ALEXANDRIA, Va., Sept. 15 -- United States Patent no. 12,735,336, issued on Sept. 15, was assigned to SOUTHERN UNIVERSITY OF SCIENCE AND TECHNOLOGY (Shenzhen, China).

"System and method for treating nitrate nitrogen sewage by constructed wetland" was invented by Junguo Liu (Shenzhen, China) and Tao Huang (Shenzhen, China).

According to the abstract* released by the U.S. Patent & Trademark Office: "A system for treating nitrate nitrogen sewage by autotrophic denitrification subsurface flow constructed wetland a method thereof. The system includes a wetland pool body, a wetland substrate, a water distribution device, a water outlet device, and plants. The wetland substrate is filled in the wetland pool body. The wetland substrate includes p...