| Title: | Unveiling the distinctive role of titanium dioxide nanoparticles in aerobic sludge digestion |
| Author(s): | Wang C; Wei W; Mannina G; Dai X; Ni BJ; |
| Address: | "State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China. Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia. Engineering Department, Palermo University, Viale delle Scienze, Ed.8, 90128 Palermo, Italy. Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia. Electronic address: bingjieni@gmail.com" |
| DOI: | 10.1016/j.scitotenv.2021.151872 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Linking) |
| Abstract: | "Aerobic digestion is considered to be a common process for the stabilization of waste activated sludge (WAS) in the small-sized wastewater treatment systems, while the broad application of titanium dioxide nanoparticles (TiO(2) NPs) results in their unavoidable existence in WAS aerobic digestion, with its role in aerobic sludge digestion being never documented. This study set up a series of aerobic sludge digesters to evaluate the previously unknown role of TiO(2) NPs on the performance of the digesters. The volatile solids (VS) degradation percentage increased from 21.9 +/- 0.6% to 26.9 +/- 0.1% - 30.0 +/- 0.3% with the different contents of TiO(2) NPs (0, 1, 20 and 50 mg/L). Similarly, the total inorganic nitrogen production increased from 23.1 +/- 0.3 to 31.0 +/- 0.1 mg N/g VS with the rising TiO(2) NPs concentrations from 0 to 50 mg/L. The microbial analysis suggested that TiO(2) NPs contributed to the accumulation of specific microbes correlated with the degradation of organic substances and the conversion of nitrogen compounds. Model-based analysis showed the higher biodegradability and hydrolysis rate of sludge with TiO(2) NPs. Further mechanistic studies indicated that the enhancement of WAS solubilization and the degradation of recalcitrant substances (e.g., humic acid and cellulose) contributed to the better performance of experimental aerobic digesters, which was confirmed by the fourier transformation infrared spectroscopy (FTIR) indicating the converting of these materials into biodegradable substrates for digestion with TiO(2) NPs. It could be inferred from this investigation that aerobic digestion rather than anaerobic digestion would be a more suitable treatment method for sludge containing TiO(2) NPs" |
| Keywords: | "Anaerobiosis Digestion *Nanoparticles *Sewage Titanium Waste Disposal, Fluid Aerobic digestion Recalcitrant organics Sludge degradation Solubilization Titanium dioxide nanoparticles;" |
| Notes: | "MedlineWang, Chen Wei, Wei Mannina, Giorgio Dai, Xiaohu Ni, Bing-Jie eng Netherlands 2021/11/27 Sci Total Environ. 2022 Mar 20; 813:151872. doi: 10.1016/j.scitotenv.2021.151872. Epub 2021 Nov 23" |
