Search Results

You searched for all publications:

with publication states 'Published (Approved)'

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

Exact matches
Related results

12 items found (0 items not approved), displaying 1 to 10.[First/Prev] 1, 2 [Next/Last]

Instruments / Technical Area	Publication Details	Published
I18-Microfocus Spectroscopy	Reuse potential of municipal solid waste incinerator bottom ash as secondary aggregate: Material characteristics, persistent organic pollutant content and effects of pH and selected environmental lixiviants on leaching behaviour Felipe E. Sepulveda Olea , Ian T. Burke , Arif Mohammad , Douglas I. Stewart Waste Management 187, 262 - 274 DOI: 10.1016/j.wasman.2024.07.026 Diamond Proposal Number(s): [33049] Open Access Show Abstract ▼ Abstract: Increasing municipal solid waste (MSW) production poses challenges for sustainable urban development. Modern energy-from-waste (EfW) facilities incinerate MSW, reducing mass and recovering energy. In the UK, MSW incineration bottom ash (MSW IBA) is primarily reused in civil engineering applications. This study characterizes UK-produced MSW IBA, examining its pH-dependent leaching behaviour and response to environmental lixiviants. Results show predominant components include a melt phase, primary glass and fine ash aggregations, and a chemical composition dominated by SiO2 (30–50 %), CaO (∼15 %), Fe2O3 (∼10 %), and Al2O3 (∼8%). X-ray absorption near edge structure (XANES) analysis shows that Zn and Cu are most likely oxygen-bound (adsorbed to oxy-hydroxides and as oxides) with some sulphur bound. Polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxins/furans (PCDD/Fs) are well below regulatory limits, and polycyclic aromatic hydrocarbons (PAHs) were undetectable. Leaching tests indicate trace elements mobilize at pHs ≤ 6. With a natural pH of 11.3 and high buffering capacity, significant acid inputs to the MSW IBA are required to reach this pH, which are improbable in the environment. Wood chip additions increase leachate’s dissolved organic carbon (DOC) and reduce pH, but had minimal impact on metal-leaching behaviour. Synthetic plant exudate solutions minimally affect metal leaching at realistic concentrations, only enhancing leaching at ≥ 1500 mg l−1 DOC. This work supports MSW IBA’s low-risk in specified civil engineering applications.	Oct 2024
I18-Microfocus Spectroscopy	Evolution of Cu and Zn speciation in agricultural soil amended by digested sludge over time and repeated crop growth Jianting Feng , Ian T. Burke , Xiaohui Chen , Douglas I. Stewart Environmental Science And Pollution Research 9 DOI: 10.1007/s11356-024-34784-8 Diamond Proposal Number(s): [33049] Open Access Show Abstract ▼ Abstract: Metals such as Zn and Cu present in sewage sludge applied to agricultural land can accumulate in soils and potentially mobilise into crops. Sequential extractions and X-ray absorption spectroscopy results are presented that show the speciation changes of Cu and Zn sorbed to anaerobic digestion sludge after mixing with soils over three consecutive 6-week cropping cycles, with and without spring barley (Hordeum vulgare). Cu and Zn in digested sewage sludge are primarily in metal sulphide phases formed during anaerobic digestion. When Cu and Zn spiked sludge was mixed with the soil, about 40% of Cu(I)-S phases and all Zn(II)-S phases in the amended sludge were converted to other phases (mainly Cu(I)-O and outer sphere Zn(II)-O phases). Further transformations occurred over time, and with crop growth. After 18 weeks of crop growth, about 60% of Cu added as Cu(I)-S phases was converted to other phases, with an increase in organo-Cu(II) phases. As a result, Cu and Zn extractability in the sludge-amended soil decreased with time and crop growth. Over 18 weeks, the proportions of Cu and Zn in the exchangeable fraction decreased from 36% and 70%, respectively, in freshly amended soil, to 28% and 59% without crop growth, and to 24% and 53% with crop growth. Overall, while sewage sludge application to land will probably increase the overall metal concentrations, metal bioavailability tends to reduce over time. Therefore, safety assessments for sludge application in agriculture should be based on both metal concentrations present and their specific binding strength within the amended soil.	Aug 2024
