Trickling filters process

The trickling filter process, including conventional rate filters, multiple-stage, high-rate systems, and bio-oxidation roughing towers. 

Primarily, activated sludge processes and, less often, trickling filter processes are employed for aerobic biological treatment. In North America and Northern Europe, effluent purification is frequently carried out in aerated oxidation ponds. Recently, anaerobic treatment has become established, especially in paper mills processing recovered paper. 

Fig. 9.2 Biological treatment process consisting of a bioreactor and secondary clarifier. (A) Activated sludge process with aeration basin, siudge recycle, and waste sludge lines (B) Trickling filter process consisting of biotower, solids contact tank, biotower effluent recycle and sludge recycle lines.

Logan, B.E., Hermanowicz, S.W. and Parker, D.S. (1987) A fundamental model for trickling filter process design. J. Water Pollut. Control. Fed. 59(12), 1029-1042. 

Air. Biofilters are an effective way of dealing with air from industrial processes that use halogenated solvents such chloromethane, dichioromethane, chloroethane, 1,2-dichloroethane and vinyl chloride, that support aerobic growth (26). Both compost-based dry systems and trickling filter wet systems are in use. Similar filters could be incorporated into pump-and-treat operations. 

Trickling Filters. The so-called trickling filter is not a filter but a bed of stones or other coarse material (packing) over which the sewage flows. In terms of the total number of installations, it is the most widely used biological treatment process. However, the greatest total volume of waste is treated by the activity-sludge process (12). 

The four most common aerobic biological treatment processes are stabilization ponds, aerated lagoons, trickling filters, and activated sludge (see... 

Attached growth processes Wastewater treatment processes in which the microorganisms and bacteria treating the wastes are attached to the media in the reactor. The wastes being treated flow over the media. Trickling filters, bio-towers, and RBCs are attached growth reactors. These reactors can be used for removal of BOD, nitrification, and denitrification. 

Distributor The rotating mechanism that distributes the wastewater evenly over the surface of a trickling filter or other process unit. 

Any of the variety of chemical engineering operations or unit processes listed in Table 17.10 may be used to treat aqueous effluents. Oxidation includes both chemical and biological processes the latter include trickling filters or an activated sludge bed. 

Due to the focus of this work, other biological processes will also be mentioned. They include trickling filters, coating biological contactors, pond stabilization, anaerobic digestion, and biological nutrient removal.23 5... 

Secondary treatments are accomplished either by an activated sludge process or a trickling filter, in which organic components of the wastewater are subjected to aerobic degradation by microbial biocoe-nosis [52]. Surfactants can be metabolised by adapted micro-organisms... 

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