Angela H Rhodes’s research while affiliated with Lancaster University and other places

What is this page?


This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.

Publications (12)


Influence of Activated Charcoal on Desorption Kinetics and Biodegradation of Phenanthrene in Soil
  • Article

October 2012

·

36 Reads

·

62 Citations

Environmental Science and Technology

Angela H Rhodes

·

Matthew J Riding

·

Laura E McAllister

·

[...]

·

The observed strong sorption of polycyclic aromatic hydrocarbons (PAHs) to black carbon (BC) presents potential implications for PAH bioaccessibility in soils. The effects of BC on the desorption kinetics and mineralisation of phenanthrene in four soils was investigated after 1, 25, 50 and 100d soil-PAH contact time, using sequential hydroxypropyl-β-cyclodextrin (HPCD) extractions in soils amended with 0, 0.1, 1 and 5% (dry wt. soil) activated charcoal (AC, a form of BC). The Rrapidly (%Frap) and slowly (%Fslow) desorbing phenanthrene fractions and their rate constants were determined using a first-order two-compartment (biphasic) desorption model. A minimum 7.8-fold decrease in %Frap occurred when AC was increased from 0-5%, with a corresponding increase in %Fslow. Desorption rate constants followed the progression krap(% h-1) > kslow(% h-1) and were in the order of 10-1 to 10-2 and 10-3 to 10-4, respectively. Linear regressions between %Frap and the fractions degraded by a phenanthrene inoculum (% Fmin) indicated that slopes did not approximate 1 at concentrations greater than 0% AC; %Fmin often exceeded %Frap, indicating a fraction of sorbed phenanthrene (%Fslow) remained microbially accessible. Therefore, sorption-HPCD-desorption kinetics alone may not be an adequate basis for the prediction of the bioaccessibility of PAHs to microorganisms and/or bioremediation potential in AC amended soils.


Impact of activated charcoal on the mineralisation of 14C-phenanthrene in soils

February 2010

·

44 Reads

·

65 Citations

Chemosphere

The development of phenanthrene catabolism in four soils amended with varying concentrations of activated charcoal (AC) (0%, 0.1%, 1% and 5%), a type of black carbon, was investigated. Mineralisation of (14)C-phenanthrene was monitored after 1, 25, 50 and 100 d soil-PAH contact time; lag phases, rates and extents of mineralisation of the (14)C-phenanthrene to (14)CO(2) were determined. At concentrations >0.1% AC rates and extents of mineralisation were reduced by more than 99%. This revealed that the presence of >0.1% AC in soils may substantially diminish the rate at which the catabolic activity of indigenous soil microflora develops in contaminated soil. Soil C, which had the highest organic carbon (OC) content, consistently exhibited the highest extents of degradation. It is suggested that, in accordance with other researchers, OC may have blocked available phenanthrene sorption sites. This enhanced phenanthrene availability ultimately facilitated a greater level of catabolic activity within this soil. Such results reflect the complex nature of interactions between soil, biota and contaminants and their influence on the degradation of contaminants in the environment.


Linking Desorption Kinetics to Phenanthrene Biodegradation in Soil

February 2010

·

37 Reads

·

77 Citations

Environmental Pollution

The desorption of polycyclic aromatic hydrocarbons (PAHs) often exhibits a biphasic profile similar to that observed for biodegradation whereby an initial rapid phase of degradation or desorption is followed by a phase of much slower transformation or release. Most investigations to-date have utilised a polymeric sorbent, such as Tenax, to characterise desorption, which is methodologically unsuitable for the analysis of soil. In this study, desorption kinetics of (14)C-phenanthrene were measured by consecutive extraction using aqueous solutions of hydroxypropyl-beta-cyclodextrin (HPCD). The data indicate that the fraction extracted after 24 h generally approximated the linearly sorbed, rapidly desorbing fraction (F(rap)), calculated using a three-compartment model. A good linear correlation between phenanthrene mineralised and F(rap) was observed (r(2) = 0.89; gradient = 0.85; intercept = 8.20). Hence HPCD extraction (24 h) and first-order three-compartment modelling appear to provide an operationally straightforward tool for estimating mass-transfer limited biodegradation in soil.


Using supercritical fluid extraction to measure the desorption and bioaccessibility of phenanthrene in soils

December 2008

·

51 Reads

·

19 Citations

Environmental Pollution

The aim of this paper was to measure the changing desorbable fraction and bioaccessibility of phenanthrene in two different soils with increasing soil-phenanthrene contact time using supercritical fluid extractions (SFE). Both soils were spiked with 100 mg kg(-1) phenanthrene and aged for 28d. Desorption profiles were measured every 7d using selective SFE conditions and the results were compared to 14C-phenanthrene mineralisation assays. Selective SFE showed significant differences in the rates and extents of desorption in the two soils, likely to be due to different organic matter composition. Post-extraction fitting of data yielded consistent SFE extraction times within ageing soils for bioaccessibility prediction.


