EDAFOLOGIA, Vol. 10 (2), pp. 135-145, 2003
ESCORRENTÍA Y GRANULOMETRIA DE SEDIMENTOS EN SUELOS TRATADOS CON DIVERSOS TIPOS DE LODOS DE DEPURADORA
G. OJEDA CASTRO, J.M. ALCAÑIZ BALDELLOU, O. ORTIZ PERPIÑÁ, D. TARRASÓN CERDÁ
Centre de Recerca Ecológica i Aplicacions Forestals (CREAF), Laboratori de Sòls, Unitat d’Ecologia, Universitat Autònoma de Barcelona. Edificio Facultad de Ciencias, Campus UAB, 08193 Bellaterra (Cerdanyola Vallés), España.
Three types of sewage sludge were applied to a calcareous loam soil and a neutral pH, sandy surface texture soil. All sludge came from the same batch, secondary treatment by anaerobic digestion (fresh sludge, 20% dry matter) and were subjected to composting with pinewood splinters (composted sludge, 66,5% dry matter) or were thermally dried (thermal sludge, 84,7% dry matter). Field plots of 20 x 5m were equipped with Gerlach channels to collect runoff and sediments. Anyone of the three types of sludge applied reduces soil losses, but only thermally-dried sludge reduces runoff. In loam soil, the percent of silt and clay in the sediments increases when runoff also increases, but not in sandy soil. In loam soil, any type of slud- ge applied reduces fine sediment losses, but in sandy soil only fresh and composted sludge.
Key words: sewage sludge, erosion, run-off, compost, land rehabilitation