Faculty

Dennis Clifford, Ph.D., P.E. (Emeritus)
Dr. Dennis Clifford, Ph.D., P.E. (Emeritus)
Thomas and Laura Hsu Professor
Office Location: 5815 Cheena Drive, Houston, TX, 77096-5901
Phone: 832-723-1593 | Fax:
Email: daclifford [at] uh [dot] edu

Education: 

Ph.D. Environmental Engineering, University of Michigan, 1976; Dissertation topic: Multicomponent chromatographic behavior of sulfate, nitrate, chloride, and bicarbonate during nitrate removal by ion exchange
M.S.E. Chemical Engineering, University of Michigan, 1974
M.S.E. Environmental Engineering, University of Michigan, 1973
46 credits of graduate and undergraduate courses in biochemistry, psychology, and business administration at Duquesne University, The University of Pittsburgh, and Central Michigan University, 1963 – 72
B.S. Chemical Engineering, Michigan Technological University, 1963

Professional Experience: 

2004 – Present: Professor of Environmental Engineering and Director of Environmental Engineering (EGR-10) Program, Cullen College of Engineering, University of Houston, Houston, Texas
2002 – 2004: Professor of Environmental Engineering, Department of Civil and Environmental Engineering, Cullen College of Engineering, University of Houston, Houston, Texas
2001 – 2002: Sabbatical Leave
1996 – 2001: Chairman and Professor of Environmental Engineering, Department of Civil and Environmental Engineering, Cullen College of Engineering, University of Houston, Houston, Texas
1989 – 1996: Professor of Environmental Engineering and Director of Environmental Engineering (EGR-10) Program (1994 to 1996), Cullen College of Engineering, University of Houston, Houston, Texas
1985 – 1989: Associate Professor of Environmental Engineering and Director of the Environmental Engineering (EGR-10) Program, Cullen College of Engineering, University of Houston, Houston, Texas
1985 (spring): Guest Professor, Engler-Bunte Institute, Water Chemistry Section, University of Karlsruhe, Karlsruhe, Germany
1984 (fall): Visiting Associate Professor, Rice University, Department of Environmental Science and Engineering, Houston, Texas
1982 – 1984: Associate Professor of Environmental Engineering and Director (1982) of the Environmental Engineering Program, Cullen College of Engineering, University of Houston, Houston, Texas
1976 – 1982: Assistant Professor of Environmental Engineering and Director (1978, 1980, 1981) Environmental Engineering Program, Cullen College of Engineering, University of Houston, Houston, Texas
1975 – 1976: Graduate Student Research Assistant, University of Michigan
1972 – 1975: Fellowships and Traineeships, University of Michigan
1971 – 1972: Senior Technical Associate, then Wastewater Laboratory Manager, C.W. Rice Division of NUS Corporation, Pittsburgh, Pennsylvania. Process design and development for treatment and disposal of industrial wastewaters.
1968 – 1971: Project Manager, Instrument Division of Fisher Scientific Company, Pittsburgh, Pennsylvania. Research development and design of digital and analog pH meters, pION meters and kinetic analyzers.
1963 – 1968: Special Assignments Engineer, then Instrument Engineer, Dow Chemical Company, Midland, Michigan. Research, development, design, and application engineering of analytical instruments for measurement of water and wastewater quality. Co-inventor and chief developer of the Total Oxygen Demand (TOD) analyzer.

Classes: 

CIVE 6377: Environmental Chemistry
CIVE 4333: Water and Wasterwater Treatment
CIVE 6387: Physicochemical Treatment Processes

Students Supervised: 

Divagar Lakshmanan (M.S.)

Priya Swaminathan (M.S.)

Awards & Honors: 

Consistently above-average teaching evaluations for 30 years. Named as one of the outstanding teachers in the Cullen College of Engineering during the calendar years 1980 and 1981.
Appointed to the Thomas and Laura Hsu Professorship in Engineering in the Cullen College of Engineering, Fall 2006.
Cullen College of Engineering Career Teaching Award for “excellence in teaching and service to the students of the College”, May, 2005.
2004 American Water Works Association Water Science and Research Division Best Paper Award for the paper "Arsenic Removal Using Ion Exchange with Spent Brine Recycling", published in the June, 2003 issue of J. AWWA.
Inducted into the Michigan Technological University Distinguished Academy of Chemical Engineering, Oct. 9, 2003
2003 Fluor Daniel Faculty Excellence Award, the highest award accorded to a College of Engineering faculty member for overall career excellence.
2000 University of Houston Chapter of Sigma Xi, Campus-wide Sigma Xi Faculty Research Award and Designation as a Sigma Xi Research Fellow.
Editorial Board, Elsevier Science Journal Waste Management, 1998-2001.
Editorial Board, Elsevier Science Journal Reactive and Functional Polymers, 1997-date.
1998 American Water Works Association Research Division Best Paper Award, with Co-Author Charles X. Liu, for the paper "Ion Exchange with Denitrified Brine Reuse", published in the November, 1996 issue of J. AWWA (Circulation 44,000).
1997 University of Houston Cullen College of Engineering Faculty Research Excellence Award, the top research award in the College, given annually.
Peer-Elected Chairman of 1985 Gordon Research Conference on Reactive Polymers, Ion Exchangers and Adsorbents.
1995 Faculty Research Advisor Award from American Water Works Association for First Place Doctoral Dissertation Award to Doctoral Student Charles Xiaosha Liu for "Development of a Nitrate Ion Exchange Process with Reuse of Denitrified Regenerant Brine."
North American Editor of the Elsevier Journal Reactive Polymers, Ion Exchangers, and Adsorbents, 1992 to 1997.
Chief Developer (and Co-inventor) of the Total Oxygen Demand (TOD) Analyzer — a winner of the "IR-100" Award for one of the most significant developments of 1969. (Instrument sales to date approximately $22,000,000.)
John C. Vaaler Award (CPI Magazine) — Top Honors to the TOD Analyzer, November 1970.
Best Applied Paper Award (1982), from the 4500-member South Texas Section of the American Institute of Chemical Engineers for "Multicomponent Ion Exchange Calculations for Selected Ion Separations."
Houston City Council Greenwood Award for national recognition as a UH faculty member, December 15, 1993.
Certification as Diplomate of the American Academy of Environmental Engineers in the specialty of water supply/wastewater treatment, April 18, 1989. Certificate No. 88-30023.
Invited Lecturer to Shuguang Purification Technology Institute, Wainan, Chengdu, Sichuan, China, December, 1995.
Invited Expert to "Arsenic in Drinking Water Workshop", Sponsored by AWWARF, AWWA, and ACWA, Ellicott City, MD, May 31-June 2, 1995.
Invited Expert to "National Workshop on Feasibility of Conducting Epidemiological Studies of Arsenic in Drinking Water", Research Triangle Park, NC, 1994.
Guest Editor for Special Issue of Reactive Polymers, Ion Exchangers, and Adsorbents, dedicated to founding editor Prof. Friedrich Helfferich, 1992-93.
Keynote Lecturer in Environmental Session at International Conference on Ion Exchange '95, Takamatsu, Japan; December 4-6, 1995.
Invited Lecturer in Ion Exchange, International Conference on Water Treatment, Beijing, China, Nov. 9-14, 1992 funded by the United Nations Industrial Development Organization (UNIDO).
Keynote Lecturer in Environmental Session at International Conference on Ion Exchange '91, Tokyo Institute of Technology, Tokyo Japan, October 1991.
Invited Lecturer and Guest Professor at Qinghua University, Department of Environmental Engineering and the Institute of Nuclear Energy Technology, Beijing, China, June 28 thru July 11, 1988; funded by the United Nations Industrial Development Organization (UNIDO).
Invited Lecturer for Association of Environmental Engineering Professors (AEEP) Workshop, "Metals Control and Recovery," Purdue University, May 1987.
Invited Speaker at 1987 National ACS Separation Science Award Symposium for Professor Friedrich Helfferich, April 1987, Denver, CO.
Keynote Speaker and Session Chairman, ACS I&EC Ion Exchange Symposium, August 1984, Philadelphia, PA.
Invited Speaker, NATO Advanced Study Institute on Ion Exchange, Maratea, Italy, June 1982.
Annual Award for Most Outstanding Graduate Student in Civil and Environmental Engineering, The University of Michigan, 1976.

Other Awards and Honors: 

Master’s student Archana Venkataramanan won second place in the Texas Statewide combined AWWA/WEF Student Paper Contest, 2007.
Doctoral student Bintuan Zhu won the American Chemical Society Division of Environmental Chemistry "Award of Excellence" for his paper "Virus Removal by Electrocoagulation Microfiltration", Presented at the ACS National Meeting in Boston (August, 2003).
Doctoral Student Tony Tripp won third place in the State-wide combined AWWA/WEF Student Paper Contest (April, 1997).
Doctoral student Charles X. Liu won first place in the 1995 National Doctoral Dissertation competition for American Water Works Association, 1995.
Master’s student Elaine Higgins won first place in Texas Statewide Water Pollution Control Federation Student Paper Contest, 1990.
Masters students Deepak Garg won first place in Texas Statewide Water Pollution Control Federation Student Paper Contest, 1988.

Research Interests: 

Dr. Clifford has been conducted research sponsored at $4.4 million from local, federal and international funds.

