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Characterising metal build-up on urban road surfaces Full text
2013
Egodawatta, Prasanna | Ziyath, Abdul M. | Goonetilleke, Ashantha
Reliable approaches for predicting pollutant build-up are essential for accurate urban stormwater quality modelling. Based on the in-depth investigation of metal build-up on residential road surfaces, this paper presents empirical models for predicting metal loads on these surfaces. The study investigated metals commonly present in the urban environment. Analysis undertaken found that the build-up process for metals primarily originating from anthropogenic (copper and zinc) and geogenic (aluminium, calcium, iron and manganese) sources were different. Chromium and nickel were below detection limits. Lead was primarily associated with geogenic sources, but also exhibited a significant relationship with anthropogenic sources. The empirical prediction models developed were validated using an independent data set and found to have relative prediction errors of 12–50%, which is generally acceptable for complex systems such as urban road surfaces. Also, the predicted values were very close to the observed values and well within 95% prediction interval.
Show more [+] Less [-]Microbial effects on the release and attenuation of arsenic in the shallow subsurface of a natural geochemical anomaly Full text
2013
Drahota, Petr | Falteisek, Lukáš | Redlich, Aleš | Rohovec, Jan | Matoušek, Tomáš | Čepička, Ivan
Critical factors leading to arsenic release and attenuation from the shallow subsurface were studied with multidisciplinary approach in the natural gold–arsenic geochemical anomaly at Mokrsko (Czech Republic). The results show that microbial reduction promotes arsenic release from Fe(III) (hydr)oxides and Fe(III) arsenates, thereby enhancing dissolved arsenic in the shallow groundwater at average concentration of 7.76 mg/L. In the organic-rich aggregates and wood particles, however, microbial sulfate reduction triggers the formation of realgar deposits, leading to accumulation of As in the distinct organic-rich patches of the shallow subsurface. We conclude that precipitation of realgar in the shallow subsurface of soil/sediment depends on specific and non-trivial combination of water and rock chemistry, microbial community composition and spatial organisation of the subsurface zone, where speciation in saturated environments varied on a centimeter scale from reduced (decomposed wood, H2S and realgar present) to oxidized (goethite and arsenate minerals are present).
Show more [+] Less [-]Levels of metals in blood samples from Mallards (Anas platyrhynchos) from urban areas in Poland Full text
2013
Binkowski, Łukasz J. | Meissner, Włodzimierz
In this paper we present the studies conducted on blood samples taken from Mallards (Anas platyrhynchos). Birds were captured for ringing purposes (n = 43) in two small and two big towns (including highly urbanized areas). For comparison samples of blood from birds shot on fish ponds were used (n = 26). Based on the body mass all sampled individuals can be assessed as being in good condition. Levels of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb) and zinc (Zn) in blood samples were measured with AAS. Concentrations of metals did not differ statistically between sexes and made up a following order: Fe > Zn > Cu > Cr ≈ Ni > Pb > Cd. Mallards from towns revealed lower concentrations of Zn and Cu but higher concentration of Fe. There was no difference in exposition to Pb between birds from towns and fish ponds.
Show more [+] Less [-]Impact of Zn, Cu, Al and Fe on the partitioning and bioaccessibility of 14C-phenanthrene in soil Full text
2013
Obuekwe, Ifeyinwa S. | Semple, K. T. (Kirk T.)
This investigation considered the effects of Zn, Cu, Al and Fe (50 and 500 mg kg−1) on the loss, sequential extractability, using calcium chloride (CaCl2), hydroxypropyl-β-cyclodextrin (HPCD) and dichloromethane (DCM) and biodegradation of 14C-phenanthrene in soil over 63 d contact time. The key findings were that the presence of Cu and Al (500 mg kg−1) resulted in larger amounts of 14C-phenanthrene being extracted by CaCl2 and HPCD. Further, the CaCl2 + HPCD extractions directly predicted the biodegradation of the PAH in the presence of the metals, with the exception of 500 mg kg−1 Cu and Zn. The presence of high concentrations of some metals can impact on the mobility and accessibility of phenanthrene in soil, which may impact on the risk assessment of PAH contaminated soil.
Show more [+] Less [-]Assessing mixed trace elements in groundwater and their health risk of residents living in the Mekong River basin of Cambodia Full text
2013
Phan, Kongkea | Phan, Samrach | Huoy, Laingshun | Suy, Bunseang | Wong, Ming Hung | Jamal Hisham Hashim, | Mohamed Yasin, Mohamed Salleh | Aljunid, Syed Mohamed | Sthiannopkao, Suthipong | Kim, Kyoung-Woong
We investigated the potential contamination of trace elements in shallow Cambodian groundwater. Groundwater and hair samples were collected from three provinces in the Mekong River basin of Cambodia and analyzed by ICP-MS. Groundwater from Kandal (n = 46) and Kraite (n = 12) were enriched in As, Mn, Ba and Fe whereas none of tube wells in Kampong Cham (n = 18) had trace elements higher than Cambodian permissible limits. Risk computations indicated that 98.7% and 12.4% of residents in the study areas of Kandal (n = 297) and Kratie (n = 89) were at risk of non-carcinogenic effects from exposure to multiple elements, yet none were at risk in Kampong Cham (n = 184). Arsenic contributed 99.5%, 60.3% and 84.2% of the aggregate risk in Kandal, Kratie and Kampong Cham, respectively. Sustainable and appropriate treatment technologies must therefore be implemented in order for Cambodian groundwater to be used as potable water.
