About Us

Gordon & Rosenblatt is an independent consulting firm formed in 2009. Our Principals, Gilbert Gordon and Aaron Rosenblatt, have worked together in a series of collaborations over more than thirty years. Their complementary capabilities provide an unusually powerful resource for addressing complex, multidimensional issues involving oxyhalogens.

Our Advisors are internationally respected scientists and engineers, with deep subject-matter expertise in allied fields. They also are esteemed colleagues with whom we have enjoyed enduring relationships over the course of many years. Their profound insight adds vital color and dimension to our work.



Dr. Gordon, a co-founder of Gordon & Rosenblatt, is Distinguished Research Professor Emeritus at Miami University of Ohio, where he was the Volwiler Distinguished Research Professor of Chemistry, taught and has conducted research for more than thirty years. He is a member of important national and international committees, including the Standard Methods for the Examination of Water and Wastewater committees on Ozone, Chlorine Dioxide, and Total Oxidants.

Dr. Gordon is a trustee and past President of the International Ozone Association (IOA). He also has served as a member of the Disinfectant/Disinfection By-Products (D/DBP) Technical Advisory Workgroup for the American Water Works Association (AWWA). Dr. Gordon is the author or co-author of more than 200 scientific publications, many of which involve oxyhalogen chemistry. Dr. Gordon has received awards in recognition of his important work, including the IOA Morton J. Kleinberg Medal of Excellence (2011), the American Chemical Society, Cincinnati Section’s Chemist of the Year (1981), and the prestigious Miami University Benjamin Harrison Medallion Award for outstanding national and international contributions to education and research. Dr. Gordon is a graduate of Bradley University (BS) and Michigan State University (Ph.D.). He did postdoctoral work with Professor Henry Taube at the University of Chicago.

Selected Publications

Pisarenko, A.N., Stanford, B.D., Quinones, O., Pacey, G.E., Gordon, G., Snyder, S.A., “Rapid Analysis of Perchlorate, Chlorate, and Bromate Ions in Concentrated Sodium Hypochlorite Solutions”, Anal. Chim. Acta, 2010, 659(1-2), 216-223.

Pepich, BV; Dattilio, TA; Fair, PS ; Munch, DJ; Gordon, G; and Kortvelyesi, Z, "An improved colorimetric method for chlorine dioxide and chlorite ion in drinking water using lissamine green B and horseradish peroxidase", Analytica chimica acta, 2007, 596 (1), 37-45.

Gordon, G. and Rosenblatt, A. "Chlorine Dioxide: The Current State of the Art", Ozone Science and Engineering, 2005, 27, 203-207.

Gordon, G. "Chlorine Dioxide Generation Impurities and By-Products -- Is All Chlorine Dioxide Created Equal?" J. Am. Water Works Assoc., 93 (4), 163-173, 2001.

Gordon, G. "Environmentally Friendly Methods of Water Disinfection: The Chemistry of Alternative Disinfectants", Progress in Nuclear Energy Journal (Global Environment & Nuclear Energy Systems - 3 International Symposium), Tokyo, H. Ninokata and T. Sawada, Editors, 2000, 37, 37-41.

Fabian, I.; Gordon, G. "The Kinetics and Mechanism of the Chlorine Dioxide-Iodide Ion Reaction", Inorg. Chem., 1997, 36, 2494-2497.

Sweetin, D. L.; Sullivan, E.; Gordon, G. "The Use of Chlorophenol Red for the Selective Determination of Chlorine Dioxide in Drinking Water", Talanta, 1996, 43, 103-108.

Adam, L; Gordon, G. "The Direct and Sequential Potentiometric Analysis of Hypochlorite, Chlorite, and Chlorate Ions When Hypochlorite Ion Is Present in Large Excess", Anal. Chem., 1995, 67, 535-540.

Griese, M.H.; Kaczur, J.J.; Gordon, G. "Combining Methods for the Reduction of Oxychlorine Residuals in Drinking Water", J. Am. Water Works Assoc., 1992, 84 (11), 69-77.

