Advantages of sewage sludge dehydration by geotube method

Abstract

This paper describes the benchmarking of municipal sewing sludge dewatering technology with traditional geotube technology and air drying beds. The use of geotube dehydration technology process occurs faster due to reagents that provide clogging sludge. Applying the technology of dehydrating the sludge in geotube leads to reducing: the time required for dehydration from 18 months up to one month; the surface of land required for the dehydration from 6.0 to 1.25 ha, and respectively, for storage, from 27.7 to 3.65 ha. Removal of toxic gases into the atmosphere is reduced from 1.4 to 6.2 times. Compared with the traditional technology of air drying beds, the dehydrated sludge in geotubes contains 2 times more carbon and total nitrogen. Total phosphorus content had a slight tendency to decrease, total potassium concentration increases with 1.76 times. One tonne of dried sewage sludge stored in geotube and stocked for one year has the humidity of 65% and contains 151 kg of organic matter, 9.0 kg N, 10 kg P2O5 and 2.9 kg K2O. Heavy metal content is below the maximum that is allowed by national legislation from 2008. The application of sewage sludge as a fertilizer provided a specific increase of the total yield over the two years of 100.5 kg per ton of grain units at the dose of 18 t/ha and 45.5 kg per ton of grain units at the dose of 36 t/ha .