Isotope effects of neodymium in different ligands exchange systems studied by ion exchange displacement chromatography

The isotope effects of neodymium in Nd-glycolate ligand exchange system were studied by using ion exchange chromatography. The separation coefficients of neodymium isotopes, epsilon's, were calculated from the observed isotopic ratios at the front and rear boundaries of the neodymium adsorption band. The values of separation coefficients of neodymium isotopes, epsilon's, for the Nd-glycolate ligand exchange system were compared with those of Nd-malate and Nd-citrate, which indicated that the isotope effects of neodymium as studied by the three ligands takes the following direction Malate > Citrate > Glycolate. This order agrees with the number of available sites for complexation of each ligand. The values of the plate height, HETP of Nd in Nd-ligand exchange systems were also calculated

Combined coagulation flocculation pre treatment unit for municipal wastewater

The potentials of using the hydraulic technique in combined unit for municipal wastewater treatment were studied. A combined unit in which processes of coagulation, flocculation and sedimentation, has been designed utilizing hydraulic mixing instead of mechanical mixing. Ajar test treatability study has been conducted to locate the optimum dose of the coagulants to be used. Alum, ferrous sulfate, ferric sulfate, a mixture of ferric and ferrous sulfates, and mixture of lime and ferrous sulfate were all tested. A pilot unit was constructed in the existing wastewater treatment plant at El Mansoura governorate located in north Egypt. The optimum dose of coagulants used in the combined unit gives removal efficiencies for COD, BOD, and total phosphorous as 65%, 55%, and 83%, respectively