Assessment of plasma gasification of high caloric waste streams

Plasma gasification is an innovative technology for transforming high calorific waste streams into a valuable synthesis gas and a vitrified slag by means of a thermal plasma. A test program has been set up to evaluate the feasibility of plasma gasification and the impact of this process on the environment. RDF (refuse derived fuel) from carpet and textile waste was selected as feed material for semi-pilot gasification tests. The aim of the tests was: (1) to evaluate the technical feasibility of making a stable synthesis gas; (2) to characterize the composition of this synthesis gas; (3) to define a suitable after-treatment configuration for purification of the syngas and (4) to characterize the stability of the slag, i.e., its resistance to leaching for use as a secondary building material. The tests illustrate that plasma gasification can result in a suitable syngas quality and a slag, characterized by an acceptable leachability. Based on the test results, a further scale-up of this technology will be prepared and validation tests run.     

2,4-Dichlorophenoxyacetic acid (2,4-D) sorption and degradation dynamics in three agricultural soils

The fate and transport of 2,4-dichlorophenoxyacetic acid (2,4-D) in the subsurface is affected by a complex, time-dependent interplay between sorption and mineralization processes. 2,4-D is biodegradable in soils, while adsorption/desorption is influenced by both soil organic matter content and soil pH. In order to assess the dynamic interactions between sorption and mineralization, 2,4-D mineralization experiments were carried using three different soils (clay, loam and sand) assuming different contact times. Mineralization appeared to be the main process limiting 2,4-D availability, with each soil containing its own 2,4-D decomposers. For the clay and the loamy soils, 45 and 48% of the applied dose were mineralized after 10 days. By comparison, mineralization in the sandy soil proceeded initially much slower because of longer lag times. While 2,4-D residues immediately after application were readily available (>93% was extractable), the herbicide was present in a mostly unavailable state (<2% extractable) in all three soils after incubation for 60 days. We found that the total amount of bound residue decreased between 30 and 60 incubation days. Bioaccumulation may have led to reversible immobilization, with some residues later becoming more readily available again to extraction and/or mineralization.     

Managing carbon emissions in China through building energy efficiency

This paper attempts to analyse the role of building energy efficiency (BEE) in China in addressing climate change mitigation. It provides an analysis of the current situation and future prospects for the adoption of BEE technologies in Chinese cities. It outlines the economic and institutional barriers to large-scale deployment of the sustainable, low-carbon, and even carbon-free construction techniques. Based on a comprehensive overview of energy demand characteristics and development trends driven by economic and demographic growth, different policy tools for cost-effective CO₂ emission reduction in the Chinese construction sector are described. We propose a comprehensive approach combining building design and construction, and the urban planning and building material industries, in order to drastically improve BEE during this period of rapid urban development. A coherent institutional framework needs to be established to ensure the implementation of efficiency policies. Regulatory and incentive options should be integrated into the policy portfolios of BEE to minimise the efficiency gap and to realise sizeable carbon emissions cuts in the next decades. We analyse in detail several policies and instruments, and formulate relevant policy proposals fostering low-carbon construction technology in China. Specifically, Our analysis shows that improving building energy efficiency can generate considerable carbon emissions reduction credits with competitive price under the CDM framework.     

Stress and recovery assessment during simulated microgravity: Effects of exercise during a long-term head-down tilt bed rest in women

The aim of this study was to determine the effects of a 60-day head-down tilt long-term bed rest (HDT) on stress and recovery in sixteen healthy female volunteers. Participants were randomly assigned to either an exercise group (Exe) that followed a training program combining resistive and aerobic exercises, or to a no-exercise control group (Ctl). Psychological states were assessed using the Rest-Q, a validated questionnaire based on stress–recovery responses. A longitudinal analysis revealed significant changes in the general and specific-stress scales for all participants throughout the experiment with a critical stage from supine to standing posture leading to a significant decrease in physical recovery. During HDT, Exe reported higher scores on stress subscales, as well as lower recovery scores compared to the Ctl. During the post-HDT ambulatory recovery period, the exercisers still reported higher scores than the non-exercisers on the Lack of energy stress-related scale, along with lower scores in general well-being and personal accomplishment. The present findings show that simulated weightlessness such as HDT may induce psychological stress and lead to subsequent alterations in perceived recovery. Exercise did not reduce HDT impaired effects on stress and recovery states. Several suggestions, including psychological preparation, are proposed to support the beneficial effects of exercise on psychological factors.     

