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This study provides information on the disaster waste management practices and disposal methods employed in Kathmandu Valley for debris generated by the Gorkha Earthquake on April 25, 2015. We also quantify the amount of building debris generated and managed at destinations within the core city area of Kathmandu Valley, which was diverted from the government-proposed disposal site. This research involved field visits, interaction with communities, meetings with officers related to debris management, and reference to published reports. Disaster waste management in Nepal included the reuse/recycling of building materials in new construction or as filling materials in land development. Debris were also disposed on low-lying areas, down the cliff, and river bank; however, the disposal method was open dumping. Of the estimated 3.23 million tons of potential debris generated in the core city area of Kathmandu Valley, 1.07 million tons were managed 2 years after the Gorkha Earthquake, of which 0.63 million tons were disposed on river banks, along the ring road, and in open spaces, and the remaining 0.44 million tons were salvaged for reuse or sold for recycling or disposed in other isolated areas. Approximately 2.17 million tons of building debris is yet to be managed.

Significant quantities of building waste were generated from collapsed residential and dilapidated buildings as a result of the disastrous Gorkha earthquake in Nepal on April 25, 2015. In this study, in relation to the field damage investigation of the earthquake hit area and based on the building types, different types of building waste produced from each building are estimated and evaluated. An estimation procedure was established to assess the amount of debris resulting from earthquake. In Kathmandu Valley, different types of buildings generated different quantities of building waste per unit area, and the values for these building types ranged from 1.90 to 3.23 ton m− 2 in weight and 0.89 to 1.57 m3 m− 2 in volume respectively. Residential buildings in Nepal generated a larger amount of waste per unit area (ton m− 2) than buildings in Japan and China. Waste amounts (excluding that in the foundation) generated by public reinforced concrete buildings in Nepal were similar to the amounts generated by reinforced concrete buildings in Japan and China. Wooden buildings had the highest volume per unit area of building waste in Japan, as compared to those in Nepal and Sri Lanka. These results can be used to estimate the amount of building debris that must be cleared for emergency response after a disaster. This information is vital to pre-disaster planning to establish disaster management protocols for smooth recovery operations.

We estimated the in-use stocks of polybrominated diphenyl ethers (PBDEs) in Japan using a population balance model. The estimation is based on the domestic demand of PBDEs and the assumed survival rate of these products. Two cases relevant to the future regulation of commercial deca-BDE are considered, namely (1) deca-BDE declines at the same rate as the current rate of decline, and (2) deca-BDE is discontinued after 2020. The estimates of the decreasing rates of in-use penta-, octa-, and deca-BDE stocks were proportional with the measured decreases in the atmospheric concentrations of these substances. The in-use penta- and octa-BDE stocks could be depleted in the near future (500 and 60 tonne in 2013, and an estimated 20 and

Since end-of-life vehicles (ELVs) contain toxic substances, they have to be treated properly. The purpose of this study was to obtain useful information for ELV management from the viewpoint of toxicity. We focused on lead as a representative toxic substance contained in vehicles and investigated the dynamic substance flow of lead contained in ELVs and its content in automobile shredder residue (ASR). A population balance model was used to estimate the number of ELVs generated between FYs (fiscal year) 1990–2020, employing a Weibull distribution for the lifespan distribution. Sixteen lead-containing components of the vehicle were considered. It was estimated that the annual number of ELVs generated would be 2.9 million as of FY2020. The results implied that it is hard to remove Pb completely. This is because 5,000–11,000 t-Pb will still remain in vehicles in use in FY2020 even though most components in new model vehicles could be replaced by lead-free alternatives. As of FY2010, the substance flow showed that Pb contained in ELVs amounted to 4,600–5,700 t-Pb. Of this, 13.2–14.0 % was contained in ASR. The Pb content in ASR could be dramatically decreased by FY2020, but it will continue to contain 240–420 mg-Pb/kg if the treatment system is not improved.

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.

