The reaction of Pd(II) with 1,8-dihydroxy-2-(pyrazol-5-ylazo)-naphthalen-3,6-disulphonic acid immobilized by physical sorption onto Dowex 1-X8 ion-exchange resin was investigated with the aim to develop the sorption-spectroscopic test method for the detection of low Pd(II) concentrations in water. The resin phase absorption spectra of the reagent and its Pd(II) complex were followed. The immobilized reagent has the spectral characteristics similar to those in the water and forms with Pd(II) 1:1 complex with the absorption maximum at 650 nm. Parameters, such as pH, wavelength and contact time have been optimized for a given amount of the sorbed reagent. The experimental conditions for the linear dependence of absorbance vs. Pd(II) concentration have been determined.

In our previous papers, it is concluded that wood sawdust can be applied as adsorbent for heavy metals removing from water. All earlier investigations are done in batches, while it is confirmed that different heavy metals are adsorbing with various efficacy on sawdust of different kind of wood. Adsorption of copper ions from model water is investigated in this paper, by its passing throw column filled with poplar and fir sawdust, granulation in the range 0.5-1 mm. Starting concentration of copper ions was the same in all experiments, and flowrates of model water and column geometry are varied. Certain volumes of water are taken on the column outlet, and copper ions concentration are determinated in this samples. On the basis of these results breakthrough curves are obtained, and adsorption parameters in dynamic conditions are determinated.