Parys Mountain Research Articles

Long-term changes in water quality downstream of three abandoned metal mines

Abandoned metal mines pollute rivers with both acidic and circumneutral metal-rich waters, sometimes from well-mapped mines, but often from long-abandoned adits with limited historical records. Changes in water quality over the monitored timescales were calculated for three mines across Wales (Nantymwyn, Parys Mountain and Frongoch), each abandoned since the early 20th century. Using all available spot sampling data provided by the environmental regulator, it was found that there was a sustained input of metals to the receiving watercourses with no or limited reduction in the concentrations from the mines without remediation, despite the passage of time and impacts of weathering. At Nantymwyn, comparison with five months’ sampling in 2019 showed no significant change (p > 0.05) in metal concentrations compared to the same months in 1985. Parys Mountain showed an increase in filtered zinc concentrations of 2 % between 2004 and 2020. At Frongoch, however, a substantial reduction in its environmental impact was observed after remediation, including a 90 % reduction in total lead concentrations. Realisation that the pollution from these sites does not reduce over the decades since abandonment should galvanize the resolve to understand the highest priority sites, and where possible remediate them.

Passive remediation of mine waters from Parys Mountain (Wales): Laboratory column experiments

This study evaluates the effectiveness of dispersed alkaline substrate (DAS) technology to treat highly acidic and contaminated leachates from the oxidation of sulfide-rich mining wastes under wet temperate oceanic climate conditions. To address this issue, leachates from the abandoned mine at Parys Mountain (NW Wales) were passed through two sets of multistep columns filled with a mixture of a fine-grained alkaline reagent (i.e., limestone, MgO, or BaCO3) scattered in an inert matrix. The set of columns with the limestone-DAS plus MgO-DAS combination achieved a near total removal of Fe, Al, Zn, Cu, Mn, As, Co, Cd, and Ni. However, the elimination of SO4 was not significant (around 7%). The limestone-DAS plus BaCO3-DAS combination also achieved a high effectiveness for base metal/loids, allowing the removal of Fe, Al, Zn, Cu, As, and Cd with rates of nearly 100%. In addition, the system with the BaCO3-step had a higher effectiveness in eliminating SO4 (around 53%) than the combined treatment with the MgO-step. According to PHREEQC code calculations, the precipitation of oxy-hydroxy-sulfates (i.e., schwertmannite and basaluminite) and carbonate (i.e., malachite, hydrozincite and calcite) phases may have controlled the solubility of pollutants during the passive treatment. The chemical compositions of the treated waters complied with the threshold values defined by irrigation standards, except for Mn in the BaCO3-DAS output.

Evolutionary patterns of archaea predominant in acidic environment

BackgroundArchaea of the order Thermoplasmatales are widely distributed in natural acidic areas and are amongst the most acidophilic prokaryotic organisms known so far. These organisms are difficult to culture, with currently only six genera validly published since the discovery of Thermoplasma acidophilum in 1970. Moreover, known great diversity of uncultured Thermoplasmatales represents microbial dark matter and underlines the necessity of efforts in cultivation and study of these archaea. Organisms from the order Thermoplasmatales affiliated with the so-called “alphabet-plasmas”, and collectively dubbed “E-plasma”, were the focus of this study. These archaea were found predominantly in the hyperacidic site PM4 of Parys Mountain, Wales, UK, making up to 58% of total metagenomic reads. However, these archaea escaped all cultivation attempts.ResultsTheir genome-based metabolism revealed its peptidolytic potential, in line with the physiology of the previously studied Thermoplasmatales isolates. Analyses of the genome and evolutionary history reconstruction have shown both the gain and loss of genes, that may have contributed to the success of the “E-plasma” in hyperacidic environment compared to their community neighbours. Notable genes among them are involved in the following molecular processes: signal transduction, stress response and glyoxylate shunt, as well as multiple copies of genes associated with various cellular functions; from energy production and conversion, replication, recombination, and repair, to cell wall/membrane/envelope biogenesis and archaella production. History events reconstruction shows that these genes, acquired by putative common ancestors, may determine the evolutionary and functional divergences of “E-plasma”, which is much more developed than other representatives of the order Thermoplasmatales. In addition, the ancestral hereditary reconstruction strongly indicates the placement of Thermogymnomonas acidicola close to the root of the Thermoplasmatales.ConclusionsThis study has analysed the metagenome-assembled genome of “E-plasma”, which denotes the basis of their predominance in Parys Mountain environmental microbiome, their global ubiquity, and points into the right direction of further cultivation attempts. The results suggest distinct evolutionary trajectories of organisms comprising the order Thermoplasmatales, which is important for the understanding of their evolution and lifestyle.

