Method To Simultaneously Improve PCB Radiolysis Rates in Transformer Oil and To Close the Chlorine Mass Balance

Abstract

The addition of alkaline 2-propanol to isooctane and transformer oil solutions of PCBs was found to increase the rate of PCB dechlorination by γ-radiolysis. Simultaneously, it facilitates the closure of the chlorine mass balance. The chlorine liberated from PCBs irradiated in alkaline 2-propanol-spiked solutions precipitated as an inorganic salt in a stoichiometric amount. This was demonstrated for an individual PCB congener (PCB 155) in isooctane and for Aroclor 1260 in transformer oil. Radiolysis rates are reported in terms of dose constants, d (kGy-1), the exponential rate constant for PCB decomposition with respect to absorbed dose. These are the highest decomposition rates yet reported for the radiolytic treatment of PCB-contaminated transformer oil.

New bis(triazinyl) pyridines for selective extraction of americium(iii)

“…2, together with the numbering scheme of the nitrogen atoms. This structure is defined as the trans,trans (tt) conformation as characterised by the N(11)-C-C-N (21) and N(31)-C-C-N(21) torsion angles. This tt conformation has been shown by quantum mechanics calculations (see later) to have a lower energy than the cis,cis (cc) conformation that is to be found in all the metal complexes with BATP (and BTP) molecules.…”

“…But the rates of reaction can be increased by the use, respectively of a free radical initiator and gamma irradiation. [20][21][22] Both the free radical initiator and gamma irradiation increase the rates of reaction by introducing the reactive species which initiate chain reactions. In both the free radical polymerisation and the radiolytic dechlorination the presence of substances which intercept the reactive intermediates (respectively oxygen and nitrobenzene) thus reduce the rate of reaction.…”

Photodegradation of 4-Chlorobiphenyl in Hexane by UV Irradiation

“…But to our knowledge, unlike γ-radiolysis of PCB, 13 there was little systematic study on the PCB photolysis including the release of chloride, and hence the quantity of chloride was meas- ured to detect the formation of chloride in hexane. Figure 8 displays the amount of free chloride actually found in irradiated hexane.…”

Photodechlorination of Aroclor 1254 in a Pilot-Scale Flow through Photoreactor

“…The poor statistics of the first-order plots are a consequence of the mixture character of Aroclor 1254. Single congeners are reported to exhibit first-order behavior ͑Chu and Kwan 2002Kwan , 2003Mincher et al 2000͒. On the basis of the rate of reactions obtained, only 1.1 kW h of energy is needed to dechlorinate 99% of Aroclor 1254 in one gallon of alkaline IPA solution in the EFEP tubes.…”