Biogenic volatile organic compounds as a potential stimulator for organic contaminant degradation by soil microorganisms

October 2008

·

46 Reads

·

17 Citations

Environmental Pollution

The effects of monoterpenes on the degradation of (14)C-2,4-dichlorophenol (DCP) were investigated in soils collected from areas surrounding monoterpene and non-monoterpene-emitting vegetation. Indigenous microorganisms degraded (14)C-2,4-DCP to (14)CO(2), after 1d contact time. Degradation was enhanced by prior exposure of the soils to 2,4-DCP for 32 d, increasing extents of mineralisation up to 60%. Monoterpene amendments further enhanced 2,4-DCP degradation, but only following pre-exposure to both 2,4-DCP and monoterpene, with total 2,4-DCP mineralisation extents of up to 71%. Degradation was greatest at the higher monoterpene concentrations (> or = 1 microg kg(-1)). Total mineralisation extents were similar between concentrations, but higher than the control and the 0.1 microg kg(-1) amendment, indicating that increases in monoterpene concentration has a diminishing enhancing effect. We suggest that monoterpenes can stimulate the biodegradation of 2,4-DCP by indigenous soil microorganisms and that monoterpene amendment in soils is an effective strategy for removing organic contaminants.


Assessing biodegradation potential of PAHs in complex multi-contaminant matrices

July 2008

·

41 Reads

·

41 Citations

Environmental Pollution

This study sought to extend validation of a cyclodextrin based extraction method for the assessment of PAH-biodegradation potential to complex multi-contaminant matrices. To this end, four reference materials (RMs) were produced by blending, in different proportions, soils impacted with diesel, lubricating oil and spent oxide. These reference materials had modest summation operatorPAH (16 US EPA) concentrations that ranged from 5.6+/-0.5 to 44.4+/-4.5 mg kg(-1). However, extractable petroleum hydrocarbon (EPH) concentrations were comparatively high (up to 2520+/-204 mg kg(-1)). To complement these RMs, two further soils from a municipal gas plant (MGP) with highly elevated concentration of PAHs ranging from 877+/-52 to 2620+/-344 mg kg(-1) were also tested. Results showed, regardless of matrix complexity, that PAH biodegradation within the four RM substrates, and two MGP soils correlated well with biodegradation predicted by hydroxypropyl-beta-cyclodextrin (HPCD) extraction.


Fate and behaviour of phenantrene in the natural and artificial soils

April 2008

·

106 Reads

·

39 Citations

Environmental Pollution

OECD artificial soil has been used routinely as a standardized substrate for soil toxicity tests. However, can be the fate, behaviour and effects of contaminants in artificial soil extrapolated to natural soils? The aim of our study was to verify this hypothesis by comparing the loss, extraction, and bioavailability of phenanthrene in three artificial and three natural soils of comparable organic carbon content. Soils were spiked with 14C-phenanthrene and total 14C-activity change, the fractions extracted by dichloromethane, 70% ethanol, and hydroxypropyl-beta-cyclodextrin, the fraction mineralized by Pseudomonas sp., and taken up by Enchytraeus albidus were measured after 1, 14, 42, and 84 d aging. The loss, extraction, biodegradation and uptake were several times lower in the artificial than natural soils and these differences increased with increasing soil-phenanthrene contact time. These results imply that artificial soil should be used cautiously for the prediction of fate and behaviour in natural soils.


Development of phenanthrene catabolism in natural and artificial soils

April 2008

·

29 Reads

·

22 Citations

Environmental Pollution

The characteristics of natural soils often vary from those of artificial soil (e.g. OECD), which may lead to substantial differences in the bioavailability of test substances. The aim of this investigation was to characterise the development of phenanthrene catabolism in both natural and artificial soils with varying total organic carbon (TOC) content after 1, 14, 42 and 84 d soil-phenanthrene contact time. Indigenous catabolic activity was measured via the addition of 14C-phenanthrene using the respirometric soil slurry assay. Notably, the lag phases, fastest rates and total extents of 14C-phenanthrene degradation were relatively comparable in soils with similar TOC content after 1 d contact time. However, natural soils generally exhibited significantly shorter lag phases, faster rates and higher extents of mineralisation, than their artificial counterparts after 42 and 84 d contact time. Such findings suggest that the extrapolation of results from artificial soils to real/natural soils may not be straightforward.


