Improving forward osmosis membrane coating

Hanh Le recently graduated as MSc in Environmental Process Engineering at RWTH Aachen University in Germany. He completed his academic studies with an Erasmus internship at Aquaporin. In his project, Hanh investigated, developed, and optimized innovative performance-enhancing and antifouling coating layers for Aquaporin’s forward osmosis membranes.  

Forwards Osmosis is an up-and-coming technology and finds its use in several applications, ranging from municipal wastewater treatment, to improving Zero Liquid Discharge systems in the textile industry. More recently the applications have extended to also include Food & Beverage treatment as the Aquaporin Inside® technology secured food contact material compliance from the US Food and Drug Administration. This entails meeting the challenges of a variety of feed solutions, which was the foundation of Hanh Le’s project as it focused on the development of an antifouling layer that also improves the overall membrane performance.

After choosing a suitable coating and crosslinking agent, a table-top coating station was constructed at which a coating protocol was developed. Several concentrations and pre-treatment as well as post-treatment procedures were investigated. Coating results were analyzed using FO and LPRO experiments. Water flux, reverse salt flux, permeability and rejection were chosen as the determine indicators for initial coating evaluation.

Promising results were obtained, which showed an increased performance of FO membranes when coated with an antifouling layer. A close range of optimal coating and crosslinking agent concentrations were identified. Furthermore, a consistent coating protocol was developed which allows for up-scaling to bigger modules in the future.


I decided to apply for the Aquaporin Academy to enrich my studies by working abroad before graduating. It was not only an invaluable opportunity to work for a research-heavy company, but also to get insights into the Danish culture.

My time at Aquaporin has been a pleasure from the get-go. The welcoming atmosphere, flat hierarchies and motivated co-workers and students create a warm and pleasant working environment. I enjoyed the assigned responsibility and freedom I had during my stay. The continuous and open communication within the research group allowed a steady and rapid progress for the project. I especially value that being part of the Aquaporin Academy extended far beyond a regular research internship from an academic as well as a cultural point of view.


Written by Hanh Le


Published on January 2021 in