M. Gopala Rao, Ph.D., P.E.
Professor

Phone: 202-806-4796
Email: [email protected]

Education
B.S. Benaras Hindu University, Benaras, India (1953)
AIISc., Indian Institute of Science, Bangalore, India (1956)
Ph.D., University of Washington, Seattle (1962)
Professional Engineer, Washington, D.C. (1996)

Research Topics
Radioactive Waste Management, Modeling Sorption of Mixtures of Radionuclides on Minerals; Ion Exchange Equilibrium and Rate Processes; Alternative Process Energy Systems.

Summary of Recent Research
The investigation dealt with sorption of Pb and Cs mixtures in aqueous phase on two different sorbents, a zeolited volcanic tuff and a clay mineral. Sorption isotherm data were obtained at a constant anion concentration of 0.0375 N in a continuous columnar-flow system at a temperature range of 27+ 1 �C. In both the cases of sorbents, the phase equilibrium data were highly non-ideal. In the case of zeolited tuff, Pb ion is strongly favored at the expense of Cs ion, and exhibited an "Azeotrope" at a Pb ion equivalent fraction of 0.64. In the case of the clay mineral, it is the cesium ion that is highly favored on the sorbent phase. Again, there is an "Azeotrope" compostion, this time at a cesium ion equivalent composition of 0.795. Ion -exchange phase-equilibrium theory was used to correlate the equilibrium data. Thermodynamic equilibrium constant and sorbent-phase ionic activity coefficients for each of the sorbent system were obtained.

Recent Publications
Gopala Rao, "Binary and Ternary Ion-Exchange Equilibria in Zeolited Tuff: CS-Sr-Co System", Separation Science and Technology, 30 (7-9), pp1385-1396, 1995.

M. Gopala Rao, and Henry N. Halle, "Modeling Sorption of Radionuclides on sorbent containing surface sites with variable charges: Ni-Sr-Goethite Systems," 5th Annual International High-Level Radioactive Waste Management Conference, Las Vegas, NV, 1994.

M. Gopala Rao, S. Ali Pourhashemi, and G.G. McBean, "Development and Validation of Ion Change Phase-Equilibrium Model for Sorption of Pb and Cs Mixtures on Zeolited Volcanic Tuff", Spectrum 98, International Conference on Decommissioning and Decontamination and on Nuclear and Hazardous Waste Management, Denver, Co., September 1998

M. Gopala Rao, S. Ali-Pourhashemi, Jagannath Gadi and G.G. McBean, "Modeling Sorption of Mixtures of Redionuclides on Zeolited Volcanic Tuff and Clay Minerals", XVIII InterAmerican Congress of Chemical Engineering, San Juan, Puerto Rico, 1998.