Tracking the Product Origins of Waste for Treatment Using the WIO Data Developed by the Japanese Ministry of the Environment

Large Virtual Transboundary Hazardous Waste Flows: The Case of China

The Basel Convention and prior studies mainly focused on the physical transboundary movements of hazardous waste (transporting waste from one region to another for cheaper disposal). Here, we take China, the world's largest waste producer, as an example and reveal the virtual hazardous waste flows in trade (outsourcing waste by importing waste-intensive products) by developing a multiregional input-output model. Our model characterizes the impact of international trade between China and 140 economies and China's interprovincial trade on hazardous waste generated by 161,599 Chinese enterprises. We find that, in 2015, virtual hazardous waste flows in China's trade reached 26.6 million tons (67% of the national total), of which 31% were generated during the production of goods that were ultimately consumed abroad. Trade-related production is much dirtier than locally consumed production, generating 26% more hazardous waste per unit of GDP. Under the impact of virtual flows, 40% of the waste-intensive production and relevant disposal duty is unequally concentrated in three Chinese provinces (including two least-developed ones, Qinghai and Xinjiang). Our findings imply the importance of expanding the scope of transboundary waste regulations and provide a quantitative basis for introducing consumer responsibilities. This may help relieve waste management burdens in less-developed "waste havens".

Activated Carbon and Carbon Quantum Dots/Titanium Dioxide Composite Based on Waste Rice Noodles: Simultaneous Synthesis and Application in Water Pollution Control

To achieve the full utilization of waste rice noodle (WRN) without secondary pollution, activated carbon (AC) and carbon quantum dots/titanium dioxide (CQDs/TiO2) composite were simultaneously synthesized by using WRN as raw material. Both of the two materials showed potential applications in water pollution control. The AC based on WRN displayed a porous spherical micro-morphology, which could absorb heavy metal elements like Pb(II) and Cr(VI) efficiently, with a maximum equilibrium uptake of 12.08 mg·g−1 for Pb(II) and 9.36 mg·g−1 for Cr(VI), respectively. The adsorption of the resulted AC could match the Freundlich adsorption isotherm and the pseudo-second-order kinetics mode. On the other hand, the CQDs/TiO2 composite based on WRN displayed a high efficient photocatalytic degradation effect on various water-soluble dyes such as methylene blue, malachite green, methyl violet, basic fuchsin, and rhodamine B under visible light irradiation, which showed better photocatalytic performance than commercial TiO2. The introduction of CQDs based on WRN to TiO2 could result in efficient electron-hole pair separation and enable more photogenerated electrons to reduce O2 and more photogenerated holes to oxidize H2O or OH−, which could cause stronger abilities in producing O2·− and ·OH radical and better photocatalytic activity.

Regional waste footprint and waste treatments analysis

This paper provides a detailed analysis of the waste footprint and waste treatments at subnational level, for Brussels, Flanders, and Wallonia. The paper details the waste footprint components into direct waste from households (disposed in bins), indirect waste generated upstream in the supply chains and induced by household consumption and waste materials from the degradation of in-use stocks. For each component, we analysed the contribution of waste types, products consumed and location where the waste was generated, as well as the associated treatments. The results show that Flanders had the highest total waste footprint in absolute terms; Brussels the highest direct waste in capita terms and Wallonia the highest indirect waste and stock depletion in capita terms. In each region, almost 78 ± 2% of the regional waste footprints were attributed to the consumption of food products, manufactured products and restaurants and accommodation services. For each region, around 45 ± 4% of the indirect waste was generated within its boundaries, 16 ± 9% in other regions and 39 ± 5% out of Belgium. Incineration was the predominant waste treatment type of the regional waste footprint, followed by recycling. Landfill was the second widely applied treatment for indirect waste. Results constitute key information relevant to enhance the waste data monitoring practices at regional level with effects at national level. We unveiled the waste footprint and associated treatments inherent to the interregional and international linkages. Results are also useful resources to substantiate waste management and circular economy policies, enacting on waste prevention and reduction, ecodesign and product lifetime extension.