Development of Electrocoagulation-Microfiltration Systems for Water Treatment

Development of Perchlorate Ion-Exchange Processes with Biological Treatment and Reuse of Spent Brine

Systematic Comparison of Arsenic Removal by Coagulation-Filtration with Zirconium and Titanium Salts in Comparison with Ferric Salts

Novel Multifunctional MnO2/Fe2O3 Nanocomposite Media for Arsenic, Chromium, and Lead Removal from Drinking Water

High-Efficiency and Cost-Effective Zirconium- and Titanium-Based Nanocomposites for Arsenic Removal from Drinking Water

Patents: 

“Water Treatment Compositions and Methods of Making and Using”, Humin Chen, Meidong Want; T. Danny Xiao, Dennis A. Clifford, Patent Application Filed October 14, 2005.
“Method for Stabilization of Biological Cultures to Allow Biological Treatment of Brines” Deborah J. Roberts, Dennis Clifford, Xiaohua Lin, Thomas Gillogly, Lee Aldridge, Stewart Lehman, Patent Application filed 18 November 2003.
Connor, J., Clifford, D.A., and King, P., "Method of Controlling the Production of Radioactive Materials from a Subterranean Reservoir", U.S. Patent No. 5,728,302; Issue date March 17, 1993.
Connor, J., Clifford, D.A., and King, P., "Methods for the Removal of Contaminants from Subterranean Fluids", U.S. Patent No. 5,196,194; Issue date March 23, 1998.
Teal, J., Hamilton, C.E., and Clifford, D.A., “Total Oxygen Demand Analysis: Method and Apparatus”; U.S. Patent No. 3,560,156, February 2, 1971.

Presentations: 

WQA Aquatech Annual Conference, Orlando, FL, March 29, 2007, “Softening and Anion Exchange for Radium and Uranium Removal from Drinking Water.”
AWWA Annual Conference, San Antonio, TX, June 14, 2006; “Ion Exchange for the Removal of Radium and Uranium from Drinking Water Supplies.”
AWWA Annual Conference, San Antonio, TX, June 14, 2006; “The Effect of pH, Silica, Phosphate, and Vanadate on As(III)/(V) Adsorption during Coagulation with Iron, Titanium, and Zirconium Salts.”
AWWA Inorganic Contaminants Workshop, Austin, TX, Jan 29, 2006, “Comparative Study of Arsenic Removal by Coagulation-Filtration with Zirconium, Titanium, and Ferric Salts.”
USEPA Arsenic Removal from Drinking Water Workshop, Cincinnati, OH, Aug 16-18, 2005, “Overview of Arsenic Chemistry, Oxidation, Speciation and Occurrence.”
USEPA Workshop on the Design and Operation of Adsorptive Media Processes for Arsenic Removal, Cincinnati, OH, Aug 9-11, 2004, "Fundamentals of Adsorption for Arsenic Removal from Water."
USEPA Radionuclides in Drinking Water Webcast, August 4, 2004, "Fundamentals of Radium and Uranium Removal from Drinking Water Supplies."
AWWA Inorganics Contaminants Workshop, Reno, NV, Feb 1-3, 2004, "Preservation of Arsenic Species in Drinking Water."
AWWA Inorganics Contaminants Workshop, Reno, NV, Feb 1-3, 2004, "Perchlorate and Nitrate Chemistry and Treatment."
American Chemical Society Division of Environmental Chemistry, Symposium Honoring Prof. Walter J. Weber, Sept.9, 2003, National ACS Meeting, N. Y., New York, "Perchlorate, Arsenate, and Nitrate Ion Exchange Processes with Brine Reuse, ", Co-authored by A. R. Tripp, G. L. Ghurye, C. X. Liu, D. J. Roberts, and X. Lin.
New Mexico Environmental Health Conference, Albuquerque, NM, October 21-22, 2003, "An Overview of Arsenic-Removal Treatment Methods for Drinking Water".
AWWA Membrane Technology Conference, Atlanta, GA, March 5, 2003. "Virus and NOM Removal by Electrocoagulation-Microfiltration" Co-authored by B. Zhu and S. Chellam.
2002 Perchlorate Conference, Ontario, CA, October 16-18, 2002, "A Fundamental Study of Ion Exchange for Perchlorate Removal from Groundwater", Part 1 Presented by Dennis Clifford, Part 2 Presented by Co-author Anthony R. Tripp.
AWWA Inorganic Contaminants Workshop, San Diego CA, February 3-5, 2002, "Modeling Ion-Exchange Treatment of Perchlorate in Ground Water", Co-authored by A. R. Tripp.
AWWA Inorganic Contaminants Workshop, San Diego CA, February 3-5, 2002, "A New Field Speciation Method for As(V) and As(III), Co-authored by S. Karori and G. Ghurye.
AWWA Inorganic Contaminants Workshop, San Diego CA, February 3-5, 2002, "Effect of pH, Silica, and Hardness on As (V) and As (III) onto Activated alumina and Granular Ferric Hydroxide (GFH)", Co-authored by Manxue Wu.
Water Quality Technology Conference, Nashville TN, November 4-6, 2001. "Arsenic Speciation Methods", Co-authored by Ganesh Ghurye and Saqib Karori.
Water Quality Technology Conference, Nashville TN, November 4-6, 2001, "Effect of pH, Silica, and Hardness on As(V) and As(III) Adsorption onto Activated Alumina", Co-authored by Manxue Wu.
Water Quality Technology Conference, Nashville TN, November, 2001. Arsenic (III) Oxidation Methods", Co-Authored by G. Ghurye.
Water Quality Technology Conference, Nashville TN, November 4-6, 2001. "Inorganic Contaminant Chemistry and Treatment."
Water Quality Association Annual Convention, Orlando, FL, March 27-31, 2001, "Oxidation and Removal of Arsenic Species".
Water Quality Association Annual Convention, Orlando, FL, March 27-31, 2001, "Occurrence and Species of Arsenic".
AWWA Water Quality Technology Conference, Salt Lake City, UT, Nov. 5-9, 2000, "Field Separation Methods for Arsenic Species", Co-authored by G. Ghurye, and A. R. Tripp.
Water Quality Association Annual Convention, Long Beach, CA, March 21-25, 2000, "Arsenic Chemistry and Treatment Options for Drinking Water".
AWWA Inorganic Contaminants Workshop, Albuquerque, NM, Feb. 27-29, 2000, "Arsenic Speciation Methods".
AWWA Arsenic Technical Work Group Treatment Meeting, Resolve Inc. Washington, D. C., February 18-19, 1999, "Arsenic Removal Options: Activated Alumina Adsorption, Anion Exchange, and Iron Coagulation-Microfiltration".
East Valley Water District Conference on Perchlorate, March 17-18, 1999, Ontario, CA, "The Treatability of Perchlorate in Groundwater Using Ion Exchange Technology".
Third International Conference on Arsenic Exposure and Health Effects, July 12-15, 1998, San Diego, California, "Development of an Anion Exchange Process for Arsenic Removal from Water".
AWWA Inorganic Contaminants Workshop, San Antonio, TX, Feb. 22-24, 1998, "Arsenic Removal by Ion Exchange with and Without Brine Reuse".
International Conference on Arsenic Pollution of Ground Water in Bangladesh: Causes Effects and Remedies, February 1998, Dhaka, Bangladesh; "Treatment Options for Removing Arsenic from Drinking Water in Small Communities".
Gordon Research Conference on Reactive Polymers, Ion Exchangers, and Adsorbents, "Arsenic Ion Exchange with Direct Reuse of Recycle Brine", Poster by Dennis Clifford, Ganesh Ghurye, and Tony Tripp, Antirm, NH, July 20-25, 1997.
Disinfection By-Products: History, State of the Art, and Research Needs Symposium, Sponsored by UH CEE, EIH, EPA, AAEE and Texas AWWA, "Anion Exchange for Removing Disinfection By-Product Precursors," (The Symons Symposium) Book Chapter (in press) by Dennis Clifford, Philip Kim, and Paul Fu, Presentation by Dennis Clifford, March 20, 1997.
AICHE Spring 97 National Meeting, "Selenium Removal from Refinery Wastewater by Ion Exchange," Written paper by Janet F. McKinney, Andrew W. Edwards, and Dennis Clifford, Presented by Janet McKinney.
AICHE Spring 96 National Meeting, "Extraction and Recovery of Lead from Soil by Washing with Chloride Salt Solutions," Written paper by Tim Nedwed and Dennis Clifford, Presented by Tim Nedwed.
International Conference on Ion Exchange; Takamatsu, Japan, Dec. 4-6, 1995, Keynote Lecture in the Environmental Session, "Development of a Nitrate Ion Exchange process with Reuse of Biologically.
Gordon Research Conference on Reactive Polymers Ion Exchangers and Adsorbents, July 24-27, 1995; "Development of a Nitrate Ion Exchange Process with Reuse of Biologically Denitrified Brine," Poster with Dr. C. X. Liu.
American Water Works Association National Meeting, June, 1995, Anaheim, CA, "A review of Processes for Removing Nitrate from Drinking Water."
Water Quality Association National Meeting, March 1995, Nashville, TN "Ion Exchange Applications for Nitrate, Arsenic, Uranium and Sulfate Removal."
University of Kansas Annual Environmental Engineering Conference, February 1, 1995, Lawrence KS, "Ion Exchange, Activated Alumina, and Membrane Processes for Arsenic Removal from Water."
Gulf Coast Hazardous Substance Research Center Annual SAC/IAC Meeting, January 9-12, 1995, "Concentrated Halide Extraction and Recovery of Lead from Soil."
Gulf Coast Hazardous Substance Research Center Annual SAC/IAC Meeting, January 9-12, 1995, "Integrated Process Treatment Train for Remediation of Texas Soils Contaminated with Hazardous Wastes," Joint Presentation (Phosphate Stabilization of Lead) with PI, C. Vipulanandan, and Co-PI, D. J. Roberts.
American Water Works Association Arsenic in Drinking Water Seminar, New York, NY, June, 1994, "Arsenic Chemistry in Relation to Removal Methods."
American Water Works Association Water Quality Technology Conference, Miami, Florida, November, 1993, "Arsenic Chemistry and Speciation."
American Water Works Association Water Quality Technology Conference, Miami, Florida, November, 1993, "Alumina, Resins, and Membranes for Removing Arsenic from Water."
Gordon Research Conference on Reactive Polymers, Ion Exchangers, and Adsorbents, August, 1993, Newport, RI, "Uranium Removal from Ground Water by Anion Exchange and Electrodialysis." Poster with Zhihe Zhang.
Gulf Coast Hazardous Substance Research Center Annual Conference, Beaumont, Texas, February 1993, "Volatilizing Toxic Metals from Soil".
American Water Works Association Water Quality Technology Conference, Toronto, Canada, November, 1992, "Simultaneous Measurement of 226Ra and 228Ra in Water by Gamma-Ray Counting after Preconcentration on Ion Exchange Resin."
American Chemical Society National Meeting, April, 1992, San Francisco, CA, "Anion Exchange Studies of Lead-EDTA Complexes."
Gulf Coast Hazardous Substance Research Center Annual Conference, Beaumont, Texas, April 1992 "Use of Ammonia and Ammonium Salts to Extract Lead and Other Toxic Metals from Soil," Poster with Tim Nedwed.
Gulf Coast Hazardous Substance Research Center Annual Conference, Beaumont, Texas, April 1992, "Inert Atmosphere Volatilization of Toxic Metals from Soil," Poster with Shen-Sin Chen and Carmen Reznik.
Gordon Research Conference on Reactive Polymers, Ion Exchangers, and Adsorbents, August 1991, Newport, RI, "Combined Radium and Uranium Removal in Water Softeners with Anion Resin Added", Poster with Zhihe Zhang.
Hazardous Materials Control Research Institute—South'91 Meeting, Houston, Texas, April 1991, "Removal of Lead from Soil by Volatilization in Hydrogen, Nitrogen, and Air".
Hazardous Materials Control Research Institute—South'91 Meeting, Houston, Texas, April, 1991, "Feasibility of Extracting Toxic Metals from Soil Using Anhydrous Ammonia."
Gulf Coast Hazardous Substance Research Center Annual Conference, February 1991, "Feasibility of Extracting Lead, Copper, Cadmium, Mercury, and Zinc from Soil Using Anhydrous Ammonia," Poster with Ming Yang.
Gulf Coast Hazardous Substance Research Center Annual Conference, February 1991, "Removal of Lead from Soil by Volatilization in Hydrogen, Nitrogen, and Air," Poster with Shen-Sin Chen.
Gulf Coast Hazardous Substance Research Center Annual Conference, February 1990, "Removal of Lead from Soil by Volatilization in Hydrogen," Poster with Shen-Sin Chen.
Gordon Research Conference on Reactive Polymers Ion Exchangers and Adsorbents, August 1989, Newport, RI, "Unique Characteristics of Radium Ion Exchange", Poster with Dr. S. Subramonian and W. Vijjeswarapu.
Water Quality Association National Meeting, March, 1989, Atlanta GA, "Radium Removal from Water Using Softeners and Point-of-Use Devices."
U. S. EPA and Texas AWWA Seminar on Emerging Technologies for Drinking Water Treatment, Arlington, TX, Feb. 7-8, 1989, "State-of-the Art for Removing Inorganic Contaminants."
Gordon Research Conference on Reactive Polymers Ion Exchangers and Adsorbents, August 3-7, 1987, Newport, RI, "Selectivity of a Series of Dicarboxylic Acids for anion Resins of Differing Functionalities," Poster with Dr. S. Subramonian.
American Water Works Association National Meeting, June 1987, Kansas City, MO, "Removing Radium from Drinking Water Using Ion Exchange, Membrane and Specific Adsorbents."
American Chemical Society 193rd National Meeting, April 1987, Denver, Colorado, "Multicomponent Chromatography Theory Applied to Fixed-Bed Anion Exchange."
International Symposium on Metals Speciation and Recovery, Chicago, IL, August 1986, Discussion of "Synthesis of Dual Mechanism Ion Exchange/Redox Resins and Ion Exchange/Coordinating Resins with Applications to Metal Ion Separations."
Third Biannual Conference on Progress in Chemical Disinfection—CD III, SUNY Binghamton, NY, April 1986, "Synergistic, Heat and Salt Disinfection of Ion Exchangers."
Water Quality Association, Fourth Point-of-Use Treatment Symposium, December 1985, Chicago, IL, "Point of Use Treatment of Inorganics."
American Chemical Society 188th National Meeting, August 1984, Philadelphia, PA, "State of the Art in Modeling Ion Exchange Kinetics and Multicomponent Chromatography."
American Chemical Society, 188th National Meeting, August 1984, Philadelphia, PA, "Chloride-Form Anion Exchange for the Removal of Chromate, Arsenate and Nitrate from Drinking Water."
American Water Works Association, XI Annual Water Quality Technology Conference, December 1983, Norfolk, VA, "The Separation of As (III) and As (V) by Ion Exchange."
Gordon Research Conference on Ion Exchange, July 1983, Plymouth, New Hampshire, "The Ion Exchange Behavior of Hydrolyzable Anions—Carbonate, Arsenate, and Chromate."
American Society of Civil Engineers, 1983 National Conference on Environmental Engineering, July 1983, Boulder, Colorado, "Ion Exchange and Membrane Processes for Nitrate Removal from Water."
American Institute of Chemical Engineers National Meeting, August 1982, Cleveland, Ohio, "Adsorption Enhancement Due to Thermal Regeneration of PAC."
NATO Advanced Study Institute: Mass Transfer and Kinetics of Ion Exchange, Maratea, Italy, June 1982, "Advances in Ion Exchange for Nitrate Removal."
American Water Works Association National Meeting, May 1982, Miami Beach, Florida, "Transportable Research Facilities for Water Treatment and Analysis."
Environmental Protection Agency Seminar on Small Water Systems, April 1982, Cincinnati, Ohio, "Inorganic Removal Studies with a Mobile Pilot Plant."
American Institute of Chemical Engineers National Meeting, November 1981, New Orleans, LA, "Thermal Regeneration of Powdered Activated Carbon (PAC) and PAC-Biological Sludge Mixtures."
American Society of Civil Engineers, 1980 National Conference on Environmental Engineering, New York, NY, "Fluoride, Arsenic, Selenium, and Nitrate Removal from Small Community Water Supplies."
Gordon Research Conference on Ion Exchange, August 1981, Meriden, NH, "Multicomponent Ion Exchange Calculations for Selected Ion Separations," Poster Presentation.
Gordon Research Conference on Ion Exchange, August 1979, Meriden, NH, "Selectivity in Anion Resins."
Third Annual Conference on New Advances in Liquid/Solid Separation Technology, October 1977, Cherry Hill, NJ, "Selectivity Considerations in Anion Exchange Resins."
American Water Works Association, 1977 Annual Meeting, Los Angeles, CA, "Nitrate Removal from Water Supplies by Ion Exchange."
National Conference on Treatment and Disposal of Wastewater and Residues, April 1977, Houston, TX, "A Nitrate Removal Process with a Land-Disposable Regenerant."
23rd Purdue Industrial Waste Conference, May 1968, Lafayette, IN, "Automatic Measurement of Total Oxygen Demand."

