Critical evaluation of PCB remediation technologies

Abstract

Polychlorinated biphenyls (PCBs) are a family of aromatic compounds consisting of a biphenyl molecule which has been chlorinated to form a large number of possible congeners. The number of chlorine atoms they can contain (from 1 to 10) varies, as does the placement of the chlorine atoms on the biphenyl molecule. Thus, a polychlorinated biphenyl is one of 209 compounds having the formula: C12H10–nCln. Due to their excellent heat stability, fire retardance and electrical insulating properties, they gained widespread use as dielectric fluid incorporated in electrical transformers and capacitors. They were also incorporated in products as various as plastics, hydraulic fluids, surface coatings, inks, paints, pesticides, lubricants, and carbonless copy paper.

Oxidative Destruction of Chlorobenzene and o-Dichlorobenzene on a Highly Active Catalyst: MnOx/TiO2–Al2O3

“…In the visible Raman spectra of TiO 2 -Al 2 O 3 , no Raman peaks of TiO 2 crystalline phase were detected for TiO 2 -FIG. 6.…”

“…Thus, many methods have been tried to destroy the chlorinated organics including PCDDs and PCDFs. Among these methods are incineration (1,2), hydrodechlorination (3,4), biological process (5), steam re-forming (6), and photocatalytic degradation (7,8). Catalytic oxidation of chlorinated aromatics to HCl, H 2 O, and carbon oxides is the most viable and economic approaches due to its low destruction temperature and its excellent selectivity toward the formation of harmless products (9)(10)(11).…”

Total Hydrodechlorination of Industrial Transformer Oil on Metal-Supported Catalysts

“…However, currently, the accumulation of used PCBs is a very serious problem because of the extremely high toxicity and chemical stability of these compounds, which should be isolated or decontaminated by using efficient technologies. The direct incineration of PCBs has been the most usual method for their destruction; however, the high temperatures (1200 C) and the presence of oxygen lead to the formation of highly toxic by-products such as dioxins and polychlorinated dibenzofurans (PCDFs) (Young and McPhillips, 1997;Amend and Lederman, 1992).…”

Concentration and congener patterns of polychlorinated biphenyls in industrial and municipal waste incinerator flue gas, Korea

“…The pyroplasma system uses a plasma torch to 0304 induce temperatures up to 15,000 • C and pyrolyse the organic liquid. The resultant products are carbon mono-oxide, nitrogen, hydrogen and some low molecular-weight-hydrocarbons [7]. In Japan, 5300 tonnes of waste liquid PCBs, namely, Kanechlors, were thermally destroyed in 1988 [8].…”