Mineralogy affects prokaryotic community composition in an acidic metal mine

The microbial ecology of acidic mine and sulfide cave ecosystems is well characterised with respect to aquatic communities, typically revealing low taxonomic complexity and dominance by a relatively limited number of cosmopolitan acidophilic bacterial and archaeal taxa. Whilst pH, temperature, and geochemistry are recognised drivers of diversity in these ecosystems, the specific question of a possible influence of substratum mineralogy on microbial community composition remains unanswered. Here we address this void, using 81 subterranean mineral samples from a low temperature abandoned, acidic, sulfide ore mine system at Mynydd Parys (Parys Mountain in English), Wales, UK. Four primary and 15 secondary minerals were identified via x-ray diffraction, each sample containing a maximum of five and an average of two minerals. The mineralogy of primary (e.g. pyrite and quartz) and secondary (e.g. melanterite and pisanite) minerals was significantly correlated with prokaryotic community structure at multiple taxonomic levels, implying that the mineralosphere effect reported in less extreme terrestrial environments is also implicated in driving prokaryotic community composition in extremely acidic, base metal-bearing sulfide mineralisation at Mynydd Parys. Twenty phyla were identified, nine of which were abundant (mean relative abundance >1%). While taxa characteristic of acidic mines were detected, for example Leptospirillum (phylum Nitrospirae), Acidithiobacillus (phylum Proteobacteria), Sulfobacillus (phylum Firmicutes) and Ferroplasma (phylum Euryarchaeota), their abundance in individual samples was highly variable. Indeed, in the majority of the 81 samples investigated the abundance of these and other typical acidic mine taxa was low, with 25% of samples devoid of sequences from recognised acidic mine taxa. Most notable amongst the bacterial taxa not previously reported in such environments were the recently cultivated Muribaculaceae family (phylum Bacteroidetes), which often dominated Mynydd Parys samples regardless of their mineralogical content. Our results pose further questions regarding the mechanisms by which taxa not previously reported in such extreme environments appear to survive in Mynydd Parys, opening up research pathways for exploring the biodiversity drivers underlying microbial community composition and function in extremely acidic mine environments.

Microbial Diversity of a Disused Copper Mine Site (Parys Mountain, UK), Dominated by Intensive Eukaryotic Filamentous Growth.

The Parys Mountain copper mine (Wales, UK) contains a wide range of discrete environmental microniches with various physicochemical conditions that shape microbial community composition. Our aim was to assess the microbial community in the sediments and overlying water column in an acidic mine drainage (AMD) site containing abundant filamentous biogenic growth via application of a combination of chemical analysis and taxonomic profiling using 16S rRNA gene amplicon sequencing. Our results were then compared to previously studied sites at Parys Mt. Overall, the sediment microbiome showed a dominance of bacteria over archaea, particularly those belonging to Proteobacteria (genera Acidiphilium and Acidisphaera), Acidobacteriota (subgroup 1), Chloroflexota (AD3 cluster), Nitrospirota (Leptospirillum) and the uncultured Planctomycetota/CPIa-3 termite group. Archaea were only present in the sediment in small quantities, being represented by the Terrestrial Miscellaneous Euryarchaeota Group (TMEG), Thermoplasmatales and Ca. Micrarchaeota (Ca. Micracaldota). Bacteria, mostly of the genera Acidiphilium and Leptospirillum, also dominated within the filamentous streamers while archaea were largely absent. This study found pH and dissolved solutes to be the most important parameters correlating with relative proportions of bacteria to archaea in an AMD environment and revealed the abundance patterns of native acidophilic prokaryotes inhabiting Parys Mt sites and their niche specificities.

High Representation of Archaea Across All Depths in Oxic and Low-pH Sediment Layers Underlying an Acidic Stream.