Invited Presentations / Lectures: 

University of Houston Challenge of Civil Engineering Seminar-CIVE 1188, Houston, TX, “Water Treatment”, October 30, 2006.

Texas AWWA SE Texas Section Mtg, “Arsenic Chemistry and Removal From Drinking Water”, Houston , TX, April 27, 2006.

Buraydah, Saudi Arabia, Ministry of Power and Water Seminar, “Radium Removal from Ground Water by Ex-Situ and In-Situ Treatment Methods”, May 24, 2005.

University of Houston Challenge of Civil Engineering Seminar-CIVE 1188, Houston, TX, “Water Treatment”, November 15, 2004.

USEPA Radionuclides in Drinking Water Webcast, “Fundamentals of Radium and Uranium Removal from Drinking Water Supplies”, August 4, 2004.

Tsinghua University Institute of New and Nuclear Energy Technology, Beijing, China, Series of Three Invited Lectures: (1) "Development of Inorganic Contaminant Removal Processes: Review of Research on Fluoride and Arsenic", (2) "Review of Research and Development on Nitrate Treatment Processes", (3) "Virus and NOM Removal by Electro-coagulation-Microfiltration Compared with Chemical Coagulation Microfiltration", May 20-25, 2004.

UH Civil and Environmental Engineering Annual Banquet, Houston, TX, "A Tribute to Dr. Michael W. O'Neill, P.E., Cullen Distinguished Professor of Civil Engineering-Teacher, Researcher, Servant, and Friend, 1940-2003", April 29, 2004.

Environmental and Energy Systems Institute of Rice University, France-Texas Water Treatment Research Congress, Houston, TX, Removal of Perchlorate, Nitrate, and Arsenate from Ground Water Using Ion-Exchange Technology, January 12, 2004.

University of Houston Challenge of Civil Engineering Seminar-CIVE 1188, Houston, TX, "Water Treatment", November 3, 2003.

University of Houston Environmental Engineering Seminar Series, Houston, TX, "Seminar on Seminars", September 10, 2002.

Water Environment Federation of Texas, Houston, TX, Gloyna Breakfast Address, "The Problem of Arsenic in Water", April 6, 2001.

2000 Sigma Xi Faculty Research Award Lecture, University of Houston, Houston, TX, Arsenic in Drinking Water: Occurrence, Health Effects, Chemistry, and Treatment, February 27, 2001.

