Evaluation of DMDOHEMA based supported liquid membrane system for high level waste remediation under simulated conditions

• Actinide transport across SLM using DMDOHEMA was investigated under SHLW condition.
• SLM with good stability has been developed using DMDOHEMA as the carrier.
• A mathematical model has been developed to simulate experimental data.
• The proposed model showed good agreement with the experimental data.

N,N′-dimethyl-N,N′-dioctyl-2,(2′-hexyloxyethyl) malonamide (DMDOHEMA) has been proposed as solvent for the partitioning of radiotoxic minor actinides from high-level waste (HLW) solutions. The facilitated transport of 241Am(III), 239Pu(IV), 233U(VI), 237Np(V) across supported liquid membrane (SLM) impregnated with DMDOHEMA solution in n-dodecane was investigated under varying conditions of feed acidity, receiver phase composition, carrier concentration, and membrane thickness. Micro porous PTFE membrane was used as the polymeric support. There was a decrease in the transport of metal ions under the pressurized heavy water reactor simulated HLW (PHWR-SHLW) conditions. The physical stability of the SLM impregnated with the carrier was investigated for ~60 days by performing Am(III) permeation studies. Marginal variation in the transport behavior suggested reasonably good stability of the impregnated carrier in the membrane pores. A simple mathematical model has been developed to simulate experimental data and to explain quantitatively the role of different parameters.