Parys Mountain or Mynydd Parys (Isle of Anglesey, United Kingdom) is a mine-impacted environment, which accommodates a variety of acidophilic organisms. Our previous research of water and sediments from one of the surface acidic streams showed a high proportion of archaea in the total microbial community. To understand the spatial distribution of archaea, we sampled cores (0–20 cm) of sediment and conducted chemical analyses and taxonomic profiling of microbiomes using 16S rRNA gene amplicon sequencing in different core layers. The taxonomic affiliation of sequencing reads indicated that archaea represented between 6.2 and 54% of the microbial community at all sediment depths. Majority of archaea were associated with the order Thermoplasmatales, with the most abundant group of sequences being clustered closely with the phylotype B_DKE, followed by “E-plasma,” “A-plasma,” other yet uncultured Thermoplasmatales with Ferroplasma and Cuniculiplasma spp. represented in minor proportions. Thermoplasmatales were found at all depths and in the whole range of chemical conditions with their abundance correlating with sediment Fe, As, Cr, and Mn contents. The bacterial microbiome component was largely composed in all layers of sediment by members of the phyla Proteobacteria, Actinobacteria, Nitrospirae, Firmicutes, uncultured Chloroflexi (AD3 group), and Acidobacteria. This study has revealed a high abundance of Thermoplasmatales in acid mine drainage-affected sediment layers and pointed at these organisms being the main contributors to carbon, and probably to iron and sulfur cycles in this ecosystem.

The association of microbial activity with Fe, S and trace element distribution in sediment cores within a natural wetland polluted by acid mine drainage

Natural recovery and remediation of acid mine drainage (AMD) reduces the generation of acidity and transport of trace elements in the runoff. A natural wetland that receives and remediates AMD from an abandoned copper mine at Parys Mountain (Anglesey, UK) was investigated for better understanding of the remediation mechanisms. Water column concentrations of dissolved Fe and S species, trace metal (loid)s and acidity decreased markedly as the mine drainage stream passed through the wetland. The metal (loid)s were removed from the water column by deposition into the sediment. Fe typically accumulated to higher concentrations in the surface layers of sediment while S and trace metal (loid)s were deposited at higher concentration within deeper (20–50 cm) sediments. High resolution X-ray fluorescence scans of sediment cores taken at three sites along the wetland indicates co–immobilization of Zn, Cu and S with sediment depth as each element showed a similar core profile. To examine the role of bacteria in sediment elemental deposition, marker genes for Fe and S metabolism were quantified. Increased expression of marker genes for S and Fe oxidation was detected at the same location within the middle of the wetland where significant decrease in SO42− and Fe2+ was observed and where generation of particulate Fe occurs. This suggests that the distribution and speciation of Fe and S that mediates the immobilization and deposition of trace elements within the natural wetland sediments is mediated in part by bacterial activity.

Archaea dominate the microbial community in an ecosystem with low-to-moderate temperature and extreme acidity

BackgroundThe current view suggests that in low-temperature acidic environments, archaea are significantly less abundant than bacteria. Thus, this study of the microbiome of Parys Mountain (Anglesey, UK) sheds light on the generality of this current assumption. Parys Mountain is a historically important copper mine and its acid mine drainage (AMD) water streams are characterised by constant moderate temperatures (8–18 °C), extremely low pH (1.7) and high concentrations of soluble iron and other metal cations.ResultsMetagenomic and SSU rRNA amplicon sequencing of DNA from Parys Mountain revealed a significant proportion of archaea affiliated with Euryarchaeota, which accounted for ca. 67% of the community. Within this phylum, potentially new clades of Thermoplasmata were overrepresented (58%), with the most predominant group being “E-plasma”, alongside low-abundant Cuniculiplasmataceae, ‘Ca. Micrarchaeota’ and ‘Terrestrial Miscellaneous Euryarchaeal Group’ (TMEG) archaea, which were phylogenetically close to Methanomassilicoccales and clustered with counterparts from acidic/moderately acidic settings. In the sediment, archaea and Thermoplasmata contributed the highest numbers in V3-V4 amplicon reads, in contrast with the water body community, where Proteobacteria, Nitrospirae, Acidobacteria and Actinobacteria outnumbered archaea. Cultivation efforts revealed the abundance of archaeal sequences closely related to Cuniculiplasma divulgatum in an enrichment culture established from the filterable fraction of the water sample. Enrichment cultures with unfiltered samples showed the presence of Ferrimicrobium acidiphilum, C. divulgatum, ‘Ca. Mancarchaeum acidiphilum Mia14’, ‘Ca. Micrarchaeota’-related and diverse minor (< 2%) bacterial metagenomic reads.ConclusionContrary to expectation, our study showed a high abundance of archaea in this extremely acidic mine-impacted environment. Further, archaeal populations were dominated by one particular group, suggesting that they are functionally important. The prevalence of archaea over bacteria in these microbiomes and their spatial distribution patterns represents a novel and important advance in our understanding of acidophile ecology. We also demonstrated a procedure for the specific enrichment of cell wall-deficient members of the archaeal component of this community, although the large fraction of archaeal taxa remained unculturable. Lastly, we identified a separate clustering of globally occurring acidophilic members of TMEG that collectively belong to a distinct order within Thermoplasmata with yet unclear functional roles in the ecosystem.

