Soil contamination by halogenated polycyclic aromatic hydrocarbons from open burning of e-waste in Agbogbloshie (Accra,Ghana)

Detailed composition of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl-PAHs and Br-PAHs) generated during informal recycling of e-waste and their toxic relevance are still poorly understood. This study investigated the occurrence of Cl-PAHs and Br-PAHs in surface soil samples from the Agbogbloshie e-waste recycling site (Accra, Ghana) using quantitative gas chromatography–mass spectrometry (GC–MS) and comprehensive two-dimensional GC–time-of-flight mass spectrometry (GC × GC–ToFMS) profiling. The results of GC–MS analysis showed elevated concentrations in open e-waste burning areas (160–220 and 19–46 ng/g dry weight for Cl- and Br-PAHs, respectively) with substantial contribution from unidentified compounds (respectively, more than 36 and 70%, based on the total areas of potential peaks). Cl- and Br-PAHs from e-waste burning had a distinctive composition dominated by ring–ring compounds. Several homologue groups not monitored with GC–MS were found using GC × GC–ToFMS: PAHs with up to 5Cl or 3Br, mixed halogenated PAHs and chlorinated methylPAHs. The dioxin-like toxic equivalents of the identified Cl-/Br-PAHs in soils, estimated from their in vitro AhR agonist potencies relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin, were much lower than the range reported for chlorinated and brominated dioxins. However, the toxicity of the unidentified halogenated PAHs remained unclear.     

Potential e-waste generated from households in Indonesia using material flow analysis

Waste of electronic and electrical equipment (e-waste) generated in Indonesia is expected to increase due to high growth of the Indonesian economy and fast development in technology. As Indonesia has not yet had specified criteria on e-waste, in this study, e-waste is defined as any obsolete or unwanted electronic and electrical equipment that is introduced into the recycling and disposal process. The objective of this study is to estimate the e-waste generated in Indonesian households using the method of material flow analysis. The amount of generated e-waste could be used for constructing an e-waste recycling management system in Indonesia. E-waste materials that need to be treated could be known. In this study, some types of equipment, such as television, washing machine, refrigerator, personal computer, and mobile phone, were chosen to be tracers. Using the modified material flow analysis model proposed by Steubing et al. (Waste Manage 30:473–482, 38), the potential e-waste that was generated from households was estimated. The total estimated accumulation of generated e-waste from households in 2015 and 2025 is about 285,000 and 622,000 tonnes, respectively. If a proper recycling system was in place, a new source for valuable materials recovery would be created, as well as protecting the environment and health.     

Batch separation of shredded bulky waste by gas-solid fluidized bed at laboratory scale

A gas-solid fluidized bed separator using various bed materials was used to separate shredded municipal bulky waste (SBW). Using 290 microm glass beads as the bed material, the apparent density of the fluidized bed was 1.5 g/cm(3) and the SBW could be separated into combustibles such as wood, paper and plastics and incombustibles such as metals and glass. The overall efficiency (Newton's efficiency) of the separation was calculated to be 0.93. In order to obtain high efficiency, the superficial velocity must be adjusted so that the fluidized bed is agitated moderately and at the same time there is no weak fluidized region. Using a mixture of particles of nylon shot and 68 microm glass beads, the apparent density of the fluidized mixture bed could be varied between 0.63 and 0.99 g/cm(3) by changing the mixing ratio of the two materials. In the case of a mixing ratio of 20% for glass beads, an apparent density of 0.65 g/cm(3) was produced, in which wood and paper components were recovered while plastics remained in the bed to give a final overall efficiency of 0.88.     

Past, present, and future of MSW landfills in Japan

This article focuses on the historical development of landfill technology since the beginning of the nineteenth century in Japan. The regulations and guidelines that form a framework for the technology are reviewed, and the historical background and the current state of Japanese municipal solid waste (MSW) management are described. Through the analysis of data collected from facility leaflets, changes in the leachate treatment system are surveyed. Finally, the concept of the “sustainable bioreactor landfill with low organics” is proposed.     

Geographic mosaic of mutually exclusive dominance of obligate commensals in symbiotic communities associated with a burrowing echiuran worm

Species richness and community composition of symbionts associated with the burrowing echiuran worm, Ochetostoma erythrogrammon Leuckart & Rüppell, 1828, were quantitatively surveyed on subtropical intertidal flats in the Ryukyu Archipelago, Japan. Overall, we recorded seven species of burrow associates, including at least six obligate commensals. According to symbiont community composition, the study sites were largely divided into two groups; one was characterized by the dominance of a snapping shrimp, Alpheus barbatus Coutière, 1897, and the other by the dominance of a scale worm, Lepidonotus sp. Furthermore, a granulometric analysis showed that the sediment characteristics differed significantly between shrimp- and scale worm-dominant sites in terms of median diameter and inclusive graphic standard deviation. These results suggest that these symbionts have different habitat requirements, resulting in the mutually exclusive dominance pattern. Our findings indicate that habitat heterogeneity is important to the evaluation and conservation of the symbiotic diversity in intertidal flats.