Sixteenth Annual Gulf Coast Environmental Management Symposium, Houston, Texas, "Arsenic and Perchlorate Removal Techniques", February 10, 2000.

Rice University, Houston Texas, Department of Environmental Sciences and Engineering, "The Bangladesh Arsenic Crisis: Some Treatment Options for Ground Water", February 23, 1999.

University of Houston, Spring-98 Environmental Engineering Seminar Series, "Treatment Options for Removing Arsenic from Drinking Water in Bangladesh", January 22, 1998.

U.S. Environmental Protection Agency, Water Supply and Water Resources Division, Cincinnati, OH, "Arsenic Removal from Water by Ion Exchange and Coagulation Microfiltration, November 14, 1996.

City of Houston Department of Public Works and Engineering Seminar Series; January, 1996; "An Historical Look at BOD5/TOC, BOD5/TOD and COD/TOD Correlation's."

The Environmental Institute of Houston, "The University of Houston Environmental Engineering Program," Nov. 15, 1995.

City of Houston Wastewater Division, Houston, Texas, "Arsenic Chemistry and Speciation," September 12, 1994.

Case Western Reserve University, Department of Civil Engineering, Cleveland, Ohio, "Combined Uranium and Radium Removal from Groundwater by Ion Exchange," October 29, 1992.

Texas Joint Interim Committee on Waste, Beaumont, Texas, "Feasibility of Removing Lead and Other Toxic Metals from Contaminated Soil by Volatilization in Nitrogen", April 30, 1992.

University of Houston Department of Chemical Engineering, "Development, Proof, and Usefulness of the Charge Separation Concept in Anion Exchange", April 10, 1992.

University of Houston Environmental Engineering Program, "Adsorption, Ion Exchange, and Thermal Processes for Water and Soil Treatment", March 12, 1992.

U.S. EPA Drinking Water Research Division, Cincinnati, OH, April 26, 1990, "Ten Years of Research with the UH/EPA Mobile Drinking Water Treatment Facility."

Conference on Business Society and Environmental Crises: Who and What Will the Public Believe? University of Houston Institute for Business, Ethics and Public Issues, March 28, 1990, "Truth, Research, and the Media."

Texas Senate Hearing on Naturally Occurring Radioactive Materials (NORM), Houston, Texas, January 25, 1990, "Radioactive Wastes Associated with Drinking Water Treatment."

Fourth Annual Groundwater Protection Seminar, Austin, Texas, October 10-11, 1989, "Occurrence and Removal of Radium and Radon in Groundwater."

Rice University, Department of Environmental Sciences and Engineering, Houston, Texas, October 3, 1989, "Radium and Uranium Removal from Water Using Ion Exchange."

U.S. EPA Drinking Water Research Division, Cincinnati, OH, May 20, 1988, "Explanation and Use of the University of Houston Multicomponent Chromatography Program Developed for the Apple Macintosh Computer."

The University of Cincinnati Department of Chemical and Nuclear Engineering, May 19, 1988, Cincinnati, Ohio, "Multicomponent Chromatography Theory Applied to Fixed-Bed Anion Exchange."

U. S. EPA and Illinois Section of AWWA, Chicago, IL, April 21, 1988 "Results of the Radium Removal Pilot Studies in Lemont, Illinois."

Illinois Institute of Technology, Department of Environmental Engineering, March 8, 1988, "Radium Removal Using Ion Exchange, Membranes and Sorbents."

Water Quality Association Mid-Year Leadership Conference, Sept. 20, 1987, Charleston, S. C. "Radon and Radium Removal from Drinking Water."

EPA Region V Seminar on Radium Removal, Lemont, IL, April 30, 1987, "Radium Removal Studies Using a Mobile Pilot Plant."

Purdue University School of Chemical Engineering, March 18, 1987, "Ion Exchange for Water and Wastewater Treatment."

Texas Water Quality Association Annual Meeting, Galveston, TX, June 29, 1986, "Point of Use Treatment of Inorganics," and "Occurrence and Removal of Radionuclides from Water."

Alcoa Technical Center, New Kensington, Pennsylvania, November 15, 1985, "Design and Execution of Mobile Water Treatment Research."

University of Houston ASCE Student Chapter, February 26, 1986, "European Drinking Water Treatment Practices."

University of Houston, Environmental Engineering Program, October 31, 1985, "European Water Treatment Practices."

Gulf Coast Instrument Analysis Group 79th Meeting, Houston, Texas, September 26, 1985, "Ion Chromatography of Polyprotic Anions."

Center for Research OTV, Water Research Division, Maisons-Lafitte, France, June 14, 1985, "Removal of Nitrate, Arsenate, Fluoride and Selenate from Water Supplies by Adsorption and Ion Exchange."

Institute of Chemical Technology, Department of Power Engineering, Prague, Czechoslovakia, May 30, 1985, "The Structure of Ion Exchange Polymers as It Influences Anion Selectivity."

Bayer, A. G., Ion Exchange Research Center, Leverkusen, Germany, May 28, 1985, "An Overview of Multicomponent Ion Exchange and Modeling."

Institute for Radiation Protection GSF, Munich, Germany, May 10, 1985, "Charge Separation Distance in Ion Exchange Polymers Used for Nitrate, Arsenate and Chromate Removal."

University of Paderborn, Paderborn, Germany, Department of Applied Chemistry, March 21, 1985, "The Structure of Ion Exchange Polymers as It Influences Their Selectivity."

Karlsruhe Nuclear Research Center, Water Technology Division, Karlsruhe, Germany, February 12, 1985, "Adsorption and Ion Exchange for the Removal of Fluoride and Arsenic from Water."

University of Karlsruhe, Department of Water Chemistry, Karlsruhe, Germany, January 30, 1985, "An Overview of Multicomponent Ion Exchange and Adsorption Research at the University of Houston."

University of Houston Environmental Engineering Program, September 13, 1984, "Ion Exchange for Drinking Water Treatment."

Rice University, Department of Environmental Science and Engineering, November 15, 1983, "Ion Exchange of Polyprotic Acid Anions."

Environmental Protection Agency, Drinking Water Research Division, March 1983, Cincinnati, Ohio, "Fundamentals of Ion Exchange" and "Selective Ion Exchange for Single Contaminant Removal."

University of Houston Sunday Evening Club, Houston, Texas, November 19, 1982, "Drinking Water Quality in the United States."

Texas Filtration Society and University of Houston Environmental Engineering Program, Houston, Texas, December 2, 1981, "Effects of Surface Functional Groups on Filtration and Ion Migration in Packed Beds."

Michigan Technological University Chemical Engineering Department, Houghton, Michigan, October 10, 1980, "Multicomponent Ion Exchange Calculations."

Environmental Protection Agency Drinking Water Research Division, Cincinnati, OH, July 7, 1980, "Removal of Inorganic Anions from High TDS Waters Using Packed Beds and Membrane Processes."

Environmental Protection Agency Drinking Water Research Division, Cincinnati, OH, July 8, 1980, "PAC Adsorption and Regeneration in Water Treatment."

Rice University, Department of Environmental Science and Engineering, Houston, TX, October 25, 1979, "Biochemical Oxygen Demand and Total Organic Carbon Analyses Correlated and Uncorrelated."

University of Houston One-Day Seminar on Instrumentation and Computer Control for Wastewater Treatment Processes and Laboratories, Houston, TX, October 19, 1978, "BOD/TOC Correlations: A Historical Perspective."

Diamond Shamrock Chemical Company Ion Exchange Resin Divisions, Redwood City, CA, August 24, 1978, "Resin Properties Which Determine Divalent Selectivity in Anion Resins."

University of Houston Environmental Engineering Program, Houston, TX, December 8, 1977, "BOD, COD, TOC, and TOD Correlations and Non-Correlations."

Rice University, Department of Environmental Science and Engineering, Houston, TX, April 14, 1977, "How Matrix and Functionality Affect Divalent/Monovalent Ion Exchange."

Peer-Reviewed Journal Articles: 

Lakshmanan, D, D. A. Clifford, and G. Samanta, “Arsenic Removal by Coagulation with Aluminum, Iron, Titanium, and Zirconium”, Accepted for publication in Journal American Water Works Association, July 3, 2007.

Liu, X, D. J. Roberts, T. Hiremath, D. A. Clifford, T. Gilloghly, S. Lehman, “Divalent Cation Addition (Ca2+ or Mg2+) Stabilizes Biological Treatment of Perchlorate and Nitrate in Ion Exchange Brine”, Environmental Engineering Science, 24 (6), pp 1-11, 2007.

Samanta, G, and D. A. Clifford, “Influence of Sulfide on Preservation and Speciation of Inorganic Arsenic in Drinking Water", Chemosphere, V 65, pp 847-853, 2006.

Karori, S, D.A. Clifford, G. Ghurye, and G. Samanta, “Development of Field Speciation Method for Inorganic Arsenic Species in Groundwater” Journal American Water Works Association, 98:5, pp 128-41, May, 2006.

Tripp, A. R., and D. A. Clifford, “Ion Exchange for the Remediation of Perchlorate in Drinking Water”, Journal American Water Works Association, 98 (4), pp 105-114 April, 2006.

Samanta, G, and D.A. Clifford, “Preservation and Speciation of Inorganic Arsenic Species in Groundwater, Water Quality Research Journal of Canada, Vol. 7, No. 2, pp 107-116, July, 2006.

Hiremath, T., D. J. Roberts, X. Lin, D.A. Clifford, T. Gillogly and G. Lehman, “Biological Treatment of Perchlorate in Spent ISEP Ion-Exchange Brine”, Environmental Engineering Science, V. 23, No. 6, 109-1016; 2006.

