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EVALUATION OF PRISTINE LIGNIN FOR HAZARDOUS WASTE TREATMENT
Citation:
O'Neil, D., C. Newman, E. Chian, AND H. Gao. EVALUATION OF PRISTINE LIGNIN FOR HAZARDOUS WASTE TREATMENT. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-87/037 (NTIS PB87191664), 1987.
Description:
A feasibility study was conducted to assess the utilization of lignin, isolated from a steam-exploded hardwood (Tulip poplar) with 95% ethanol and 0.1n NaOH, as a potential adsorbent for hazardous waste treatment. Eight organic compounds and two heavy metals were selected to allow comparison of lignin isolates with activated carbon. It was found that the adsorption capacity of lignin for heavy metals (chromium and lead) is comparable to activated carbon, despite a huge divergence in surface area (0.1 m2/g vs. 1000 m2/g). The surface area discrepancy and the extensive aromatic substitution in lignin macromolecule impeded the achievement of an adsorption capacity of lignin for polar organic compounds which would allow it to be cost-competitive with activated carbon although results with phenol and, to a lesser degree, naphthalene indicate significant potential for achieving competitive capacities. A recommended plan for surface area and structural enhancement is presented on the basis that lignin can be developed as an effective and low-cost adsorbent for polar priority pollutants and/or as an ion-exchange resins for heavy metal wastewater clean-up.