B18-Core EXAFS	Antimony and arsenic behaviour in lead/zinc mine tailings during storage under vegetation cover I. T. Burke , R. Courtney , W. M. Mayes Applied Geochemistry 14 DOI: 10.1016/j.apgeochem.2023.105806 Diamond Proposal Number(s): [29970] Open Access Show Abstract ▼ Abstract: The high-volume, fine grained tailings produced from Pb/Zn ore processing need to be carefully managed. Metalloid elements, As and Sb, are present in tailings at ∼800 and ∼80 mg kg−1 respectively, and in neutral pH leachates at 5–50 μg L−1. Despite these relatively low leachate concentrations, As and Sb can cause regulatory concern due to their high toxicity and propensity for bioaccumulation. As and Sb mobility in tailings are controlled by their chemical speciation and associations with mineral phases. Changes in As and Sb speciation were, therefore, determined in depth profile samples taken from an active tailings management facility during waste storage up to 8 years since deposition. At this site, primarily to prevent dust formation, a vegetation cover was established by addition of organic compost to surface layers and seeding grasses. Over time a robust vegetation cover was established consisting of perennial grasses, clovers, and after 8 years, small trees and shrubs. The surface layer of the tailings also became progressively more oxidised over time producing a substrate more suitable for plant growth enabling the establishment of beneficial vegetation cover and the development of a thin soil-like surface layer. As and Sb were both present in predominately reduced 3+ forms in freshly deposited tailings but were converted to oxidised 5+ forms in older samples. Oxidation of Fe(II) in pyrite also occurred, producing increased amounts of weak acid leachable Fe(III)-oxides in the tailings. Sorption of As to neoformed iron oxides in leachate drains reduced concentrations in leachates to below regulatory limits, but Sb sorption was relatively ineffective resulting in higher Sb concentration in site drainage waters, which may require specific treatments to reduce Sb concentrations prior to discharge.	Oct 2023
B18-Core EXAFS	Mechanism of enhanced strontium uptake into calcite via an amorphous calcium carbonate (ACC) crystallisation pathway Janice L. Littlewood , Samuel Shaw , Caroline L. Peacock , Pieter Bots , Divyesh Trivedi , Ian T. Burke Crystal Growth & Design DOI: 10.1021/acs.cgd.6b01599 Diamond Proposal Number(s): [8269] Show Abstract ▼ Abstract: Calcite formation via an amorphous calcium carbonate (ACC) precursor phase potentially offers a method for enhanced incorporation of incompatible trace metals, including Sr2+. In batch crystallisation experiments where CaCl2 was rapidly mixed with Na2CO3 solutions the Sr2+ : Me2+ ratio was varied from 0.001 to 0.1; and, the pathway of calcite precipitation was directed by either the presence or absence of high Mg2+ concentrations (i.e. using a Mg2+ : total Me2+ ratio of 0.1). In the Mg-free experiments crystallisation proceeded via ACC → vaterite → calcite and average Kd Sr values were between 0.44-0.74. At low Sr2+ concentrations (Sr2+ : Me2+ ratio ≤ 0.01) EXAFS analysis revealed that the Sr2+ was incorporated into calcite in the 6 fold coordinate Ca2+ site. However, at higher Sr2+ concentrations (Sr2+ : Me2+ ratio = 0.1), Sr2+ was incorporated into calcite in a 9-fold site with a local coordination similar to Ca2+ in aragonite, but calcite-like at longer distances (i.e. > 3.5 Å). In the high-Mg experiments the reaction proceeded via an ACC → calcite pathway with higher Kd Sr of 0.90-0.97 due to the presence of Mg2+ stabilising the ACC phase and promoting rapid calcite nucleation in conjunction with higher Sr2+ incorporation. Increased Sr2+ concentrations also coincided with higher Mg2+ uptake in these experiments. Sr2+ was incorporated into calcite in a 9-fold coordinate site in all the high-Mg experiments regardless of initial Sr2+ concentrations, likely as a result of very rapid crystallisation kinetics and the presence of smaller Mg2+ ions compensating for the addition of larger Sr2+ ions in the calcite lattice. These experiments show that the enhanced uptake of Sr2+ ions can be achieved by calcite precipitation via ACC, and may offer a rapid, low temperature, low-cost, method for removal of several incompatible Me2+ ions (e.g. Pb2+, Ba2+, Sr2+) during effluent treatment.	Jan 2017