Zhu, B., D. A. Clifford, and S. Chellam, “Electrocoagulation Microfiltration Compared with Chemical Coagulation Microfiltration for Virus Removal”, Water Research, V. 30, No. 13, pp 3098-3108, July, 2005.

Samanta, G, and D.A. Clifford, “Preservation of Inorganic Species in Groundwater”, Environmental Science and Technology, V 39 pp 8877-82, Oct 2005.

Zhu, B., D. A. Clifford, and S. Chellam, “Virus Removal by Iron Coagulation-Microfiltration”, Water Research, v. 39, pp. 5153-61, Oct. 2005.

Zhu, B., D. A. Clifford, and S. Chellam, "Electrocoagulation Microfiltration Compared with Chemical Coagulation Microfiltration for Virus Removal", Submitted to Water Research, Dec 8, 2004.

Lin, X, D. J. Roberts, T. Hiremath, D. A. Clifford, T. Gillogly, G. Lehman, "Divalent Cation Addition (Ca2+ or Mg2+) Stabilizes Biological Treatment of Perchlorate and Nitrate in Ion Exchange Spent Brine", In preparation for Journal American Water Works Association, October 2004.

Tripp, A. R., and D. A. Clifford, "Ion Exchange for the Remediation of Perchlorate in Drinking Water", Sumbitted to Journal American Water Works Association, Sept. 2, 2004.

Zhu, B., D. A. Clifford, and S. Chellam, "Virus Removal by Iron Coagulation-Microfiltration", In Revision for Water Research, October 28, 2004.

Cang. Y., D. J. Roberts and D. A. Clifford, "Development of Cultures Capable of Reducing Perchlorate and Nitrate in High Salt Solutions", Water Research, v. 38 No. 14-15, pp 3322-3330, August, 2004.

Xu, W., S. Chellam, and D. A. Clifford, "Indirect Evidence for Deposit Rearrangement during Dead-End Microfiltration of Iron-Coagulated Suspensions" Journal of Membrane Science, V. 239, No.2, pp 243-254, August, 2004.

Ghurye, G., D. A. Clifford, A. R. Tripp, "Pilot Study of Coagulation Microfiltration for Arsenic Removal from Groundwater" J. Amer. Water Works Assoc. V. 96, No. 4, pp 143-152, April, 2004.

Ghurye, G. and D. A. Clifford, "Arsenic III Oxidation Using Chemical and Solid-Phase Oxidants", J. Amer. Water Works Assoc., V. 96, No. 1, pp 84-96, Jan., 2004.

Clifford, D.A., G. Ghurye, and A. R. Tripp, "Arsenic Removal from Drinking Water Using Ion-Exchange with Spent Brine Recycling", J. Amer. Water Works Assoc., pp 119-130, V. 35, No. 6, June, 2003. This paper won the 2004 AWWA Water Science and Research Division Best Paper Award.

Chellam, S., and D. A. Clifford, "Physical-Chemical Treatment of Groundwater Contaminated by Leachate from Surface Disposal of Uranium Tailings", ASCE Journal of Environmental Engineering, pp. 942-52, Oct., 2002.

Nedwed, T., and D. A. Clifford, "Feasibility of Extracting Lead from Lead Battery Recycling Soil Using High-Concentration Chloride Solutions", J. Environmental Progress, V. 19, No. 3, pp.197-206, Fall 2000.

Ghurye, G. L., D. A. Clifford, and A. R. Tripp, "Combined Arsenic and Nitrate Removal by Ion Exchange", J. Amer. Water Works Assoc., V. 91, No. 10, pp. 85-96, Oct., 1999.

Chen, H-W, M. Frey, D. A. Clifford, L, McNeill, and M. Edwards, "Arsenic Treatment Considerations: Raw Water Quality, Cost, and Residual Handling", J. Amer. Water Works Assoc., V. 91, No. 2, pp. 74-85, Feb, 1999.

Nedwed, T., and D. A. Clifford, "A Survey of Lead Battery Recycling Sites and Soil Remediation Processes," J. Waste Management, Vol. 17, No. 4, pp. 257-269, 1998.

Horng, L. L., and D. A. Clifford, "The Behavior of Polyprotic Anions in Ion-Exchange Resins," J. Reactive and Functional Polymers, Vol. 35, No. 1/2, pp 41-54, December, 1997.

Liu, C. X., and D. A. Clifford, "Ion Exchange with Denitrified Brine Reuse," J. Amer. Water Works Assoc., Vol. 88, pp. 88-99, November, 1996.

Connor, J., and D. A. Clifford, "NORM Waste Minimization using In-Situ Treatment Method", Fluid Particle Separation Journal, V. 7, No. 3, pp 118-123, September, 1994.

Clifford, D. A., and Z. Zhang, "Combined Uranium and Radium Removal by Ion Exchange", J. Amer. Water Works Assoc., Vol. 86, No. 4, pp. 214-227 April, 1994.

Z. Zhang, and D. A. Clifford, "Exhaustion and Regeneration of Resins for Uranium Removal", J. Amer. Water Works Assoc., Vol. 86, No. 4, pp. 228-241, April, 1994.

Clifford, D. A., M. Yang, and T. Nedwed, "Feasibility of Extracting Toxic Metals from Soil Using Anhydrous Ammonia," Waste Management, Vol. 13, No. 3, pp 207-219, 1993.

Clifford, D. A., S. Chen, C. Reznik, "Volatilizing Toxic Metals from Soil", Waste Management, V. 13, pp 467-479, 1993.

Clifford, D. A., and X. Liu, "Biological Denitrification of Spent Regenerant Brine Using a Sequencing Batch Reactor", Water Research, Vol 27, No. 9, pp 1477-84, 1993.

Clifford, D. A., and X. Liu, "Nitrate Removal Using Ion Exchange with Batch Denitrification of Spent Regenerant Brine, J. Amer. Water Works Assoc., V 85, No. 4, pp. 135-143, April, 1993.

Clifford, D.A. and E. A. Higgins, "Measurement of 226Ra and 228Ra in Water by Gamma-Ray Counting after Preconcentration on Ion-Exchange Resin," Health Physics, V. 62, No. 5, p. 413-421, May, 1992.

Dudzinska, M., and D. A. Clifford, "Anion Exchange Studies of Lead-EDTA Complexes," Reactive Polymers, V 16, p 71-80, Dec. 1991.

Subramonian, S., Clifford, D. A., and W. Vijjeswarapu, "Evaluating Ion Exchange for the Removal of Radium from Groundwater," AWWA Journal, pp 61-70, May, 1990.

Subramonian, S. and D. A. Clifford, "Aqueous-Phase Ion Solvation and the Selectivity of Ion Exchange Resins for Monovalent Anions," Journal of Solution Chemistry, V. 18, No. 6, p. 529-43, 1989.

Clifford, D. A., W. Vijjeswarapu, and S. Subramonian; "Evaluating Various Adsorbents and Membranes for Removing Radium from Groundwater," AWWA Journal, pp 94-104, July, 1988.

Woodring, S. L. and D. A. Clifford, "A Comparison of the Graphical and Standard Methods for the Determination of Biochemical Oxygen Demand (BOD)," WPCF Journal, pp. 537-42, April, 1988.

Subramonian, S. and D. A. Clifford, "Monovalent/Divalent Selectivity and the Charge Separation Concept," Reactive Polymers, V. 9, p. 195-209, 1988.

Sengupta, A. K., S. Subramonian, and D. A. Clifford, "More on the Mechanism and Some Important Properties of Chromate Ion Exchange," Journal of Environmental Engineering, V.114, pp 137-153, Feb. 1988.

Werner, P., D. A. Clifford and G. Strauss, "A New Disinfection Method for Cation Exchange Resin," Vom Wasser, V. 68, pp. 191-97, 1987.

Clifford, D. A., T. J. Sorg, and S. Subramonian, "Removing Dissolved Inorganic Contaminants from Water," Enviro. Sci. & Tech., feature article, V. 20, No. 11, pp. 1072-80, 1986.

Sengupta, A. K. and D. A. Clifford, "Chromate Ion Exchange Process at Alkaline pH," Water Research, V. 20, No. 9, pp. 1177-84, 1986.

Sengupta, A. K. and D. A. Clifford, "Chromate Ion-Exchange Mechanism for Cooling Water," Ind. & Eng. Chem. Fundam., V. 25, No. 2, pp. 249-58, 1986.

Sengupta, A. K. and D. A. Clifford, "Some Unique Characteristics of Chromate Ion Exchange, Reactive Polymers, Holland, V. 4, pp. 113-30, 1986.

Sengupta, A. K. and D. A. Clifford, "Important Process Variables in Chromate Ion Exchange," Environ. Sci. & Tech., V. 20, No. 2, pp. 149-55, 1986.

Clifford, D. A. and W. J. Weber, Jr., "The Determinants of Divalent/Monovalent Selectivity in Anion Exchangers," Reactive Polymers, 77-89, 1983.

Clifford, D. A. and P. Chu, "Thermal Regeneration of Powdered Activated Carbon (PAC) and PAC-Biological Sludge Mixtures," Water Research, 17, pp. 1125-38, 1983.

Clifford, D. A. and L. M. McGaughey, "The Simultaneous Determination of Total Nitrogen (TN) and Total Oxygen Demand (TOD) in Aqueous Samples," Analytical Chemistry, 54, 1345-50, July 1982.

Clifford, D. A., "Multicomponent Ion Exchange Calculations for Selected Ion Separations," Industrial and Engineering Chemistry-Fundamentals, 21, pp. 141-53, May 1982.

