DCH18C6 using strontium extraction selectivity investigation and sequential soil fractionation study

85Sr as radioindicator has been applied to strontium separation selectivity study using cisdicyclohexano-18-crown-6 (DCH18C6) as extraction agent and picric acid as counter ion with the aim to contribute to the development of a rapid method of strontium extraction. The same radioindicator has been used for strontium fractionation study in chosen soils by application of Tessier- and BCR sequential extraction procedures. Experimental results have shown, that the mentioned extraction system is applicable for IDA determination of Sr2+ in ∼1000-fold abundance of Ca2+, ∼1000-fold abundance and Mg2+, ∼10-fold abundance of K+ and ∼0.2-fold abundance of Ba2+. For the soil samples - chernozems developed on loess - from the near vicinity of NPP Jaslovské Bohunice the exchangeable strontium fraction reached as much as 50 – 60 %.

Extraction kinetics of solid phase extraction of dissolved organic matter in environmental samples from various aquatic system

<p>Progress has been made towards optimizing extracting dissolved organic matter (DOM) using a styrene-divinylbenzene copolymer (PPL) sorbent, which is a widely used solid phase extraction (SPE) method to separate DOM from different aquatic samples. To establish the suitable extraction conditions, the effects of critical SPE variables such as loading mass, concentration, flow rate, as well as the extraction selectivity of the PPL sorbent have been systematically studied. Tens liters of water samples were collected from various aquatic environments, including headwater, downstream river water, coastal seawater, surface seawater from open ocean, seawater from open ocean at the depth of fluorescence maximum, and deep ocean water. 5g-Bond Elut PPL columns were used and the extraction kinetics of DOM were monitored liter-by-liter while extraction. Fluorescence spectrum were decomposed into their underlying chemical components resolved by PARAllel FACtor analysis (PARAFAC). Extraction selectivity of the PPL sorbent among different types of waters was verified through those fluorescence excitation emission matrices (EEMs) and chromophoric dissolved organic matter (CDOM) measurements.</p>

Extraction of Pd(ii) and Pt(ii) from aqueous hydrochloric acid with 1,3-diaminocalix[4]arene: switching of the extraction selectivity by using different extraction modes

1,3-Diaminocalix[4]arene shows extraction ability toward Pd(ii) and Pt(ii), the selectivity of which can be switched by changing the concentrations of H+ and Cl− in the aqueous phase.

Extraction of Copper and Zinc from Waste Printed Circuit Boards

The recovery of valuable metals from waste printed circuit boards (WPCBs) is crucial in order to harness their economic resources, and prevents potential environmental contamination. However, selective extraction of Cu and Zn, and the co-extraction of other metals as impurities at ambient temperature using selected lixiviants such as HCl, H2SO4, HNO3, trifluoromethanesulfonic acid (TFMS), NaOH, and mixtures of NaCl and CuCl2 was studied. It is shown that the extraction efficiencies of all the metals increased with increases in lixiviant concentrations. High selectivity of Cu and Zn toward Fe were achieved in dilute H2SO4, HNO3, TFMS, and 0.5 M NaCl + 0.1 M CuCl2, and low dissolution of Pb (<5%) was observed in all H2SO4 lixiviants. Almost 100% Zn extraction using NaOH lixiviants without trace of other metals was achieved. Therefore, 0.5 M NaCl + 0.5 M CuCl2, 1.0 M HNO3, 0.5 M H2SO4, and 1.0 M TFMS showed high extraction selectivity toward Cu and Zn with low chemical consumption, and produced pregnant leach solution rich in Cu and Zn, as well as residue containing Fe, Ni, and other metals.

Lanthanide extraction selectivity of a tripodal carbamoylmethylphosphine oxide ligand system

Lanthanide extraction selectivity is attained by variation of the ligand structure and extraction conditions for a series of CMPO-based ligands.