Pierre Appriou

Behaviour of metals following intensive pig slurry applications to a natural field treatment process in Brittany (France)

It is well-known that heavy metals brought by intensive pig slurry applications accumulate in the soil; because of their potential impact on the environment, studying their behaviour is of utmost interest. The Solepur process has been developed in Brittany (France) where pig farming causes serious environmental problems; it enables the soil to be used as a treatment medium to process pig slurry. Numerous pig slurry applications were performed from 1991 to 1995 on an experimental hydrologically-isolated field specially equipped to recover all the leachate. These applications approximately corresponded to the amount which might have been spread over one century. The Solepur process can be considered as a simulation model for what happens to metals in pig slurry under normal field conditions over a long period of time. This work measured the concentrations of Cu, Zn, Mn, Co, Fe and Cd in pig slurry, in soil and in drainage water, and the results are discussed. Total concentrations and speciation data within the three different compartments were analysed and showed that Cu and Zn accumulate in the surface layer, whereas other metals, such as Mn and Co, dissolve and are washed away in the leachate. The increase in the bioavailability and toxicity of these metals as well as their impact on the environment are discussed.

Behaviour and speciation of metallic species Cu, Cd, Mn and Fe during estuarine mixing

This paper, based on laboratory experiments, deals with the behaviour of metallic species Cu, Cd, Fe, Zn and Mn during the mixing of river and seawaters. The present study focused on the variations of metals speciation in both the dissolved phase and the suspended particulate matter. For the dissolved metals, a protocol using chelating resins permitted to perform trace metals speciation, i.e. fractionation into ‘organic-metal’ and ‘inorganic-metal’, and to preconcentrate them. The speciation of suspended particulate matter (SPM) was performed according to the sequential extraction procedure of Tessier et al., 1979, to partition particulate metals into five different fractions. All total metals had a conservative behaviour. However, there were great differences from one metal to another in the partitioning into dissolved and particulate phase. For iron, the metal was partly removed from the dissolved phase during the mixing, probably because of organic matter flocculation. Particulate iron was conservative because 90% of it remained in the ‘residual’ fraction of SPM. Copper had a conservative behaviour in both the dissolved and the particulate phases. The affinity for organic matter was well established for dissolved copper as well as for particulate copper, i.e. respectively 40% in ‘organic’ form and more than 60% in the ‘organic’ fraction. Manganese and cadmium were non-conservative: a clear enrichment of the dissolved phase was observed at low salinities (< 7.5). These metals were desorbed in inorganic form from the particulate phase and for a large part from the ‘carbonates’ fraction of the SPM.

Preconcentration of trace metals from sea water with the chelating resin Chelamine

Abstract The complexing properties (capacity, pH effect, breakthrough curve) of the chelating resin Chelamine, containing a pentamine ligand, were investigated. The resin was used in a column procedure for the preconcentration of Cd(II), Cu(II), Mn(II), Ni(II), Pb(II) and Zn(II) from deionized water and sea water and the recoveries were 93–105 and 91–102%, respectively. The absolute blanks varied from less than 0.6 ng for Cd to 11 ng for Cu, permitting the determination of the above six metals in oceanic water. The accuracy of the method was demonstrated by replicate analyses of the marine reference material CASS-2. The high selectivity of the resin leads to low concentration of alkali and alkaline earth metal ions in the acidic eluate.

Partitioning of mercury onto suspended sedimentsin estuaries

Radiochemical partitioning experiments using 203Hg have been undertaken with mixtures of river, seawater and sediment samples taken from three geochemically contrasting UK estuaries: the Plym, Beaulieu and Mersey. Species of dissolved Hg were determined using reversed-phase C18 chelating columns and particulate species were determined by sequential leaching with 1 M NH4OAc and 1 M HCl. Mercury had a high particle reactivity with partition coefficients, KDs, ranging from 10(4) to 5 x 10(5) ml g(-1), depending on salinity, the chemical composition of the end-member waters, and on the physico-chemical characteristics of the sediment. Dissolved organic matter present in the waters (humic substances and/or anthropogenic compounds) was found to be the main factor governing the forms of dissolved Hg and their reactivity. From the spiked 203Hg, up to 95% of the dissolved metal was retained on the C18 columns for the Mersey waters, whereas this fraction was < 60% in the Plym and Beaulieu waters. Quasi-irreversible adsorption of Hg onto particles from each estuary was observed over a time-scale of a few hours and < 20% of total particulate Hg was released by the sequential leach. In this paper, physico-chemical processes are proposed to explain the estuarine behaviour of Hg and the results are discussed in terms of Hg availability in estuarine systems.

