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SLUDGE TREATMENT AND DRYING REED BED SYSTEMS IN DENMARK
Author(s) -
Nielsen Steen,
Willoughby Neil
Publication year - 2005
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/j.1747-6593.2005.tb00566.x
Subject(s) - biosolids , dewatering , environmental science , sewage sludge treatment , sewage sludge , sewage treatment , waste management , environmental engineering , sludge bulking , pulp and paper industry , engineering , geotechnical engineering
Sludge Reed beds have been used for dewatering (draining and evapotranspiration) and mineralisation of sludge in Denmark since 1988 when the first sludge processing system was introduced. Sludge from wastewater treatment plants (2,500‐125,000 pe) is treated in sludge reed bed systems with 1–18 basins with loading rates of 25–2,200 tonnes dry solids/year for ten years. In 2002, approximately 95 systems were in operation. Dimensioning and design of reed bed systems depends on the sludge production rate, sludge type, quality and regional climate. The maximum sludge loading rate is approximately 50–60 kg DS/m 2 /year. Loading cycles are related to the sludge type and the age of the sludge reed systems. The sludge residue will, after approximately ten years of operation, reach an approximate height of 1.2–1.5 metres with dry solids content of 30–40%. Experience has shown that the quality of the final product with respect to heavy metals, hazardous organic compounds and pathogen removal after ten years of treatment make it possible to recycle the biosolids to agriculture as an enhanced treated product.