TY - JOUR N2 - The paper deals with the problem of the determination of the effects of temperature on the efficiency of the nitrification process of industrial wastewater, as well as its toxicity to the test organisms. The study on nitrification efficiency was performed using wastewater from one of Polish chemical factories. The chemical factory produces nitrogen fertilizers and various chemicals. The investigated wastewater was taken from the influent to the industrial mechanical-biological wastewater treatment plant (WWTP). The WWTP guaranteed high removal efficiency of organic compounds defined as chemical oxygen demand (COD) but periodical failure of nitrification performance was noted in last years of the WWTP operation. The research aim was to establish the cause of recurring failures of nitrification process in the above mentioned WWTP. The tested wastewater was not acutely toxic to activated sludge microorganisms. However, the wastewater was genotoxic to activated sludge microorganisms and the genotoxicity was greater in winter than in spring time. Analysis of almost 3 years’ period of the WWTP operation data and laboratory batch tests showed that activated sludge from the WWTP under study is very sensitive to temperature changes and the nitrification efficiency collapses rapidly under 16°C. Additionally, it was calculated that in order to provide the stable nitrification, in winter period the sludge age (SRT) in the WWTP should be higher than 35 days. L1 - http://journals.pan.pl/Content/86127/PDF/aep-2016-0003.pdf L2 - http://journals.pan.pl/Content/86127 PY - 2016 IS - No 1 DO - 10.1515/aep-2016-0003 KW - nitrification failure KW - activated sludge KW - industrial wastewater KW - high ammonium concentrations KW - (geno) toxicity A1 - Gnida, Anna A1 - Sikora, Jan A1 - Wiszniowski, Jarosław A1 - Felis, Ewa A1 - Surmacz-Górska, Joanna A1 - Miksch, Korneliusz PB - Polish Academy of Sciences VL - vol. 42 DA - 2016.01.01 T1 - The effect of temperature on the efficiency of industrial wastewater nitrification and its (geno)toxicity UR - http://journals.pan.pl/dlibra/publication/edition/86127 T2 - Archives of Environmental Protection ER -