Gordon, G.; Cooper, W.J.; Rice, R.G.; Pacey, G.E. Disinfectant Residual Measurement Methods, American Water Works Association - Research Foundation (ISBN 0-89867-617-7) Denver Colorado, Second Edition, 1992, 889pp.

Gordon, G. "Redox Reactions and the Analytical Chemistry of Chlorine Dioxide and Ozone", CHEMICAL OXIDATION: Technology for the Nineties, W.W. Eckenfelder, A.R. Bowers, J. Roth, Editors, 1992, 157-170.

Tachiyashiki, S.; Gordon, G. "The Kinetics and Mechanism of the Formation of Chlorate Ion from the Hypochlorous Acid - Chlorite Ion Reaction at pH 6-10", Env. Sci. and Tech., 1991, 25, 468-474.

Standard Methods for the Examination of Water and Wastewater, 17th, Ed. Published by The American Public Health Association, The American Water Works Association, and The Water Pollution Control Federation, Clesceri, L.S.; Greenberg, A.E.; Trussell, R.R., Editors, Gordon, G., Section 500. Ozone (Residual), pp 4-162 - 4-165, 1989.

Gordon, G. "Improved Methods of Analysis for Chlorate, Chlorite and Hypochlorite Ions Down to the sub-mg/L Level", U.S. Environ. Protection Agency, RES. DEV., (EMSL), NITS EPA 600/4/85/074 (PB 86-118684/AS), 1986, 36pp.

Tang, T.-F.; Gordon, G. "Stoichiometry of the Reaction between Chlorite Ion and Hypochlorous Acid at pH 5", Env. Sci. & Tech., 1984, 18, 212-216.

Gordon, G.; Kieffer, R.G.; Rosenblatt, D. "The Chemistry of Chlorine Dioxide", Prog. in Inorg. Chem., Lippard, S.J., Ed., 1972, 15, 201-286.

Kieffer, R.G.; Gordon, G. "The Disproportionation of Chlorous Acid. Part II-Kinetics", Inorg. Chem., 1968, 7, 239.

Kieffer, R.G.; Gordon, G. "Disproportionation of Chlorous Acid. Part I--Stoichiometry", Inorg. Chem., 1968, 7, 235.


Mr. Rosenblatt is a co-founder of Gordon & Rosenblatt. From 1994-2009, he was the chairman of CDG Technology, Inc. and CDG Research Corporation, companies that developed, produced, sold and serviced chlorine dioxide products. Previously, he was founder of The Scopas Technology Company, a chlorine dioxide research and development firm.

Mr. Rosenblatt is the inventor or co-inventor of more than twenty US patents, patents pending and corresponding foreign patents. He is also the author of a number of scientific and technical papers on chlorine dioxide.

Mr. Rosenblatt is a member of ASHRAE Standard Project Committee, Prevention of Legionellosis associated with Building Water Systems. He has served on the Board of the International Ozone Association-Pan American Group (IOA-PAG). He also has served as a member of the American Water Works Association (AWWA) Disinfection and Disinfectants Committees and the Microbial and Disinfection By-Product (M/DBP) Technical Advisory Workgroup (as chair of the chlorine dioxide subgroup), during regulatory negotiations for USEPA M/DBP Rule II. He is a past Trustee of the Chemists’ Club of New York and past Chairman of the Chemists’ Club Library. Mr. Rosenblatt is a graduate of The Johns Hopkins University (BA).

Selected Publications

Rosenblatt, A., Grubbs, T. and Gordon, G. Chlorine dioxide at the end of the line, Presentation at the Edwin C. Tifft Jr. Water Supply Symposium, American Water Works Association – New York Section, September 21 - 23, 2010 Verona, NY

Rosenblatt, A., Grubbs, T. and Gordon, G. “Regulatory requirements pertaining to the use of chlorine dioxide for treatment of potable water in non-transient non-community water systems”, Presentation at Association of State Drinking Water Administrators, Twenty- Fourth Annual Conference, Portland, OR October 26-28, 2009

Gordon, G. and Rosenblatt, A. "Chlorine Dioxide: The Current State of the Art", Ozone Science and Engineering, 2005, 27, 203-207.