Books / Book Chapters: 

Tripp, A. R., and D. A. Clifford, "Selectivity Considerations in Modeling the Treatment of Perchlorate Using Ion Exchange Processes", Chapter 5 in Ion Exchange and Solvent Extraction Volume 16, Edited by A. K. SenGupta and Yizhak Markus, Marcel Dekker Inc., pp. 267-338, April 2004.
Clifford, D. A., and G. Ghurye, "Metal Oxide Adsorption, Ion Exchange, and Coagulation-Microfiltration for Arsenic Removal from Water", Chapter 9 in Environmental Chemistry of Arsenic, Edited by W. T. Frankenberger, Marcel-Dekker, Inc., 35 pp., January, 2002.
Clifford, D. A., P. H-S. Kim, and P. Fu, "Anion Exchange for the Removal of TOC and DBP Precursors", Chapter 17 in Disinfection By-Products: History, State of the Art, pp. 351-369, Edited by P. Singer, American Water Works Association, Denver, CO, American Water Works Association, 1999.
Clifford, D. A., "Ion Exchange and Inorganic Adsorption," Chapter Nine in Water Quality and Treatment Fifth Edition, pp. 9.1-9.91, Ray Lettermam, ed., McGraw Hill, Inc., New York, 1999.
Clifford, D. A., and Z. Zhang, "Removing Uranium and Radium from Ground Water by Ion Exchange Resins," in Ion Exchange Technology: Recent Advances in Pollution Control, Arup K. Sengupta, ed., pp. 1-59, Technomic Publishing Co., Lancaster, PA, 1995.
Clifford, D. A., "Ion Exchange and Inorganic Adsorption," Chapter Nine in Water Quality and Treatment, Fred Pontius, ed. 4th Ed., pp. 561-639, McGraw Hill, June, 1990.
Clifford, D. A., "Removal of Radium From Drinking Water," Chapter 16 in Radon, Uranium and Radium in Drinking Water, pp. 225-247, Lewis Publishers, Chelsea, MI, June, 1990.
Clifford, D. A., L. L. Horng, and C. C. Lin, "Salt Conservation, Selectivity Reversal, and Breakthrough Detection in Ion Exchange Nitrate Removal," in Fundamentals and Applications of Ion Exchange, L. Liberti and J. Millar eds., pp. 102-16, Martinus Nijhoff Publ., Dordrecht, Netherlands, 1985.

Conference Proceedings / Technical Papers Published in Refereed Conference Proceedings: 

