What does a scrubber water treatment unit remove?

A scrubber water treatment unit (WTU) filters scrubber wash water to remove harmful elements stemming from the combustion process, such as PAH and PM, for a greener shipping industry and a more sustainable world. Let us be more detailed about what a scrubber water treatment unit removes and why this is essential to remove.

As a scrubber treats sulfuric exhaust gases, it generates sulfuric wash water. Although the scrubber neutralizes this using alkali, the wash water still contains harmful elements stemming from the combustion process. This is crucial to avoid ocean pollution, ultimately harming aquatic species, especially shellfish and corals A scrubber water treatment unit plays a vital role in boosting a greener shipping industry for a more sustainable future by removing harmful elements.

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Polycyclic Aromatic Hydrocarbons (PAH)

Polycyclic aromatic hydrocarbons are various organic compounds of chemicals in coal, gasoline, and crude oil. PAH is also produced once coal, gasoline, and crude oil are burned, meaning that PAH is to find in marine exhaust gas streams. Before the IMO 2020 regulation, the PAH went into the atmosphere and contaminated the air for people to inhale. As the exhaust gas is scrubbed, the wash water absorbs the PAHs. It is unknown how low amounts of PAH affect human health. Still, large amounts of PAH are linked with cataracts, kidney and liver damage, and jaundice.

Additionally, the PAHs may cause eye irritation, harm breathing passages, and frequent PAH skin contact, leading to redness and inflammation. Moreover, it can affect ocean chemistry and cause damage to aquatic species. A scrubber water treatment unit removes PAH, ultimately delivering significantly improved marine life.

Particulate Matter (PM)

Particulate matter (PM) is an airborne substance of hundreds of different hazardous solid particles and liquid droplets. Therefore, PM is often denoted as particle pollution. Particulate matter may include both organic and inorganic particles, including elements such as soot, smoke, and liquid droplets. The scrubber removes some of the PM. Still, as the exhaust gas is scrubbed, some PM is absorbed by the wash water. The particles of particulate matter can take different sizes, compositions, and origins. Some particles you can see with the naked eye, while others are microscopic. Some PM stems from a direct source, such as an operating engine. Still, most PM takes form in the atmosphere when chemicals meet each other and form complex reactions. This is often the case with SOx and NOx emitted from power plants, industrial operations, vehicles, and vessels. PM makes up a significant health risk, as it is being inhaled. The smallest particles constitute the most critical health threat as they can enter deep into the human lungs and bloodstream. A water treatment unit can remove substantial amounts of PM.


Heavy Metals 

Heavy metals are high-density metallic chemical matter, and they are toxic to humans and wildlife at high concentrations. Heavy metal intoxication can happen via contaminated drinking water, high ambient air concentration from exhaust gases, and food consumption. As the scrubber cleans the exhaust gas, the heavy metals are absorbed by the wash water.

Two problematic and harmful heavy metals are cadmium and mercury.

Cadmium can cause kidney failures, lung diseases, and lung cancer. Long-term exposure to cadmium can lead to bone defects in humans and animals. The LiqTech scrubber water treatment unit can reduce cadmium to less than 0.15µ per liter.

High mercury concentrations can cause brain malfunctions, kidney damage, lung diseases, eye irritation, inflammable skin, vomiting, and diarrhea. Previously, mercury has been found n the oceans, causing fish to be contaminated, ultimately resulting in food chain pollution. It is possible to remove heavy metals with a LiqTech scrubber water treatment unit installed with a coagulation module. The LiqTech WTU can reduce mercury significantly to less than 0.05µ per liter.

A water monitoring unit (WMU) is placed before the discharge outlet to ensure that the closed-loop scrubber wash water always abides by IMO’s discharge limits. Learn more about the scrubber water discharge limits.

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Marine Knowlegde Ebook Download

Marine Knowledge E-book

If you want to learn more about the marine industry, you can download our Marine Industry Knowledge e-book.

Learn everything worth knowing about marine scrubbers, wash water treatment, and how to comply with the IMO 2020 sulfur cap.

Read about emerging trends affecting the maritime industry, marine regulations, and how to stay compliant now and in the future. 

At LiqTech, our goal is to minimize the negative impacts of living an improved lifestyle. With innovative clean technology, we reduce the harmful effects caused by various polluting industries, including the marine industry, in line with current and emerging environmental regulations. We want to share our knowledge with you; therefore, we have created a universe full of marine knowledge.

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