Geosyntec Consultants, Inc.
Mr. Petty is a Senior Principal chemical and civil engineer in Geosyntec Consultants’ Huntington Beach office as well as a leader of Geosyntec’s nationwide process engineering group. He has over 16 years of experience in water treatment and engineering design for the built environment. As part of his process engineering and water/wastewater treatment experience, Brian has designed, implemented, and operated numerous water production, conveyance, and treatment systems. These systems range from an innovative, one-of-a-kind fixed-film bioreactor treating selenium and nutrients in urban runoff to complex Superfund groundwater extraction and treatment systems. Brian has managed numerous projects involving impaired water sources, including the design of pump-and-treat Superfund remedies with potable end uses as well as treatment plants for naturally-occurring inorganic constituents, 1,4-dioxane, heavy metals, emerging chemicals, disinfection by-products, and trace organics. Current work to advance the state of the practice for 1,4-dioxane treatment includes development of biological treatment processes to deploy a unique mixed culture that has proven success at treating a range of 1,4-dioxane concentrations.
Breakthroughs and Lessons Learned from Treating 1,4-Dioxane in a Chemically Complex Water Stream
News of 1,4-dioxane detections in drinking water, groundwater, wastewater, and surface water is becoming increasingly more common, yet the list of proven and cost-effective treatment technologies remains relatively short. The need for a larger variety of treatment options is especially pronounced when faced with treating 1,4-dioxane concentrations that are near the regulatory levels (i.e., less than 10 micrograms per liter) being developed in numerous states. Recent bench, pilot, and full-scale treatability studies performed on a chemically complex wastewater in southern California have provided comparative performance data at a range of 1,4-dioxane concentrations for several technologies including advanced oxidation, carbon adsorption, synthetic media adsorption, and biological degradation. The studies have clearly shown that the treatment technologies each have strengths and weaknesses, and those strengths and weaknesses are highly dependent on the overall quality of the liquid matrix.
The presentation will compare the results of the treatability tests and describe the unique lessons learned in treating chemically complex water which poses varying degrees of treatment challenges and interferences to each technology. In recognition of the challenges posed by 1,4-dioxane and the widespread need for polishing treatment technologies, biofilm reactor configurations are being tested at the bench scale. Findings and recommendations regarding biofilm reactor loading rates, media, and enrichment cultures will also be presented.