Bioremediation processes for recovery and reuse of CCA-treated wood invariably increase the cost of any secondary products manufactured from the remediated fiber. Microbial remediation using either bacteria or fungi has been shown to remove heavy metals from CCA-treated southern yellow pine (SYP). In a two-step remediation process utilizing oxalic acid extraction and the metal-tolerant bacterium Bacillus licheniformis, 70-100% of the copper, chromium and arsenic can be removed from CCA-treated SYP, but the liquid culture medium used to support the bacterial growth renders this process costly. Processing costs could be partially offset if the culture medium were replaced with an industrial by-product. In this study, an abundant by-product of the brewing industry, malted barley, was evaluated as a replacement for commercial nutrient broth in the bioremediation process for CCA-treated SYP. Malted barley’s high moisture and nutrient content should support bacterial growth. When malted barley was substituted as a growth substrate for nutrient broth, it was discovered that either the culture inoculum or wood itself provided sufficient nutrients for the growth of B. licheniformis. Seventeen percent of the copper and 15% of the arsenic was removed from an aqueous slurry of CCA-treated SYP following bacterial remediation with B. licheniformis. When oxalic acid extraction preceded the aqueous bacterial culture of CCA-treated SYP, 21% Cu, 54% Cr and 63% As were removed. Incidentally, malted barley acted as a biosorbent, removing heavy metals from the liquid culture upon their release from CCA-treated SYP.

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