Three-column system for preconcentration and speciation determination of trace metals in natural waters

A three-column system consisting of a combination of C18 reversed phase, Dowex anion-exchange resin and the chelating resin Chelamine is described. This method permits the simultaneous preconcentration and differentiation between neutral hydrophobic organic metal complexes, anionic complexes and the “free ion” concentration of the transition metals in water samples with complex matrices. General operating conditions were established by numerous experiments with model substances. The sample analyses can be made without any previous treatment and hence the pre-established natural equilibria are unadulterated. The method was used in the investigation of several fresh-water and sea-water samples for the determination of Cu2+, Cd2+, Pb2+ and Mn2+ and showed excellent reproducibility.

Column preconcentration of trace metals from sea-water with macroporous resins impregnated with lipophilic tetraaza macrocycles

Macroporous resins impregnated with lipophilic tetraaza macrocyclic derivatives were used for the uptake and enrichment of trace metals from sea-water prior to their determination by electrothermal atomic absorption spectrometry. The effects of the size of the macrocycle cavity, the support used for impregnation, the pH of the extraction and the parameters of the back-extraction were studied in a column process. The preconcentration of trace metals (Cd, Cu, Mn, Ni, Pb and Zn) from de-ionized water and sea-water was investigated. Satisfactory results were obtained for Cd, Mn, Pb and Zn with an average recovery of 98 ± 8%. Absolute blanks are in the range 1–10 ng and the detection limit varies from 0.7 ng for Cd to 15 ng for Pb. The accuracy of the method was demonstrated by replicate analyses of the National Research Council of Canada marine reference material NASS-2 (open ocean sea-water). The precision is better than 15%(1σ). The selectivity of the resin for Cd, Cu, Mn, Ni, Pb and Zn over NaI, CaII and MgII was studied.

Application of a tetraaza macrocycle immobilized on an organic polymer to the determination of trace amounts of manganese in sea water

Abstract Poly(vinylbenzyltetraaza-1,4,8,11-cyclotetradecane) was synthesized and used for the preconcentration of manganese from sea water prior to its determination by graphite furnace atomic absorption spectrometry. The improvement in the porosity of this new polymer has a significant effect on the rates of the extraction and back-extraction steps in comparison with previously described polymers. Swelling, capacity and pH effects were studied by the batch technique. The validity of the method is demonstrated by comparison with the quinolin-8-ol-chloroform liquid—liquid extraction system. The blank of the method is ca. 0.15 nmol 1−1 and the relative standard deviation for duplicate analyses of coastal sea water is 8%.

Electrothermic factors optimization in electrothermal atomic absorption spectrometry via an optimal experimental design matrix

Abstract A new approach is proposed to optimize some instrumental electrothermic parameters, i.e. injected volume, calcination duration, calcination and atomization temperatures, gas flow, in electrothermal atomic absorption spectrometry. It is based on the monitoring of the detection limit estimation variation by using an unconventional experimental design well adapted to a particular experimental domain. This method was tested on Cd, Mn and Cu in sea water. By comparison with the default operating conditions, the limits of detection were improved in some cases and always obtained on carrying out less experiments than usual.

Tetraaza 1.4.8.11, cyclotetradecane greffe sur polymere: synthese et application a l'extraction de cu2+, Ni2+ et Co2+.

Abstract Polymer-supported cyclam is prepared from 1.4.8.11 tetraaza cyclotetradecane and chloromethylated polystyrene resin. Retention capacities for Cu(II), Ni(II) and Co(II) are reported.

Determination of trace amounts of copper and zinc in sea water with polymer-supported 1,4,8,11-tetraazacyclotetradecane

Abstract The very low affinity of tetraaza macrocycles for alkali and alkaline earth metals make them attractive for the preconcentration of transition metals from seawater. Three different procedures for determinations of copper and zinc with 1,4,8,11-tetraazacyclotetradecane (cyclam) bound to poly(chloromethyl)vinylbenzene are described. Results for both metals in estuarine and oceanic waters, compared to those obtained with Chelex-100 resin, show that the polymer-supported cyclam provides > 95% extraction of these two metals. The resin is used as a solid sample for electrothermal atomic absorption spectrometry, or the metal is back-extracted with nitric acid for injection.