Environmental Remediation

An assessment of the utilization of waste resources for the immobilization of Pb and Cu in the soil from a Korean military shooting range

by Christopher Shope

Crystal Structure of ChrR - A Quinone Reductase with the Capacity to Reduce Chromate

by Sebastien Poulain

PLoS ONE, 2012
Eswaramoorthy S and Poulain S (equal contributors), Hienerwadel R, Brémond N, Sylvester MD, Zhang Y-B, Berthomieu C, Van Der Lelie D, Matin A.

The Escherichia coli ChrR enzyme is an obligatory two-electron quinone reductase that has many applications, such as... more The Escherichia coli ChrR enzyme is an obligatory two-electron quinone reductase that has many applications, such as in chromate bioremediation. Its crystal structure, solved at 2.2 Å resolution, shows that it belongs to the flavodoxin superfamily in which flavin mononucleotide (FMN) is firmly anchored to the protein. ChrR crystallized as a tetramer, and size exclusion chromatography showed that this is the oligomeric form that catalyzes chromate reduction. Within the tetramer, the dimers interact by a pair of two hydrogen bond networks, each involving Tyr128 and Glu146 of one dimer and Arg125 and Tyr85 of the other; the latter extends to one of the redox FMN cofactors. Changes in each of these amino acids enhanced chromate reductase activity of the enzyme, showing that this network is centrally involved in chromate reduction.

History of the Toronto Port Lands

by Sandra C. Neill

Co-authored with A. Plover. Presented March 2012 in graduate course "Environmental Challenges in Urban Areas", Department of Physical and Environmental Sciences, University of Toronto at Scarborough.

Novel approach to zinc removal from circum-neutral mine waters using pelletised recovered hydrous ferric oxide

by William Mayes

Journal of Hazardous Materials

Data are presented which evaluate the performance of a pilot-scale treatment system using pelletised hydrous ferric... more Data are presented which evaluate the performance of a pilot-scale treatment system using pelletised hydrous ferric oxide (HFO; a waste stream from coal mine water treatment) as a high surface area sorbent for removing zinc (Zn) from a metal mine water discharge in the North Pennines Orefield, UK. Over a 10-month period the system removed Zn at mean area- and volume-adjusted removal rates of 3.7 and 8.1 g m−3 day−1, respectively, with a mean treatment efficiency of 32% at a low mean residence time of 49 min. There were seasonal effects in Zn removal owing to establishment and dieback of algae in the treatment tank. This led to increased Zn uptake in early summer months followed by slight Zn release upon algae senescence. In addition to these biosorptive processes, the principal sinks for Zn appear to be (1) sorption onto the HFO surface, and (2) precipitation with calcite-dominated secondary minerals. The latter were formed as a product of dissolution of portlandite in the cement binder and calcium recarbonation. Further optimisation of the HFO pelletisation process holds the possibility for providing a low-cost, low footprint treatment option for metal rich mine waters, in addition to a valuable after-use for recovered HFO from coal mine water treatment facilities.

Mines and microbes: Public responses to biological treatment of toxic discharge

by Justin Page

To be published in Society and Natural Resources

This paper examines public acceptability of ecogenomics-enhanced bioremediation (EEB), a novel technology designed to... more This paper examines public acceptability of ecogenomics-enhanced bioremediation (EEB), a novel technology designed to treat polluted mine drainage.  Given the newness of EEB and its application to a controversial area, it is important to assess its public acceptability; however, no assessments of EEB acceptability currently exist.  Drawing on the Public Acceptability of Controversial Technologies framework, we treat acceptability as the conditional willingness of social groups to consider a technology as an option.  Interviews were conducted with 9 community groups and 3 First Nations living adjacent to a pilot EEB system.  Participants express generally positive attitudes toward EEB, but are worried about potential unintended consequences.  With low levels of trust in authorities, groups propose public monitoring as a condition of acceptability – but are sceptical that this condition will be met.  Future research could facilitate processes in which acceptability conditions can be met and examine consequent changes to public acceptability.

