TY - JOUR
T1 - Engineered digestate-derived biochar mediated peroxymonosulfate activation for oxytetracycline removal in sustainable wastewater remediation
AU - Akaniro, Ifunanya R.
AU - Zhang, Ruilong
AU - Chai, Xuyang
AU - Tsang, Christina H.M.
AU - Wang, Peixin
AU - He, Shan
AU - Yang, Zhu
AU - Zhao, Jun
N1 - This work was supported by the Hong Kong Environment and Conservation Fund (Ref.46-2020, 09-2021).
Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/11/1
Y1 - 2024/11/1
N2 - Nowadays, biochar is extensively used in wastewater remediation with the aim of achieving water security and circularity with minimal impacts on ecosystems and the environment. In this study, digestate biochar was prepared and modified using different methods and then employed as a peroxymonosulfate (PMS) activator to oxidize oxytetracycline, a model antibiotic pollutant in wastewater. The optimal biochar catalyst was characterized, spin trapping tests were carried out to confirm the dominant catalytic mechanism, and in silico toxicity prediction was conducted based on structure-activity relationships. Assessment of the catalytic performance of the pristine and engineered biochar showed that nitrogen doping increased oxytetracycline degradation efficiency by 1.92-fold (i.e., 100% oxytetracycline degradation with the engineered biochar compared to 52% with pristine biochar), while pyrrolic nitrogen was identified as a major PMS activation site. It was discovered that several parameters, such as catalyst dose, pH, PMS concentration, and competing ions, affected oxytetracycline degradation efficiencies. Additionally, the toxicity of the degradation intermediate was studied. Scavenger trapping tests showed that 1O2 and SO4•- were the most prevalent species during oxytetracycline degradation in the system, with four possible degradation pathways proposed, including secondary alcohol oxidation, hydroxylation, dehydration, and deamidation. Overall, it is anticipated that this study would contribute to our understanding of metal-free biochar activation of PMS as an attractive treatment scheme for antibiotic-polluted water.
AB - Nowadays, biochar is extensively used in wastewater remediation with the aim of achieving water security and circularity with minimal impacts on ecosystems and the environment. In this study, digestate biochar was prepared and modified using different methods and then employed as a peroxymonosulfate (PMS) activator to oxidize oxytetracycline, a model antibiotic pollutant in wastewater. The optimal biochar catalyst was characterized, spin trapping tests were carried out to confirm the dominant catalytic mechanism, and in silico toxicity prediction was conducted based on structure-activity relationships. Assessment of the catalytic performance of the pristine and engineered biochar showed that nitrogen doping increased oxytetracycline degradation efficiency by 1.92-fold (i.e., 100% oxytetracycline degradation with the engineered biochar compared to 52% with pristine biochar), while pyrrolic nitrogen was identified as a major PMS activation site. It was discovered that several parameters, such as catalyst dose, pH, PMS concentration, and competing ions, affected oxytetracycline degradation efficiencies. Additionally, the toxicity of the degradation intermediate was studied. Scavenger trapping tests showed that 1O2 and SO4•- were the most prevalent species during oxytetracycline degradation in the system, with four possible degradation pathways proposed, including secondary alcohol oxidation, hydroxylation, dehydration, and deamidation. Overall, it is anticipated that this study would contribute to our understanding of metal-free biochar activation of PMS as an attractive treatment scheme for antibiotic-polluted water.
KW - Catalytic PMS activation
KW - Nitrogen-doped biochar
KW - Oxytetracycline degradation
KW - Sustainable wastewater treatment
UR - http://www.scopus.com/inward/record.url?scp=85199943396&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2024.124640
DO - 10.1016/j.envpol.2024.124640
M3 - Journal article
AN - SCOPUS:85199943396
SN - 0269-7491
VL - 360
JO - Environmental Pollution
JF - Environmental Pollution
M1 - 124640
ER -