In research the fertilizer value of sludge from reed beds is evaluated based on the sampling sludge on different depths from 4 Danish STRB after long periods of stabilization. The dewatering efficiency of sewage sludge in the STRB is comparable to mechanical dewatering. The long-term stabilization of sewage sludge progressively decreases the concentration of organic matter due to the process of humification. The aim of the work was to determine the changes of organic matter concentration, nutrients concentrations as well as speciation of selected heavy metals (Cd, Pb, Ni, Cr, Cu and Zn) in vertical profile of the sewage sludge stabilized in the STRBduring7–15years. The analyzedsewage sludge was collected from the STRB treating sludge systems from four municipal WWTPs located in Denmark serving from 9,000 to 40,000 p.e. Analyzed heavy metals (except for Zn) were mostly bound with the most stable – residual fraction. The most stable metals were: Pb and Cr where the share of residual fraction exceeded 80.0%. Themostmobilemetalwas Znwhere the share of mobile fractions (calculated as the sum of I, II and III fraction) exceeded 85.0%. The high concentration of nitrogen and phosphorus is the decisive factor in the high valuation of sludge stabilized in the STRB as fertilizer.
Authors
Additional information
- DOI
- Digital Object Identifier link open in new tab 10.2166/wst.2013.393
- Category
- Publikacja w czasopiśmie
- Type
- artykuł w czasopiśmie wyróżnionym w JCR
- Language
- angielski
- Publication year
- 2013
