Determination of 1-hydroxypyrene in Atlantic cod (Gadus morhua) bile

The polyaromatic hydrocarbons (PAH‘s)are the major pollutants related to shipping activities and oil exploitation. On exposure for PAH‘s the absorbed amount is rapidly metabolized to hydrophillic metabolites. These metabolites are important biomarkers for PAH´s exposure In this work HPLC with fluorescence detection was used in order to measure the concentration of PAH metabolites in Atlantic cod (Gadus morhua) bile from different fishing sites around Iceland and Norway. An enzymatic hydrolysis step before analysis is needed in order to deconjugate the phase II metabolites to hydroxy compounds which can be measured.The 1-hydroxypyrene was detected in all samples,and it has been successfully quantified for Norwegian samples. it can be used as a good bio marker

Is dissolved COD a suitable design parameter for ozone oxidation of organic micropollutants in wastewater?

Ozone oxidation of organic micropollutants in biologically treated wastewater was investigated in pilot-scale after a high- and a low loaded activated sludge process. Higher ozone doses were required to remove organic micropollutants in the effluent wastewater from the high loaded activated sludge process. Further comparison of the micropollutant removal was based on normalized ozone doses, expressed as g O3/g DOC and g O3/g soluble COD (sCOD). A clear difference was noted for the two effluents when the micropollutant removal was normalized by DOC. This difference disappeared almost completely when the removal was linked to ozone doses normalized by sCOD. The dose-response curves for the organic micropollutants were practically linear in the removal range up to 95%. A linear prediction model was developed and compared with literature values to test the transferability of the obtained results. Results from this comparison indicated that the slope of the dose-response functions could be used to predict the removal efficiency of organic micropollutants at a third plant with an average uncertainty of 10%. The modeled ozone requirements were then set in relation to the COD concentrations in the discharged water from approximately 90 Swedish activated sludge treatment plants with and without nitrogen removal. This comparison highlighted the need for a well-functioning biological treatment for an effective ozone oxidation of organic micropollutants. The results in this study suggest that soluble COD should be further explored for design and modeling of ozone oxidation of organic micropollutants in biologically treated wastewater

Ozonation efficiency in removing organic micro pollutants from wastewater with respect to hydraulic loading rates and different wastewaters

Organic micro pollutants can be removed from water by ozonation. In this article we studied the performance of ozonation under real life conditions and compared results of the same ozonation pilot plant installed at different wastewater treatment plants (WWTPs) thus operating with different waters. The comparability of the removal and reaction rate constants from one waste water treatment plant were low in respect to reaction rate, removal as well as to response to the specific ozone dose. Neither pH-value nor residual nitrite concentrations were the driving force considering these differences. Further tests with different loadings were conducted at the same WWTP under different weather conditions. For the different hydraulic loading of the biological plant, the ozonation was running with rather similar removal rates concerning the same specific (TOC normalized) ozone dose. The compounds that were removed quantitatively under dry weather were still removed well with three times dry weather flow. Using a dataset from one WWTP to optimize operation in another one is thus questionable

PAC dosing to an MBBR – Effects on adsorption of micropollutants, nitrification and microbial community

Two nitrifying MBBR reactors were operated in parallel, one with PAC dosing and one without, to determine the effects of PAC dosing on nitrification and micropollutant adsorption in municipal wastewater. The removal of micropollutants was evaluated for several doses of PAC and batch experiments were performed to measure adsorption kinetics and nitrification rates. The influence of PAC on the nitrifying microbial community was examined by high-throughput amplicon sequencing. Long-term operation of the pilot reactors showed that nitrification could be maintained while supplying PAC at increasing doses, as confirmed by high nitrification rates and significant abundance of nitrifying bacteria. The adsorption of organic micropollutants could be controlled by the PAC dose, and increased dosing resulted in corresponding improvements in removal efficiency. Biomass, suspended or attached to carriers, did not interfere with the adsorption of organic micropollutants. Freundlich isotherms obtained from the batch experiments were used to predict removal of organic micropollutants in the pilot reactors, suggesting that batch adsorption experiments can be used to predict micropollutant removal on a full scale. Collectively, the results show that nitrification and adsorption of organic micropollutants can be performed simultaneously in an MBBR