PNNL

Abstract

Mechanically robust engineered sorbents were constructed by embedding Ag-loaded aerogels or xerogels in a polyacrylonitrile (PAN) matrix at 30 or 50 mass% loadings of gel in PAN. The process for making the base gels as well as the composite materials is described herein, a technology that is very flexible for making hybrid sorbents using various inorganic or organic active sorbents. The PAN-gel composite materials were evaluated for iodine uptake in the form of gaseous iodine [I2(g)] at room temperature and at 150°C as well as iodide (I–) at room temperature from simulated liquid nuclear wastes. The composites show high I2(g) uptake and high I– uptake (= 93 mass%) in simulated liquid secondary waste spiked with 5 mg L-1 I–. These results demonstrate the utility of such a composite form for iodine removal from contaminated gas and liquid streams.