Ecolab Water, a subsidiary of U.S.-based water and hygiene company Ecolab Inc., has filed a joint patent with Samsung Electronics Co. for a semiconductor wastewater treatment system.

The technology treats wastewater generated during semiconductor manufacturing processes, including the deposition and patterning of material films on wafers. It removes nitrogen compounds such as nitrates (NO3?) by reducing them to nitrogen gas (N2) through microbial reactions, a process known as denitrification. Nitrogen in wastewater can cause eutrophication in rivers and oceans.

The patent improves denitrification efficiency compared with existing processes, increasing the amount of nitrogen removed. Tests showed nitrogen levels in treated water fell by more than 30% compared with conventional methods. Processing costs were also reduced. Chronic problems such as sludge generation and odor were minimized, while organic levels in discharged water were lowered, improving overall water quality stability.

The technology works by supplying an organic carbon-source composition to induce microbial reactions. The composition consists of ethylene glycol, glucose, ethanol and sodium acetate, which serve as energy sources for microorganisms. The microbes consume the organic matter and reduce nitrates to nitrogen gas.

Wastewater is processed sequentially through three stages: a pre-denitrification tank, a nitrification tank, and a post-denitrification tank. In the pre-denitrification stage, a portion of nitrates is reduced to nitrogen gas through microbial reactions. In the nitrification stage, ammonia in the wastewater is oxidized into nitrates. In the post-denitrification stage, the carbon-source composition converts the remaining nitrates into nitrogen gas. The water then undergoes aeration and sedimentation, after which microorganisms are separated as sludge and the treated water is discharged.

Ecolab supplies ultrapure water used in semiconductor manufacturing processes, though water-conservation solutions account for the majority of its revenue. About 70% of the company’s annual revenue currently comes from water-related solutions, including water treatment, water-quality management and operational-efficiency services for semiconductor plants and data centers.

The company launched a data center division in March last year. Data centers consume large volumes of cooling water to manage heat, making water conservation and water-quality management critical. Ecolab provides turnkey solutions covering installation and operations, while real-time monitoring and control systems enable early detection and response to water-quality changes. The division also contributes to process stability and maintenance cost reductions.

As of 2024, the company achieved savings of approximately 30 million gallons of water, 1 million kilowatt-hours of energy, and reductions of about 1,000 metric tons of greenhouse gas emissions.

Ecolab has also developed water-treatment solutions tailored to the South Korean data center environment and has secured projects related to direct liquid cooling (DLC) on that basis. The company plans to expand its cooling-water quality management solutions based on DLC technology going forward.

By: DocMemory
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