BIOLOGICAL TREATMENT OF HYPERSALINE WASTE-WATER BY A BIOFILM OF HALOPHILIC BACTERIA

Each year, billions of gallons of wastewaters containing high concentr ations of salt (>3.5% w/v) and waste organics are generated by industr y. Biological treatment of these hypersaline waste brines to remove or ganics could reduce the environmental impact and cost of waste disposa l. Unfortunately, the salinity of many waste brines makes them difficu lt to treat with conventional waste treatment cultures. This paper dem onstrates that heterotrophic, halophilic organisms can be used to remo ve phenol from a synthetic waste brine containing 15% salt. The reacto r system used in this study was a novel periodically operated biofilm reactor, the Sequencing Batch Biofilm Reactor (SBBR). The SBBR uses pe rmeable silicone tubing to supply oxygen to the reactor. A biofilm of halophiles isolated from the Great Salt Lake, Utah, ecosystem readily developed on the tubing surface and degraded waste organics. The exper imental results presented herein demonstrate that the SBBR can produce a stable, high-quality effluent despite fluctuations in influent phen ol concentration. The results of periodic track studies illustrate tha t biomass accumulation increases oxygen demand but does not significan tly improve overall reactor performance