Hoehn, Robert C.; Ellenberger, Christine S.; Gallagher, Daniel L.; Wiseman, Eurman "Toby" V., Jr.; Benninger, Robert W.; Rosenblatt, Aaron. “ClO2 and By-Product Persistence in a Drinking Water System.” In Journal AWWA, Vol. 95 Iss. 4, April 2003, pp. 141-150

W.R. Knocke, W.R., Wiseman, E.V., Benninger, R.W. and Rosenblatt, A. “Water Quality Impacts of Pure Chlorine Dioxide Pretreatment at the Roanoke County (Virginia) Water Treatment Facility” In Conference Proceedings, AWWA Annual Conference. Dallas, TX 1998

Long, B.W., Miller, R.F. and Rosenblatt, A.A. “Pilot Study: The Use of High-Purity, Chlorine-Free Chlorine Dioxide to Minimize Trihalomethane formation.” In Chemical Oxidation: Technology for the Nineties. Volume VI, 1997.

Gordon, G.; Rosenblatt, A. "Gaseous, Chlorine-Free Chlorine Dioxide for Drinking Water", CHEMICAL OXIDATION, Technology for the Nineties, W.W. Eckenfelder, A.R. Bowers, and J. Roth, Editors, Technomic Publishing Co., Lancaster, PA, 5, 1996, 250-259.

Hoehn, R., Rosenblatt, A., and Gates, D. “Considerations for Chlorine Dioxide Treatment of Drinking Water.” In Conference Proceedings, AWWA Water Quality Technology Conference,1996.




Dr. Aieta is a Partner in Carollo Engineers, PC and Director of Water Practice. Dr. Aieta works with Carollo clients to provide planning, technology and policy solutions to meet regulatory and infrastructure challenges in the areas of water, wastewater and water reuse. He has extensive experience in the areas of technology development and evaluation, strategic planning, project management, contract negotiations, quality assurance/quality control, engineering productive enhancements, financial planning, decision analysis and intellectual property.

Dr. Aieta is a member of the American Academy of Environmental Engineers. He presently serves on the Research Advisory Council of the Water Reuse Foundation.  In the past, he has served on the Research Advisory Council of the AWWA Research Foundation; on the USEPA National Drinking Water Advisory Council; and on the Board of Directors of Engineers without Borders-USA. He also is a member of a number of professional organizations, including AWWA and The Association of Metropolitan Water Agencies. Dr. Aieta graduated from University of Cincinnati (BSCE Civil Engineering), Stanford University (MS, PhD Environmental Engineering) and Harvard University (Advanced Management Program, Graduate School of Business).


Dr. Hoehn is Professor Emeritus of Environmental Engineering at Virginia Polytechnic and State University (Virginia Tech). Previously, until 1997, he was professor of Environmental Engineering at Virginia Tech for 27 years. Much of Dr. Hoehn’s scientific work has focused on chlorine dioxide for disinfection and pre-oxidation of water supplies, and on the distribution and control of chlorine dioxide by-products in finished water supplies. Dr. Hoehn has served as chairman of the AWWA Disinfection Committee and of the AWWA Water Quality Division Board of Trustees. He also served a three-year term on the Journal AWWA Editorial Advisory Board, and as a trustee (and as chairman in 1993) of the Virginia Section of AWWA.

Dr. Hoehn has served for many years on Virginia’s State Health Commissioner’s Waterworks Advisory Committee, among other state-level appointments, and has been a consultant to Black & Veatch for many years. In 1996, AWWA awarded Dr. Hoehn the prestigious A. P. Black Research Award for his significant contributions to the waterworks industry. In 2002, he received the AWWA Abel Wolman Award of Excellence, the water industry’s highest honor. Dr. Hoehn is the author of more than 100 technical papers published in journals, conference proceedings, AWWA Research Foundation publications, and book chapters. Dr. Hoehn is a graduate of North Texas State University (BS and MA) and the University of Missouri (PhD).

Dr. Jacangelo is an adjunct associate professor at the Johns Hopkins University Bloomberg School of Public Health. He also is Vice President and Director of Strategy and Research for MWH, a large environmental engineering firm.

