EXPERIMENTAL-STUDY ON THE DECONTAMINATION KINETICS OF SEAWATER POLLUTED BY OXYTETRACYCLINE CONTAINED IN EFFLUENTS RELEASED FROM A FISH FARMLOCATED IN A SALT-MARSH

A rapid procedure for the quantitative determination of oxytetracyclin e (OTC) in seawater using high performance liquid chromatography is pr esented. The limits of detection and determination were respectively 0 .01 mug/ml and 0.05 mug/ml (precision +/- 10%) when injecting a 50 mul sample of seawater. The mean recovery of OTC from the seawater was 91 ,9%. Also included is an experimental study of the OTC kinetics in sea water. Experimental shellfish farms were polluted by effluents contain ing OTC coming from an experimental fish farm located in a salt-marsh. The disappearance of OTC from seawater was faster in the fish farm th an in the shellfish farms where two kinetic phases were observed; the first one with an average half-life of 30.27 h and the second one with a higher average half-life of 318.57 h. Only the first phase was stud ied because it was assumed that the second phase would be complicated by the disappearance of OTC occurring simultaneously with diffusion fr om the sediment and shellfish. The results varied between tanks becaus e of the differences in temperature, light intensity and flow from one tank to another. Fourteen days after the end of the chemotherapy in t he experimental fish farm, the average OTC concentration in seawater o f the shellfish farms was 0.2 mug/ml.