Is the Remediation at Parys Mountain Successfully Reducing Acid Mine Drainage?

Metal ion concentrations and acidity were used as indicators of acid mine drainage (AMD) at Parys Mountain, a large abandoned copper mine on An-glesey, Wales. Water samples were collected in two sessions and taken from a linear stream flowing from the northern side of the mine, and a stream flowing from the south side of the mine that has two settling ponds and long stretches of wetland along its path. pH measurements were taken to measure acidity levels and metal ions (Fe, Al, Zn, Cu, Mn, and Pb) were quantified by inductively coupled plasma (ICP-OES) spectrometry. The pH values at the settling ponds and northern stream were between 2 and 3 while the wetlands had pH values of 5 - 6 implying that it was the wetlands that reduced acidity, and not the distance downstream. Both streams showed a reduction in concentrations of all elements with distance downstream. The decrease was linear for the northern stream and exponential for the southern stream, suggesting that the reed beds and settling ponds were successful at removing metal ions; potentially, through slower flow rates allowing more time for redox reactions to occur, thus precipitating metal hydroxides and pure metals and removing them from solution. In November, the northern stream had substantially higher concentrations of Fe, Al, Zn, Cu, and Mn, but not Pb (126, 34.0, 29.1, 14.6, 10.4, and 0.064 mg/L respectively) in solution when compared to the southern stream, which had concentrations of 10.2, 12.2, 11.9, 2.43, 6.11, and 0.706 mg/L for Fe, Al, Zn, Cu, Mn, and Pb respectively. However, in January the first sample site had higher concentrations of all elements except Mn; (107, 22.0, 26.1, 10.3, 1.48, and 0.506 mg/L for Fe, Al, Zn, Cu, Mn, and Pb respectively) when compared to the northern stream (55.0, 10.6, 7.55, 6.10, 1.59, and 0.041 mg/L for Fe, Al, Zn, Cu, Mn, and Pb respectively): but by the second sample site, the southern stream concentrations had dropped to concentrations present in the northern stream. This data indicates less AMD was produced on the southern side during low rainfall periods. Remediation was measured by calculating the percentage reduction in concentration (PRC) between sample sites. PRCs were higher in January for most of the sites; possibly due to dilution by surface runoff from surrounding farmland. The northern stream had consistently lower PRCs between 15% - 55%. The settling ponds had higher PRCs but did not maintain consistent levels with a range of 5% - 90%, while the bogs had consistently high PRCs of 40% - 100%. The combination of the high PRC and pH in the bogs at Parys Mountain makes this the most effective area at remediating Parys Mountains AMD.

Selenium and Other Trace Element Mobility in Waste Products and Weathered Sediments at Parys Mountain Copper Mine, Anglesey, UK

The Parys Mountain copper mining district (Anglesey, North Wales) hosts exposed pyritic bedrock, solid mine waste spoil heaps, and acid drainage (ochre sediment) deposits. Both natural and waste deposits show elevated trace element concentrations, including selenium (Se), at abundances of both economic and environmental consideration. Elevated concentrations of semi-metals such as Se in waste smelts highlight the potential for economic reserves in this and similar base metal mining sites. Selenium is sourced from the pyritic bedrock and concentrations are retained in red weathering smelt soils, but lost in bedrock-weathered soils and clays. Selenium correlates with Te, Au, Bi, Cd, Hg, Pb, S, and Sb across bedrock and weathered deposits. Man-made mine waste deposits show enrichment of As, Bi, Cu, Sb, and Te, with Fe oxide-rich smelt materials containing high Pb, up to 1.5 wt %, and Au contents, up to 1.2 ppm. The trace elements As, Co, Cu, and Pb are retained from bedrock to all sediments, including high Cu content in Fe oxide-rich ochre sediments. The high abundance and mobility of trace elements in sediments and waters should be considered as potential pollutants to the area, and also as a source for economic reserves of previously extracted and new strategic commodities.

