The ultra-nano aerosol reoxygenation technology awakens the life memory of oxygen-depleted water bodies.

Have you ever passed by a river like this?

On summer evenings, I’d usually plan to take a leisurely stroll along the riverbank—but somehow, every time, I’d end up turning around halfway and heading straight home to hide in an air-conditioned room to cool down, because a smell that seemed like “rotten eggs mixed with overripe bananas” was simply unbearable.

If you really dare to walk to the riverbank, you’ll find that the water no longer looks like water—it’s more like a pair of dark-brown sunglasses, so opaque that not even a ray of light can penetrate. You can’t see any fish, nor can you spot a single shrimp—what on earth has happened to this river?

They are facing the danger of running out of oxygen.

I. Can bodies of water “suffocate” too?

Just as humans need air, organisms in aquatic ecosystems—microorganisms, fish, and aquatic plants—depend on oxygen dissolved in water, an oxygen known as dissolved oxygen (DO).

Dissolved oxygen is a key indicator for assessing the self-purification capacity of water bodies and their ecological health status. Adequate dissolved oxygen is essential for the degradation of pollutants by aerobic microorganisms, supports the respiration of aquatic animals, and ensures the growth of higher aquatic plants.

Once dissolved oxygen drops below 2 mg/L, the water body will gradually enter “asphyxiation mode”:

Organic pollution + oxygen-consuming microorganisms rapidly proliferate → dissolved oxygen levels plummet sharply → anaerobic bacteria take over the “decomposition process” → producing hydrogen sulfide (H₂S), ammonia (NH₃), and methane (CH₄)—precisely the substances responsible for the foul odors → phosphorus and heavy-metal ions previously trapped in sediments are re-released → triggering algal blooms and intensifying toxicity → ultimately leading to massive die-offs of fish and shrimp, thereby precipitating the collapse of aquatic ecosystems.

So, what you’re smelling isn’t actually a “bad odor”—what you’re sensing isn’t just resistance, but rather the suffocating signals emitted by a river.

The black-and-odorous phenomenon is merely a “symptom” of deteriorating water quality—while the real “root cause” behind the water turning dark brown and the disappearance of fish and shrimp populations is, in fact, oxygen depletion.

Therefore, unless the issue of oxygen deficiency is addressed, any effort to restore rivers and lakes to their former beauty—clear, pristine waters shimmering with sunlight—will be no different from building a castle on the sand: as soon as a wave comes crashing in, it will wash everything away, forcing you to start all over again.

II. Return to the Root and Explore the Path to Solutions

Let’s bring all issues back to the most fundamental ecological principle:

Only by restoring the fundamental physicochemical conditions of the environment can we guide the biological community toward succession toward a climax community.

Restore the most fundamental and critical physicochemical conditions—namely, an oxidizing environment.

Why is restoring an oxidizing environment a crucial step? Because it has three fundamental requirements:

1. Irreplaceability: In a continuously anaerobic environment, no chemical agents or ecological methods can effectively and safely perform their functions. Meanwhile, aerobic microbial communities are the “main force” in the natural self-purification process of aquatic ecosystems. If we regard pollutants as the microbes’ “enemies,” then oxygen is their “weapon”—an indispensable tool for breaking down these harmful substances.

2. Foundational: It provides an indispensable prerequisite for all subsequent advanced ecological restoration measures (such as planting submerged aquatic plants and introducing aquatic animals). Without oxygen, it’s like building a house without laying a solid foundation—no matter how substantial the investment in large-scale bioengineering projects may be, they could easily fall short of their goals in the short term or become completely useless in the face of sudden, excessive pollution events.

3. Cost-effectiveness: Compared to large-scale dredging projects that involve massive investments but only address the symptoms rather than the root causes, or to extensive sewage interception network construction projects—both of which are time-consuming and costly—aeration measures represent a quick-acting and relatively low-cost intervention, buying valuable time for launching fundamental source-control and pollution-reduction initiatives.

Third, the supply of oxygen in aquatic bodies is not as straightforward as it seems.

Is this really just a matter of exposing oxygen to water in order to increase the dissolved oxygen level? Has no one ever tried other methods to boost oxygen levels in aquatic environments?

Traditional aeration methods, such as diffuser plates and fountain-type aerators, produce a large number of rapidly rising bubbles, causing more than 90% of the oxygen to escape into the atmosphere before it has had sufficient time to dissolve fully. Consequently, these conventional technologies cannot meet the requirements needed to maintain adequate dissolved oxygen levels in water bodies.