B18-Core EXAFS I20-Scanning-X-ray spectroscopy (XAS/XES)	EXAFS study of Sr sorption to illite, goethite, chlorite and mixed sediment under hyper-alkaline conditions Adam Fuller , Sam Shaw , Caroline Peacock , Divyesh Trivedi , Ian T. Burke Langmuir 32 (12), 2937–2946 DOI: 10.1021/acs.langmuir.5b04633 Diamond Proposal Number(s): [8667] Open Access Show Abstract ▼ Abstract: Strontium is an important contaminant radionuclide at many former nuclear sites. This paper investigates the effect of changing pH and ionic strength on the sorption Sr to a range of common soil minerals. Specifically it focuses on the sorption of Sr onto illite, chlorite, goethite and a mixed sediment. The interplay between ionic strength and pH was determined by varying the background ionic strength of the system using both NaCl (for a constant pH) and NaOH (to also vary pH). Under conditions of moderate pH Sr sorption decreased with increasing ionic strength, due to competition between the Na and Sr atoms for the outer-sphere complexes. However, where increasing ionic strength was accompanied by increasing pH Sr sorption remained high. This suggested that Sr was sorbed to the minerals without competition from background Na ions. Extended X-ray Absorption Fine Structure (EXAFS) spectra confirmed that at highly alkaline pH (>12.5) Sr was forming inner-sphere complexes on the surfaces of all minerals. This specific adsorption of the Sr (as SrOH+) explains why it was still adsorbed to the minerals under very high ionic strength conditions and was not out-competed by Na.	Mar 2016
B18-Core EXAFS	Caesium incorporation and retention in illite interlayers Adam J. Fuller , Sam Shaw , Michael B. Ward , Sarah Haigh , J. Frederick W. Mosselmans , Caroline Peacock , Stephen Stackhouse , Andrew Dent , Divyesh Trivedi , Ian T. Burke Applied Clay Science DOI: 10.1016/j.clay.2015.02.008 Diamond Proposal Number(s): [4901] Open Access Show Abstract ▼ Abstract: Radioactive caesium (chiefly 137Cs) is a major environmental pollutant. The mobility of Cs in temperate soils is primarily controlled by sorption onto clay minerals, particularly the frayed edges of illite interlayers. This paper investigates the adsorption of Cs to illite at the molecular scale, over both the short and long term. Transmission electron microscopy (TEM) images showed that after initial absorption into the frayed edges, Cs migrated into the illite interlayer becoming incorporated within the mineral structure. Caesium initially exchanged with hydrated Ca at the frayed edges, causing them to collapse. This process was irreversible as Cs held in the collapsed interlayers was not exchangeable with Ca. Over the long term Cs did not remain at the edge of the illite crystals, but diffused into the interlayers by exchange with K. Results from extended X-ray absorption fine structure spectroscopy (EXAFS) and density functional theory modelling confirmed that Cs was incorporated into the illite interlayer and revealed its bonding environment.	Feb 2015
I18-Microfocus Spectroscopy	Mobilisation of arsenic from bauxite residue (red mud) affected soils: Effect of pH and redox conditions Cindy L. Lockwood , Roger J. G. Mortimer , Douglas I. Stewart , William M. Mayes , Caroline L. Peacock , David A. Polya , Paul R. Lythgoe , Alizée P. Lehoux , Katalin Gruiz , Ian T. Burke Applied Geochemistry 51, 268-277 DOI: 10.1016/j.apgeochem.2014.10.009 Diamond Proposal Number(s): [7525] Open Access Show Abstract ▼ Abstract: The tailings dam breach at the Ajka alumina plant, western Hungary in 2010 introduced ∼1 million m3 of red mud suspension into the surrounding area. Red mud (fine fraction