TY - JOUR
T1 - Evaluating UV254 absorbance reductions in landfill leachate for municipal sewage co-treatment through timed UV/electrooxidation
AU - Sato, Yugo
AU - Xiang, Yingying
AU - Cooper, Patrick
AU - Cassol, Gabriela Scheibel
AU - Luo, Yu
AU - Zeng, Qian
AU - Shang, Chii
AU - Ren, Zhiyong Jason
AU - Chen, Guanghao
N1 - Funding Information:
This research was supported by the Research Grants Council of the Hong Kong Special Administrative Region ( T21-604/19-R ), Hong Kong Innovation and Technology Commission ( ITC-CNERC14EG03 ), and the Green Tech Fund ( GTF202020095 ). Special thanks are extended to Dr. Douglas F. W. Pollard for valuable comments on the manuscript.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2023/3/5
Y1 - 2023/3/5
N2 - Landfill leachate contains dissolved organic matter (DOM) exhibiting high ultraviolet absorbance at 254 nm (UVA254). The UVA254 limits leachate co-treatment with municipal sewage by hindering the downstream UV disinfection efficiency at wastewater treatment plants. Here, we alleviated the UVA254 by timing the radiation in a UV/electrooxidation (UV/EO) process to accelerate reactive species formation. At 200 A·m−2, the UV radiation was delayed by 10 min to accumulate 21 mg·L−1 as Cl2, which enhanced the initial radical formation rate by 5.25 times compared with a simultaneous UV/EO. The timed operation increased the steady-state concentrations of ClO• by 700 times to 4.11 × 10−14 M and reduced the leachate UVA254 by 78.2% after 60 min. We identified that aromatic formulas with low oxygen content were susceptible to UV/EO from Fourier-transform ion cyclotron resonance mass spectrometry analysis. The toxicity of the treated leachate and generated byproducts was assessed through specific oxygen uptake rates (SOUR) and developmental assays with Platynereis dumerilii. After quenching the residual chlorine, leachate co-treatment at 3.5% v/v presented minimal toxicological risk. Our findings provide operational insights for applying UV/EO in high UVA254 matrices such as landfill leachate.
AB - Landfill leachate contains dissolved organic matter (DOM) exhibiting high ultraviolet absorbance at 254 nm (UVA254). The UVA254 limits leachate co-treatment with municipal sewage by hindering the downstream UV disinfection efficiency at wastewater treatment plants. Here, we alleviated the UVA254 by timing the radiation in a UV/electrooxidation (UV/EO) process to accelerate reactive species formation. At 200 A·m−2, the UV radiation was delayed by 10 min to accumulate 21 mg·L−1 as Cl2, which enhanced the initial radical formation rate by 5.25 times compared with a simultaneous UV/EO. The timed operation increased the steady-state concentrations of ClO• by 700 times to 4.11 × 10−14 M and reduced the leachate UVA254 by 78.2% after 60 min. We identified that aromatic formulas with low oxygen content were susceptible to UV/EO from Fourier-transform ion cyclotron resonance mass spectrometry analysis. The toxicity of the treated leachate and generated byproducts was assessed through specific oxygen uptake rates (SOUR) and developmental assays with Platynereis dumerilii. After quenching the residual chlorine, leachate co-treatment at 3.5% v/v presented minimal toxicological risk. Our findings provide operational insights for applying UV/EO in high UVA254 matrices such as landfill leachate.
KW - advanced oxidation process
KW - dissolved organic matter
KW - electrooxidation
KW - landfill leachate
KW - municipal sewage
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U2 - 10.1016/j.jhazmat.2022.130624
DO - 10.1016/j.jhazmat.2022.130624
M3 - Article
AN - SCOPUS:85145689124
SN - 0304-3894
VL - 445
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 130624
ER -