\u2018ARMAN\u2019 archaea depend on association with euryarchaeal host in culture and in situ

Intriguing, yet uncultured ‘ARMAN’-like archaea are metabolically dependent on other members of the microbial community. It remains uncertain though which hosts they rely upon, and, because of the lack of complete genomes, to what extent. Here, we report the co-culturing of ARMAN-2-related organism, Mia14, with Cuniculiplasma divulgatum PM4 during the isolation of this strain from acidic streamer in Parys Mountain (Isle of Anglesey, UK). Mia14 is highly enriched in the binary culture (ca. 10% genomic reads) and its ungapped 0.95 Mbp genome points at severe voids in central metabolic pathways, indicating dependence on the host, C. divulgatum PM4. Analysis of C. divulgatum isolates from different sites and shotgun sequence data of Parys Mountain samples suggests an extensive genetic exchange between Mia14 and hosts in situ. Within the subset of organisms with high-quality genomic assemblies representing the ‘DPANN’ superphylum, the Mia14 lineage has had the largest gene flux, with dozens of genes gained that are implicated in the host interaction.

Characterization and Geochemical Modeling of Cu and Zn Sorption Using Mineral Systems Injected with Iron Sulfide: Case Study of Mine Waste Water, Wales, United Kingdom

Sorption of Cu and Zn was investigated using single and mixed mineral systems under sulfidic-anoxic condition to treat wastewater obtained from disused mine pits at Parys Mountain in, United Kingdom. Water courses are the recipients of these contaminants. In these water courses fishing activities exist. Attempt was made to reduce the Cu and Zn levels intake in the watercourses using mineral systems of clays and goethite. These were tested with the mine waste water for characterization of copper and zinc removal at variable pH, solid concentration and contact time. In addition, levels of saturation of hydroxyl complexes were modeled. Batch reactions conducted at ambient temperature (23±2°C) reveal all systems of assorted minerals sorbed more Cu than Zn. In addition, Cu sorbed on iron sulfide exhibited increase in sorption with increasing pH. There was cross cutting effect of Cu and Zn sorbed on iron sulfide at pH 6 and Cu sorbed on goethite at about pH 7, These indicate similar metal removal characteristics. Differences in removal of copper and zinc ions may be assigned to outer sphere complexation and specific adsorption of copper and zinc ions. Non-promotive Cp effect (i.e. decrease in metal removal with increase in concentration of particle) was observed in all minerals. This effect may be assigned to increase in aggregation of the mineral particle size. Ageing characterization progresses as residence time was increased. This may be assigned thiol (=S-H) and hydroxyl (=Me-OH) groups and sites of reactions. There is no link to stable hydroxylation of copper and zinc species that could significantly contribute to the removal of these metals.

Petrochemistry and hydrothermal alteration within the Tyrone Igneous Complex, Northern Ireland: implications for VMS mineralization in the British and Irish Caledonides

Although volcanogenic massive sulfide (VMS) deposits can form within a wide variety of rift-related tectonic environments, most are preserved within suprasubduction affinity crust related to ocean closure. In stark contrast to the VMS-rich Appalachian sector of the Grampian-Taconic orogeny, VMS mineralization is rare in the peri-Laurentian British and Irish Caledonides. Economic peri-Gondwanan affinity deposits are limited to Avoca and Parys Mountain. The Tyrone Igneous Complex of Northern Ireland represents a ca. 484–464 Ma peri-Laurentian affinity arc–ophiolite complex and a possible broad correlative of the Buchans-Robert’s Arm belt of Newfoundland, host to some of the most metal-rich VMS deposits globally. Stratigraphic horizons prospective for VMS mineralization in the Tyrone Igneous Complex are associated with rift-related magmatism, hydrothermal alteration, synvolcanic faults, and high-level subvolcanic intrusions (gabbro, diorite, and/or tonalite). Locally intense hydrothermal alteration is characterized by Na-depletion, elevated SiO2, MgO, Ba/Sr, Bi, Sb, chlorite–carbonate–pyrite alteration index (CCPI) and Hashimoto alteration index (AI) values. Rift-related mafic lavas typically occur in the hanging wall sequences to base and precious metal mineralization, closely associated with ironstones and/or argillaceous sedimentary rocks representing low temperature hydrothermal venting and volcanic quiescence. In the ca. 475 Ma pre-collisional, calc-alkaline lower Tyrone Volcanic Group rift-related magmatism is characterized by abundant non-arc type Fe-Ti-rich eMORB, island-arc tholeiite, and low-Zr tholeiitic rhyolite breccias. These petrochemical characteristics are typical of units associated with VMS mineralization in bimodal mafic, primitive post-Archean arc terranes. Following arc-accretion at ca. 470 Ma, late rifting in the ensialic upper Tyrone Volcanic Group is dominated by OIB-like, subalkaline to alkali basalt and A-type, high-Zr rhyolites. These units are petrochemically favorable for Kuroko-type VMS mineralization in bimodal-felsic evolved arc terranes. The scarcity of discovered peri-Laurentian VMS mineralization in the British and Irish Caledonides is due to a combination of minimal exploration, poor-preservation of upper ophiolite sequences, and limited rifting in the Lough Nafooey arc of western Ireland. The geological and geochemical characteristics of the Tyrone Volcanic Group of Northern Ireland and peri-Gondwanan affinity arc/backarc sequences of Ireland and northwest Wales represent the most prospective sequences in the British and Irish Caledonides for VMS mineralization.