An integrated remediation system using synthetic and natural zeolites for treatment of wastewater and contaminated sediments.

by Danen Appasamy

Effects of biochar and the earthworm Eisenia fetida on the bioavailability of polycyclic aromatic hydrocarbons and potentially toxic elements

by Tom Sizmur

Research highlights

► Biochar reduced total and bioavailable PAH concentrations.
► Biochar was less effective at immobilising PTEs, due to its low cation exchange capacity.
► E. fetida increased PAH bioavailability and PTE mobility.
► When used in combination biochar reduced the concentration of PTEs mobilised by E. fetida.
► Biochar had a negative effect on E. fetida in terms of weight loss.

Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) were monitored over 56 days in... more Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) were monitored over 56 days in calcareous contaminated-soil amended with either or both biochar and Eisenia fetida. Biochar reduced total (449 to 306 mg kg−1) and bioavailable (cyclodextrin extractable) (276 to 182 mg kg−1) PAHs, PAH concentrations in E. fetida (up to 45%) but also earthworm weight. Earthworms increased PAH bioavailability by >40%. Combined treatment results were similar to the biochar-only treatment. Earthworms increased water soluble Co (3.4 to 29.2 mg kg−1), Cu (60.0 to 120.1 mg kg−1) and Ni (31.7 to 83.0 mg kg−1) but not As, Cd, Pb or Zn; biochar reduced water soluble Cu (60 to 37 mg kg−1). Combined treatment results were similar to the biochar-only treatment but gave a greater reduction in As and Cd mobility. Biochar has contaminated land remediation potential, but its long-term impact on contaminants and soil biota needs to be assessed.

Impact of earthworms on trace element solubility in contaminated mine soils amended with green waste compost

by Tom Sizmur

► Compost reduced the mobility of Cu, Pb and Zn.
► Compost increased the mobility of As.
► Earthworms decreased water soluble As and Cu but increased Pb and Zn in porewater.
► These effects are explained by the impact of the earthworms and compost on pH and DOC.

The common practice of remediating metal contaminated mine soils with compost can reduce metal mobility and promote... more The common practice of remediating metal contaminated mine soils with compost can reduce metal mobility and promote revegetation, but the effect of introduced or colonising earthworms on metal solubility is largely unknown. We amended soils from an As/Cu (1150 mgAs kg−1 and 362 mgCu kg−1) and Pb/Zn mine (4550 mgPb kg−1 and 908 mgZn kg−1) with 0, 5, 10, 15 and 20% compost and then introduced Lumbricus terrestris. Porewater was sampled and soil extracted with water to determine trace element solubility, pH and soluble organic carbon. Compost reduced Cu, Pb and Zn, but increased As solubility. Earthworms decreased water soluble Cu and As but increased Pb and Zn in porewater. The effect of the earthworms decreased with increasing compost amendment. The impact of the compost and the earthworms on metal solubility is explained by their effect on pH and soluble organic carbon and the environmental chemistry of each element.

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

by Tom Sizmur

The aim of this study was to test the impact of compost and biochar, with or without earthworms, on the mobility and... more 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.

A review of biochars’ potential role in the remediation, revegetation and restoration of contaminated soilsand restoration of contaminated soils

by Tom Sizmur

► Biochars can reduce mobilities of some organic and inorganic pollutants in soil.
► Source material and production conditions influence pollutant retention.
► Highly alkaline pH and water soluble carbon can undesirably mobilise some elements.
► Large surface area may be toxic to soil fauna but create microbial niches.
► Efficacy of biochar may depend on other organic materials applied in combination.

Biochars are biological residues combusted under low oxygen conditions, resulting in a porous, low density carbon rich... more Biochars are biological residues combusted under low oxygen conditions, resulting in a porous, low density carbon rich material. Their large surface areas and cation exchange capacities, determined to a large extent by source materials and pyrolysis temperatures, enables enhanced sorption of both organic and inorganic contaminants to their surfaces, reducing pollutant mobility when amending contaminated soils. Liming effects or release of carbon into soil solution may increase arsenic mobility, whilst low capital but enhanced retention of plant nutrients can restrict revegetation on degraded soils amended only with biochars; the combination of composts, manures and other amendments with biochars could be their most effective deployment to soils requiring stabilisation by revegetation. Specific mechanisms of contaminant-biochar retention and release over time and the environmental impact of biochar amendments on soil organisms remain somewhat unclear but must be investigated to ensure that the management of environmental pollution coincides with ecological sustainability.

