HONG KONG, China – Boston-based Gradiant Corporation has signed a project to provide industrial wastewater reuse technology to Hong Kong-based textile firm, Esquel Group.
As part of the project, Gradiant will supply its humidification and dehumidification (HDH) system to remove harmful pollutants and recover clean water during the textile manufacturing process.
Textile and garment production requires roughly 150 liters of water to produce one kilo of textile material or the equivalent of one day’s attire for one person. Resulting wastewater contains dyes and chemicals requiring advanced treatment to be safely discharged into the environment or reused in the process.
As a result, progressive textile manufacturers are adopting desalination and evaporation technologies to remove dissolved salts and achieve zero liquid discharge.
Gradiant first demonstrated its HDH technology at full scale in 2013 treating produced water from North American oil and gas exploration and production.
The evaporator alternative is designed to mimic “nature’s rain cycle”, according to the company, to reduce the cost of treatment by as much as 50 percent.
The technology was developed by company co-founders Anurag Bajpayee (now CEO) and Prakash Govindan (chief technical officer) in the lab of Professor John H. Lienhard (Top 25 Global Water Leader) at Massachusetts Institute of Technology (MIT).
According to MIT, HDH is a “decades-old concept” – water is vaporized and condensed on a cold metallic surface to remove salts. However, commercial-scale systems have always been too “energy intensive because water must be boiled while condensing surfaces must be kept very cold”.
The Gradiant system uses readily available carrier gas (dry air) that vaporizes water below boiling temperatures, incorporating a column of microbubbles that optimizes condensing surfaces.
This latest contract is part of the company’s focus on the growing $500 wastewater desalination and zero liquid discharge market in Asia.