An Investigation on the Importance of Initial Loading in the Removal of Nutrients from Liquid Digestate Through Sorption and Nutrient Recovery from the Solid Phase To Be Used as Fertilizer

This article attempts to present the findings of an investigation on nutrient recovery mainly focusing upon effect of initial loading on the ammonium and potassium removal from the liquid phase of digestate by ion exchange using clinoptilolite with a short touch upon the use of stagewise operation and conditions of recovery. Nutrient removal from liquid digestate is investigated by concentrating nitrogen and potassium onto natural zeolites, with the option of applying nutrient-enriched clinoptilolite as fertilizer. Further, stagewise operation is conducted to assess any improvement in residual nutrient quality. Effect of contac time is investiagted on the recovery efficiency of nutriet enriched clinoptilolite. The results revealed that although surface concentrations increase upon increasing initial loadings, nutrient removal efficiency for ammonium declined from 93 to 46% and for potassium from 88 to 27% as the initial loading increased. The additional benefit of stagewise processing was effective in terms of organic matter. Within the range of 5 to 100 min, increasing the contact time resulted in longer time requirement to reach the desired recovery. The recovery of potassium was not successful due to high amount of potassium in tap water. Overall, it was as observed that clinoptilolite application is a promising solution for managing liquid digestate and its valorization as a source of fertilizer.