Aqueous mercury precipitation with the synthetic dithiolate, BDTH2

by Lisa Blue

Ultra resolution chemical fingerprinting of dense non-aqueous phase liquids from manufactured gas by reverse phase comprehensive two-dimensional gas chromatography

by Russell Thomas

McGregor LA, Gauchotte-Lindsay C, Daéid NN, Thomas R, Daly P, Kalin RM.
Journal of Chromatography A
Volume 1218, Issue 29, 22 July 2011, Pages 4755-4763

Ultra resolution chemical fingerprinting of dense non-aqueous phase liquids (DNAPLs) from former manufactured gas... more Ultra resolution chemical fingerprinting of dense non-aqueous phase liquids (DNAPLs) from former manufactured gas plants (FMGPs) was investigated using comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry (GC×GC TOFMS). Reversed phase GC×GC (i.e. a polar primary column coupled to a non-polar secondary column) was found to significantly improve the separation of polycyclic aromatic hydrocarbons (PAHs) and their alkylated homologues. Sample extraction and cleanup was performed simultaneously using accelerated solvent extraction (ASE), with recovery rates between 76% and 97%, allowing fast, efficient extraction with minimal solvent consumption. Principal component analysis (PCA) of the GC×GC data was performed in an attempt to differentiate between twelve DNAPLs based on their chemical composition. Correlations were discovered between DNAPL composition and historic manufacturing processes used at different FMGP sites. Traditional chemical fingerprinting methods generally follow a tiered approach with sample analysis on several different instruments. We propose ultra resolution chemical fingerprinting as a fast, accurate and precise method of obtaining more chemical information than traditional tiered approaches while using only a single analytical technique.

Gas Purification

by Russell Thomas

The Note describes the process of gas purification, this process was the last stage in the manufacture of gas and was... more The Note describes the process of gas purification, this process was the last stage in the manufacture of gas and was primarily focussed on the removal of hydrogen cyanide and hydrogen sulphide.

If you have any specific enquiries on this subject please contact Dr Russell Thomas on thomasru@pbworld.com.

Tully Gas Plants

by Russell Thomas

The Tully Gas Plant was the invention of Cornelius Britiffe (C.B.) Tully, it was a hybrid of other gasworks plant and... more The Tully Gas Plant was the invention of Cornelius Britiffe (C.B.) Tully, it was a hybrid of other gasworks plant and considered in practical terms to be a vertical retort fixed over a water gas producer. The Tully Gas plant like water gas produced a mixture of hydrogen and carbon monoxide. The fuel would pass down the vertical retort, undergoing the various stages of carbonization. It would enter the producer in the form of coke which was then gasified as it would be in the usual water gas apparatus. The gases produced would travel out of the Tully gas Plant at the bottom of the producer, they would then be passed through a washbox and scrubber to the relief holder.

The First plant was built at the Swindon Works of the GWR and on completion of its successful operation sufficient orders were received to set up a manufacturing plant in Westmnster under the Name of Bale and Hardy Ltd in 1919. The plants were gradually modified and became known for the “complete gasification of coal”. In 1921 the Company relocated to Newark in Nottinghamshire and became known as the Tully Gas Plants Ltd, they produced these gas plants for gasworks all across the UK and also worldwide, we know that because they liked to advertise where they had built the plant.

The Gas Plants popularity stemmed from relatively cheap capital costs, they did require a very high level of precision to operate them, often greater than that willing to be provided by the operatives, and as a result they are believed to have often fallen out of favour.

A small profile will be produced to cover the subject which will be posted to the website in the coming weeks.

If you have any specific enquiries on this subject please contact Dr Russell Thomas on thomasru@pbworld.com.

Phase II report on the MGP Glasgow Site

by Ovo Adagha

A site investigation of an MGP site located in Glasgow has been completed. It is understood that the subject property... more A site investigation of an MGP site located in Glasgow has been completed. It is understood that the subject property formerly served as a gas work site and the client intends it for light industrial use. The investigation involved an assessment of the contamination levels at the site and to determine its suitability for future use. The Investigation consisted of excavating ten test pits; collecting and analyzing soil samples suspected to be contaminated with CoCs; evaluation of the analytical data obtained; and preparation of this report. RISC4 Computer modeling procedure was adopted in the analysis. The data obtained indicate that the threshold values of the observed CoCs are elevated. Thus, a clean-up or remediation action is recommended.

