Magnetic ion exchange treatment of stabilized landfill leachate

Stabilized landfill leachate is characterized by a high concentration of non-biodegradable organic matter, which is similar in chemistry to dissolved organic matter (DOM) in the natural aquatic environment. Magnetic ion exchange (MIEX) resin treatment is well-studied in drinking water for removal of DOM from natural waters. There are fewer studies evaluating MIEX treatment of waste waters, and there is no previous work evaluating MIEX treatment of landfill leachate. This work systematically evaluated MIEX treatment of stabilized landfill leachate and evaluated the results in the context of previous studies of MIEX treatment of natural and waste waters. Five leachates from four landfills were evaluated as a function of MIEX resin dose, mixing time, and regeneration efficiency. MIEX resin removed DOM from landfill leachate, even in the presence of a reported high background concentration of inorganic ions. MIEX resin that was exhausted with leachate DOM was effectively regenerated with a concentrated NaCl solution, and regenerated MIEX resin performed similarly to virgin resin. For a majority of the leachates, the removal trend for MIEX resin was color > UV-absorbing substances > dissolved organic carbon ≈ COD > total nitrogen. Finally, MIEX resin removed a wider range of DOM from leachate than coagulation. The most important contribution of this work is that MIEX treatment of leachate followed very similar trends as MIEX treatment of natural waters, which will allow previous MIEX data to be used to estimate the treatment efficiency of other waste waters.     

Assessing the recovery potential of alpine moss-sedge heath: reciprocal transplants along a nitrogen deposition gradient

The potential of alpine moss-sedge heath to recover from elevated nitrogen (N) deposition was assessed by transplanting Racomitrium lanuginosum shoots and vegetation turfs between 10 elevated N deposition sites (8.2-32.9 kg ha⁻¹ yr⁻¹) and a low N deposition site, Ben Wyvis (7.2 kg ha⁻¹ yr⁻¹). After two years, tissue N of Racomitrium shoots transplanted from higher N sites to Ben Wyvis only partially equilibrated to reduced N deposition whereas reciprocal transplants almost matched the tissue N of indigenous moss. Unexpectedly, moss shoot growth was stimulated at higher N deposition sites. However, moss depth and biomass increased in turfs transplanted to Ben Wyvis, apparently due to slower shoot turnover (suggested to result partly from decreased tissue C:N slowing decomposition), whilst abundance of vascular species declined. Racomitrium heath has the potential to recover from the impacts of N deposition; however, this is constrained by the persistence of enhanced moss tissue N contents.     

Effect of fresh green waste and green waste compost on mineral nitrogen, nitrous oxide and carbon dioxide from a Vertisol

Incorporation of organic waste amendments to a horticultural soil, prior to expected risk periods, could immobilise mineral N, ultimately reducing nitrogen (N) losses as nitrous oxide (N₂O) and leaching. Two organic waste amendments were selected, a fresh green waste (FGW) and green waste compost (GWC) as they had suitable biochemical attributes to initiate N immobilisation into the microbial biomass and organic N forms. These characteristics include a high C:N ratio (FGW 44:1, GWC 35:1), low total N (<1%), and high lignin content (>14%). Both products were applied at 3 t C/ha to a high N (plus N fertiliser) or low N (no fertiliser addition) Vertisol soil in PVC columns. Cumulative N₂O production over the 28 day incubation from the control soil was 1.5 mg/N₂O/m², and 11 mg/N₂O/m² from the control + N. The N₂O emission decreased with GWC addition (P < 0.05) for the high N soil, reducing cumulative N₂O emissions by 38% by the conclusion of the incubation. Analysis of mineral N concentrations at 7, 14 and 28 days identified that both FGW and GWC induced microbial immobilisation of N in the first 7 days of incubation regardless of whether the soil environment was initially high or low in N; with the FGW immobilising up to 30% of available N. It is likely that the reduced mineral N due to N immobilisation led to a reduced substrate for N₂O production during the first week of the trial, when soil N₂O emissions peaked. An additional finding was that FGW + N did not decrease cumulative N₂O emissions compared to the control + N, potentially due to the fact that it stimulated microbial respiration resulting in anaerobic micro sites in the soil and ultimately N₂O production via denitrification. Therefore, both materials could be used as post harvest amendments in horticulture to minimise N loss through nitrate-N leaching in the risk periods between crop rotations. The mature GWC has potential to reduce N₂O, an important greenhouse gas.     

