Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Identification and specification of occurring wastewaters

The occurring wastewater shows high values of suspended solids and COD. The suspended solid concentrations range from 40 to 1000mg/l and COD from 20 to 545mg/l. According to the German regulations these values are very high. The quantity of oxygen used in biological and non-biological oxidation of materials in water is the COD, it is therefore a measure of water quality. In shipyards the high COD demand results from the use of paints, glues and detergents.

A large number of organic halogens, which are of environmental concern, were found in the examined wastewater. Instead of analysing the concentration of each compound separately, the sum parameter of the absorbable organic halogens AOX is determined. The load of AOX at the shipyard results from the cleaning and washing of the ships. Regarding the German restrictions AOX concentrations have to be below 0,5 mg/l. Three of the samples, which were analysed, exceed this limit.

Due to the discharge of ballast water and dry docking activities a lot of mineral oil hydrocarbons can be found in the wastewater of shipyards which are very difficult to reduce. According to the analysis the hydrocarbons seem not to be a big problem in comparison to the suspended solids and COD. Except one sample all the other values were under the limit.

The heavy metal concentrations of copper, nickel and chromium in the filtrate, sediments and suspended solids pass the limit values.

Reported by

Verein zur Foerderung des Technologietransfers an der Hochschule Bremerhaven eV
16 An der Karlstadt 10
27568 Bremerhaven
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