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The advanced treatment of polluted liquid streams containing traces of pharmaceutical compounds is a major issue, since more and more effluents from pharma labs and wastewaters containing the excretions of medically treated humans and animals are discharged in the conventional wastewater treatment plants without previous effective treatments. Ibuprofen is a widely used non-steroidal anti-inflammatory drug (NSAID), which explains why it is found in wastewaters so often. In this paper, the removal of IBP from simulated water streams was investigated by using a lab-scale experimental device, consisting of a batch reactor equipped with a lamp emitting monochromatic UV light at a fixed wavelength (254 nm) and various intensities. Three sets of experiments were carried out: the first to study IBP concentration as a function of time, at different volumes of treated solutions (V = 10–30 mL); the second to explore the effect of pH on IBP degradation as a function of time (pH = 2.25–8.25) and the third to evaluate the effect of different UV light intensities on IBP degradation (E = 100–400 mJ m−2). The IBP initial concentration (IBP 0) was varied in the range 30–60 mg L−1. The results obtained show that the concentration of IBP decreases along with treatment time, with a negative effect of the treated volume, i.e. smaller volumes, such as lower liquid heights, are more easily degraded. Moreover, the higher the pH, the better the IBP degradation; actually, when pH increases from 2.25 to 6.6 and 8.25, the IBP concentration, after an hour of treatment, decreases respectively to 45, 34 and 27 % of its initial value. In addition, as the intensity of light increases from 100 to 400 mJ m−2, the IBP concentration decreases to 34 % of its initial value. A reaction scheme is put forward in the paper, which well describes the effects of volume, pH and light intensity on the IBP degradation measured experimentally. Moreover, the IBP degradation by-products have been identified.

A major environmental concern has recently developed due to emerging pollutants (EC) that are nowadays being detected in the effluents of municipal and industrial wastewater treatment plants (WWTP) at very low concentrations, thanks to improved analytical techniques. Pharmaceutical compounds (PhACs) are some of the most hazardous EC. These compounds can be retained into the water cycle (from users to WWTP, and then to water sources by discharge) virtually endlessly. Thus innovative solutions are required, such as the advanced oxidation processes (AOP). Among them, combined treatments based on UV light appear to be eco-friendly, giving very interesting removal efficiencies if opportunely devised. In this paper, the removal of diclofenac, a widely used non-steroidal anti-inflammatory drug (NSAID), from synthetic water streams was explored by using a lab-scale experimental device, consisting of a batch reactor equipped with a lamp emitting monochromatic UV light at fixed wavelength and intensity (254 nm; 400 mJ m–2). The experimental tests have been carried out to evaluate the effect of treatment time and to verify the possibility of further degrading the obtained compound. The preliminary results confirm what has been recently and unexpectedly found in literature, that is the formation of a dimer during the first minutes of photolysis, carbazole, a very stable coloured intermediate. A major environmental concern has recently developed due to emerging pollutants (EC) that are nowadays being detected in the effluents of municipal and industrial wastewater treatment plants (WWTP) at very low concentrations, thanks to improved analytical techniques. Pharmaceutical compounds (PhACs) are some of the most hazardous EC. These compounds can be retained into the water cycle (from users to WWTP, and then to water sources by discharge) virtually endlessly. Thus innovative solutions are required, such as the advanced oxidation processes (AOP). Among them, combined treatments based on UV light appear to be eco-friendly, giving very interesting removal efficiencies if opportunely devised. In this paper, the removal of diclofenac, a widely used non-steroidal anti-inflammatory drug (NSAID), from synthetic water streams was explored by using a lab-scale experimental device, consisting of a batch reactor equipped with a lamp emitting monochromatic UV light at fixed wavelength and intensity (254 nm; 400 mJ m(-2)). The experimental tests have been carried out to evaluate the effect of treatment time and to verify the possibility of further degrading the obtained compound. The preliminary results confirm what has been recently and unexpectedly found in literature, that is the formation of a dimer during the first minutes of photolysis, carbazole, a very stable coloured intermediate.

The presence of trace of pharmaceutical compounds (PhACs) in groundwater and in drinking and superficial waters is a major public health concern. Recently, various advanced treatment technologies have been studied to remove these kinds of pollutants; among them, combined treatments based on UV light appear to be more eco-friendly and with very interesting removal efficiencies if properly modified. In this paper, the removal of Ibuprofen (IBP) from synthetic water streams was investigated by using a lab-scale experimental device consisting of a batch reactor equipped with a lamp emitting monochromatic UV light (254 nm; 400 mJ m−2). The IBP initial concentration (C IBP 0 ) was 45.9 mg L−1. Two sets of experiments were carried out; the first one was aimed at studying the IBP concentration as a function of time, at different volumes of treated solution; the second one was aimed at exploring the effect of pH on IBP degradation as a function of time. The results obtained show that the concentration of IBP decreases along with treatment time, with a negative effect of the treated volume, i.e., smaller volumes, that is lower liquid heights, are more easily degraded. Moreover, the higher the pH, the better the IBP degradation; actually when pH increases from 2.25 to 5.51 and finally to 8.25, the IBP concentration, after an hour of treatment, decreases respectively to 45, 34, and 27 % from its initial value. A reaction mechanism is suggested, which well describes the effects of volume and pH on the experimentally measured IBP degradation.