Dear Li,

The following publications describe chemical degradation of polychlorinated biphenyls:

1-J Environ Sci Health A Tox Hazard Subst Environ Eng. 2009 Sep;44(11):1120-6. doi: 10.1080/10934520903005145.

Chemical degradation of PCB in the contaminated soils slurry: direct Fenton oxidation and desorption combined with the photo-Fenton process.

Quiroga JM1, Riaza A, Manzano MA.

Author information

Abstract

This paper reports the results of the direct treatment of PCBs sorbed to solid particles (glass beads and sand) employing the Fenton process. The results obtained with contaminated sandy soils show 98% removal of the original PCB structure and 82% dechlorination, all within a reaction time of 72 hours. The degree of removal was observed to be dependent on the level of congener chlorination. The optimized conditions were: 5% H(2)O(2); 100 ppm Fe(3+); sandy soil mass/volume of oxidizing solution ratio (m/V) of 1/3 g/mL, vigorous agitation and dispensed with the need for heat. Results obtained by applying an integrated desorption treatment followed by photo-Fenton oxidation to sandy soils contaminated with PCBs are also present in this paper. Desorption of PCBs with surfactant solutions took place to an extent of around 90% (92.2% with K-perfluoroalkyl sulfonate, FT800, and 87% with Lineal Alkyl benzene Sulfonate, LAS), while photo-Fenton oxidation at 254 nm achieved degradation percentages close to 100% in 30 minutes for PCBs in solution, both with FT800 (98%) and LAS (97%) surfactants.

http://www.ncbi.nlm.nih.gov/pubmed/19847702

2-https://encrypted.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwiTlIyWwLnMAhWjK5oKHX9pCu4QIAgtMAE&url=http%3A%2F%2Fwebcache.googleusercontent.com%2Fsearch%3Fq%3Dcache%3AToh1dGEEs68J%3Awww.dtic.mil%2Fget-tr-doc%2Fpdf%253FAD%253DADA541875%2B%26cd%3D2%26hl%3Den%26ct%3Dclnk%26gl%3Dus&usg=AFQjCNFB_M2CHRjonSJHPuqE6s_QBNYd0g&sig2=PYeSwOHiAWl-gFu3JY4iEw

3-Degradation of Polychlorinated Biphenyls Induced by Ionizing Radiation in Aqueous Micellar Solutions

Daniel C. Schmelling ,† Dianne L. Poster ,‡ Mahnaz Chaychian ,† Pedatsur Neta ,§ Joseph Silverman ,† andMohamad Al-Sheikhly *†

Department of Materials and Nuclear Engineering, University of Maryland at College Park, College Park, Maryland 20742-2115, Analytical Chemistry Division, Chemistry Building, Room B208, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, and Physical and Chemical Properties Division, Chemistry Building, Room A261, National Institute of Standards and Technology, Gaithersburg, Maryland 20899

Environ. Sci. Technol., 1998, 32 (2), pp 270–275

DOI: 10.1021/es9704601

Publication Date (Web): January 15, 1998

Copyright © 1998 American Chemical Society

Abstract

This investigation examines the γ-radiation-induced degradation of polychlorinated biphenyls (PCBs) in aqueous surfactant solutions. Dichloro-, tetrachloro-, and decachlorobiphenyl congeners were solubilized in water using a commercially available non-ionic surfactant, Triton X-100, and subsequently irradiated by a 60Co γ-source. Rates and extent of dechlorination were determined at different surfactant concentrations, and intermediate species and byproducts were quantified. Pulse radiolysis was used to measure rates of reaction between PCBs and the solvated electron as well as rates of electron scavenging by the surfactant. Experiments were also conducted in organic solvents, and these results have been compared to those observed in the aqueous surfactant solutions. Each PCB congener was fully dechlorinated by ionizing radiation in the micellar systems. Initial chloride yields were directly proportional to the level of chlorination of the PCB congeners. Scavenging of the aqueous electron by the surfactant was significant, and PCB degradation efficiency improved markedly at lower surfactant concentrations. PCB transformation occurred primarily through reductive dechlorination, forming lower chlorinated PCBs and biphenyl. Rates of PCB degradation were substantially higher in aqueous surfactant solutions than in diethyl ether and petroleum ether. This suggests that solubilizing PCBs in water using a surfactant prior to irradiation may provide a considerable improvement in contaminant degradation efficiency in comparison to using an organic solvent or irradiating PCBs directly in oil.

http://pubs.acs.org/doi/abs/10.1021/es9704601

4-Studies on Degradation of Polychlorinated Biphenyls by Means of Fenton’s Reagent

D. Prządo1 *, P. Kafarski1 , M. Steininger2

Received: March 8, 2007

Accepted:August 22, 2007

Abstract

Fenton’s reagent was applied for degradation of selected congeners of PCBs (PCB28, PCB52, PCB101, PCB138) present in aqueous solution at ppb concentrations. The effectiveness of degradation by this chemical process was determined and the toxicity of degradation products was evaluated. The experiments lasted 96 hours under stable pH during the whole process. In 24 h intervals the samples were extracted and analyzed by GC, GC/MS and IC. At the same time the Microtox® test was applied to assess the toxicity of the resulting solution. It has been observed that the concentration of two congeners, namely PCB28 and PCB52, decreased rapidly within the first 24 h of the experiment, whereas the two remaining ones (PCB101, PCB138) were degraded poorly. After 96 hours of the process, apart from other oxygenated products, acetate and fumarate also were determined. Concentration of Cl-ions was only slightly increased, indicating that the substrates were not mineralized.

http://www.pjoes.com/pdf/16.6/881-887.pdf

Hoping this will be helpful,

Rafik