SITE Demonstration of Minergy Glass Furnace Treatment of PCBs, PCDDs/Fs, and Metals in River Sediment

The U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation (SITE) program selected the Glass Furnace Technology (GFT) treatment process for evaluation. The GFT was developed by Minergy Corporation as an ex situ remediation technology to treat river sediment contaminated with polychlorinated biphenyls (PCBs), other organic compounds, and metals. The pilot-scale demonstration of the GFT was conducted at Minergy’s GlassPack Test Center facility in Winneconne, Wisconsin. In the GFT treatment, dewatered sediment is dried, flux is added to control melting temperatures and improve the physical properties of the glass aggregate product, and then the sediment and flux mixture is melted at a temperature of about $\mathrm{1,600}°\mathrm{C}$ , removing or destroying PCBs and organic contaminants, and encapsulating metals. The product consists of glass aggregate with particles the size of coarse sand. The developer claims the glass aggregate meets state regulatory criteria for beneficial reuse. The main objectives of the SITE GFT demonstration were to determine the treatment efficiency of PCBs in river sediment when processed in the GFT and to determine whether the GFT glass aggregate product meets the criteria for beneficial reuse under relevant federal and state regulations. In August of 2001, a technology evaluation was conducted on about 17,000 pounds of river sediment dredged from the Lower Fox River in Green Bay, Wisconsin; the geometric mean concentration of polychlorinated biphenyls (PCBs) in the melter feed (dried sediment) was $27.8\mu \mathrm{g}∕\mathrm{g}$ , while the geometric mean in the glass aggregate product was $136\mathrm{pg}∕\mathrm{g}$ . Analytical data indicate that the GFT was able to significantly reduce PCB contamination in all samples. Overall, the GFT successfully removed or destroyed 99.9995% of the PCBs in the river sediment, measured as total PCBs. The GFT also reduced the concentration of dioxins and furans in dried sediment. The geometric mean of the total dioxin and furan concentrations in the melter feed was $\mathrm{116,000}\mathrm{pg}∕\mathrm{g}$ , while the geometric mean in the glass aggregate product was $2.26\mathrm{pg}∕\mathrm{g}$ , a reduction of greater than 99.9995%. Samples of the glass aggregate were crushed and subjected to ASTM and synthetic precipitation leaching procedure analyses. The results of the leaching tests indicated no detections of contaminants of concern in leachates for either method. The GFT produced glass aggregate that met Wisconsin Administrative Code Chapter NR 538 Category 2 criteria and qualified for beneficial reuse under the regulation. This qualification allows a range of uses, including as an additive to concrete, a material in floor tiles, and as construction fill. Based on information from Minergy and observations made during the SITE evaluation, the estimated treatment cost is $\mathrm{\$}38.74\text{per}\text{ton}$ of dredged-and-dewatered sediment containing 50% moisture. Unit costs are based on a $15\text{-}\text{year}$ project life expectancy and may depend on the location of the treatment facility, amount of moisture in the sediment, and potential end use of the product.