Ammonia recovery from nitrogen rich wastewater by membrane stripping with Nitrycle

Short general project overview

Ammonia Membrane Stripping (AMS) reduces the overall energy consumption of conventional wastewater treatment plants, reduces greenhouse gas emissions and ensures a good final treated water quality. Removal of nitrogen from wastewater treatment plants minimizes the impact of eutrophication of downstream surface waters. Biological removal of ammonia has limitations of high energy and carbon usage for nitrification/denitrification. Furthermore, it produces greenhouse gas (N2O), is sensitive to variations in temperature and pH and is space consuming. In Nitrocycle special membrane modules recover ammonia from side streams at wastewater treatment plants in order to recover it as Ammonium Sulphate, which can be used as fertilizer. The goal of the project was to lift the AMS technology towards TRL 6 by applying, testing and optimizing membrane modules on pilot scale for concentration of ammonia rich feed streams.

TNO's contribution consisted of making process calculations, Georg Fisher took care of the design and implementation of module-construction and advised on materials. EAWAG was responsible for upscale calculations and Blue-tec as technology-provider for process and organization.

Results of the project

In the project it was demonstrated that ammonia membrane stripping can be successfully applied for the removal of ammonia from nitrogen rich streams and be recovered as a valuable fertilizer product. Based on the project, new developments have been initiated to increase the performance of the membranes and to decrease the use of chemicals.

Currently, Blue-Tec is discussing the upscaling of the technology at the project site with the newly developed membranes, where a capacity of 60,000 m3/year of ammonia rich water from the digestion process is treated.