𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Degradation of perchloroethylene and dichlorophenol by pulsed-electric discharge and bioremediation

✍ Scribed by Dennis C. Yee; Sadhana Chauhan; Efim Yankelevich; Vitaly Bystritskii; Thomas K. Wood


Publisher
John Wiley and Sons
Year
1998
Tongue
English
Weight
150 KB
Volume
59
Category
Article
ISSN
0006-3592

No coin nor oath required. For personal study only.

✦ Synopsis


Pulsed electric discharge (PED) and bioremediation were combined to create a novel two-stage system which dechlorinates the halogenated pollutants, 2,4dichlorophenol and perchloroethylene, with repetitive (0.1-1 kHz), short pulse (∼100 ns), low voltage (40-80 kV) discharges and then mineralizes the less chlorinated products with aerobic bacteria. A 6.1 mM aqueous dichlorophenol sample was cycled through the PED reactor (60 kV of applied pulsed voltage and 300 Hz) 6 times, resulting in the release of 55% of the initial dichlorophenol chloride ions (1 mM Cl -removed each cycle). The respective average specific efficiency is 0.4-0.6 keV/(Cl - molecule). Pseudomonas mendocina KR1, which grows in minimal medium supplemented with phenol but not with dichlorophenol, increased in cell density in all cultures supplemented with the PED-treated DCP samples and yielded a maximum of two-fold additional Cl -released compared to the PED-related alone. The number of PED-treatment cycles, voltage, and frequency were also varied, showing that both cell densities and overall dichlorophenol dechlorination were highly dependent upon the number of PED-treatment cycles, rather than the tested voltages and frequencies. Using this two-stage treatment system, PED released 31% of the initial chloride ions from dichlorophenol (after three cycles at 40-45 kV and 1.2 kHz) while P. mendocina KR1 in the second stage increased dechlorination to 90%. These results were corroborated by the 35% additional chloride release found with activated sludge cultures. Perchloroethylene (0.6 mM) was similarly treated in a first-stage PED reactor (80% chloride removal after four cycles) followed by biodegradation of the dechlorinated products with a recombinant toluene o-monooxygenase-expressing Pseudomonas fluorescens strain. Gas chromatographic analysis showed that the PED reactor created less-chlorinated byproducts (i.e., trichloroethylene) that were removed (74%) upon exposure to the recombinant bacterium.


πŸ“œ SIMILAR VOLUMES


Aerobic degradation by white-rot fungi o
✍ Ernest Marco-Urrea; Xavier Gabarrell; Gloria Caminal; Teresa Vicent; C Adinaraya πŸ“‚ Article πŸ“… 2008 πŸ› Wiley (John Wiley & Sons) 🌐 English βš– 136 KB

## Abstract **BACKGROUND:** Trichloroethylene (TCE) and perchloroethylene (PCE) are considered among the most important groundwater pollutants around the world. These compounds are usually found together in polluted environments but little is known about the ability of microorganisms to simultaneou

Numerical analysis of effects of electri
✍ Kohei Ito; Katuyuki Hagiwara; Hiroyuki Nakaura; Kazuo Onda; Hidekazu Tanaka πŸ“‚ Article πŸ“… 2002 πŸ› John Wiley and Sons 🌐 English βš– 401 KB

## Abstract By virtue of its comparatively high denitrification (deNOx) efficiency and its compactness, the pulsed‐discharge deNOx process is considered to be one of the deNOx processes suitable for combustion gas. However, there has been insufficient clear guidance on the optimum electric field, p