Membrane fouling due to concentrating leachate after methane fermentation and nitrification

The article presents the results of research on the process of leachate concentration at a nanofiltration installation over the course of six experiments (lasting from 31 to 53 d each), with special emphasis on the process of membrane fouling. The results have shown that organic and mineral sediments, including struvite-type compounds, caused the fouling of nanofiltration membranes even if the concentration of ammonia nitrogen was low. The precipitation of mineral compounds was mostly influenced by the concentration of phosphates in the feed water. Adding magnesium nitrate Mg(NO 3 ) 2 did not speed up the precipitation of crystals on the membrane surface. Studies have shown that the phenomenon of struvite-type compounds precipitation occurs not only on the surface of the membrane but also inside the membrane structure, causing permanent damage to its physical structure.