Impact of Black Carbon in the Extraction and Mineralization of Phenanthrene in Soil

March 2008

·

48 Reads

·

210 Citations

Environmental Science and Technology

During the past century, increased biomass burning and fossil fuel consumption have drastically increased the input of black carbon (BC) into the environment, and that has been shown to influence the behavior of organic contaminants in soil. A study was conducted to investigate the effects of BC on the relationship between aqueous hydroxypropyl-beta-cyclodextrin (HPCD) extraction and microbial mineralization (bioaccessibility) of 14C-phenanthrene (10 mg kg(-1)) in four soils amended with 0, 0.1, 0.5, 1, 2.5, and 5% (% dry wt soil) activated charcoal, a type of BC. Mineralisation was monitored over 20 d incubation, within respirometric assays, using an inoculum containing a phenanthrene-degrading pseudomonad and compared to HPCD extraction (24 h) using 50 mM aqueous solution; analyses were conducted after 1, 25, 50, and 100 d soil-phenanthrene contact time. Statistical analyses revealed that for each soil the addition of BC led to significant (P < 0.001) reductions in both HPCD extractability and microbial mineralization. Linear correlations for BC concentrations of 0% (r2 = 0.95; slope = 0.89) and 0.1% (r2 = 0.67; slope = 0.95) revealed a highly significant (P < 0.01) relationship between HPCD extractability and total mineralization (20 d), indicating a direct prediction of phenanthrene bioaccessibility by HPCD. However, in soils amended with 0.5, 1, 2.5, and 5% BC exhibited r2 values ranging 0.51-0.13 and slopes of 2.19-12.73. This study has shown that BC strongly sorbs phenanthrene causing reductions in extractability and, to a lesser extent, bioaccessibility to degrading microorganisms.


Relationship between cyclodextrin extraction and biodegradation of phenanthrene in soil

February 2008

·

16 Reads

·

38 Citations

Environmental Toxicology and Chemistry

A number of soil extraction techniques have been proposed to determine the microbial degradability of organic contaminants in soil. Exhaustive methods using organic solvents have little relevance to the concentration of contaminants actually available to microorganisms. The present study investigated the relationship between sequential hydroxypropyl-beta-cyclodextrin (HPCD) extractions and microbial mineralization of [14C]phenanthrene in four soils over time. The desorption of [14C]phenanthrene was assessed at 24-h intervals over 10 d and compared to cumulative mineralization of the [14C]phenanthrene using an enriched pseudomonad inoculum. The cumulative total of [14C]phenanthrene extracted by HPCD exceeded the mineralization asymptote by more than 20%. The overall total extents mineralized after both single and multiple degrader inoculations, however, were statistically similar to that extracted after the first 24 h by HPCD; the ratios of extractable to mineralizable [14C]phenanthrene consistently approached one. Furthermore, a good linear correlation between mineralized and extracted phenanthrene was observed (single: r2 = 0.99, gradient = 0.90, intercept = 3.09; multiple: r2 = 0.95, gradient = 1.01, intercept = -0.48), suggesting that a single HPCD extraction accurately and reproducibly predicts the total fraction of phenanthrene available for microbial mineralization in all soils tested in the present study.


Citations (12)


... Although a linear relationship was established between the residual contaminants after microbial degradation and the extracted contaminants, the fractional range of the best-fit slope varied widely. Due to the presence of steric hindrance and carbonaceous materials such as activated carbon, the prediction of bioaccessibility of HPCD extraction for highcyclic PAHs is insufficient (Rhodes et al. 2008;Rhodes et al. 2012). ...

Reference:

A novel bioaccessibility prediction method for complex petroleum hydrocarbon mixtures in soil
Influence of Activated Charcoal on Desorption Kinetics and Biodegradation of Phenanthrene in Soil
  • Citing Article
  • October 2012

Environmental Science and Technology

... SFE was shown to directly extract the bioaccessible contaminant fraction (Hawthorne et al., 2005) and to successfully predict the biodegradation extent of polycyclic aromatic hydrocarbons (PAHs) (Hawthorne and Grabanski, 2000). SFE allows various extraction (from mild to harsh) conditions to be sequentially applied by increasing the extraction pressure and temperature, thus providing information on the distribution of a chemical among the soil sorption sites (Björklund et al., 1999;Hawthorne et al., 2005;Stroud et al., 2008). XAD extractions are simple shaking extractions based on the release of the sorbed contaminant from the soil matrix, to the water phase and to the adsorbents that operate under infinite sink conditions. ...