A simplified life cycle assessment was conducted to estimate greenhouse gas (GHG) emissions and energy production from each component of biogenic waste treated in an open dumping site, and by composting, anaerobic digestion, and incineration employed with additional options. The impact of uncertainties and sensitivities of the parameters in the treatment methods were investigated. We conducted a sensitivity analysis to identify the most sensitive parameters, and we discussed the relationship between uncertainty and sensitivity. Our results revealed that the moisture content of food waste and the biomass-derived carbon and methane concentration of the landfill gas of biogenic waste subjected to open dumping are the most sensitive parameters across all the treatment methods. The net GHG emissions from food waste treated in an open dumping site ranged over ten times (0.30 − 3.67 Gg CO2 eq/Gg). In addition, by employing additional options for the open dumping site, including soil cover, a landfill gas collection system, shifting to a semi-aerobic condition, and energy conservation by using a gas engine, we found that the net GHG emissions could be reduced by 10, 27.9, 37.4 %, and up to 56.7 %, respectively. Shifting to a semi-aerobic system is the most effective method for reducing GHG emissions, followed by landfill gas collection.

Reduce, reuse, and recycle (3R) policies form the basis of waste management and global warming countermeasures globally, so we conducted a comparative study of 3R and waste management policies in the European Union (EU), USA, Korea, Japan, China, and Vietnam. An international workshop for 3R and waste management policymakers was held in Kyoto, Japan, and a bibliographic survey was also conducted to collect data. 3R policies are clearly given priority in the hierarchy of waste management in every country studied. Thermal recovery, which includes power generation from waste heat and methane gas collected from organic waste, is also a priority; this is consistent with the increased use of countermeasures to reduce greenhouse gas (GHG) emissions. In the EU, waste management is characterized by practical and effective 3R policies through the development of realistic regulations and by the policymakers’ desire to simplify management systems. The policy ideal in China, however, is the development of a circular economy that targets reductions in the amount and hazardousness of waste. Limits on the number of final disposal sites, strategies for procuring resources, and GHG emission countermeasures are closely linked with 3R policies, and further development of 3R policies in parallel with such issues is expected.

Atmospheric emissions of deca-brominated diphenyl ether (DBDE) in Japan were estimated based on the material flow of DBDE products and their emission factors. In 2002, the demand for DBDE in Japan was 2200 ton/year and the stock level was about 60 000 ton. The DBDE flow into the waste stream was estimated to be about 6000 ton/year and the flow out through second-hand product exports was more than 700 ton/year. Home appliance recycling facilities dismantle and crush domestic wastes containing about 600 ton of DBDE annually. Material recycling of crushed plastics is not commonly practiced as yet. Emission factors from plastics processing (2 × 10−9–1 × 10−7), textile processing (9 × 10−7), home appliance recycling (8 × 10−9–5 × 10−6), and waste incineration (1 × 10−7–2 × 10−6) were estimated using field measurement data. The DBDE emission rate through house dust during the service life of final products (2 × 10−7–9 × 10−7 per year) was estimated using the DBDE concentration in dust and the amount of dust in used televisions. Emission factors from previous studies were also used. The estimated total DBDE emission was 170–1800 kg/year. These results suggest the necessity of characterizing emissions during the service life of products, which is essential information for formulating an appropriate e-waste recycling strategy.

End-of-life vehicles (ELV) have become a global concern as automobiles have become popular worldwide. An international workshop was held to gather data and to discuss 3R policies and ELV recycling systems, their background and present situation, outcomes of related policies and programs, the framework of recycling and waste management, and case studies on related topics in several countries and regions, as well as the essential points of the comparison. Legislative ELV recycling systems are established in the EU, Japan, Korea, and China, while in the US, ELV recycling is managed under existing laws on environmental protection. Since automobile shredding residue (ASR) has a high calorific value and ash content, and includes heavy metals as well as a mass of unclassified fine particles, recycling ASR is considered highly difficult. Countries with a legislative ELV system commonly set a target for recovery rates, with many aiming for more than 95 % recovery. In order to reach this target, higher efficiency in ASR recovery is needed, in addition to material recycling of collectable components and metals. Environmentally friendly design was considered necessary at the planning and manufacturing stages, and the development of recycling systems and techniques in line with these changes are required for sound ELV management.