Estrone direct photolysis: by-product identification using LC-Q-TOF

The identification of degradation products generated upon photolysis of estrone (E1), a natural estrogenic hormone, under simulated UV irradiation conditions was addressed by the use of LC-Q-TOF mass spectrometry. The structures of the main degradation products were elucidated, demonstrating how the use of model molecules 5,6,7,8-tetrahydro-2-naphtol (THN), 2-methylcyclopentanone (MCP), labeled molecule estrone D(4) (E1-D(4)), the investigation of the fragmentation pathways of the parent E1, the concurrent use of CID and exact mass measurements permit the characterization of structural modifications induced by photodegradation processes. In the present study, we identified nine major by-products of which seven photoproducts correspond to E1H(+) modified in positions other than the C-2, C-4 and C-16 of E1. Most of them showed one to three additional hydroxylations preferentially located on the aromatic ring of the parent E1, which confirms that these products may present environmental risk. Applications to real water samples have been conducted to extend the validity of the present study to environmental samples.     

Assessment of successful experiments and limitations of phytotechnologies: contaminant uptake, detoxification and sequestration, and consequences for food safety

Purpose  

The term “phytotechnologies” refers to the application of science and engineering to provide solutions involving plants, including phytoremediation options using plants and associated microbes to remediate environmental compartments contaminated by trace elements (TE) and organic xenobiotics (OX). An extended knowledge of the uptake, translocation, storage, and detoxification mechanisms in plants, of the interactions with microorganisms, and of the use of “omic” technologies (functional genomics, proteomics, and metabolomics), combined with genetic analysis and plant improvement, is essential to understand the fate of contaminants in plants and food, nonfood and technical crops. The integration of physicochemical and biological understanding allows the optimization of these properties of plants, making phytotechnologies more economically and socially attractive, decreasing the level and transfer of contaminants along the food chain and augmenting the content of essential minerals in food crops. This review will disseminate experience gained between 2004 and 2009 by three working groups of COST Action 859 on the uptake, detoxification, and sequestration of pollutants by plants and consequences for food safety. Gaps between scientific approaches and lack of understanding are examined to suggest further research and to clarify the current state-of-the-art for potential end-users of such green options.     

Beach geomorphic factors for the persistence of subsurface oil from the Exxon Valdez spill in Alaska

Oil from the 1989 Exxon Valdez oil spill persists in some of the Prince William Sound (Alaska) beaches and continues to be a potential threat to the fauna. This paper reports a field investigation during the summer of 2008 of groundwater flow and solute transport in a tidal gravel beach in Smith Island, Prince William Sound. The beach contains oil on one side, the left side (facing landward). Field measurements of water table, salinity, and tracer (lithium) concentration were obtained for an approximate duration of 64 h for two transects, the oiled transect and a clean transect (the right transect). It was found that the hydraulic conductivity and the fresh groundwater recharge into the two transects were similar. It was also found that the beach slope of the mid to high tidal zone along the oiled (left) transect was ~7.4% which is considerably smaller than that of the clean (right) transect (~11.8%). This suggests a higher flushing/replenishing of the right transect with nutrients and/or oxygen, which would have enhanced biodegradation of oil on the right transect if that oil was not washed by waves. We also found that the degree of oiling at each location was inversely dependent on the armoring of the beach surface with clasts and boulders. The applied tracer concentration at the left transect was less than 2% of the source or close to the background level at all locations except a seaward well closest to the applied location, indicating that the tracer applied was diluted or washed out from the beach during the application. Thus, in situations where oil biodegradation is limited by the availability of nutrients and/or dissolved oxygen, applying the chemicals on the beach surface would most likely not enhance oil biodegradation as the applied chemicals would be greatly diluted prior to reaching the oil. Thus, deep injection of nutrients and/or dissolved oxygen is probably the only option for enhancing oil biodegradation.     

The FAIR model: A tool to analyse environmental and costs implications of regimes of future commitments

This article describes the policy decision-support tool, FAIR, to assess the environmental and abatement costs implications of international regimes for differentiation of future commitments. The model links long-term climate targets and global reduction objectives with regional emission allowances and abatement costs, accounting for the Kyoto Mechanisms used. FAIR consists of three sub-models: a simple climate model, an emission-allocation model and a cost model. The article also analyses ten different rule-based emission allocation schemes for two long-term concentration stabilisation targets for greenhouse gases. This analysis shows that evaluating regimes requires not only an assessment of the initial allocation, but also of the distribution of abatement costs and the impacts from emissions trading. The Multi-Stage approach (with a gradual increase of Parties adopting emission intensity or reductions targets) and the Triptych approach (with sectoral targets for all Parties) seem to provide the best prospects for most of the Parties when compared to the other allocation schemes analysed.