title: A downflow hanging sponge (DHS) reactor for faecal coliform removal from an upflow anaerobic sludge blanket (UASB) effluent.
abstract: This research was conducted to study the faecal coliforms removal capacity of downflow hanging sponge (DHS) reactors as a post-treatment for an upflow anaerobic sludge blanket (UASB) reactor. Three long-term continuous laboratory-scale DHS reactors, i.e. a reactor with cube type sponges without recirculation, a similar one with recirculation and a reactor with curtain type sponges, were studied. The porosities of the applied medium were 91%, 87% and 47% respectively. The organic loading rates were 0.86 kgCOD m(-3) d(-1), 0.53 kgCOD m(-3) d(-1) and 0.24 kgCOD m(-3) d(-1) correspondingly at hydraulic loading rates of 1.92 m3 m(-2) d(-1), 2.97 m3 m(-2) d(-1) and 1.32 m3 m(-2) d(-1), respectively (COD: chemical oxygen demand). The corresponding averages for faecal coliform removal were 99.997%, 99.919% and 92.121% respectively. The 1989 WHO guidelines standards, in terms of faecal coliform content for unrestricted irrigation (category A), was achieved with the effluent of the cube type DHS (G1) without recirculation. Restricted irrigation, category B and C, is assigned to the effluent of the cube type with recirculation and the curtain type, respectively. Particularly for organic compounds, the effluent of evaluated DHS reactors complies with USEPA standards for irrigation of so called non-food crops like pasture for milking animals, fodder, fibre, and seed crops.
authors.forename: Rosa Elena
authors.initials: RE
authors.lastname: Yaya Beas
authors.affiliation: Sub-department of Environmental Technology, University of Wageningen, 6700 AA, Wageningen, The Netherlands; Lettinga Associates Foundation (LeAF), P.O. Box 500, 6700 AM, Wageningen, The Netherlands.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kujawa-Roeleveld
authors.affiliation: Section Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, 2600 GA, Delft, The Netherlands; Unesco-IHE Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands.
authors.forename: Jules B
authors.initials: JB
authors.lastname: van Lier
authors.affiliation: Sub-department of Environmental Technology, University of Wageningen, 6700 AA, Wageningen, The Netherlands; Lettinga Associates Foundation (LeAF), P.O. Box 500, 6700 AM, Wageningen, The Netherlands.
authors.forename: Grietje
authors.initials: G
authors.lastname: Zeeman
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D005243:Feces / Q000737:chemistry*; D011161:Porifera / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D012722:Sewage