Risks of Mercury in Wastewater

Mercury has always fascinated people, partly because of its properties and the way it’s used. This metal is found naturally in the composition of the earth’s crust. These amounts don’t pose a significant risk to the ecosystem and people.


Nowadays, most people know about this liquid metal because of thermometers and dental fillings. But modern scientists point out the problems of mercury in wastewater rather than its functionality. That’s why companies around the world cut the use of this metal. Some countries even completely exclude it from industrial use, marking it as a dangerous pollutant.

What Is Mercury Pollution?

The liquid metal naturally found in soil and water is not a problem. But the concern stems from human and industrial actions, as plants release significant amounts of this metal into the environment. Most of this pollution comes from electricity production and waste incineration.

Mercury waste comes from various sources, including industries, mines, and fossil fuels. The electric utility industry is the largest source of this pollutant in the United States. Also, coal-fired power plants are among the worst culprits.

How Risky Is Mercury in Wastewater?

Mercury pollution is a significant problem for people worldwide. This heavy metal becomes toxic in larger quantities, and the soil, water, and air become polluted for many years. It eventually gets into fish, from where it reaches humans and animals that eat them.

Once it enters the human body, this liquid metal triggers various health problems, affecting different body parts. For example, it can cause birth defects, neurological disorders, and fetal brain damage.

The intake of this liquid metal can lead to poisoning, which you can recognize by the following symptoms: https://www.healthline.com/health/mercury-poisoning

How to Solve Wastewater Pollution

Removing pollutants from wastewater can be challenging, but there are ways to ensure their levels are well below the legal thresholds. One way is to change the way mercury users operate. For example, power plants can reduce their emissions of this toxic metal by changing fuels to renewable.

wastewater sampling

Minor polluters can also contribute. For example, dental offices are not the largest polluters but are a major source of mercury discharge to local wastewater. So they can contribute by using alternatives like composite resin or porcelain for dental fillings. Also, they should have amalgam separators and line cleaners.

Water treatment facilities must ensure that the levels of this liquid metal are well below the maximum. They’re usually set as close to health goals as possible while balancing the benefits of mercury reduction. And to keep the pollution low, water treatment facilities can use mercury-free filters and purifiers.

Pollution Treatments

There are several efficient methods for removing this toxic metal from wastewater. They usually use different coagulants and purifiers. Their effectiveness depends on the number of pollutants in wastewater and how the ‘cleaning media’ works. Also, the treatment choice depends on the pollution sources.

Chemical Precipitation

This method is simple and cost-effective, so companies usually rely on it. First, they use chemicals to filtrate mercury from wastewater. When added to the stream, these chemicals go with the flow and dissolve particles of this metal along the way.

Then, following this reaction, facilities can remove insoluble solids from wastewater. Finally, chemical precipitants bind dissolved particles. When that happens, it’s easy to dispose of this pollutant at a hazardous waste landfill.


Another widely-used method is adsorption. It requires the use of granular activated carbon as an absorber. It’s something like a porous media to bind dissolved contaminants. But other chemicals can help, too. In general, an adsorbent should have a high capacity to bind heavy metals and be able to resist clogging.

The facilities using this method release wastewater through filters made of porous adsorbents. Their role is to collect pollutants on their surface based on forces of molecular attraction. As the wastewater goes through, mercury molecules stick to the media, so removing them from the water is easy.

Once the adsorbent is saturated, it should be replaced. That brings us to the most significant drawback of this method – expenses. So facilities must choose proper adsorbents for their needs, considering their filtration power and replacement costs.

Biological Treatment

Mercury is inorganic, so removing it using conventional technologies can be tricky. So instead, it calls for so-called biological processes. They use the activity of living microorganisms that break down pollutants molecules and make them readily removable.

This method is excellent for highly polluted waters. Still, it must be adequately managed not to compromise living biomass. Its disturbing amounts can endanger surrounding ecosystems. More on the pros and cons of this treatment read here.


Mercury in high amounts can be toxic and cause health problems in humans. Although its use in industry is minimal, this metal is still present and gets in the air, water, and soil. So only proper waste management and removal treatments can put pollution under control.

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