Biodegradation of a mixture of benzophenone, benzophenone-3, caffeine and carbamazepine in a laboratory test filter

The biodegradation of a mixture of four pharmaceutical and personal care products (PPCPs) (benzophenone (BP), benzophenone-3 (BP-3), caffeine (CF) and carbamazepine (CBZ)) was studied in a laboratory test filter. The column was filled with inert material to exclude adsorption processes and to enable the development of the biofilm, while river water was recirculated. High removal for BP, BP-3 and CF was observed from the beginning of the experiment at initial concentration of 20 µg L -1 (90-99 %). In the case of CBZ analytical difficulties were experienced. Efficacy of b iodegradation r eflected as a change of the overall toxicity of initial mixture of selected PPCPs vs . toxicity of samples undergone different biodegradation phases was assessed with two standard laboratory tests with apical endpoint - acute toxicity test with Daphnia magna (immobilisation) and bioluminescence inhibition with Vibrio fisheri . T oxicity tests s howed the substantial reduction of overall mixture toxicity in a laboratory test filter. The residual toxicity to D. magna might be attributed to undetected transformation products.