37680-65-2

Usage

Uses

2,2'',5-Trichlorobiphenyl is a polychlorinated biphenyl (PCB) congeners.

Safety Profile

Moderately toxic byintraperitoneal route. When heated to decomposition itemits toxic vapors of Clí.

Upstream product

• 35693-99-3 2,2',5,5'-Tetrachlorobiphenyl 
• 41464-39-5 2,2',3,5'-Tetrachlorobiphenyl 

Relevant academic research and scientific papers

METHOD FOR SEPARATING AND CLEANING UP POLYHALOGENATED BIPHENYLS

The method for separating and cleaning up polyhalogenated biphenyls (PHBs) is characterized by comprising the following three steps: (1) the step of bringing a sample containing PHBs into contact with a fibrous activated carbon; (2) the step of washing the fibrous activated carbon with hexanes; and (3) the step of eluting PHBs from the fibrous activated carbon.

Congener-specific dechlorination of dissolved PCBs by microscale and nanoscale zerovalent iron in a water/methanol solution

Polychlorinated biphenyl (PCB)-contaminated sediments remain a significant threat to humans and aquatic ecosystems. Dredging and disposal is costly, so viable in situ technologies to dechlorinate PCBs are needed. This study demonstrates that nanoscale zerovalent iron (ZVI) dechlorinates PCBs to lower-chlorinated products under ambient conditions, provides insight into structure-activity relationships between PCB isomers, and compares the reactivity of nanoscale ZVI to that of palladized microscale ZVI. Six PCB congeners were studied (22′, 34′, 234, 22′35′, 22′45′, and 33′44′) to compare the initial rate of dechlorination of each and to monitor the order in which chlorines are removed. Using 200 g/L of nanoscale ZVI in a 30% MeOH/water mixture, observed surface-area-normalized pseudo-first-order PCB dechlorination rate constants ranged from 1 × 10-6 to 5.5 × 10-4 L yr -1 m-2 depending on the PCB congener tested. Using 200 g/L of palladized (0.05 wt %) microscale ZVI, surface-area-normalized pseudo-first-order PCB dechlorination rate constants were significantly faster and ranged from 3.8 × 10-2 to 1.7 × 10-1 L yr-1 m-2, but these rates were not sustainable. For nanoscale ZVI, nonorthosubstituted congeners had faster initial dechlorination rates than orthosubstituted congeners in the same homologue group. Chlorines in the para and meta position were predominantly removed over chlorines in the ortho position, which suggests that more-toxic coplanar PCB congeners are not likely to form from less-toxic noncoplanar, orthosubstituted congeners. Complete dechlorination was not observed over the course of the experiments. PCB dechlorination is rapid enough that nanoscale ZVI may offer novel in situ remedial alternatives for PCB-contaminated sediments.

Relative resistance of positional isomers of polychlorinated biphenyls toward reductive dechlorination by zerovalent iron in subcritical water

Relative resistance of positional isomers within the same homologue of polychlorinated biphenyls (PCBs) was studied by comparing the reduction efficiencies (REs) of these isomers by 100-mesh zerovalent iron in subcritical water at 250 °C and 10 MPa. The REs for meta and para isomers were found to be significantly higher than that of the ortho's. These results revealed that variation in relative resistance of the positional isomers to reductive dechlorination does exist, and the order increases from para to meta to ortho substituents. This variation in relative resistance to reduction is correlated with the lowest unoccupied molecular orbital (LUMO) energy of individual PCB congeners. A model based on the empirical relative resistance of the PCBs to reductive dechlorination is developed, and an equation is established to predict the efficiency of a reductive dechlorination system that employs zerovalent iron and pressurized hot water. Relative resistance of positional isomers within the same homologue of polychlorinated biphenyls (PCBs) was studied by comparing the reduction efficiencies (REs) of these isomers by 100-mesh zerovalent iron in subcritical water at 250°C and 10 MPa. The REs for meta and para isomers were found to be significantly higher than that of the ortho's. These results revealed that variation in relative resistance of the positional isomers to reductive dechlorination does exist, and the order increases from para to meta to ortho substituents. This variation in relative resistance to reduction is correlated with the lowest unoccupied molecular orbital (LUMO) energy of individual PCB congeners. A model based on the empirical relative resistance of the PCBs to reductive dechlorination is developed, and an equation is established to predict the efficiency of a reductive dechlorination system that employs zerovalent iron and pressurized hot water.