Clifford, D. A., “Ion Exchange for the Removal of Radium and Uranium from Drinking Water Supplies” AWWA Annual Conference, San Antonio, TX, June 14, 2006.
Lakshmanan, D., D. A. Clifford, and G. Samanta “The Effect of pH, Silica, Phosphate, and Vanadate on As(III)/(V) Adsorption during Coagulation with Iron, Titanium, and Zirconium Salts” AWWA Annual Conference, San Antonio, TX, June 14, 2006.
Lakshmanan, D., D. A. Clifford, and G. Samanta, “Comparative Study of Arsenic Removal by Coagulation-Filtration with Zirconium, Titanium, and Ferric Salts” AWWA Inorganic Contaminants Workshop, Austin, TX, Jan 29, 2006.
Samanta, G., and D. A. Clifford, “Influence of Sulfide on Preservation and Speciation of Inorganic Arsenic in Drinking Water”, AWWA Inorganic Contaminants Workshop, Austin, TX, Jan 29, 2006.
Clifford, D. A. “Overview of Arsenic Chemistry, Oxidation, Speciation, and Occurrence”, USEPA Arsenic Removal from Drinking Water Workshop, August, 2005, Cincinnati, OH.
Roberts, D. J., T. Hiremat, and D. A. Clifford, “Biological Treatment of ISEPTM Brine Contaminated with Perchlorate and Nitrate”, Proceedings of the 2005 AWWA Annual Conference, June, 2005, San Francisco, CA.
Ghurye, G. G., and D. A. Clifford, “Selectivity Considerations During Arsenic Removal Using Anion Exchange”, Proceedings of the 2005 AWWA Annual Conference, June, 2005, San Francisco, CA.
Ghurye, G. G., and D. A. Clifford, “Water Quality Considerations for Arsenic Removal from Groundwaters Using Adsorption Processes”, East Valley Water District-AWWA 2004 Water Quality Conference, Ontario, CA, Oct 27-29, 2004.
Clifford, D.A. “Fundamentals of Adsorption for Arsenic Removal from Water”, USEPA Workshop on the Design and Operation of Adsorption Media Processes for Arsenic Removal, August, 2004, Cincinnati, OH.
Clifford, D. A., and G. Samanta, "Preservation of Arsenic Species in Drinking Water", AWWA Inorganics Contaminants Workshop, Reno, NV, Feb 1-3, 2004.
Clifford, D. A., A. R. Tripp, and D. J. Roberts "Perchlorate and Nitrate Chemistry and Treatment" AWWA Inorganics Contaminants Workshop, Reno, NV, Feb 1-3, 2004.
Clifford, D. A., A. R. Tripp, G. L. Ghurye, C. X. Liu, D. J. Roberts, X. Lin, "Perchlorate, Arsenate, and Nitrate Ion Exchange Processes with Brine Reuse, Preprinted Extended Abstracts for American Chemical Society Division of Environmental Chemistry, Sept. 2003, National Meeting, N. Y., New York.
Gilloghly, T., S. Lehman, L. Aldridge, D. Clifford, D. Roberts, "Brine Treatment and Reuse: Demonstrating the Options During Perchlorate Removal by Ion-Exchange.", Proceedings of the 2003 American Water Works Association National Meeting, June, 2003.
Zhu, B., D. A. Clifford, and S. Chellam "Virus and NOM Removal by Electrocoagulation-Microfiltration" Proceedings of the AWWA Membrane Technology Conference, Atlanta, GA, March, 2003.
Gilloghly, T., S., Lehman, L. Aldridge, D. Clifford, D. Roberts, "Elimination and Minimization of Ion-Exchange Brine Disposal During Perchlorate and Nitrate Treatment", Proceedings of the 2002 American Water Works Association National Meeting, June, 2002.
Xu, W, S. Chellam, and D. Clifford, "Modeling and Experimental Verification of Dead-End Membrane Filtration of Coagulated Suspensions", Proceedings of the 2002 American Water Works Association National Meeting, June, 2002.
Tripp, A. R., and D. A. Clifford, "Treatability of Perchlorate in Groundwater Using Ion Exchange Technology-IV", Proceedings of the 2000 AWWA Water Quality Technology Conference in Salt Lake, City, 12 pp., AWWA, Denver, CO, Nov. 2000.
Ghurye, G. and D. Clifford, "Arsenic Oxidation Methods", Proceedings of the 2000 AWWA Water Quality Technology Conference in Salt Lake, City, 10 pp., AWWA, Denver, CO, Nov. 2000.
Clifford, D. and G. Ghurye, "Field Separation Methods for Arsenic", Proceedings 0f the 2000 AWWA Water Quality Technology Conference in Salt Lake, City, 12 pp., AWWA, Denver, CO, Nov. 2000.
Tripp, A. R., and D. A. Clifford, "Treatability of Perchlorate in Groundwater Using Ion Exchange Technology-III", Proceedings of the AWWA/AwwaRF Inorganic Contaminants Workshop in Albuquerque, NM, 8 pp., February 27-29, 2000.
Clifford, D. and G. Ghurye, "Arsenic Speciation Methods", Proceedings of the AWWA/AwwaRF Inorganic Contaminants Workshop in Albuquerque, NM, 11 pp., February 27-29, 2000.
Ghurye, G. and D. A. Clifford, "Arsenic (III) Oxidation by chemical Oxidants, UV and a Solid-Phase Oxidizing Media", Proceedings of the AWWA/AwwaRF Inorganic Contaminants Workshop in Albuquerque, NM, 9 pp., February 27-29, 2000.
Tripp, A. R., and D. A. Clifford, "Treatability of Perchlorate in Groundwater Using Ion Exchange Technology-II", Proceedings of the ACS Division of Environmental Chemistry Symposium: Perchlorate in the Environment, 218th Annual ACS Meeting, New Orleans, LA, August 22-26, 1999.
Clifford, D. A., D. J. Roberts, and A. R. Tripp, "The Treatability of Perchlorate in Groundwater Using Ion Exchange Technology," Proceedings of the East Valley Water District Conference on Perchlorate, March 17-18, 1999, Ontario, CA.
Najm, I., R.R. Trussell, L. Boulos, B. Gallagher, R. Bowcock, and D. Clifford, "Evaluating Ion Exchange Technology for Perchlorate Removal", Proceedings of the 1999 AWWA Annual Conference, Water Research, American Water Works Assoc., Denver, CO.
Clifford, D. A., G. G. Ghurye, and A. R. Tripp, "Development of an Anion Exchange Processes for Arsenic Removal from Water", Proceedings of the Third International Conference on Arsenic Exposure and Health Effects, pp. 379-87, July 12-15, 1998, Society for Environmental Geochemistry and Health.
Clifford, D. A., G. Ghurye, A. R. Tripp, "Arsenic Ion-Exchange Process with Reuse of Spent Brine", Proceedings of the 1998 AWWA Annual Conference, June 21-25, 1998,Water Research, Vol. C, pp. 491-514, American Water Works Assoc., Denver, CO.
Clifford, D. A., G. Ghurye, A. R. Tripp, "Arsenic Removal by Ion Exchange with and Without Brine Reuse", AWWA Inorganic Contaminants Workshop, San Antonio, TX, Feb. 22-24, 1998 (9-page extended abstract).
Ghurye, G., D. A. Clifford, J. Tong, "Iron Coagulation/Microfiltration for Arsenic Removal, AWWA Inorganic Contaminants Workshop, San Antonio, TX, Feb. 22-24, 1998 (8-page extended abstract).
Clifford, D. A., and C. X. Liu, "Development of a Nitrate Ion Exchange process with Reuse of Biologically Denitrified Brine," Proceedings of the 1995 International Conference on Ion Exchange; Takamatsu, Japan, Dec. 4-6, 1995, Japan Association of Ion Exchange, Yokohama, Japan.
Clifford, D. A., and C. X. Liu, "Review of Processes for Removing Nitrate from Drinking Water," Proceedings of the 1995 AWWA Annual Conference, 32 pp., American Water Works Assoc., Denver, CO, Sept. 1995.
Clifford, D. A. and C. C. Lin "Ion Exchange, Activated Alumina, and Membrane Processes for Arsenic Removal from Groundwater," Proc. of the 45th Annual University of Kansas Environmental Engineering Conference, February, 1995.
Clifford, D. A., and Z. Zhang, "Arsenic Chemistry and Speciation" Proceedings of the 1993 Water Quality Technology Conference, AWWA Denver, CO, pp. 1955-68, April 1994.
Connor, J. A., and D. A. Clifford, "NORM Waste Minimization Using In-Situ Treatment Method-II," in Environmental Issues and Solutions in Petroleum Exploration, Production and Refining, Proceedings of the International Petroleum Environmental Conference, March 1994, pp. 862-74, Univ. of Tulsa, Tulsa, OK, 1994.
Connor, J. A., and D. A. Clifford, "NORM Waste Minimization Using In-Situ Treatment Method," Proceedings of 4th Annual Produced Water Seminar, 9 pp., Paper No. 4, Texas Chapter of American Filtration Society, Jan. 20-21, 1994.
Liu, X., and D. A. Clifford, "Determination of Radium 226 by EPA Method 900.1-the Gross Radium Alpha Screening Procedure", Proceedings of the 1993 AWWA Annual Conference, Sept. 1993.
Connor, J. A., D. A. Clifford, and P. King, "In-Situ Method for Reducing the Production of Naturally-Occurring Radioactive Materials (NORM) from Subsurface Reservoirs" Proceedings of the Petrosafe Conference, Jan. 26-28, 1993, Book III, V. 9, pp. 461-78 (1993).
Clifford, D. A., "Theory, Design, and Operation of Processes for Removing Nitrate from Drinking Water," Proceedings of the UNIDO-Qinghua University Workshop on Industrial Water Treatment," Nov. 9-14, 1992, pp. 14-49, Qinghua University, Beijing, China, (1992).
Clifford, D. A., E. A. Higgins, and D. Wilds, "Simultaneous Measurement of 226Ra and 228Ra in Water by Gamma-Ray Counting after Preconcentration on Ion Exchange Resin," Proceedings of the 1992 AWWA Water Quality Technology Conference, pp. 489-500, Amer. Water Works Assoc., Denver, CO (1993).
Clifford, D. A., "Chromatographic Peaking of Toxic Contaminants during Water Treatment by Ion Exchange", Proceedings of 1991 International Conference on Ion Exchange, Japan Assoc. of Ion Exchange, pp. 270-76, Tokyo, (1992).
Clifford, D. A., and S. Chen, "Removal of Lead from Soil by Volatilization in Hydrogen, Nitrogen, and Air," Proceedings of the Hazardous Materials Control Research Institute--South'91 Meeting, pp. 162-165, HMCRI, Greenbelt, MD, (1991).
Clifford, D. A., and M. Yang "Feasibility of Extracting Toxic Metals from Soil Using Anhydrous Ammonia," Proceedings of the Hazardous Materials Control Research Institute--South'91 Meeting, pp. 166-170, HMCRI, Greenbelt, MD, (1991).
Clifford, D. A., "Truth Research, and the Media", Proceedings of the University of Houston Conference on Business, Society, and Environmental Crises: Who and What Will the Public believe? Univ. of Houston College of Business Administration, Houston, Texas (1990).
Clifford, D. A., "Radium Removal from Water Using Softeners and Point-of-Use Devices," Proceedings of the National Water Quality Association Educational Seminar, Atlanta GA, March 1-5, 1989; WQA, Naperville, IL, 1989.
Clifford, D. A., W. Vijjeswarapu, and S. Subramonian, "Removing Radium from Drinking Water Using Ion Exchange, Membranes and Specific Adsorbents: A Preliminary Report on the Lemont, Illinois Study," Proceedings of AWWA Seminar on Radionuclides in Drinking Water, June 14, 1987, No. 20019, pp. 69-82, AWWA Denver, CO, 1988.
Clifford, D. A., "Discussion of Synthesis of Dual Mechanism Ion Exchange/Redox Resins and Ion Exchange/Coordinating Resins with Applications to Metal Ion Separations," Proceedings International Symposium on Metal Speciation Separation and Recovery, pp. VI-21-26, Illinois Institute of Technology, 1987.
Clifford, D. A., P. Werner and G. Strauss, "Synergistic Heat and Salt Disinfection of Ion Exchangers," Proc. 3rd Biannual Conf. on Progress in Chemical Disinfection-CD-III, SUNY Binghamton, pp. 180-196, April 1986.
Clifford, D. A., "Point of Use Treatment for Inorganics Removal," Proc. Fourth Domestic Water Quality Symposium, Chicago, Ill., Dec. 1985, pp. 26-30 Water Quality Association, Lisle, Ill.
Kuhn, W. and D. A. Clifford, "Experience with Specific Organic Analyses for Water Quality Control in West Germany," Proc. 1985 AWWA Water Quality Technology Conference, Houston, TX, AWWA, Denver, CO, pp. 353-363.
Clifford, D. A., L. Ceber and S. Chow, "Separation of Arsenic (III) and As (V) by Ion Exchange," Proc. 1983 AWWA Water Quality Technology Conference, Norfolk, VA, pp. 223-236, AWWA, Denver, CO, December 1983.
Clifford, D. A. and C. C. Lin, "Ion Exchange and Membrane Processes for Nitrate Removal from Water," Proc. 1983 National Conference on Environmental Engineering, pp. 14-23, ASCE, NY, July 1983.
Clifford, D. A., T. Sorg, and P. Frank, "Survey of Inorganic Contaminants," Proc. 1983 AWWA Seminar on Inorganic Contaminant Removal, AWWA, Denver, CO.
Clifford, D. A., "Transportable Research Facilities for Water Treatment and Analysis," Proceedings AWWA Seminar on Design of Pilot Plant Studies, Miami Beach, Fla., May 16, 1982, pp. 77-87, AWWA, Denver, CO, 1983.
Sengupta, A. K. and D. A. Clifford, "The Importance of Chromate Speciation in Chromate Recovery from Cooling Tower Blowdown by Ion Exchange," Proc. of Water Reuse Symposium II, Washington, D.C., August 1981, Vol. 2, pp. 1496-1510, AWWA Research Foundation, Denver, CO.
Clifford, D. A., M. R. Bilimoria, G. Singh and T. Sorg, "Fluoride, Arsenic, Selenium, and Nitrate Removal from Small Community Water Supplies," Proceedings of 1980 National Conference on Environmental Engineering, July 10, 1980, pp. 514-19, ASCE, EED, NY, 1981.
Clifford, D. A. and W. J. Weber, Jr., "Nitrate Removal from Water Supplies by Ion Exchange: Anion Resin Selectivity, Multicomponent Column Behavior, Economics, and Regenerant Wastewater Disposal for Two-Bed and Single-Bed Systems," Proceedings of the 97th Annual AWWA Conference, May 197, pp. 14-B4 thru B24, AWWA, Denver, CO, 1978.
Clifford, D. A. and W. J. Weber, Jr., "A Nitrate Removal Process with a Land-Disposable Regenerant," Proceedings of the 1977 National Conference on Treatment and Disposal of Industrial Wastewater and Residues, pp. 216-25, Ann Arbor Science, Ann Arbor, Mich., 1977.
Clifford, Dennis A., "Automatic Measurement of Total Oxygen Demand," Proceedings of the 23rd Purdue Industrial Waste Conference - 1968, Part II, 53, pp. 775-85, Ann Arbor Science, Ann Arbor, Mich., 1969.

Invited Papers: 

Clifford, D. and G. Ghurye, "Oxidizing Arsenic III to Arsenic V for Better Removal", Water Quality Products Magazine, March 2001.
Clifford, D., "Removing Arsenic from Water: The Importance of pH, Background Contaminants, and Oxidation," Water Conditioning and Purification, pp. 30-33, August 2000.
Clifford, D. A., "Computer Prediction of Arsenic Ion Exchange" Aqualink Column for Journal AWWA, Vol. 87, No. 4, April 1995.
Clifford, D. A. and T. J. Nedwed, "Concentrated-Chloride Extraction and Recovery of Lead," Superfund Innovative Technology Evaluation Program Technology Profiles, Seventh Ed., EPA/540/R-94/526, pp. 372-73., U.S. EPA, ORD, Washington, D.C., Nov. 94.
Connor, J. A., and D. A. Clifford, "NORM Waste Minimization Using In-Situ Treatment Method", The American Oil and Gas Reporter, Dec., 1994
Clifford, D. A. "Tribute to Fred Helfferich," Reactive Polymers, V. 19, No. 1, pp. ix-x, 1993.
Clifford, D. A., "Computer Prediction of Ion Exchange" Aqualink Column for Journal AWWA, Vol. 85, No. 4, p 20, April 1993.
Clifford, D. A., "Point of Use Treatment for Nitrate Removal," Water Technology, pp. 26-36, October 1984.
Clifford, D. A., "Ion Exchange, Activated Alumina Adsorption, Reverse Osmosis, and Electrodialysis for Removal of Inorganic Contaminants," Water Engineering and Management: Annual Reference Handbook, pp. 31-38, May 1982.
Matson, J. V., D. A. Clifford and R. Mouche, "Advances in the Treatment of Cooling Tower Blowdown," ASME Pub. No. 80-IPC/PWR-6, 7 pp., Industrial Power Conference, Houston, Texas, October 26, 1980.
Clifford, D. A., J. V. Matson, and R. Kennedy, "Activated Alumina: Rediscovered Adsorbent for Fluoride, Humic Acids and Silica," Industrial Water Engineering, pp. 6-12, November 1978.
Clifford, D. A. and W. J. Weber, Jr., "Multicomponent Ion Exchange: Nitrate Removal Process with Land-Disposable Regenerant," Industrial Water Engineering, pp. 18-26, March 1978.