Dr. Jacangelo has more than 25 years of experience in the field of environmental health engineering, and has specialized in the areas of water quality and treatment, water and wastewater disinfection, and public health. He has served as Principal Investigator, Technical Director, Project Manager or Engineer for over 80 water and wastewater projects. For the past 20 years, Dr. Jacangelo has focused on the use of membrane technology for treatment of drinking water supplies and for wastewater reuse. He has published over 100 technical papers and is a past recipient of the Journal AWWA Best Paper Award for water quality, and the Golden Spigot Award, AWWA Water Quality and Technology Division, 2007.

Dr. Jacangelo holds various service positions in professional organizations, including AWWA and the International Water Association (IWA). He currently is Chair of the AWWA Technical and Education Council and a member of the AWWA Board of Directors. In addition, he is Vice Chair of the Board of Directors of the WateReuse Foundation and serves on the Board of Scientific Advisors for the Institute for Public Health and Water Research. He also served three years as a Peace Corps Volunteer in the Republic of the Congo. Dr. Jacangelo is a graduate of the Johns Hopkins University (PhD).


Mr. Owen is a Vice President and Chief Technology Officer of Malcolm Pirnie-ARCADIS, a large environmental engineering firm. He is responsible for the application and distribution of technology in client solutions, for applied research throughout the firm, for outreach to the academic community in technology areas and for maintaining technology perspectives in the firm’s executive level decision-making. Mr. Owen is also responsible for the firm’s sustainability approach, integrating practices into client services and evaluating adaptation strategies for climate change.

Mr. Owen has specialized in water treatment, planning, and policy since he completed his Masters Degree in Environmental Sciences and Engineering from the University of North Carolina at Chapel Hill in 1982. He has led applied research projects on advanced technologies, consulted with utilities on treatment and facility for over 6 billion gallons per day of treatment capacity throughout the United States, and has provided technical and facilitation support to USEPA and AWWA on a range of policy issues since 1990, including drinking water regulatory development, advanced technology implementation, and utility compliance.

Mr. Owen currently serves on USEPA National Drinking Water Advisory Council, has served as a Trustee in AWWA Water Science and Research Division and as the Chair of the Editorial Advisory Board for Journal AWWA, and has published widely on water treatment and planning topics in books, peer-reviewed journals, and at national and international conferences.



Our Advisors' service is personal, and not as representatives of the entities by which they are employed. In order to avoid potential conflicts of interest, Gordon & Rosenblatt Advisors who are affiliated with consulting engineering firms do not have visibility to, and are not involved in, our work for municipal water treatment utilities.


May 1, 2012. The US Environmental Protection Agency (EPA) has published a list of contaminants  that public water systems will monitor as part of the agency’s unregulated contaminant monitoring program. The chemical contaminants listed include chlorate ion, which is associated with drinking water disinfectants chlorine dioxide and hypochlorite (bleach). 

January 23, 2012. 
 American Water Works Association (AWWA) Water Quality & Technology Division names Best Paper 2012.   Stanford, B. et al. "Perchlorate, Bromate, and Chlorate in Hypochlorite Solutions: Guidelines for Utilities" (Journal AWWA, Vol. 103, Issue 6) describes recent work to develop a predictive model for quantifying the by-product formation in hypochlorite solutions during storage.  Dr. Gilbert Gordon, a co-author of the paper, is Distinguished Research Professor (Emeritus) of Chemistry at Miami University of Ohio and a Principal of Gordon & Rosenblatt, LLC. 

September 18, 2011.  The International Ozone Association (IOA) has announced that Gilbert Gordon, a Past President of IOA, will be awarded the Morton J. Klein Medal of Excellence. The inscription on the medal reads: "An award of excellence to recognise contributions of the highest order to the International Ozone Association in commemoration of the clear vision, diplomatic proficiency, and unparalleled leadership which characterised the life of Morton J. Klein."  Dr. Gordon is Distinguished Research Professor (Emeritus) of Chemistry at Miami University of Ohio and a Principal of Gordon & Rosenblatt, LLC.