The Florida Institute for Phosphate Research (FIPR) awarded a research grant to New Logic Research, Inc., of Emeryville, California to study the use of its reverse osmosis membranes for treatment of acidic process water stored in large ponds known as phosphogypsum stacks. The pilot trials were recently completed at an active phosphate plant in Bartow, Fla., and the results prove the patented VSEP Vibrating Membrane Filtration System efficiently filters the wastewater, producing filtrate suitable for surface water discharge.
The typical phosphogypsum stack covers 600 ac and contains billions of gallons of very low pH wastewater made up of hazardous and even radioactive substances that cannot be discharged without treatment. Treating this volume of water with traditional methods requires very large quantities of lime and creates even larger quantities of residual sludge that also must be disposed of.
An active phosphate pond contains about 5% dissolved solids. After VSEP reverse osmosis filtration, the effluent contains less than 0.005% dissolved solids - water clean enough to meet stringent Florida Department of Environmental Protection standards for surface water discharge. And unlike traditional lime treatment, VSEP treatment does not create large volumes of sludge, which creates additional cost and handling issues.
New Logic Research CEO Greg Johnson said, "Conventional reverse osmosis membranes with pretreatment have been used for many years for seawater desalination. However, these systems have limited functionality when used for other wastewaters containing high levels of scale forming minerals. VSEP, a vibrating membrane system which employs torsional oscillation of the membrane media, is capable of filtering these difficult wastewaters as a standalone system without any pretreatment or added process complexity."