Collated Gasworks Profiles

by Russell Thomas

An easy to handle collated collection of the 4 gasworks profiles and 1 gas manufacturing note.

See the individual profiles and notes for more information.

If you have any specific enquiries on this... more See the individual profiles and notes for more information.

If you have any specific enquiries on this subject please contact Dr Russell Thomas on thomasru@pbworld.com.

Gasworks in Scotland

by Russell Thomas

A low resolution plot of gasworks in Scotland to give an idea of the geographical distribution of public and private gasworks in Scotland.

If you have any specific enquiries on this subject please contact Dr Russell Thomas on If you have any specific enquiries on this subject please contact Dr Russell Thomas on thomasru@pbworld.com.

Water Gas Profile

by Russell Thomas

PLEASE NOTE THIS PROFILE IS UNDER REVIEW (SOME SLIGHT ERRORS NOTED), IT WILL SOON BE REPLACED WITH A NEW VERSION.

One of the major issues with producing gas from coal was the time taken to get the gas plant operational and producing... more One of the major issues with producing gas from coal was the time taken to get the gas plant operational and producing gas, this lead to a heavy reliance on storage in gas holders or alternatively by operating gas plant inefficiently so there was always gas available to meet peak demand.

As satisfying peak demand for gas became ever more problematic an alternative solution was required. The saviour in response to this problem came in the form of Water Gas. This process could produce gas much more rapidly than traditional coal based plant, allowing gas companies to satisfy peak demand in a more cost effective manner.

Producer Gas Plants

by Russell Thomas

William Murdock used coal gas to light his house and office in Redruth in 1792; this was the first commercial... more William Murdock used coal gas to light his house and office in Redruth in 1792; this was the first commercial application of gas in the world. Gas has been used ever since for commercial, industrial and domestic applications. Gas was first produced from coal and later on from oil until its replacement by natural gas in the mid 1970s. The conventional production of gas from coal is well documented; however, there was also another method of gas production which is less well known, this was called “producer gas”.

Producer gas plants started to become popular in the early 1880 and were in extensive use by 1910. As producer gas plants evolved from the first plant built by Bischof (figure 1) through to their demise in competition in the mid 20th century, many varied types evolved. Following Bischof’s early development of the gas producer the next major development was that of Fredrick Siemens who developed a combined gas producer and regenerative furnace in 1857. This system was gradually improved and introduced to the UK through William Siemens. Producer gas plants provided a great benefit to those industries requiring high and uniform temperatures. This greatly aided those industrial processes which were unable or found it very difficult to use directly fired solid fuel furnaces, it also saved fuel as the gas could be burnt at the exact point required.

If you have any specific enquiries on this subject please contact Dr Russell Thomas on thomasru@pbworld.com.

Country house Gasworks

by Russell Thomas

Gas was manufactured continuously in the UK between 1792, when William Murdock first used coal gas to light his house... more Gas was manufactured continuously in the UK between 1792, when William Murdock first used coal gas to light his house and office in Redruth and the mid 1970s, when it was replaced by natural gas from the North Sea. One particular aspect of gas manufacture which has often been overlooked was the use of gas in remote country houses. These large properties were often expensive to light using oil lamps and candles, with their owners often keen to have the most up to date technologies used where possible to show their wealth. Coal gas lighting was much cheaper to use than candles or oil lamps and being fixed were relatively safe and actually resulted in lower fire insurance premiums when fitted.

As these sites were remote they were not able to connect to local gas mains and their only option was to build a small gasworks of their own. These small gasworks were very much in line with the philosophy of William Murdoch who proposed the use of small gas plants at individual establishments rather than that of Fredrich Winsor, who proposed the concept of large gasworks with gas distribution mains supplying towns and cities.

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If you have any specific enquiries on this subject please contact Dr Russell Thomas on thomasru@pbworld.com.