Biomembrat -plus

Rautenbach and MeUis [75] describe a process in which a UF-membrane fermentor and a subsequent NF-treatment of the UF-permeate are integrated. The retentate of the NF-step is recycled to the feed of the UF-membrane reactor (Fig. 13.8). This process has been commercialised by Wehrle-Werk AG as the Biomembrat -plus system [76] and is well suited for the treatment of effluents with recalcitrant components. The process also allows for an additional treatment process, like adsorption or chemical oxidation of the NF-retentate, before returning the NF-retentate to the feed of the UF-membrane fermentor. Usually, the efficiency of these treatment processes is increased as the NF-retentate contains higher concentrations of these components. Pilot tests with landfiU leachates [75] and wastewater from cotton textile and tannery industry have been reported [77]. An overview of chemical oxygen demand (COD) reduction and COD concentrations in the permeate are shown in... 

Tab. 13.5 Percentage COD elimination and NF-effluent concentrations for various applications of the Biomembrat -plus process...

Wehrle-Werk AG information leaflet Biomembrat( )-plus , wmv.wehrle-werk.de, 2001. 

Reverse osmosis is used full scale for the treatment of landfill leachates (Linde et al., 1995). The RO retentate can be recycled to the landfill either directly or after evaporation. If this is not allowed, as is the case in Germany, more expensive solutions are to be found for the concentrate (Melin et al., 2005). A possible treatment method is activated carbon adsorption/oxidation, patented as Biomembrat-Plus, or even the combination of high-pressure RO, a crystallizer, and NF (Melin et al., 2005). 

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