job is oxygen demand. The budget stops balancing, and it does so quietly, at depth, where nothing at the quayside will show it.
We call the answer a ventilator because the analogy holds further than we expected it to. Nobody puts a patient on one because breathing is the illness. They do it because breathing is the thing that has to keep happening while the illness is dealt with.
Three settings, one duty
- After a treatment Oxidation consumes oxygen, and so does whatever the oxidation has just broken down. Running the vent immediately behind a sterilisation pass is not an upsell; it is the difference between finishing a job and half-finishing it.
- After an incident A release, a die-off or a slug of organic material arriving at once leaves a demand on the water that outlasts the headlines. The vent takes that water in and hands it back enriched, for as long as the demand runs.
- Through a bad season Some basins simply run out of oxygen every August. That is chronic rather than acute, it is entirely predictable, and it is the case where held capacity across a season beats any number of emergency call-outs.
Nanobubble delivery is what makes the third case affordable rather than absurd. Conventional aeration returns most of its gas to the sky within seconds; sub-micron gas stays in suspension and hands its oxygen to the water instead. Published aeration work put the coefficient governing that transfer at roughly eleven times its conventional value for the same gas volume, which is the entire reason a vessel-sized gas budget can touch a basin-sized problem.
Outfalls, and the water that receives them
A discharge consent is a boundary condition, not a description of an ecosystem. Meet every number on it, every day of the year, and the receiving water can still sit below the hypoxia line for six weeks each summer — because the consent regulates your contribution and the water responds to everything at once.
Terminal and outfall operators tend to discover this the way everybody does: through somebody else's complaint. A fishing association, a swimming club, a hotel with a view of the basin, a newspaper with a photograph. At that point the conversation is no longer technical.
Operators who get ahead of it usually do two things. They measure dissolved oxygen at depth rather than at the surface, and they do it in August rather than in March. Both are inconvenient and both are cheap compared with finding out from a headline.
Where a toxin ends up decides who dredges later
The treatment neutralises toxins by disabling the functional groups that make them toxic, rather than dropping them out of solution as a precipitate. That work happens in the reactor, on water already drawn aboard, so nothing is settled onto the bed of your basin and no dredging obligation follows a pass. On a basin with an industrial history behind it, that distinction is frequently the reason the first phone call happens at all.
Dissolved metals sit outside it. A hydroxyl radical does not destroy a metal, so metals are not an oxidation target and no metal destruction is claimed here or anywhere else in the programme.
The finding comes from a Cooperative Research and Development Agreement with NOAA, under which Alarivean worked on precisely this question with the agency scientist Dr Peter Moeller. The agreement is private and was never posted anywhere; that is how CRADAs work. A research agreement is not an endorsement, and NOAA has not endorsed this system.
No removal percentage is quoted for your water before somebody has measured your water. That holds for every contaminant on this page.
How it is bought
Held capacity beats an emergency number.
An oxygen deficit is not an event. It is a condition with a season, which makes it one of the few things in marine operations you can genuinely plan against.
A ventilator duty inside a service zone means vessels available for the contracted weeks, gases carried, telemetry running and reporting produced throughout — rather than a call-out priced against the panic of the day you make it.
Where the same basin also needs ballast work or a spill capability, it is one contract and one crew. That is usually what makes the economics work for a port authority rather than for an oil major.
Asked by operators
Three that come up every time
Is oxygenation actually required of us anywhere?
Almost certainly not. Consents govern what leaves your outfall, not what the receiving water can still support.
That asymmetry is exactly why this is a commercial service rather than a compliance product — and why the operators who buy it are usually the ones who have to look at the basin from their own office window.
What does ChemSlayer do about toxins in the water?
Neutralises them inside the reactor, by disabling the functional groups that make them toxic rather than precipitating them out. The sediment inherits nothing and no dredging obligation follows a pass.
Dissolved metals sit outside that duty; a hydroxyl radical does not destroy a metal. The toxin finding rests on work done with NOAA under a Cooperative Research and Development Agreement, which is private, as those agreements always are. It is Alarivean's own account of that work.
How long does restored dissolved oxygen last?
For as long as whatever is consuming it allows. Oxygen delivered into a basin still receiving heavy organic load will be consumed again.
Which is why this is contracted as capacity across a season, with measurement throughout, rather than sold as a visit.
Aquatic Prosperity as a Service
Send us your August readings.
Dissolved oxygen at depth, in the worst month, next to your consent limits. If the two tell different stories, that gap is the conversation worth having.