Richard Lord

Influence of electrical fields (AC and DC) on phytoremediation of metal polluted soils with rapeseed (Brassica napus) and tobacco (Nicotiana tabacum)

The combined use of electrokinetic remediation and phytoremediation to decontaminate soil polluted with heavy metals has been demonstrated in a laboratory-scale experiment. The plants species selected were rapeseed and tobacco. Three kinds of soil were used: un-contaminated soil from forest area (S1), artificially contaminated soil with 15mgkg(-1) Cd (S2) and multi-contaminated soil with Cd, Zn and Pb from an industrial area (S3). Three treatment conditions were applied to the plants growing in the experimental vessels: control (no electrical field), alternating current electrical field (AC, 1Vcm(-1)) and direct current electrical field (DC, 1Vcm(-1)) with switching polarity every 3h. The electrical fields were applied for 30d for rapeseed and 90d for tobacco, each experiment had three replicates. After a total of 90d growth for rapeseed and of 180d for tobacco, the plants were harvested. The pH variation from anode to cathode was eliminated by switching the polarity of the DC field. The plants reacted differently under the applied electrical field. Rapeseed biomass was enhanced under the AC field and no negative effect was found under DC field. However, no enhancement of the tobacco biomass under the AC treatment was found. The DC field had a negative influence on biomass production on tobacco plants. In general, Cd content was higher in both species growing in S2 treated with AC field compared to the control. Metal uptake (Cd, Cu, Zn and Pb) per rapeseed plant shoot was enhanced by the application of AC field in all soils.

An overview of the PGE concentrations in the Shetland ophiolite complex

Abstract Extremely anomalous platinum-group element (PGE) concentrations are known at one site, Cliff, in the Shetland ophiolite complex. Systematic PGE analysis of all the mafic and ultramafic igneous and alteration lithologies in the ophiolite has revealed many lower grade anomalous PGE occurrences throughout the cumulate ultramafic sequence and their distribution is described here. More sites with PGE enrichments as anomalous as those at Cliff have not been found. At Cliff the anomalous values of over 60 ppm Pt + Pd are restricted to a chromite-rich sulphide-bearing dunite forming a small part of a 200 m dunite lens in mantle harzburgite close to the basal thrust of the ophiolite. Lower values of up to 6.4 ppm Pt + Pd occur in chromite-poor, sulphide-rich dunites also within this dunite lens. The only other chromite-rich dunite lens in the Cliff area also has detected Pt and Pd but with low Pt + Pd values of 200 ppb. In contrast, harzburgites, metasediments underlying the basal thrust, serpentinites from the basal thrust and internal faults are all barren of Pt and Pd (detection limit = 20 ppb). In the Cliff area, therefore, detected PGE values are restricted to magmatic chromite-rich dunite lenses. PGE analyses of drill core from beneath the disused chromite quarries at Cliff are low (227 ppb Pt + Pd) indicating that the extremely anomalous PGE values are very restricted. This supports the idea that PGE, concentrated magmatically within the dunite lens at Cliff, may have been remobilized locally to produce extremely anomalous PGE values in an alteration zone only a few metres in diameter. Elsewhere in the ophiolite, anomalous Pt + Pd values of up to 4 ppm occur in chromite-rich, sulphide-bearing dunite within the dunite unit, which stratigraphically overlies the harzburgite. Pt + Pd concentrations of up to 1 ppm are present in the pyroxenites and wehrlites of the upper part of the ultramafic sequences. High-level wehrlites and pyroxenites within the gabbro unit, representing late ultramafic differentiates, contain lower levels of PGE of up to 310 ppb Pt + Pd. The gabbros all have less than 20 ppb Pt and Pd. This distribution indicates that the PGE concentrations occur in specific primary magmatic lithologies and pathfinder analysis shows that they are associated with Ni, Cu, Au and Cr. PGE have not been found above detection limits in fault zones away from primary PGE mineralization sites and it is concluded that PGE are not significantly hydrothermally reconcentrated. At Cliff, remobilization may have occurred over short distances of only a few metres at most.