bauxite residue) has a characteristically alkaline pH and contains several potentially toxic elements, including arsenic. Aerobic and anaerobic batch experiments were prepared using soils from near Ajka in order to investigate the effects of red mud addition on soil biogeochemistry and arsenic mobility in soil–water experiments representative of land affected by the red mud spill. XAS analysis showed that As was present in the red mud as As(V) in the form of arsenate. The remobilisation of red mud associated arsenate was highly pH dependent and the addition of phosphate to red mud suspensions greatly enhanced As release to solution. In aerobic batch experiments, where red mud was mixed with soils, As release to solution was highly dependent on pH. Carbonation of these alkaline solutions by dissolution of atmospheric CO2 reduced pH, which resulted in a decrease of aqueous As concentrations over time. However, this did not result in complete removal of aqueous As in any of the experiments. Carbonation did not occur in anaerobic experiments and pH remained high. Aqueous As concentrations initially increased in all the anaerobic red mud amended experiments, and then remained relatively constant as the systems became more reducing, both XANES and HPLC–ICP-MS showed that no As reduction processes occurred and that only As(V) species were present. These experiments show that there is the potential for increased As mobility in soil–water systems affected by red mud addition under both aerobic and anaerobic conditions.	Oct 2014
B18-Core EXAFS	Ionic strength and pH dependent multi-site sorption of Cs onto a micaceous aquifer sediment Adam J. Fuller , Sam Shaw , Caroline L. Peacock , Divyesh Trivedi , Joe S. Small , Liam G. Abrahamsen , Ian T. Burke Applied Geochemistry 40, 32 - 42 DOI: 10.1016/j.apgeochem.2013.10.017 Diamond Proposal Number(s): [7525] Open Access Show Abstract ▼ Abstract: Caesium-137 (t1/2 = 30 years) is a common contaminant at nuclear legacy sites. Often the mobility of 137Cs in the environment is governed by its sorption to charged sites within the sediment. To this end it is important to understand the sorption behaviour of caesium across a wide range of environmental conditions. This work investigates the effect of varying solution composition (pH and competing ions) on the sorption of caesium to micaceous aquifer sediment across a large concentration range (1.0 × 10−11 – 1.0 × 10−1 mol L−1 Cs+). Experimental results show that Cs+ exhibits three distinct sorption behaviours at three different concentration ranges. At very low concentrations < 1.0 × 10−6 mol L−1 Cs+ sorption was unaffected by competition with Na+ or H+ but significantly reduced in high ionic strength K+ solution. Secondly between 1 × 10−6 and 1.0 × 10−3 mol L−1 Cs+ is strongly sorbed in a neutral pH, low ionic strength background but sorption is significantly reduced in solutions with either a high concentration of Na+ or K+ ions or low pH. At high concentrations > 1.0 × 10−3 mol L−1 Cs+ sorption is reduced in all systems due to saturation of the sediment’s sorption capacity. A multi-site cation exchange model was used to interpret the sorption behaviour. From this it was determined that at low concentrations Cs+ sorbs to the illite frayed edge sites only in competition with K+ ions. However, once the frayed edge sites are saturated the Cs+ sorbs to the Type II and Planar sites in competition with K+, Na+ and H+ ions. Therefore sorption of Cs+ at concentrations > 1.0 × 10−6 mol L−1 is significantly reduced in both high ionic strength and low pH solutions. This is a significant result with regard to predicting the migration of 137Cs+ in acidic or high ionic strength groundwaters.	Jan 2014