Preventing corruption in humanitarian assistance: perceptions, gaps and challenges

Corruption is a threat to the purpose of humanitarian assistance. Until fairly recently, humanitarian assistance has not been considered an important arena in broader efforts aimed at curbing corruption, and corruption has not always been considered a particularly important concern for humanitarian assistance despite the obviously challenging nature of the context of humanitarian emergencies. Corruption, though, is a threat to humanitarian action because it can prevent assistance from getting to the people who most need it, and because it can potentially undermine public support for such assistance. This paper examines perceptions of corruption and its affects, documents best practices, and outlines gaps in understanding. It suggests recommendations for improving the capacity of humanitarian agencies to prevent and manage the risk of corruption. Agencies have taken steps to combat corruption and improve accountability--downwards and upwards--but scope remains for improvement and for greater sharing of learning and good practice.     

Influence of fish size and sex on mercury/PCB concentration: importance for fish consumption advisories

Fish advisories for polychlorinated biphenyls (total-PCBs) and mercury are often given on a length-specific basis and fish sex is usually not considered. The relationship between concentration and length is well established for mercury, however its suitability for total-PCBs and the influence of sex over the large scale covered by most monitoring programs is not well known. Here we use what is perhaps the largest consistent sport fish contaminant dataset to evaluate the relationship between total-PCB/mercury and length and sex. We evaluated seven of the most commonly consumed fishes from the Canadian Great Lakes and two Ontario (Canada) inland lakes. For mercury, the relationship between concentration and length was significant (p<0.05) in most fish species and locations. For total-PCB, this relationship was also generally significant in Chinook salmon and lake trout, which are the species with the most advisories for this compound. In contrast, significant relationships were found less often for whitefish, northern pike, smallmouth bass, walleye, and especially yellow perch. However, mercury usually drives fish consumption advisories for these species. Overall, our results support the protocol of issuing contaminant advice on a length-specific basis in fish monitoring programs with reasonable confidence when at least a moderate number of samples over the natural size range of a species are included in the analysis. Sex differences were common for walleye (males>females, p<0.05) but not other species, suggesting that an equal number of male and female walleye should be used in deriving fish advisories for walleye.     

Aerial measurement of radioxenon concentration off the west coast of Vancouver Island following the Fukushima reactor accident

In response to the Fukushima nuclear reactor accident, on March 20th, 2011, Natural Resources Canada conducted aerial radiation surveys over water just off the west coast of Vancouver Island. Dose-rate levels were found to be consistent with background radiation, however a clear signal due to ¹³³Xe was observed. Methods to extract ¹³³Xe count rates from the measured spectra, and to determine the corresponding ¹³³Xe activity concentration, were developed. The measurements indicate that ¹³³Xe concentrations on average lie in the range of 30-70 Bq/m³.     

Innovation in the minerals industry: Australia in a global context

The pattern of innovation in the global minerals industry is changing as the industry becomes increasingly globalised. In this paper, we look at the structure of innovation in the industry and the drivers of change. We first consider the broad international trends and then examine these more closely with special reference to the Australian industry. Issues addressed include the apparent decline in corporate research and development spending, changing patterns in research collaboration and outsourcing, and the uptake of information and communication technologies in the industry. We also look at the potential implications of these trends for step-change technological developments and at the role of technological innovation in the future development of the industry.     

