Arrested municipal solid waste incinerator fly ash as a source of heavy metals to the UK environment

Arrested fly ash samples from most currently operating municipal solid waste (MSW) incinerators in the UK have been analysed for a range of elements. Some of the more important heavy metals ranged in concentration as follows: Cd, 21-4646 (median = 271) mg kg(-1); Cu, 296-1307 (642) mg kg(-1); Cr, 44-1328 (574) mg kg(-1); Ni, 45-2204 (74) mg kg(-1); Pb, 447-9704 (4337) mg kg(-1); and Zn, 2285-13,500 (9232) mg kg(-1). These concentrations represent considerable enrichments relative to median UK soil concentrations. Enrichment ratios (defined as median fly ash: median UK soil) were as follows: Mn 1.6; Co 2.6; Ni 3.3; Ba 11; Sr 11; Cr 15; Cu 35; Pb 108; Zn 113; Cd 387. It is estimated that MSW incinerator ash contributes c. 15 t Cd and 241 t Pb to UK landfill sites per annum. These figures compare with previous studies by Hutton & Symon (Hutton, M. & Symon, C. (1986). The quantities of cadmium, lead, mercury and arsenic entering the UK environment from human activities. Sci. Total Environ., 57, 129-50.) which estimated that annual inputs to UK landfills from coal fly ash are c. 60 t Cd and 1270 t Pb. However, it is argued that metals associated with MSW ashes are potentially of greater environmental significance than in coal ashes, because they are much more available and present at much higher concentrations.     

Investigation of geothermal energy utilization for thermal regulation of aquaculture raceway

ABSTRACT

Aquaculture raceway temperature has a direct impact on the aquatic specie being reared. In regions that undergo significant seasonal temperature variations, the thermal management of the raceway temperature becomes a challenge, directly impacting the production yield. This study investigates a novel approach to regulate the raceway temperature in a sustainable way by utilizing geothermal energy. A numerical energy model was developed to simulate heat transfer in a geothermal system encompassing both the individual borehole heat exchangers and their thermal interactions. Simulations were conducted for different configurations of the geothermal system over a complete seasonal cycle. Results show that flow rate, number of boreholes and the borehole spacing influence the temperature of the fluid at the raceway inlet. An increase in the number of boreholes provided better thermal regulation but an increase in the flow rate through the boreholes provided less thermal regulation. A borehole spacing of 6 m was found to be appropriate to reduce thermal interference. It was also observed that an increase in the fraction of the fluid passed through the geothermal system enhances the overall thermal regulation, with higher thermal regulation at lower flow rates. Results show that when 100% of the fluid passed through a 64 boreholes geothermal system, the average regulated raceway inlet temperature was 23% higher in winter months and 16% lower in summer months at the flow rate of 21.5 L/s compared to than at 43 L/s.     

Integrating total cost assessment with new management practices and mandates

Today's environmental manager cannot afford to operate in a vaccum, but continually adjusts to the latest management initiatives, whether it is Activity Based Costing, ISO 14000, or Total Quality Management. These paradigms offer an excellent structure to view process improvements and implement changes, however, they all tend to miss the mark in one critical area—quantifying and tracking the true cost of environmental management. The recent upsurge of interest in Total Cost Assessment (TCA) is proof positive that, although many excellent management programs exist, something is still missing. In this article, the author shows how using TCA in conjunction with these practices enhances their effectiveness and shows the total picture of environmental management costs.     

The need to consider time,level, and trends: A turnover perspective

We focus on the contributions to research generated by considering attitudes and behaviors as dynamic over time and across different levels. Using turnover research as an example, we demonstrate how a past, present, and future focus, across levels, may enhance both theory and methodology. Copyright © 2013 John Wiley & Sons, Ltd.     

PICABUE: a methodological framework for the development of indicators of sustainable development

SUMMARY

Significant interest in the concept of sustainable development exists amongst scientists, planners, policy makers and the public, and considerable effort and expenditure is made or envisaged at local, national and international levels to promote a more sustainable society. Until ‘green accounting’ and similar systems are made available and are implemented, the sustainability indicator will be the most effective tool available for monitoring progress towards a more sustainable society. Sustainability indicators are already available but are characterized by a poor or absent theoretical underpinning. This paper addresses this problem by proposing a methodological framework that can be applied to the construction of indicators of sustainable development. In order to be consistent with widely accepted definitions of sustainable development, considerations relating to the measurement of quality of life and ecological integrity are central to the methodology. The methodological framework has relevance to a variety of spatial scales and to geographically diverse areas (urban or rural, developed or developing countries) so that a suite of sustainability indicators can be produced that is tailored to the needs and resources of the indicator user, but which remains rooted firmly in the fundamental principles of sustainable development.     