Natural Wetlands Are Efficient at Providing Long-Term Metal Remediation of Freshwater Systems Polluted by Acid Mine Drainage

This study describes the first long-term (14-year) evaluation of the efficacy of an established (>100 years) natural wetland to remediate highly acidic mine drainage (AMD). Although natural wetlands are highly valued for their biodiversity, this study demonstrates that they also provide important ecosystem service functions through their ability to consistently and reliably improve water quality by mitigating AMD. The Afon Goch river flows from Parys Mountain copper mine via a natural wetland, and was the major source of Zn and Cu contamination to the Irish Sea. Prior to 2003 the wetland received severe acidic metal contamination and retained a large proportion of the contamination (55, 64, and 37% in dissolved Fe, Zn, and Cu) leading to a greatly reduced metal flow to the Irish Sea. Reduced wetland loadings midway through the sampling period led to a reduction of metals by 83-94% and a pH increase from 2.7 to 5.5, resulting in long-term improvements in the downstream benthic invertebrate community. High root metal accumulation by the dominant wetland plant species and the association of acidophilic bacteria in the wetland rhizosphere indicate that multiple interacting processes provide an efficient and self-sustaining system to remediate AMD.

Lumbricus terrestris L. does not impact on the remediation efficiency of compost and biochar amendments

Abstract The aim of this study was to test the impact of compost and biochar, with or without earthworms, on the mobility and availability of metals, and on the growth of grass to re-vegetate contaminated soil from the Parys Mountain mining site, Anglesey. We also determined if the addition of earthworms compromises remediation efforts. In a laboratory experiment, contaminated soil (1343 mg Cu kg −1 , 2511 mg Pb kg −1 and 262 mg Zn kg −1 ) was remediated with compost and/or biochar. After 77 days Lumbricus terrestris L. earthworms were added to the treatment remediated with both compost and biochar, and left for 28 days. L. terrestris was not able to survive in the biochar, compost or unamended treatments. A germination and growth bioassay, using Agrostis capillaris (Common Bent) was then run on all treatments for 28 days. The combination of biochar and compost decreased water soluble Cu (from 5.6 to 0.2 mg kg −1 ), Pb (from 0.17 to less than 0.007 mg kg −1 ) and Zn (from 3.3 to 0.05 mg kg −1 ) in the contaminated soil and increased the pH from 2.7 to 6.6. The addition of L. terrestris to this treatment had no effect on the concentration of the water soluble metals in the remediated soil. The compost was the only treatment that resulted in germination and growth of A. capillaris suitable for re-vegetation purposes. However, the combination of compost and biochar (with or without L. terrestris ) produced the lowest concentrations of Cu (8 mg kg −1 ) and Zn (36 mg kg −1 ) in the aboveground biomass, lower than the compost treatment (15 mg Cu kg −1 and 126 mg Zn kg −1 ). The addition of biochar and compost both separately and as co-amendments was effective in reducing the mobility and availability of metals. The addition of L. terrestris did not re-mobilise previously sequestered metals.

Effect of Composts, Lime and Diammonium Phosphate on the Phytoavailability of Heavy Metals in a Copper Mine Tailing Soil

Soil samples from a historic copper mine tailing site at the Parys Mountain, North Wales (UK) were amended with green waste compost (GC), GC+30% sewage sludge (GCS), lime and diammonium phosphate (DAP), to determine the effect of amendments on DTPA- and Ca(NO 3) 2-extractable metals in the mine tailing and on the phytoavailability of heavy metals by a lettuce ( Lactuca sativa L.). Both compost were added at the rate of 10% by weight, lime was added as calcium carbonate equivalent (pH = 7) and DAP at a 2 300 mg kg −1 soil level. The experiment was arranged in randomised complete design with three replicates in pots under control environment. Addition of lime resulted in the largest reduction in metal extractability with DTPA and Ca(NO 3) 2 and phytoavailability of Cu, Fe and Zn while DAP was effective in lowering Pb extractability and phytoavailability. With exception of Zn, all other metals extracted decreased with time after amendment applications. The distribution of heavy metals between and within the four procedures of potentially bioavailable sequential extraction (PBASE) varied significantly ( P < 0.001). Stronger relationships were noted between the metals extracted with PBASE SE1 and Cu, Pb ( P < 0.01) and Fe ( P < 0.001) in the lettuce. These results indicate that addition of lime is sufficient to restore the vegetative cover to a high metal mine waste while DAP is good for stabilizing Pb, but its detrimental role on plant growth and the risk associated with presence of N in DAP (through N leaching) may restrict its chances for remediation of contaminated sites.

