No abstract

To investigate the formation and decomposition behaviors of dioxin-like PCBs during incineration of municipal solid wastes in a recently constructed facility, the concentrations of dioxin-like PCBs were measured in municipal solid waste before incineration and in the incinerator emission gas and residues. Using these values, release/inflow ratios of dioxin-like PCB congeners (ratio of the amount released from the incinerator to the amount flowing into the incinerator through waste) were calculated. For PCB congeners 126, 169, and 189, these ratios were greater than 1. In contrast, ratios of the other dioxin-like congeners were much less than 1. To take into account atmospheric sources, the amounts of dioxin-like PCBs released via emissions from municipal solid waste incineration were compared with atmospheric depositions in the Kyoto City area. Most of the PCDD/F congeners and homologue groups were deposited in amounts similar to those found in emissions from the waste incinerator. Deposition of dioxin-like PCB congeners 81, 126, 169, and 189 were also found in amounts similar to those released via the waste incinerator emissions. However, depositions of congeners 105, 114, and 118 greatly exceeded the amounts released via waste incinerator emissions. In reviewing the congener profiles of industrial PCB products and emission gas, the following general trends were observed: (i) For congeners whose contents are high in industrial PCB products (e.g., 105 and 118), the amounts deposited were much higher than the amounts released with waste incineration emission gas. (ii) For congeners whose percentages were high in the waste incineration emission gas (e.g., 126 and 189), the amounts deposited were similar to the amounts released in the waste emission gas.

In Japan, water-quality monitoring with the environmental dioxin standard of 1 pg-TEQ/L at basic monitoring points set in a border between operation-area water and normal water is necessary for removal operations for bottom sediments containing dioxins. This paper presents a technique for combining on-site graphitic carbon (GrC) solid-phase extraction and bioassay method for the simplification and facilitation of water-quality monitoring. Using this method, we conducted experiments at an actual sediment removal site. Comparative analyses using high-resolution GC/MS (HRGC-HRMS) between the dioxin concentrations detected using a GrC solid-phase extraction kit and the official analytical method yielded similar concentrations and distributions of isomers for detected PCDD/Fs and DL-PCBs. The GrC solid-phase extraction method is inferred to have capacity equal to official analytical method extraction. Toxicity equivalent concentrations estimated using DR-CALUX correlate with equivalent concentrations with HRGC/HRMS. No false positive or false negative result was obtained for the standard value 1 pg-TEQ/L.