Using supercritical fluid extraction to measure the desorption and bioaccessibility of phenanthrene in soils
  • Citing Article
  • December 2008

Environmental Pollution

... And desorption can reflect the possibility of the re-release of organic pollutants from sorbent under actual environmental conditions, and thus can assess the releasing risk of organic pollutants effectively (Ortega-Calvo et al., 2015). Furthermore, the desorption behavior of organic pollutants from soil/sludge can be divided into three fractions: rapid, slow, and resistant desorption fraction (Rhodes et al., 2010(Rhodes et al., , 2012, where the slow and resistant desorption fractions may be related to the presence of hard carbon (such as black carbon, kerogen, HM), while the rapid desorption fraction refers to the weakly adsorbed part such as soft carbon (such as HA, FA) with a more sparse structure. It shows that the composition and content of OM affect the desorption behavior and bioavailability of organic pollutants in soil/sludge, as well as the correlation between sorption and desorption (Wang et al., Water Air Soil Pollut (2023) 234:242 Page 3 of 13 242 ...

Linking Desorption Kinetics to Phenanthrene Biodegradation in Soil
  • Citing Article
  • February 2010

Environmental Pollution

... Marchal (2013) demonstrated for phenanthrene sorbed to soils that the stronger the adsorbent (AC, biochar, compost), the lower desorbed concentration, and the lower the microbial degradation (Marchal 2013). These results are not unique (Rhodes 2010), but they may be specific to adsorbates having high heats of adsorption like phenanthrene. Three-ring PAH, as is phenanthrene, degradation has been reported to be inhibited by AC, but 4 and 5-ring PAHs degradation is supported by AC (García-Delgado 2019). ...

Impact of activated charcoal on the mineralisation of 14C-phenanthrene in soils
  • Citing Article
  • February 2010

Chemosphere

... It is widely considered that terpenes are plant or fungal metabolites [140], but predicted terpene synthases were also found in bacteria belonging orders like Myxococcales, Burkholderiales, Rhizobiales, Sphingobacteriales, Pseudomonadales [141] detected in our experimental conditions. The identified microbial consortium may have utilized terpenes/terpenoids as C source and energy for the subsequent soil contaminants degradation [142][143][144]. However, further studies on bacterial terpenome [145] and its role in bioremediation are required. ...

Biogenic volatile organic compounds as a potential stimulator for organic contaminant degradation by soil microorganisms
  • Citing Article
  • October 2008

Environmental Pollution

... Many products from oil spills are toxic to wildlife, which, when incorporated into the food chain, will also be poisonous to humans. This knowledge has increased scientific interest in studying the distribution, fate, and behavior of oil and its derivatives in the environment (Semple et al. 2006). Fishing and farming, which are the traditional means of livelihood of the people of the oilproducing communities, are adversely affected. ...

Can microbial mineralization be used to estimate microbial availability of organic contaminants in soil?
  • Citing Article
  • April 2006

Environmental Pollution

... When between −50% and 50%, the matrix effect is stronger, and the matrix standard curve must be quantified to eliminate the matrix effect on the results. However, the sample preparation method should be re-optimized when ME > 50% or ME < −50% [36]. All matrices had low matrix effects (−20% < ME < 20%), indicating that it can be ignored ( Figure 3). ...

Biodegradation of 2,4-dichlorophenol in the presence of volatile organic compounds in soils under different vegetation types
  • Citing Article
  • May 2007

FEMS Microbiology Letters

... Additionally, kaolin clay has a low adsorption capacity when compared to other naturally occurring clay types, possibly leading to higher bioavailability of certain chemicals. Previous studies have shown that OM quality and chemical properties play an important role in changing the sorption behavior of lipophilic organic chemicals (Belfroid et al., 1996;Hofman et al., 2008;Peters et al., 2007). In a study performed by Vlčková and Hofman (2012), the bioaccumulation of several lipophilic chemicals in E. fetida was assessed in artificial and natural soils containing similar OM content. ...

Fate and behaviour of phenantrene in the natural and artificial soils
  • Citing Article
  • April 2008

Environmental Pollution

... There has been considerable research surrounding the development of less exhaustive extraction techniques to estimate the bioaccessibility and accurately predict the degradability of organic contaminants in soil Rhodes et al., 2008). However, it has also been observed that the ability of different extraction solutions to predict bioaccessibility of the contaminant can show significant variations from case to case (Škulcová et al., 2016). ...

Relationship between cyclodextrin extraction and biodegradation of phenanthrene in soil
  • Citing Article
  • February 2008

Environmental Toxicology and Chemistry