Biodegradation of paint stripper solvents in a modified gas lift loop bioreactor
✍ Scribed by Laura Vanderberg-Twary; Karen Steenhoudt; Bryan J. Travis; John L. Hanners; Trudi M. Foreman; James R. Brainard
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 92 KB
- Volume
- 55
- Category
- Article
- ISSN
- 0006-3592
No coin nor oath required. For personal study only.
✦ Synopsis
Paint stripping wastes generated during the de-and decommissioning of former actinide processing sites contamination and decommissioning of former nuclear at DOE laboratories has been generated in significant facilities contain paint stripping organics (dichloromethquantities. These wastes contain cheesecloth rags, orane, 2-propanol, and methanol) and bulk materials conganic paint stripper residues (dichloromethane, 2-protaining paint pigments. It is desirable to degrade the panol, toluene etc), lead-based paint with chromate pigorganic residues as part of an integrated chemicalbiological treatment system. We have developed a modi-ments, and suspect plutonium. We have developed a fied gas lift loop bioreactor employing a defined consorcombined biological/chemical treatment process for the tium of Rhodococcus rhodochrous strain OFS and destruction of hazardous organic compounds, the con-Hyphomicrobium sp. DM-2 that degrades paint stripper centration and removal of RCRA metals, and the reducorganics. Mass transfer coefficients and kinetic constants tion of final waste volume. An in-barrel treatment profor biodegradation in the system were determined. It was found that transfer of organic substrates from surrogate cess was initially considered. However, toxicity of metals waste into the air and further into the liquid medium (hexavalent Cr and Pb) to organics-degrading microbes in the bioreactor were rapid processes, occurring within led us to develop a system in which volatile organics are minutes. Monod kinetics was employed to model the bioair-stripped from solids into a bioreactor (Vanderbergdegradation of paint stripping organics. Analysis of the Twary et al., 1995).
bioreactor process was accomplished with BIOLAB, a Biological destruction of paint stripping wastewaters mathematical code that simulates coupled mass transfer and biodegradation processes. This code was used to fit containing phenol and methylene chloride in rotating experimental data to Monod kinetics and to determine biological contactors (RBC) has been studied (Cobb et kinetic parameters. The BIOLAB code was also employed al., 1979; Mandlekar, 1990). Microbial populations in to compare activities in the bioreactor of individual microthe RBC and also in activated sludge reactors employed bial cultures to the activities of combined cultures in the for the same purpose as the RBC have been characterbioreactor. This code is of benefit for further optimization and scale-up of the bioreactor for treatment of paint stripized (Arquiaga and Canter, 1988;Arquiaga et al., 1995; ping and other volatile organic wastes in bulk materials. Jeter, 1985).