Reports / Manuals: 

Clifford, D. A., and M. Wu, "Arsenic Treatment Technology Demonstration: Predicting the Effect of Water Quality on Arsenic Adsorption by Activated Alumina", Report to the Montana State University Water Resources Center, 96 pp., March 2001.

Clifford, D. A., G. Ghurye, A. R. Tripp, and J. Tong, "Final Report: Phase 3 City of Albuquerque Arsenic Study, Field Studies on Arsenic Removal in Albuquerque, New Mexico using the University of Houston/USEPA Mobile Drinking Water Treatment Research Facility", 50 pp., Submitted to City of Albuquerque Dept. of Public Works, August, 1998.

Clifford, D. A., G. Ghurye, A. R. Tripp, and J. Tong, "Final Report: Phases 1 and 2 City of Albuquerque Arsenic Study, Field Studies on Arsenic Removal in Albuquerque, New Mexico using the University of Houston/USEPA Mobile Drinking Water Treatment Research Facility", 136 pp., Submitted to City of Albuquerque Dept. of Public Works, December, 1997.

Majano R. E., and Clifford D. A., "Development of a Multicomponent Chromatography Program for the Apple Macintosh Computer", University of Houston, Dept. of Civil and Environmental Eng., Dec. 1990.

Clifford, D. A., Program Director; "Status of the Environmental Engineering Graduate Program--Fall 1989," Cullen College of Engineering, University of Houston, 38 pp., September 11, 1989.

Clifford, D. A., Program Director; "Stage Two Review of the University of Houston Doctoral Program in Environmental Engineering," for the Texas College Coordinating Board, 152 pp., November, 1988.

Clifford, D. A., Program Director; "Status of the Environmental Engineering Graduate Program--Spring, 1988," Cullen College of Engineering, University of Houston, 58 pp., February 25, 1988.

PEER-REVIEWED GOVERNMENT REPORTS Published by EPA, NTIS and AwwaRF

  • Lakshmanan, D, Clifford, D.A., and Samanta, G., “A Systematic Comparison of Arsenic Removal by Coagulation-Filtration with Zirconium, and Titanium Salts in Comparison with Alum and Ferric Salts” 188 pp, Draft report submitted to Awwa Research Foundation, May 2007.
  • Lakshmanan, D, Clifford, D.A., and Samanta, G., “Simultaneous Oxidation and Removal of As(III) and As(V) by Electrocoagulation-Filtration”, 128 pp, Draft report submitted to Awwa Research Foundation, January 2007.
  • Samanta, G., and D. A. Clifford, “Ferrous Carbonate Beds as an Inexhaustible Source of Fe(OH)3(s) for Arsenic Removal” 46 pp., Draft report submitted to Awwa Research Foundation, October 2006.
  • Samanta, G., and D. A. Clifford, “Preservation of Arsenic Species”, AWWA Research Foundation, Denver CO, 121 pp, 2006.
  • Lowry, J, D. Clifford, G. Ghurye, S. Karori, B, Thompson. “Arsenite Oxidation by Solid-Phase Media or a UV-Sulfite Process”, 137 pp, Awwa Research Foundation, Denver, CO, 2005.
  • Aldridge, L, T. Gilloghly, J. Oppenheimer, G. Lehman, K. Witter, A. Burbano, D. A. Clifford, and A. R. Tripp, “Treatment of Perchlorate Using Single-Use Ion Exchange Resins”, 56 pp, AWWA Research Foundation, Denver, CO, 2004.
  • Clifford, D. A., S. Karori, G. L. Ghurye and G. Samanta, "Field Speciation Method for Arsenic Inorganic Species", AwwaRF Project No. 2663, 111 pp., AWWA Research Foundation, Denver, CO, 2004.
  • Lee Aldridge, Thomas Gillogly, and Geno Lehman, Dennis Clifford, Deborah Roberts, Xioahua Lin "Treatability of Perchlorate in Groundwater by Ion-Exchange Technology, Phase II Pilot Plant Study", AWWA Research Foundation, Denver, CO, 110 pp, July, 2004.
  • Tripp, A.R., D. A. Clifford, D. J. Roberts, Y. Cang, L. Aldridge, T. Gilloghly, and L. Boulos, "Treatment of Perchlorate in Groundwater by Ion-Exchange Technology", AWWA Research Foundation, Denver, CO, 219 pp, May 2003.
  • Ghurye, G., and D. Clifford, "Laboratory Study on the Oxidation of Arsenic III to Arsenic V", 98 pp., EPA/600/R-01/021, USEPA Office of Research and Development, Washington, D. C., March, 2001.
  • Patel, R. and D. A. Clifford, "Radium Removal from Water by Manganese Dioxide Adsorption and Diatomaceous Earth Filtration," 90 pp, PB92-115260/AS, NTIS, Springfield, VA 22161; Summary report. EPA /600/S2-91/063, 8 pp, U.S. EPA, Cincinnati, OH, 45268, March, 1992.
  • Garg, D. and D. A. Clifford, "Removing Radium from Water by Plain and Treated Activated Alumina," 85 pp, PB920-164 789/AS, NTIS Springfield VA, Summary Report, 7 pp, EPA/600/SR/92/048, U.S. EPA, Cincinnati, OH, April, 1992.
  • Clifford, D. A. and C. C. Lin, "Arsenic(III) and Arsenic(V) Removal from Drinking Water in San Isidro, New Mexico," 117 pp., NTIS, Springfield, VA 22161; Summary report. EPA /600/S2-91/011, 7 pp, U.S. EPA, Cincinnati, OH, 45268, June, 1991.
  • Clifford, D. A. and J. M. Chau, "The Fate of Chromium (III) in Chlorinated Water," PB 88-130 992/AS., 70 pp., NTIS, Springfield, VA 22161; Summary report. EPA /600/S2-87/100, 8 pp, U.S. EPA, Cincinnati, OH, 45268, Jan. 1988.
  • Siegel, S. K. and D. A. Clifford, "Removal of Chromium from Ion Exchange Regenerant Solution," PB 88-158 084/AS, 70 pp., NTIS, Springfield, VA 22161, Summary report, EPA/600/S-288/007, 7 pp, U.S. EPA, Cincinnati, OH 45268, April, 1988.
  • Clifford, D. A., C. C. Lin, L. L. Horng and J. V. Boegel, "Nitrate Removal from Drinking Water in Glendale, Arizona, PB 87-129 284/AS, 138 pp., 1987, NTIS, Springfield, VA 22161, Summary rep., EPA/600/52-86/107, 8 pp, U.S. EPA, Cincinnati, OH 45268, March, 1987.
  • Boegel, J. V. and D. A. Clifford, "Selenium Oxidation and Removal by Ion Exchange," PB 86-171 428/AS, 77 pp., 1986, NTIS, Springfield, VA.22161, Summary rep. EPA/600/52-86/031, 7 pp., U.S. EPA, Cincinnati, OH 45268, May 1986.
  • Frank, P. and D. A. Clifford, "Arsenic (III) Oxidation and Removal from Drinking Water," PB 86-158 607/AS, 80 pp., 1986, NTIS, Springfield, VA.22161, Summary report EPA/600/52-86/021, 8 pp., U.S. EPA, Cincinnati, OH 45268, April, 1986.
  • Rosenblum, E. R. and D. A. Clifford, "The Equilibrium Arsenic Capacity of Activated Alumina," PB 84/10 527, NTIS, Springfield, VA 22161, 94 pp., 1984. Summary rep. EPA-600/52-83-107, 5 pp., U.S. EPA, Cincinnati, OH 45268, Feb. 1984.
  • Clifford, D. A. and M. R. Bilimoria, "A Mobile Drinking-Water Treatment Research Facility for Inorganic Contaminants Removal," PB 84-145 507, NTIS, Springfield, VA 22161, 75 pp., 1984. Summary report EPA-600/2-84-018, 6 pp., U.S. EPA, Cincinnati, OH 45268, May, 1984.
  • Singh, G. and D. A. Clifford, "The Equilibrium Fluoride Capacity of Activated Alumina," PB 81-204 075, 59 pp , NTIS, Springfield, VA , 1981. Summary rep. EPA-600/52-81-082, 5 pp., U.S. EPA, Cincinnati, OH 45268, July, 1981.
  • Clifford, Dennis A. and W. J. Weber, Jr., "Nitrate Removal from Water Supplies by Ion Exchange," EPA-600/2-78-052, 292 pp., U.S. EPA, Cincinnati, OH, 1978.
  • Clifford, D. A. and W. J. Weber, Jr., "Nitrate Removal from Water Supplies by Ion Exchange: Executive Summary Report," EPA-600/8-77-015, 42 pp. U.S. EPA, Cincinnati, OH, November 1977.