Show more [+] Less [-]Mycorrhizal colonization affects the elemental distribution in roots of Ni-hyperaccumulator Berkheya coddii Roessler Full text
2013
Orłowska, Elżbieta | Przybyłowicz, Wojciech | Orlowski, Dariusz | Mongwaketsi, Nametso P. | Turnau, Katarzyna | Mesjasz-Przybyłowicz, Jolanta
The effect of arbuscular mycorrhizal fungi (AMF) on the distribution and concentration of elements in roots of Ni-hyperaccumulating plant Berkheya coddii was studied. Micro-PIXE (particle-induced X-ray emission) analysis revealed significant differences between AMF-inoculated and non-inoculated plants as well as between main and lateral roots. The accumulation of P, K, Mn and Zn in the cortical layer of lateral roots of inoculated plants confirmed the important role of AMF in uptake and accumulation of these elements. Higher concentration of P, K, Fe, Ni, Cu and Zn in the vascular stele in roots of AMF-inoculated plants than in the non-inoculated ones indicates more efficient translocation of these elements to the aboveground parts of the plant. These findings indicate the necessity of including the influence of AMF in studies on the uptake of elements by plants and in industrial use of B. coddii for Ni extraction from polluted soils.
Show more [+] Less [-]Assessment of biochar and iron filing amendments for the remediation of a metal, arsenic and phenanthrene co-contaminated spoil Full text
2013
Sneath, Helen E. | Hutchings, Tony R. | de Leij, Frans A.A.M.
Sites contaminated with mixtures of metals, metalloids and organics are difficult to remediate as each contaminant type may require a different treatment. Biochar, with high metal sorption capacity, used singly and in combination with iron filings, is investigated in microcosm trials to immobilise metal(loid)s within a contaminated spoil, thereby enabling revegetation and degradation of organic pollutants. A mine spoil, contaminated with heavy metals, arsenic and spiked with phenanthrene was treated with either 1%w/w biochar, 5%w/w iron or their combination, enhancing phenanthrene degradation by 44–65%. Biochar treatment reduced Cu leaching and enabled sunflower growth, but had no significant effect on As mobility. Iron treatment reduced Cu and As leaching but negatively impacted soil structure and released high levels of Fe causing sunflower plant mortality. The combined treatment reduced both Cu and As leaching and enabled sunflower growth suggesting this could be a useful approach for treating co-contaminated sites.
Show more [+] Less [-]Estimation of the algal-available phosphorus pool in sediments of a large, shallow eutrophic lake (Taihu, China) using profiled SMT fractional analysis Full text
2013
Zhu, Mengyuan | Zhu, Guangwei | Li, Wei | Zhang, Yunlin | Zhao, Linlin | Gu, Zhao
Because large, shallow lakes are heavily influenced by wind–wave disturbance, it is difficult to estimate internal phosphorus load using traditional methods. To estimate the potential contribution of phosphorus from sediment to overlying water in eutrophic Lake Taihu, phosphorus fractions of surface and deep layer sediments were quantified and analyzed for algal bloom potential using a Standard Measurements and Testing (SMT) sequential extraction method and incubation experiments. Phosphorus bound to Fe, Al and Mn oxides and hydroxides (Fe–P) and organic phosphorus (OP) were to be found bioactive. The difference in Fe–P and OP contents between surface and deep layers equates to the sediment pool of potentially algal-available phosphorus. This pool was estimated at 5168 tons for the entire lake and was closely related to pollution input and algal blooms. Profiled SMT fractionation analysis is thus a potentially useful tool for estimating internal phosphorus loading in large, shallow lakes.
Show more [+] Less [-]Space and time resolved monitoring of airborne particulate matter in proximity of a traffic roundabout in Sweden Full text
2013
Wilkinson, Kai E. | Lundkvist, Johanna | Netrval, Julia | Eriksson, Mats | Seisenbaeva, Gulaim A. | Kessler, Vadim G.
Concerns over exposure to airborne particulate matter (PM) are on the rise. Currently monitoring of PM is done on the basis of interpolating a mass of PM by volume (μg/m3) but has the drawback of not taking the chemical nature of PM into account. Here we propose a method of collecting PM at its emission source and employing automated analysis with scanning electron microscopy associated with EDS-analysis together with light scattering to discern the chemical composition, size distribution, and time and space resolved structure of PM emissions in a heavily trafficated roundabout in Sweden. Multivariate methods (PCA, ANOVA) indicate that the technogenic marker Fe follows roadside dust in spreading from the road, and depending on time and location of collection, a statistically significant difference can be seen, adding a useful tool to the repertoiré of detailed PM monitoring and risk assessment of local emission sources.
Show more [+] Less [-]Carbonate minerals in porous media decrease mobility of polyacrylic acid modified zero-valent iron nanoparticles used for groundwater remediation Full text
2013
Laumann, Susanne | Micić, Vesna | Lowry, Gregory V. | Hofmann, Thilo
The limited transport of nanoscale zero-valent iron (nZVI) in porous media is a major obstacle to its widespread application for in situ groundwater remediation. Previous studies on nZVI transport have mainly been carried out in quartz porous media. The effect of carbonate minerals, which often predominate in aquifers, has not been evaluated to date. This study assessed the influence of the carbonate minerals in porous media on the transport of polyacrylic acid modified nZVI (PAA-nZVI). Increasing the proportion of carbonate sand in the porous media resulted in less transport of PAA-nZVI. Predicted travel distances were reduced to a few centimeters in pure carbonate sand compared to approximately 1.6 m in quartz sand. Transport modeling showed that the attachment efficiency and deposition rate coefficient increased linearly with increasing proportion of carbonate sand.
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