Seoul Institute of Health and Environment Develops Resource Recovery Technology for Sewage Sludge

Volume of Sewage Sludge Reduced by Up to 40%... Nitrogen Concentration Improved Fourfold

[Asia Economy Reporter Jo In-kyung] The Seoul Institute of Health and Environment announced on the 12th that it has jointly developed a technology with Bio Energy Development Co., Ltd. and Seonam Environment Seonam Water Reclamation Center to reduce the moisture content of sewage sludge, minimize its volume, and recover phosphorus (P).

The patented technology is named "Filter Press Device for Phosphorus Recovery from Sewage Sludge and Phosphorus Recovery Method Using Ultrasound Thereby." It involves ultrasonic treatment of sewage sludge followed by pressure dewatering through a membrane filter press.

According to the 2018 sewage statistics, the annual amount of sewage sludge generated at sewage treatment plants nationwide is approximately 4.09 million tons, with an estimated 700,000 tons generated in Seoul alone, making the establishment of sewage sludge treatment measures urgent.

Using the newly developed technology in small-scale field experiments, the moisture content of sewage sludge was reduced to 54%, which is about 24 percentage points lower than the moisture content (approximately 78%) when using conventional centrifugal dewatering machines, confirming that the final volume of sewage sludge can be reduced by about 40%. The Institute of Health and Environment explained that if this technology is applied in the field, the sludge treatment costs, which account for a large portion of the total sewage treatment expenses, will be significantly reduced.

In particular, ultrasonic treatment of sewage sludge increased the phosphorus concentration in the filtrate by more than four times, enhancing the economic feasibility of phosphorus recovery technology. The extracted phosphorus can be used as a main raw material for fertilizers or livestock feed. Since phosphorus is not produced domestically in Korea, the country relies entirely on imports.

Choi Ye-deok, a researcher at the Seoul Institute of Health and Environment who led the technology development, said, "We have achieved both goals by reducing moisture and recovering resources," adding, "In the future, we will focus our research capabilities on developing foundational technologies for recycling and resource recovery of sewage sludge and incineration ash."

Shin Yong-seung, the director, promised, "In a country with scarce natural resources, the development of waste resource recovery technologies is not an option but a necessity," and pledged, "We will continue research and development through public-private collaboration."

Perspective view of the sewage sludge dewatering and phosphorus (P) recovery system.

This content was produced with the assistance of AI translation services.