AWWA MTC53935

Reuse of water can be implemented to obtain sustainable groundwater production ina dune area of Belgium. Pilot tests proved that it is possible to reusewastewater effluent and drainage water using a combination of membranetechnologies such as pre-treatment with microfiltration (MF) followed by reverse osmosis(RO). Although the feed water for reverse osmosis had been treated withmicrofiltration, biofouling proved to be the major problem with low-energy ROmembranes. As biofouling has an important impact on the economics of the process,experiments were conducted to prevent biofouling on RO membranes. Chloraminationof the wastewater effluent was tested for 16 months and proved capable tocontrolling biofouling. In an additional trial on wastewater effluent, theintermittent use of chloramination was investigated in order to reduce theenvironmental impact. Another experiment was conducted in which soil passage infront of membrane filtration was used. This proved to be a good way to preventbiofouling and chemical consumption could be reduced. The use of UV-disinfectionwas also tested. UV had an impact on the potential of biofouling organisms but noresidual effect is present when the water passes the RO membranes. Briefexperiments were undertaken with low-fouling membranes. This paper gives a fulldescription of all experiments including the methods, results, advantages anddisadvantages. It also provides information on RO plants that were built forindustry in the vicinity and where no precautions were taken to preventbiofouling problems. Includes 18 references, tables, figures.