Treatment methodology for sludge and scale TENORM waste from petroleum industry in Egypt

Abstract

In this present laboratory work, experiments have been steered to decrease the activity concentration of 226Ra in sludge and scale (TENORM) which Technically Enhanced Naturally Occurring Radioactive Materials waste samples deposited in oilfield tubes and tools, sludge and scale, Egypt, respectively. The influence of the leaching parameters on the radium dissolution mechanism using nonionic surfactant tween 20 as a leaching agent has been determined. The greatest leaching percent of radium isotopes approximated 58.31 % of the total radium percentage in bulk sludge TENORM waste sample (size < 2.5 mm) using tween 20 as surfactant solutions through three successive cycles at the optimum conditions. The greatest leaching percent of radium isotopes was 77.98 and 86.12 % of the total radium percentage in scale TENORM waste samples from two different places, the first place is the western desert area and the second place is Ras Shukeir area, respectively, (size < 1 mm) using tween 20 solutions through four successive cycles at the optimum conditions. The kinetic calculations indicated that the leaching procedure can be explained by the Shrinking Core Model with activation energy equivalent to 18.18 kJ/mol. The low value of activation energy illustrated that the diffusion process controls the sludge TENORM waste sample leaching rate. The estimated values of thermodynamics parameters (ΔG°, ΔH°, ΔS°) were appointed in this study and showed the dissolution of radium is a non-spontaneous response and temperature dependent.