Removal of heavy metals from acid mine drainage (AMD) using coal fly ash, natural clinker and synthetic zeolites

Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations, resulting from the microbial oxidation of pyrite in presence of water and air, affording an acidic solution that contains toxic metal ions. The generation of AMD and release of dissolved heavy metals is an important concern facing the mining industry. The present study aimed at evaluating the use of low-cost sorbents like coal fly ash, natural clinker and synthetic zeolites to clean-up AMD generated at the Parys Mountain copper–lead–zinc deposit, Anglesey (North Wales), and to remove heavy metals and ammonium from AMD. pH played a very important role in the sorption/removal of the contaminants and a higher adsorbent ratio in the treatment of AMD promoted the increase of the pH, particularly using natural clinker-based faujasite (7.70–9.43) and the reduction of metal concentration. Na-phillipsite showed a lower efficiency as compared to that of faujasite. Selectivity of faujasite for metal removal was, in decreasing order, Fe > As > Pb > Zn > Cu > Ni > Cr. Based on these results, the use of these materials has the potential to provide improved methods for the treatment of AMD.

Anglesey: The Concise History

This is the first in a new series of single volume histories of the historic Welsh counties. To encompass the history of a county within the space of less than 200 pages is a challenge; all the counties of Wales have their own distinct identities, but Anglesey, being an island, is more distinct than most. At the same time any historian approaching the history of a county has to keep in touch with the main trends of national history and show how this history has manifested itself within a territory which is both a microcosm of the nation and a community with its own identity and history. The author, himself an Anglesey man, has risen to the challenge and in six chapters he has taken the story from the emergence of Anglesey as an island to the present day. We read of the great Iron Age votive deposit at Llyn Cerrig Bach, of the beginnings of the kingship of Gwynedd based on Aberffraw and of the recently discovered evidence of Viking settlement at Llanbedr-goch. Perhaps in the discussion of the medieval period there is a tendency to generalise, but the main trends are brought out. The powerful Anglesey-based family which snatched the greatest prize of all in 1485 is placed in its context and the later power struggles between local families, particularly the Bulkeleys of Beaumaris, whose political and social domination survived until the late nineteenth century, are not ignored, nor are the changes of the sixteenth and seventeenth centuries. Major change begins in the eighteenth century; the discovery of rich copper deposits on Mynydd Trysglwyn (Parys Mountain) made the island for a time the centre of the world copper industry under the control of a local attorney, Thomas Williams. Like the rest of Wales, Anglesey felt the impact of the Methodist Revival and was particularly associated with two figures, the Baptist, Christmas Evans, and the Calvinistic Methodist, John Elias. By the end of the century the campaign for a bridge across the Menai Straits was gathering momentum and Telford's suspension bridge was opened in 1826, to be followed by the coming of the railway and the bridging of the Straits by Robert Stephenson in 1850. The eighteenth century saw one of Anglesey's greatest poets, Goronwy Owen, and the astonishing Morris brothers who were significant contributors to the Welsh cultural revival of the period and whose letters shed so much light on contemporary life. When discussing the nineteenth century the author deals with the impact of such national topics as the rise of nonconformity, the growth of political radicalism and the 1847 Education Reports, but it is the local developments which will be of most interest to the reader. The pioneering attempt to organise the agricultural labourer, associated with the journalist John Owen Jones (Ap Ffarmwr), did not succeed, but the fight continued; ironically the farmers, who were less than enlightened employers, were among the leaders of the nonconformist fight against the gentry; the shipowning Davies family, one of whom was the first nonconformist MP for the island and then the first nonconformist Lord Lieutenant, had an equally bad reputation. The triumph of political nonconformity was symbolised by the removal of the county town from Beaumaris to Llangefni following the election of the first County Council in 1888. Like so much of rural Wales, nineteenth- and early twentieth-century Anglesey was a place of grinding rural poverty and deprivation; in 1933 unemployment in the county amounted to 42.1 per cent of the insured population, and alongside this was the scourge of tuberculosis. Anglesey politics were and are rather more individualistic and volatile than those of its neighbours. In 1918 the county elected the first Labour MP in rural north Wales and since 1945 the seat has been held by all four of the main Welsh parties. Intriguingly, Anglesey was the first British education authority to adopt a system of universal comprehensive education. The story is brought up to the present day with the examination of the increasing dependence of the economy on tourism, the underlying problems of that same economy, Anglesey being one of the most deprived regions of Wales, and the cultural effects of immigration from England. Mr Pretty has produced a comprehensive and readable history which will be of interest both to Monwysion and to all who know this highly individualistic community.

