Behavior of PCDD/Fs during open burning of municipal solid waste in open dumping sites

Open dumping sites in Surabaya and Palembang, Indonesia, have been studied to investigate emissions of polychlorinated dibenzo-para-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs), as well as the resulting soil contamination that might be caused by open burning of municipal solid waste. The emission factors of the waste residue, accounting for the ratio of waste burned, have also been characterized. The concentrations of PCDD/Fs and DL-PCBs in soil from Palembang were 61–310 pg-TEQ/g (dry weight) and 6.3–32 pg-TEQ/g, respectively. In Surabaya, very low levels of PCDD/Fs and DL-PCBs, ranging from 0.075 to 0.098 and 0.00032 to 0.095 pg-TEQ/g, respectively, were observed in soil for an open dumping site that included a top cover layer of soil above the compacted waste. The large difference in concentrations can be explained by the fact that open burning of waste is the source of PCDD/Fs and DL-PCBs. The emission factors for the residue for PCDD/Fs ranged from 27 to 140 pg-TEQ/g, and a sensitivity analysis found that the maximum emission factor to the residue could be 5600 pg-TEQ/g. Our results indicate that emissions of PCDD/Fs can be controlled by modifying the open dumping process to one that involves depositing soil layers on top of the compacted waste.     

Estimation of contribution from non-point sources to perfluorinated surfactants in a river by using boron as a wastewater tracer

The contribution of non-point sources to perfluorinated surfactants (PFSs) in a river was evaluated by estimating their fluxes and by using boron (B) as a tracer. The utility of PFSs/B as an indicator for evaluating the impact of non-point sources was demonstrated. River water samples were collected from the Iruma River, upstream of the intake of drinking water treatment plants in Tokyo, during dry weather and wet weather, and 13 PFSs, dissolved organic carbon (DOC), total nitrogen (TN), and B were analyzed. Perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUA), and perfluorododecanoate (PFDoDA) were detected on all sampling dates. The concentrations and fluxes of perfluorocarboxylates (PFCAs, e.g. PFOA and PFNA) were higher during wet weather, but those of perfluoroalkyl sulfonates (PFASs, e.g. PFHxS and PFOS) were not. The wet/dry ratios of PFSs/B (ratios of PFSs/B during wet weather to those during dry weather) agreed well with those of PFS fluxes (ratios of PFS fluxes during wet weather to those during dry weather), indicating that PFSs/B is useful for evaluating the contribution from non-point sources to PFSs in rivers. The wet/dry ratios of PFOA and PFNA were higher than those of other PFSs, DOC, and TN, showing that non-point sources contributed greatly to PFOA and PFNA in the water. This is the first study to use B as a wastewater tracer to estimate the contribution of non-point sources to PFSs in a river.     

Japan’s greenhouse gas reduction scenarios toward net zero by 2050 in the material cycles and waste management sector

The first draft scenario toward net zero greenhouse gas (GHG) emissions by 2050 for the material cycles and waste management sector was presented by the Ministry of the Environment, Japan in August 2021. The details of the future GHG emission estimation used to create the draft scenario are described in this document. For multiple scenarios where more aggressive measures, such as carbon capture, utilization, and storage (CCUS), were included in addition to business-as-usual and the current policy continuity scenario, future GHG emissions were estimated as the sum of the products of activities and emission factors indicating changes in measures between scenarios. The estimation outcomes demonstrated that future GHG emissions from the solid waste management sector could be anticipated to be zero or even negative when material conversion to biomass, primarily for plastics, recycling to raw materials, and installation of CCUS at incineration facilities are assumed. Extensions of prior plans are not enough to reach the goal of net zero emissions, according to the measures necessary and the volume and pace of their implementation suggested in this study. Stakeholders should collaborate with great ambition.