Agri-environmental schemes: their role in reversing floral decline in the Brue floodplain, Somerset, UK

This paper explores whether the introduction of an agri-environmental scheme has altered the course of long-term trends in plant species abundance in the Somerset Levels and Moors Environmentally Sensitive Area (ESA), UK. A semi-quantitative approach has been taken which integrates disparate but important historical datasets relating to flora and land management with more contemporary digital information. Species datasets from four time periods throughout the 20th century have been collated within a Geographic Information System and analysed with respect to ancillary data relating to elevation, under-drainage and ESA designation. Qualitative reconstruction of the historical ecology of this internationally important area of lowland wet grassland showed that a steady decline in abundance and extent of key components of the flora had already started by 1900. Analysis of historical under-drainage records dating from 1940s to 1980s showed a clear link between the length of time an area had been under-drained and the subsequent diversity of flora recorded in later surveys. In addition, the relative persistence of the rarer components of the wetland flora between surveys in 1980 and 1997 was related to the spatial pattern of under-drainage on the site since 1940. When overall species diversity was compared before and after ESA designation (1980-1997) there was some evidence of an increase in the number of species present and their spatial extent. The historical dataset provided useful contextual information with respect to species trends and allowed the interpretation of contemporary datasets to be placed within a longer timeframe. This pilot study using 18 species gives some evidence that long-established trends in species decline in the Somerset Levels and Moors ESA are starting to be reversed.     

Development and validation of a method for analysis of "dioxin-like" PCBs in environmental samples from the steel industry

A method, previously used for determination of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), has been modified for quantitative analysis of "dioxin-like" polychlorobiphenyls (PCBs) in environmental samples from the steel industry. The existing sample clean-up procedure, involving liquid chromatography on multi-layered silica and Florisil columns, has been extended to include a third chromatography stage on a basic alumina stationary phase. The additional clean-up stage is required for PCB analysis in order to eliminate interferences from relatively large concentrations of saturated cyclic and aliphatic hydrocarbons. Samples were analysed for WHO-12 congeners using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) and standard solutions of the method US EPA 1668A. Replicate analysis of method blanks revealed background contamination for PCBs 118, 105 and 77, which are generally abundant in ambient air. These contaminants were taken into account using a subtraction method. The entire procedure was validated by replicate analysis (N = 3) of a certified reference sediment. The RSD for each WHO-12 congener was below 15%, 13C12-labelled PCB internal standard recoveries were in the range 70-95%. A waste dust sample collected in the electrostatic precipitator of a UK sinter plant was analysed for determination of PCDD/Fs and WHO-12 PCBs and exhibited a PCDD/F I-TEQ of 148.5 +/- 21.2 ngkg(-1) and a WHO-TEQ of 7.2 +/- 1.5 ngkg(-1). WHO-12 congeners contributed only 4.6% to the overall TEQ and PCB 126 was the major congener contributing to the WHO-TEQ (96%). The contribution to the overall TEQ of the waste dust sample was mainly attributed to PCDF followed by PCDD, which accounted for 86.6% and 8.7% to the overall TEQ, respectively.     

Adjusting irrigation abstraction to minimise the impact on stream flow in the East of Scotland

Abstractions of surface and groundwater for irrigation in Scotland are currently subject to control in only two small catchments. Under the terms of the EU Water Framework Directive, it will be necessary to introduce new legislation to control abstractions elsewhere. To help in the development of appropriate policy for Scotland a study has been carried out to examine the significance of irrigation and the effectiveness of different types of control strategies in terms of the economics of potato cropping and stream hydrology in Scotland. This paper presents the findings of the hydrological study and highlights some of the spatial and temporal issues that need to be considered in the selection of control mechanisms, if they are to be successful in achieving objectives for environmental improvement.The study was focussed on two catchments in the east of Scotland, the Tyne and West Peffer. The effectiveness of several different abstraction control strategies was examined to see how stream flows in the catchment would be modified by their implementation. The results of the study demonstrated that the West Peffer catchment in particular is significantly affected by irrigation abstractions. Control mechanisms based on allowable monthly abstraction volumes and flow-based abstraction bans would be of considerable help in restoring stream flows to their natural levels, but would modify the hydrological regime in slightly different ways. A spatial analysis of stream flows demonstrated that implementation of controls based on a single monitoring point may be ineffective at maintaining acceptable levels of flow throughout the catchment and that this may require a tighter control at the monitoring point.