Anwendung einfacher Konservierungsverfahren für Wasseruntersuchungen

Samples taken from the influent and effluent of a biological wastewater treatment plant were immediately analysed and investigated at different intervals within four weeks after sampling. They were stored in the dark at 277 and 293 K and at pH 2 and pH 12 each. None of the measures resulted in a correct stabilization or preservation of the samples: orthophosphate cannot be stabilized by any measure, the total phosphate needs not be stabilized, the COD gives values which are still useful only at pH 2 and 277 K, TOC and DOC do not show useful results with none of the applied techniques, equally insufficient are the results for ammonium- and nitrate-ions. In addition, differences occur in the behaviour of the samples taken from the influent and effluent. In agreement with the results published in the literature, the chemical analysis has to be carried out within 6 h after sampling.