Sustainable membrane cleaning for drinking water preparation and wastewater treatment

In the last decades membrane processes have established themselves worldwide as key separation processes for drinking w ater preparation and wastewater treatment. A trend which started w ith reverse osmosis for seawater desalination in the 1970ies and which accelerated with membrane bioreactors for wastewater treatment since 2000. Following this global trend, membrane processes have entered now also Swedish facilities for drinking water preparation and wastewater treatment. Highlights of this development are the membrane units for drinking water preparation at Lackarebäck WTP and the world largest membrane bioreactor for municipal wastewater treatment under construction at Henriksdal WWT - both projects introduce new concepts to the Swedish drinking water and wastewater industry. The key challenge with membrane technology is the membrane cleaning to counter-balance
the inevitable fouling of membranes resulting in a capacity decline of membrane units over time. Current membrane cleaning methods and protocols are developed based on experience typically by the operator. The proposed project will combine self-learning automatic control of the membrane cleaning with sustainable cleaning protocols. Information gathered from in-line and real-time measurements of fouling and cleaning will be used to predict the optimal time and sequence for the cleaning. This will lead to reduced cleaning chemical (caustic/acid) and water consumption during cleaning plus minimise plant dow n time, and thus improve plant OPEX and CAPEX. The project w ill be relevant for all drinking w ater preparation and wastewater treatment plants and it is foreseen that the results can be transferred to other industries - dairies or pulp and paper using membranes.