Photocatalytic Degradation of Polyphenols and Polyaromatic Amines in Textile Industry Wastewaters by Nano-Cerium Dioxide Doped Titanium Dioxide and the Evaluation of Acute Toxicity Assays with Microtox and Daphnia magna

Abstract

In this study, nano-cerium dioxide doped titanium-dioxide (CeO2 -TiO2 ) Nanocomposites (NCs) was used for the photocatalytic degradation of pollutant parameters (color, polyphenols, polyaromatics) from a textile industry wastewater (TI ww) treatment plant located in Izmir, Turkey, at different operational conditions such as at increasing photocatalytic time (0, 10, 15, 20, 30, 60, 90 and 120 min), at different CeO2 -TiO2 mass ratios (1%, 3%, 5%, 10%, 15%, 16%, 25%, 30%, 50%), at the different amounts of CeO2 (1, 3, 5, 8, 10, 15, 20 and 25 mg/L) under 130 W Ultraviolet (UV) and 35 W sun lights irradiations, respectively. Color, polyphenols (quercetin, fi setin, ellargic acid, carminic acid, luteolin, and curcumin) and polyaromatics [2,6-dimethylaniline (2,6-DMA), 2-aminoanisole (MOA), 2,4-toluenediamine (TDA), 2-naphthylamine (NA), 4,40-thiobisbenzenamine (TOA), 3,3-dichlorobenzidine (DCB) and 3,30-dimethoxybenzidine (DMOB)] removal effi ciencies were observed between 78% and 99% during photocatalytic experiments, under ¬130 W UV light, at 15% CeO2 -TiO2 NCs, at 21° C, after 30 min irradiation time. 15% CeO2 -TiO2 NCs shows the highest photodegradation yield of color under both UV and visible-light irradiation, with maximum photodegradation rates of 99% and 98.5%, respectively, after 30 min irradiation time. 94.44% maximum Microtox acute toxicity yield was found in CeO2 -TiO2 NCs = 20 mg/L, at 5% CeO2 mass ratio, after 150 min photodegradation time at 60o C. 90% maximum Daphnia magna acute toxicity removal was obtained in CeO2 -TiO2 NCs = 20 mg/L, at 5% CeO2 mass ratio, after 150 min photodegradation time at 60° C. The results show that the CeO2 -TiO2 NCs has a high photocatalytic activity to remove the pollutants from TI ww.