Gross-Wen Technologies announces patent for removal of total dissolved solids

Gross-Wen Technologies (GWT) and the Metropolitan Water Reclamation District of Greater Chicago (MWRD) jointly announced the approval of patent number US20240343620A1 for improved methods for the removal of total dissolved solids (TDS) in wastewater.

The inventors of the patent are Martin A. Gross and Dr. Zhiyou Wen with GWT, Thomas Kunetz and Kuldip Kumar with MWRD, and Juan Peng with the Iowa State University Research Foundation.

The method and technology patented is a renewable energy solution using GWT’s revolving algal biofilm (RAB) system for cost-effective and environmentally friendly wastewater treatment.

According to a press release, the improvements increase the rate of TDS removal by moving an algal biofilm through wastewater and moving the algal biofilm through a gas. It can enable greater reduction of carbon emissions, recovery of nutrients and improvements in water quality.

The new patent could impact how the wastewater industry handles TDS. TDS is not just a concern for the city of Chicago and the 5.19 million citizens that MWRD serves, but a ever-growing concern around the globe.

TDS can harm aquatic life and build up in pipes causing corrosion. Another persistent challenge for recovery facilities is how to remove TDS from wastewater streams economically and sustainably.

“We are thrilled to receive another patent approval for our important technology using algae to solve one of the most challenging problems faced with wastewater,” said Martin A. Gross, co-founder and CEO of GWT, in a press release. “This new patent approval is another confirmation that the RAB system is a sustainable and environmentally friendly method for wastewater remediation. Our team of scientists and engineers are tenacious and committed to the pursuit of effective climate solutions.”

The new patent builds upon the work of a previous patent approved on July 4, 2023. This additional patent specifically addresses how the RAB system enhances algae to remove TDS at a faster rate.

According to a press release, the patent received impressive technical results. The new efficiencies of removing TDS, chloride, and other ions by the RAB reactors were higher than those of the suspended algal culture system and depended on the hydraulic retention time. The extracellular polymeric substances (EPS) content of the algal biofilm, particularly the protein and polysaccharides in EPS, was higher in RAB reactors than in suspended culture systems and was responsible for the high TDS removal efficiencies.

“This wastewater treatment marvel in algae harvesting continues to yield multiple benefits that optimize the water reclamation process, leading to cleaner water and lower carbon emissions,” said MWRD President Kari K. Steele in a press release. “We applaud our partners from Gross-Wen Technologies and Iowa State University Research Foundation and our scientists at the MWRD for their ingenuity and determination to apply this practice to our treatment process.”