The EU directive 2013/39/EU has incorporated four biocidal compounds as priority substances: diuron, isoproturon, cybutryne, and terbutryn. The research was undertaken to determine the concentration of biocides in surface waters in three locations in southern Poland: the Wisła River in Kraków, the Wisłoka River in Mielec, and the drainage ditch draining water from arable fields located near Mielec. Environmental samples were taken in two series: winter (February) and spring (May and June). The analyses were carried out using gas chromatography with mass spectrometry. The seasonality of biocides in surface waters was observed. In winter samples, the concentrations were below MQL, while in spring, they ranged from a few to several dozen nanograms per liter. The highest concentrations of all analyzed compounds were recorded in water taken from the Wisła River. According to directive 2013/39/EU, the maximum allowable concentration was exceeded only in the case of cybutryne in water from the Wisła, both in May and in June. The assessment of the toxicity with the tested compounds was defined based on the Environmental Risk Assessment method. Low risk was estimated for diuron and isoproturon, while moderate risk for terbutryn and cybutryne.

Particular attention is devoted to pharmaceutical residues in sewage sludge caused by their potential ecotoxicological effects. Diclofenac, ibuprofen and carbamazepine, 17-α-ethinylestradiol, β-estradiol, were analysed in four types of fertilizers, based on sewage sludge commercial products, in compliance with Polish requirements. The release of active pharmaceutical compounds from fertilizers to water the phase after 24 h and 27 days was analysed. Solid-water partition coefficients (Kd) and partitioning coefficient values normalized on organic carbon content (log KOC) were evaluated. The environmental risk to terrestrial ecosystems, due to the application of fertilizers onto soils, was estimated. Cumulative mass of pharmaceuticals emitted to water from fertilizers ranged from 0.4 to 30.8 µg/kg after 24 h contact. The greatest amount of the material that was released, over 70%, was observed for carbamazepine. No presence of compounds except ibuprofen was observed after 27 days of testing. The highest environmental risk in fertilizers is due to carbamazepine, risk quotation, RQ = 0.93 and diclofenac RQ = 0.17. The values of risk quotation estimated for soil were below RQ = 0.01. This fact means that no risk to terrestrial ecosystems is expected to occur. The important decrease of the concentrations of active compounds after passing from sewage sludge to fertilizers [and] to fertilized soil could be observed.

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Organic compounds are the most diverse group of contaminants. The largest anthropogenic source of these contaminants in water is municipal and industrial wastewater. One of the indicators of surface water pollution is biological oxygen demand (BOD). Purifying water from organic micropollutants is a serious challenge and requires the development of newer and more effective methods. The removal of such contaminants is most effective only in advanced oxidation processes (AOP), which include UV photolysis and photocatalysis. The presented results are from preliminary research to evaluate the effectiveness of water treatment by ultraviolet (UV) photolysis and photocatalysis. Treatment efficiency was evaluated on the basis of changes in the BOD index before and after the advanced oxidation process of raw water. The values of the BOD5 index determined in accordance with PN-EN 25813:1997. The exposure time of the samples was a maximum of 60 minutes. The tested material was water samples taken from the Rudawa River, which is one of the drinking water sources for Krakow. The initial BOD5 value (expressed as concentration of O2) for all samples was about 8 mg/L but it has decreased to over 2 mg/L due to AOP processes. This means that after an hour, more than 75% of organic compounds present in the raw water were removed. For photocatalysis (TiO2-MMT), the exposure time of the samples was a maximum of 35 minutes. Water samples taken from the Rudawa River were also used as test material. The initial BOD5 value for all samples was about 9 mg/L but it has decreased to about 4 mg/L due to the photocatalysis process. This means that after 35 minutes, 55% of the organic compounds present in the raw water were removed.

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