Biological Treatment of Wood Preserving Site Groundwater by BioTrol, Inc.

This document is an evaluation of the BioTrol, Inc., Aqueous Treatment System (BATS), a fixed-film, aerobic biological treatment process for contaminated groundwaters and other wastewaters. This report summarizes and analyzes the results of the Superfund Innovative Technology Evaluation (SITE) Program’s six week demonstration at the MacGillis and Gibbs Company wood preserving site in New Brighton, MN. Other pertinent data from BioTrol investigations are included to support the demonstration results. Conclusions were reached concerning the technological effectiveness and economics of the process and its suitability for use at other sites. During the SITE demonstration, operations and sampling and analysis were carefully monitored to establish a database against which the vendor’s claims for the technology could be evaluated reliably. These claims were that the BATS could achieve 90% removal of pentachlorophenol (PCP) and polynuclear aromatic hydrocarbons (PAHs) and that penta removal was by mineralization. The conclusions from the pilot scale demonstration study and other available data are: (1) the fixed film aerobic process is capable of degrading pentachlorophenol (PCP) and other organic pollutants to more than 95% removal; (2) effluent concentrations of PCP well below 1 mg/L are attainable, if necessary by increasing the retention time, i.e., decreasing the throughput rate; (3) removal of PCP is largely by mineralization to carbon dioxide, water and saltbasedonchlorideyields; (4) acute toxicity of the PCP-contaminated groundwater, at least to minnows and water fleas, is eliminated, (5) operating cost for labor, chemicals, and energy range from $3.45/1000 gal at 5 gpm to $2.43/1000 gal at 30 gpm and total capital and operating cost can be as low as $2.94/1000 gallons, and (6) other factors, including ambient temperature and the presence of other contaminants in the feedwater, may affect total cost and operating efficiency.