SENSITIVITY OF ERICOID MYCORRHIZAL FUNGI AND MYCORRHIZAL CALLUNA VULGARIS TO COPPER MINE SPOIL FROM AVOCA, COUNTY WICKLOW

Ericoid mycorrhizal fungi were isolated from roots of Calluna vulgaris collected from mine spoil at abandoned copper mines at Avoca, County Wicklow, Ireland, and Parys Mountain, Anglesey, Wales. Two isolates were morphologically identical to Hymenoscyphus ericae and formed typical ericoid mycorrhizal associations. Four fungal isolates— the two mine-site isolates and two H. ericae isolates (obtained from uncontaminated sites) were grown in liquid media containing elevated levels of Cu and Zn. All isolates were determined to have a low sensitivity to these metals, with EC₅₀ values (concentration of metal causing 50% reduction in mycelial dry mass) in the range 0.3-0.9mM Cu and 1.2-5.5mM Zn, but there were differences in metal sensitivity between isolates. There was a significant decline in the tolerance of each isolate to increasing concentrations of mine spoil (up to 10% in the agar medium). Mycorrhizal amelioration of heavy-metal toxicity was determined by growing mycorrhizal (M) and non-mycorrhizal (NM) rooted cuttings of C. vulgaris on mine spoil. Rooted cuttings obtained from an uncontaminated site showed no response to mycorrhizal colonisation. However, C. vulgaris obtained from the Avoca site and inoculated with H. ericae performed better than NM plants. The improved growth of these plants was associated with a reduction in Cu within the host's shoot. Inoculation of C. vulgaris with an ericoid mycorrhizal fungus isolated from the Avoca mine site also reduced Cu accumulation within shoots but there was no change in the growth and Zn accumulation of C. vulgaris on mine spoil. Results are discussed in relation to the potential benefit of the ericoid mycorrhizal association to C. vulgaris at metal contaminated sites.

Sensitivity of Ericoid Mycorrhizal Fungi and Mycorrhizal &lt;i&gt;Calluna vulgaris&lt;/i&gt; to Copper Mine Spoil from Avoca, County Wicklow

Ericoid mycorrhizal fungi were isolated from roots of Calluna vulgaris collected from mine spoil at abandoned copper mines at Avoca, County Wicklow, Ireland, and Parys Mountain, Anglesey, Wales. Two isolates were morphologically identical to Hymenoscyphus ericae and formed typical ericoid mycorrhizal associations. Four fungal isolates? the two mine-site isolates and two H. ericae isolates (obtained from uncontaminated sites) were grown in liquid media containing elevated levels of Cu and Zn. All isolates were determined to have a low sensitivity to these metals, with EC50 values (concentration of metal causing 50% reduction in mycelial dry mass) in the range 0.3-0.9mM Cu and 1.2-5.5mM Zn, but there were differences in metal sensitivity between isolates. There was a significant decline in the tolerance of each isolate to increasing concentrations of mine spoil (up to 10% in the agar medium). Mycorrhizal amelioration of heavy-metal toxicity was determined by growing mycorrhizal (M) and non-mycorrhizal (NM) rooted cuttings of C. vulgaris on mine spoil. Rooted cuttings obtained from an uncontaminated site showed no response to mycorrhizal colonisation. However, C. vulgaris obtained from the Avoca site and inoculated with H. ericae performed better than NM plants. The improved growth of these plants was associated with a reduction in Cu within the host's shoot. Inoculation of C. vulgaris with an ericoid mycorrhizal fungus isolated from the Avoca mine site also reduced Cu accumulation within shoots but there was no change in the growth and Zn accumulation of C. vulgaris on mine spoil. Results are discussed in relation to the potential benefit of the ericoid mycorrhizal association to C. vulgaris at metal contaminated sites. Brian R. Gibson, Division of Food Sciences, School of Biosciences,