Dynamics of potassium content in sewage sludge during its composting with different additives.

摘要

This study aims to determine the changes in the potassium content of sewage sludge during composting with the addition of the lime equivalent to 1 Hh, 20 and 40% of coniferous tree sawdust, 20 and 40% of rye straw, and 20 and 40% of cattle manure. The content of total potassium and potassium soluble in 0.5 M HCl of the initial material depended mainly on the amount and type of additives used for composting. The dry matter content in the sludge accounted for 37.8%, hence, it was called earthen sludge. The pH reached 6.4. During composting, a steady increase in total potassium was observed in all objects. The composting process contributed to an increase in soluble potassium content from 2-fold (with the addition of 20% of sawdust) to 20-fold (with 40% of straw) in all experimental objects..