16 research outputs found
Direct speciation analysis of thallium based on solid phase extraction and specific retention of a Tl(III) complex on alumina coated with sodium dodecyl sulfate
Fast and simple procedure for fractionation of zinc in soil using an ultrasound probe and FAAS detection. Validation of the analytical method and evaluation of the uncertainty budget
Limitation of environmental impact of metallurgical waste by bioleaching
Various bioleaching processes are applied to recover valuable elements from low-grade ores and metallurgical waste. The activity of microorganisms leads to solubilization of metals from solid substrates and, in this way, makes possible recovery of elements from solutions. The study of wastes from the nickel-chromium steelworks in Szklary showed that a mobile fraction of elements remaining in residues from bioleaching process was substantially larger than in raw waste material. The highest mobility was displayed by metals in wastes leached by heterotrophic bacteria prior to autotrophic ones. In that case the mobile fraction makes up 60–80% of the total concentration of Ni, Cr, Cu and Zn. Storage of bioleached mine tailings increases risk of permeation of hazardous matter to aquifers. When this is the case, a careful flushing and use of metal-binding materials such as bentonite, zeolites, cement, and commercial preparations containing these ingredients are recommended. The obtained results showed that concrete, which is the cheapest of the applied materials, bound almost entirely the mobile fractions of Ni, Cr, Co, Pb, Cu and Zn
Analytical chemistry in investigation and protection of the environment
The main goal of studies carried in our reasearch group – analytical chemistry
in investigation and protection of the environment is the evaluation of the impact of
human activity on environmental pollution, and creation of analytical procedures
that can be applied in environmental analysis. Detailed description of our research
can be found on webpage http://www.chem.uw.edu.pl/labs/pcas. In this paper we
would like to present only a few topics and analytical challenges that we were dealing
with during the last years. The application of anodic and cathodic stripping voltammetry
for trace analysis of hazardous metals (cadmium, lead, thallium, platinum,
rhodium) in natural samples is described [4–6]. Voltammetry is also presented as
a tool used in speciation analysis, which is particularly important in the case of
elements which toxicity and assimilation depends on chemical form of the element
that is present in the environment (e.g. As) [8]. Attention is also paid to fractionation,
which is a specific case of speciation analysis, extremely important for evaluation
of mobility and bioavailability of harmful or nutritious substances from soil.
As environmental monitoring often requires carrying measurements at trace levels,
it might be necessary to preconcentrate the analytes or simplify the composition of
the sample before the analysis. For such purposes solid phase extraction (SPE) is
widely used and frequently applied. Another analytical task presented in this work
is recognition of the defense mechanisms developed by hyperaccumulating plants,
e.g. white mustard. This species was investigated for synthesis of phytochelatins –
sulphur-rich polipeptides induced by high concentrations of As, Tl, Cd, Pt, Pd and
Rh [14]. It is worth noting that plant species that are able to cumulate high amounts
of xenobiotics can be used for phytoremediation, which is one of so called “green
technologies”, used for restitution of polluted environment, particularly soil [19]
Element fractionation in soil from urban-industrialized areas using sequential extraction
Overlapping toxic effect of long term thallium exposure on white mustard (Sinapis alba L.) photosynthetic activity
Tl-speciation of aqueous samples – a review of methods and application of IC-ICP-MS/LC-MS procedures for the detection of (CH 3
Thallium in spawn, juveniles, and adult common toads (Bufo bufo) living in the vicinity of a zinc-mining complex, Poland
The comparison of sample extraction procedures for the determination of cations in soil by IC and ICP-AES
Major inputs and mobility of potentially toxic elements contamination in urban areas
Soil quality in urban areas is affected by anthropogenic activities, posing a risk to human health and ecosystems. Since the pseudo-total concentrations of potentially toxic elements may not reflect their potential risks, the study of element mobility is very important on a risk assessment basis. This study aims at characterising the distribution and major sources of 34 elements in two Portuguese urban areas (Lisbon and Viseu), with different geological characteristics, industrial and urban development processes. Furthermore, the potential availability of As, Co, Cr, Cu, Ni, Pb and Zn was assessed, by measuring the fraction easily mobilised. Lisbon is enriched in elements of geogenic and anthropogenic origin, whereas in the smaller city, the high levels observed are mainly related to a geogenic origin. Background values can be more relevant than the dimension of the city, even when anthropogenic components may be present, and this parameter should be considered when comparing results from different cities. Regarding the potential available fraction, a high variability of results was observed for elements and for sampling sites with an influence of the soil's general characteristics. Elements showing very high concentrations due to geological reasons presented, in general, a low mobility and it was not dependent on the degree of contamination. For elements with major anthropogenic origin, only Zn was dependent on the pseudo-total content. Yet, the highest available fractions of some elements, both with major geogenic and anthropogenic origin, were observed in specific contaminated samples. Therefore, a site-specific evaluation in urban soils is important due to the high spatial variability and heterogeneity.This work was supported by CESAM and by the Fundação para a Ciência e Tecnologia through the research project POCTI/CTA/44851/2002:SOLURB (‘Towards a methodology for the assessment of environmental quality in urban soils’) and individual research grants attributed to A. Cachada (SFRH/BD/38418/2007), P. Pato (SFRH/BPD/35068/ 2007), C. Mieiro (SFRH/BD/28733/2006) and T. Rocha-Santos (SFRH/BPD/65410/2009). The authors wish to thank Pedro Faria for the English revisions.publishe