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in Wiley InterScience (www.interscience.wiley.com).The removal of carbon dioxide (CO 2 ) from industrial emissions has become essential in the fight against climate change. In this study, we employed Zeolite 13X for the capture and recovery of CO 2 in a flow through system where the adsorbent was subjected to five adsorption-desorption cycles. The influent stream contained 1.5% CO 2 at standard conditions. The adsorbent bed was 1 in. in length and 1 in. 3/8 in dia., and was packed with 10 g of the zeolite. Temperature swing adsorption (TSA) was employed as the regeneration method through heating to approximately 135 8C with helium as the purge gas. The adsorbent capacity at 90% saturation was found to decrease from 78 to 60g CO 2 /kg Zeolite13X after the fifth cycle. The CO 2 capture ratio or the mass of CO 2 adsorbed to the total mass that entered the system decreased from 63% to only 61% after the fifth cycle. The CO 2 recovery efficiency ranged from 82 to 93% during desorption, and the CO 2 relative recovery, i.e., CO 2 desorbed for the nth cycle to CO 2 adsorbed for the first cycle, ranged from 88 to 68%. The service life of the adsorbent was determined to be equal to eleven cycles at a useful capacity of 40g CO 2 /kg Zeolite13X .

The polychlorinated biphenyl congener 2,3,4,5,6-pentachlorobiphenyl and hexachlorobenzene were reductively dechlorinated in an aqueous biomimetic model system containing vitamin B12. The products of 2,3,4,5,6-pentachlorobiphenyl dechlorination were 2,3,5,6and 2,3,4,6-tetrachlorobiphenyl. Hexachlorobenzene dechlorinated to pentachlorobenzene and a mixture of 1,2,4,5and 1,2,3,5-tetrachlorobenzene. The proton from water was shown to be the source of the hydrogen atom used for the replacement of chlorine on the biphenyl ring.

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