A double-feed anaerobic filter for the treatment of high strength wastewaters

Summary An Upflow Anaerobic Filter (UAF) treating cheese whey showed a non-homogeneous biomass distribution and COD degradation along the reactor. Higher biomass concentration with a higher methanogenic activity was present in the lower than in the upper part of the filter. In order to increase the methanogenic capacity of the filter, a double-feed system was tested. The UAF with the double feeding presented higher methane production and completely homogeneous characteristics regarding biomass distribution and activity as well as COD removal along the reactor.     

Inert filter media for the biofiltration of waste gases – characteristics and biomass control

Soil biofilters and related systems based onthe use of natural filter beds have been usedfor several years for solving specific airpollution problems. Over the past decade,significant improvements have been brought tothese original bioprocesses, among which thedevelopment and use of new inert packingmaterials. The present paper overviews the mostcommon inert packings used in biofiltration ofwaste gases and their major characteristics. Apotential problem recently encountered whenusing inert filter beds is the heterogenousdistribution of biomass on the packingmaterial, and the excessive growth andaccumulation of biomass when treating highorganic loads, eventually leading to cloggingof the biofilter and reduced efficiency.Several strategies that have been proposed forsolving such problems are described in thispaper. Technologies for controlling excessbiomass accumulation can be grouped into fourcategories based on the use of mechanicalforces, the use of specific chemicals, thereduction of microbial growth, and predation.