VOLTAMMETRIC COMPLEXATION CAPACITY OF WATERS OF THE PISUERGA RIVER

The copper complexation capacity (CC) and the conditional formation co nstant of the resulting complexes, beta', have been measured in the Pi suerga River at its passage through the town of Valladolid, by means o f a voltammetric titration of the water at ''natural pH'' (acetate buf fer) using DPASV as analytical technique. The effect of both sampling site and sampling time on CC and beta' have been evaluated, finding th at only sampling site has a significant effect on CC, whereas both fac tors affected beta'. We have also found a significant correlation (at P = 0.05) of CC with Chemical Oxygen Demand and no correlation between CC and Dissolved Organic Carbon. The CC of Pisuerga River has been mo nitored during a 127-week period, finding a progressive increase of it s level with the time, a significant correlation with the stream flow, as well as a periodical behaviour that has been elucidated with the a id of signal processing techniques (smoothing and Fourier transform), finding long term variations than can be attributed to seasonal change s in the river stream flow.