A pilot biological fluidized‐bed plant with a capacity of 40 m3/h has been in operation since January 1988 at De Blankaart drinking water production center for removing nitrate from surface water. Methanol is used as the reductant. With a nitrate removal efficiency of 9.0 kg NO3−/m3 reactor.day at 3.5°C, the system has shown superior performance compared with conventional fixed‐bed biofilm reactors. With an influent concentration of 75 mg NO3−/L, complete nitrate removal was achieved at an empty bed contact time of 15 min. Nitrite was not detected in the effluent, provided there was a slight excess of methanol (1–2 mg/L). Residual methanol was easily removed by the existing downstream drinking water treatment processes.
Fluidized‐bed denitrification of surface water with methanol as the carbon source is currently being studied in Belgium. Residual methanol and microbial excretion products increased the dissolved assimilable organic carbon in the reactor effluent. Hyphomicrobium sp. was isolated as a methylotrophic denitrifier of primary importance. The anoxic denitrifying environment apparently provides a favorable niche for a large diversity of associated bacterial strains. Hydraulic shear resulted in the constant washout of these indicator species from the reactor. Thus, the microbiological quality of the effluent is altered by the denitrifying process, and the treated water has to be further subjected to filtration and disinfection in order to guarantee the removal of residual organic carbon and prevent breakthrough of indicator organisms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.