I18-Microfocus Spectroscopy	Behavior of aluminum, arsenic, and vanadium during the neutralization of red mud leachate by HCl, gypsum, or seawater Ian T. Burke , Caroline Peacock , Cindy Lockwood , Douglas Stewart , Robert J. G. Mortimer , Michael B. Ward , Philip Renforth , Katalin Gruiz , Will Mayes Environmental Science & Technology 47 (12), 6527-6535 DOI: 10.1021/es4010834 Diamond Proposal Number(s): [7525] Show Abstract ▼ Abstract: Red mud leachate (pH 13) collected from Ajka, Hungary is neutralized to < pH 10 by HCl, gypsum, or seawater addition. During acid neutralization >99% Al is removed from solution during the formation of an amorphous boehmite-like precipitate and dawsonite. Minor amounts of As (24%) are also removed from solution via surface adsorption of As onto the Al oxyhydroxides. Gypsum addition to red mud leachate results in the precipitation of calcite, both in experiments and in field samples recovered from rivers treated with gypsum after the October 2010 red mud spill. Calcite precipitation results in 86% Al and 81% As removal from solution, and both are nonexchangeable with 0.1 mol L–1 phosphate solution. Contrary to As associated with neoformed Al oxyhydroxides, EXAFS analysis of the calcite precipitates revealed only isolated arsenate tetrahedra with no evidence for surface adsorption or incorporation into the calcite structure, possibly as a result of very rapid As scavenging by the calcite precipitate. Seawater neutralization also resulted in carbonate precipitation, with >99% Al and 74% As removed from solution during the formation of a poorly ordered hydrotalcite phase and via surface adsorption to the neoformed precipitates, respectively. Half the bound As could be remobilized by phosphate addition, indicating that As was weakly bound, possibly in the hydrotalcite interlayer. Only 5–16% V was removed from solution during neutralization, demonstrating a lack of interaction with any of the neoformed precipitates. High V concentrations are therefore likely to be an intractable problem during the treatment of red mud leachates.	Jun 2013
I18-Microfocus Spectroscopy	Enhancing microbial iron reduction in hyperalkaline, chromium contaminated sediments by pH amendment R. A. Whittleston , D. I. Stewart , R. J. G. Mortimer , I. T. Burke Applied Geochemistry 28, 135 - 144 DOI: 10.1016/j.apgeochem.2012.10.003 Show Abstract ▼ Abstract: Soil collected from beneath a chromite ore processing residue (COPR) disposal site contained a diverse population of anaerobic alkaliphiles, despite receiving a continuous influx of a Cr(VI) contaminated, hyperalkaline leachate (pH 12.2). Chromium was found to have accumulated in this soil as a result of an abiotic reaction of Cr(VI) with Fe(II) present in the soil. This sediment associated Fe(II) was, therefore, acting as a natural reactive zone beneath the COPR and thereby preventing the spread of Cr(VI). In anaerobic microcosm experiments soil microorganisms were able to reduce NO3- at pH 11.2 coupled to the oxidation of electron donors derived from the original soil organic matter, but progressive anoxia did not develop to the point of Fe reduction over a period of 9 months. It is not clear, therefore, if Fe(II) can be actively replenished by microbial processes occurring within the soil at in situ conditions. Sodium bicarbonate was added to this soil to investigate whether bioreduction of Fe in hyperalkaline Cr contaminated soils could be enhanced by reducing the pH to a value optimal for many alkaliphilic bacteria. The addition of NaHCO3 produced a well buffered system with a pH of ∼9.3 and Fe reducing conditions developed within 1 month once complete denitrification had occurred. Fe(III) reduction was associated with an increase in the proportion of genetic clone libraries that were from the phylum Firmicutes, suggesting that these species are responsible for the Fe(III) reduction observed. Amendment of the pH using bicarbonate may provide a suitable strategy for stimulating the bioreduction of Fe(III) in COPR leachate contaminated soils or other environments where microbial reduction is inhibited by elevated pH.	Oct 2012

Publications Database

Search Results

You searched for all publications:

Search Again...

Subject Areas (check all that apply) select all

Instruments used to collect data (check all that apply) select all

Collaborations involved (check all that apply) select all

Diamond Offline Facilities used

Relevant Technical Areas (check all that apply) select all

Menu for Anonymous User