Environmental Impact Assessment, ecosystems services and the case of energy crops in England

A consequence of the increased requirements for renewable energy is likely to be allocation of more land to bio-energy crop production. Recent regulatory changes in England, as in other parts of the UK, mean that changes in land-use are increasingly subject to screening through Environmental Impact Assessment (EIA). This paper reviews these regulatory changes and explores the potential benefits of incorporating a fuller examination of ecosystem services within EIA procedures. The authors argue that such an approach could help achieve sustainability by identifying the best options within an area, rather than concentrating on the negative effects of selected proposed projects. It could also help highlight the benefits provided by existing and proposed agricultural, forestry, peri-urban and urban systems. However, successful implementation of an ecosystem services approach would also require a greater understanding of the societal preferences for the full range of ecosystem services at a landscape scale, aswell as the trade-offs and synergies between uses of specific services.

Biomass, remediation, re-generation (bioregen life project): reusing brownfield sites for renewable energy crops

Biomass fuel composition is compared to host soil contamination for energy crops grown on five contrasting sites in NE England. These include three contaminated brownfield sites and control sites in both urban and rural settings. Fuel quality is compared for willow (Salix spp.) short rotation coppice (SRC), miscanthus (Miscanthus spp.), reed canarygrass (Phalaris arundinacea) and switchgrass (Panicum virgatum). The information is used to assess the potential for long-term remediation of contaminated land during energy crop growth. Concentrations of Zn and Cd are consistently higher in SRC willow for a given site, whereas the grasses have higher ash contents, which are richer in SiO2 but lower in K2O. Initial actions of the full-scale demonstration plantings carried out under the Life III Environment Programme are described together with an analysis of the wider economic, environmental and social benefits of this sustainable type of reuse of derelict brownfield land and carbon neutral approach to remediation.

Regional lead isotope study of a polluted river catchment: River Wear, Northern England, UK

High precision, lead isotope analyses of archived stream sediments from the River Wear catchment, northeast England (1986-88), provide evidence for three main sources of anthropogenic lead pollution; lead mining, industrial lead emissions and leaded petrol. In the upper catchment, pollution is totally controlled and dominated by large lead discharges from historic mining centres in the North Pennine Orefield ((208)Pb/(206)Pb, (207)Pb/(206)Pb ratios range from 2.0744-2.0954 and 0.8413-0.8554 respectively). In the lower catchment, co-extensive with the Durham Coalfield and areas of high population density, pollution levels are lower and regionally more uniform. Isotope ratios are systematically higher than in the upper catchment ((208)Pb/(206)Pb, (207)Pb/(206)Pb ratios range from 2.0856-2.1397 and 0.8554-0.8896 respectively) and far exceed values determined for the geogenic regional background. Here, the pollution is characterised by the atmospheric deposition of industrial lead and petrol lead. Lead derived from the combustion of coal, although present, is masked by the other two sources. Recent sediments from the main channel of the River Wear are isotopically indistinguishable from older, low order stream sediments of the North Pennine Orefield, indicating that contamination of the river by lead mining waste (up to several 1000 mg/kg Pb at some locations) continues to pose an environmental problem; a pattern that can be traced all the way to the tidal reach. Using within-catchment isotope variation and sediment lead concentrations, estimates can be made of the discharges from discrete mines or groups of mines to the overall level of lead pollution in the River Wear. As well as providing information pertinent to source apportionment and on-going catchment remediation measures, the database is a valuable resource for epidemiologists concerned with the health risks posed by environmental lead.

Bioremediation of Petroleum Sludge using Bacterial Consortium with Biosurfactant

Several strategies have been attempted for bioremediation of hydrocarbonpolluted sites. Bioaugmentation with designed bacterial consortium, followed by the addition of rhamnolipid biosurfactant and NPK solution to soils contaminated with up to 10% tank bottom sludge, enhanced the rate of biodegradation over a period of 56 days. Pre-treatment of hydrocarbon contaminated soil with biosurfactants enhanced bioavailability of the hydrocarbons to microbial population. Furthermore, supplementation with inorganic nutrients like NPK solution enhanced the secondary successions of crude petroleum utilizers. For bioremediation, a single inoculation with the biosufactant-producing hydrocarbon degrading bacterial consortium at the beginning of the process would reduce the cost of inoculum preparation considerably. Hence we suggest a combined treatment as a possible bioremediation technology for the reclamation of oil sludge polluted soils.

Metal contamination of active stream sediments in upper Weardale, northern Pennine Orefield, UK.