Ontogenetic differences in chemical alarm cue production determine antipredator responses and learned predator recognition

How individuals assess, respond and subsequently learn from alarm cues is crucial to their survival and future fitness. Yet this information is not constant through time; many individuals are exposed to different predators throughout their life as they outgrow some predators or move to habitats containing different predators. To maximise overall fitness, individuals should discriminate between different cues and respond and learn from only those that are relevant to their current ontogenetic stage. We tested whether juvenile spiny chromis, Acanthochromis polyacanthus, could distinguish between chemical alarm cues from conspecific donors of different ontogenetic stages and whether the cue ontogenetic stage of the cue donor affected the efficacy of learning about predators. Juveniles displayed a significant antipredator response when conditioned with juvenile chemical alarm cues paired with predator odour but failed to respond when conditioned with predator odour paired with either adult alarm cues or with saltwater. Subsequently, individuals only recognised the predator odour alone as a threat when conditioned with juvenile alarm cues. This demonstrates that prey may be highly specific in how they use information from conspecific alarm cues, selectively responding to and learning from only those cues that are relevant to their developmental stage.     

A pilot study on iodine in soils of Greater Kabul and Nangarhar provinces of Afghanistan

A robust and rapid methodology for the determination of iodine by inductively coupled plasma mass spectrometry in environmental samples is presented. Data were initially obtained for the validation of the analytical measurements, using 17 commercially available soil reference materials. The methodology was then tested on soil and water samples collected in Afghanistan where iodine deficiency and its effects are reportedly prevalent. Sample collections were conducted in Greater Kabul; the iodine in agricultural soils was determined to be in the range of 1.6–4.2 mg/kg and that in water drawn for drinking and irrigation was found to range from 9.9 to 22.7 μg/L. Samples were also collected in a second region, Nangarhar province, which is located to the east of Kabul, where goitres in the local population had been reported. The iodine content in soils and water at this location was 0.5–1.9 mg/kg and 5.4–9.4 μg/L, respectively. The organic content of soils in Kabul was found to be in the range of 1.9–4.2%; in Nangarhar, organic content ranged from 1.7 to 4.5%. All of the Afghan soils were slightly alkaline at pH 7.6–8.2.     

Asymmetric competition via induced resistance: specialist herbivores indirectly suppress generalist preference and populations

Species may compete indirectly by altering the traits of a shared resource. For example, herbivore-induced responses in plants may make plants more resistant or susceptible to additional herbivorous insect species. Herbivore-induced plant responses can significantly affect interspecific competition and herbivore population dynamics. These herbivore-herbivore indirect interactions have been overlooked in aquatic ecosystems where previous studies used the same herbivore species to induce changes and to assess the effects of these changes. We asked whether seaweed grazing by one of two herbivorous, congeneric snail species (Littorina obtusata or Littorina littorea) with different feeding strategies and preferences would affect subsequent feeding preferences of three herbivore species (both snails and the isopod Idotea baltica) and population densities of three herbivore species (both snails and a third periwinkle snail, Lacuna vincta). In addition, we measured phlorotannin concentrations to test the hypothesis that these metabolites function as induced defenses in the Phaeophyceae. Snail herbivory induced cue-specific responses in apical tissues of the seaweed Fucus vesiculosus that affected the three herbivore species similarly. When compared to ungrazed controls, direct grazing by Littorina obtusata reduced seaweed palatability by at least 52% for both snail species and the isopod species. In contrast, direct grazing by L. littorea did not decrease seaweed palatability for any herbivore, indicating herbivore-specific responses. Previous grazing by L. obtusata reduced populations of L. littorea on outplanted seaweeds by 46% but had no effect on L. obtusata populations. Phlorotannins, a potential class of inducible chemicals in brown algae, were not more concentrated in grazed seaweed tissues, suggesting that some other trait was responsible for the induced resistance. Our results indicate that marine herbivores may compete via inducible responses in shared seaweeds. These plant-mediated interactions were asymmetric with a specialist (L. obtusata) competitively superior to a generalist (L. littorea).