Moreover, it’s not just the water at the surface that truly needs oxygen—what’s even more critical are the sediments on the riverbed and the bottom-layer water.

Therefore, research related to ultra-nano bubbles has begun to attract attention from water treatment professionals.

Interest in ultranano-bubbles first emerged 25 to 30 years ago, with the initial research stemming from challenges to classical theories—such as the Epstein-Plesset theory—which had predicted that ultranano-bubbles would collapse instantaneously. Although indirect evidence had been available since early on, their existence has long remained a subject of intense debate.

Around the year 2000, thanks to advances in technologies such as atomic force microscopy (AFM), scientists in China and Japan were able to directly observe stable, ultra-nanoscale bubbles, thereby confirming their existence and triggering a major sensation in the academic community. Since then, research has gradually shifted toward elucidating the mechanisms behind these bubbles’ remarkable stability—such as the surface-charge theory—and exploring their potential applications.

By 2019, relevant professional committees and standards committees had been established one after another across the country, promoting the widespread application of this technology in fields such as environment and healthcare. This also marked China’s completion of the journey from theoretical exploration to technological innovation.

4. Why are ultra-nano bubbles so unique?

Ultra-nano bubbles (UNBs) are bubbles with diameters smaller than 200 nanometers, invisible to the naked eye.

The technology of preparing and introducing supersaturated oxygenated water into water bodies in the form of ultra-nano bubbles is known as ultra-nano bubble aeration and oxygenation technology. This technology has demonstrated particularly outstanding performance in the field of water treatment, with its key advantages being:

Directly targeting the core of internal pollution: Delivering supersaturated, oxygen-rich water in the form of ultra-nano bubbles to the hypoxic bottom layer, enabling it to act directly on the contaminated sediments.

 

 

Long-lasting durability: Ultra-nanoscale bubbles can directly penetrate deep into sediments and remain on their surfaces for extended periods, effectively addressing deep-seated pollution. Due to their extremely slow rising speed and long residence time in water, these bubbles ensure a continuous and stable oxygenation effect.

Synergistic Purification: The physicochemical effects inherent in nanobubbles—such as the generation of ·OH radicals—can act synergistically to degrade recalcitrant organic pollutants.

5. How can we determine whether a body of water has truly regained its vitality, or is merely experiencing a brief resurgence—a fleeting “last gasp” of recovery?

This isn’t just about sight or smell—it’s all about letting the data do the talking.

The key indicators for data monitoring include the sustained increase in bottom-layer dissolved oxygen concentration and redox potential (ORP), as well as the gradual transformation of sediment color from dark brown to yellowish-brown.

This most directly indicates that internal contamination has been effectively controlled, and the biochemical reaction pathways have shifted from anaerobic to aerobic.

VI. Take the latest achievements in water environment governance as an example.

In 2022, the Moshui Lake in Hanyang District, Wuhan City, underwent a sediment improvement project during which ultra-nano aerosol oxygenation technology was employed. In addition, a grouped control experiment was conducted by dividing the lake surface into several enclosed compartments.

Before the experiment, the sediment collected from the three experimental groups was almost entirely black and emitted a pungent, foul odor. The surface showed no sign of oxidation and exuded an extremely strong, unpleasant smell. Notably, the control group—the group that received neither medication nor aeration—remained consistently black and malodorous throughout the entire experiment, emitting an unbearably sharp and offensive odor.

 

 

After two months of ultra-nano aeration, the surface characteristics of Test Group 1 and Test Group 2 underwent significant changes, forming a yellow-brown oxide layer approximately 2 to 3 centimeters thick. At the same time, the offensive odor almost completely disappeared.

 

 

7. Restoring breathing is only the beginning of ecological healing.

The era of relying solely on human effort to defy natural laws and tackle black-and-odorous water bodies is gradually coming to an end.

Ultra-nano aerosol reoxygenation technology delivers oxygen in a precise and highly biomimetic manner—efficient, sustainable, and thoroughly penetrating—to reinitiate the water body’s natural self-purification mechanisms.

Although curbing internal pollution is only the first step, once the foundation is firmly established, we can move forward steadily. We must ensure that technology keeps pace with social progress and transforms “water governance” from a mere engineering project into a holistic approach capable of reviving oxygen-depleted water bodies—helping them to autonomously return to their natural state.