In the Upper Weardale area the headwaters of the River Wear bisect the Northern Pennine Orefield, where Pb-Zn-F-Ba vein-type mineralisation has been exploited since the Roman Conquest. The area contains evidence of open pit, underground and hydraulic mining of base metal ores, associated mineral processing and smelting, exploitation of ironstones during the industrial revolution, recent extraction of fluorite and active quarrying. The aim of this study was to determine the extent of modern sediment contamination arising from these past activities. Samples of active stream sediments were collected from all major drainage channels at 1 km intervals. The sediments were analysed for Pb, Zn, Ba, Mn, Fe, Co, Ni, Cu, Cr, As, Sb, Ag and compared to data from earlier regional geochemical surveys of low order drainage samples using ArcView software. The significance of contamination levels was assessed using the Ontario aquatic sediment quality guidelines. Our results indicate widespread contamination of some major drainages by Pb, Mn, Zn and As at concentration levels anticipated to significantly affect use of the sediments by benthic organisms. Furthermore, Pb contamination shows persistence in stream sediments downstream towards agricultural areas of the floodplain and drinking water abstraction points, above which interaction with colliery mine water discharges may occur.

Development of a visual whole life-cycle energy assessment framework for built environment

The United Nations Framework Convention on Climate Change (UNFCC) adopted the Kyoto protocol, establishing legally binding targets for the developed world countries that ratified the protocol. It aims to reduce greenhouse gas emissions by an overall 5% below 1990 levels during the period between 2008 and 2012. Our review of current literature and research projects in the area of sustainability, energy and assessment applied to built environment identified gaps in current knowledge and tools. There is also a need to integrate sustainability within the whole life cycle of a building from design through construction to operation. This paper aims to give an overall review of the knowledge and technologies in the research area. We present a framework, methodologies and technologies that will facilitate the integration of Environmental Impact Assessment (EIA), Whole Life Cycle Cost Assessment (WLCCA) and Life Cycle Assessment (LCA) using 3D and Building Information Model (BIM) technologies.

Bioremediation of hydrocarbon contaminated gasoline station soil by a bacterial consortium

A study was undertaken to find methods for enhancing rates of hydrocarbon biodegradation in gasoline-contaminated soil by ex-situ bioremediation. Garden soil was treated with gasoline-spilled soil from a gasoline station and different combinations of amendments were prepared using mixed bacterial consortium, poultry litter, coir pith and rhamnolipid biosurfactant produced by Pseudomonas aeruginosa. Bacterial growth, hydrocarbon degradation and growth parameters of Phaseolus aureus RoxB (including seed germination, chlorophyll content, shoot and root length) were measured for a period of 90 days. Approximately 78% of the hydrocarbons were effectively degraded within 60 days in soil samples amended with all additives. Maximum germination rate, shoot length, root length and chlorophyll content in Phaseolus aureus were each recorded after 60 days. Further incubation to 90 days did not cause significant improvements. Statistical analysis using Analysis of Variance and Duncan’s Multiple Range test revealed that the level of amendments, incubation time and combination of amendments significantly influenced bacterial growth, hydrocarbon degradation, seed germination and chlorophyll content (1% probability level). All tested additives, including rhamnolipid biosurfactant, had significant positive effects on the bioremediation of gasoline-contaminated soils.

Comprehensive database of Manufactured Gas Plant tars – Part A Database

RATIONALE Coal tars are a mixture of organic and inorganic compounds that were by-products from the manufactured gas and coke making industries. Different manufacturing processes have resulted in the production of distinctly different tar compositions. This study presents a comprehensive database of compounds produced using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS), analysing 16 tar samples produced by five distinct production processes. METHODS Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatised post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatised samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). RESULTS A total of 16 tar samples originating from five different production processes: Low Temperature Horizontal Retorts, Horizontal Retorts, Vertical Retorts, Carbureted Water Gas and Coke Ovens, were analysed. A total of 2369 unique compounds were detected with 948 aromatic compounds, 196 aliphatic compounds, 380 sulfur-containing compounds, 209 oxygen-containing compounds, 262 nitrogen-containing compounds and 15 mixed heterocycles. Derivatisation allowed the detection of 359 unique compounds, the majority in the form of hydroxylated polycyclic aromatic hydrocarbons, many of which would not have been detected without derivatisation. Of the 2369 unique compounds detected, 173 were found to be present within all samples. CONCLUSIONS A unique comprehensive database of compounds detected within 16 tar samples from five different production processes was produced. The 173 compounds identified within every sample may be of particular importance from a regulatory standpoint. This initial study indicates that different production processes produce tars with different chemical signatures and it can be further expanded upon by in-depth analysis of the different compound types. The number of compounds presented within this database clearly demonstrates the analytical power of GCxGC/TOFMS.