TY - JOUR
T1 - Quantifying the effects of chlorine disinfection on microplastics by time-resolved inductively coupled plasma-mass spectrometry
AU - Ho, Wai Kit
AU - Lum, Judy Tsz Shan
AU - Lam, Tsz Ki
AU - Yip, Tai Nam
AU - Hor, Catherine Hong Huan
AU - Leung, Kelvin Sze Yin
N1 - K. S.-Y Leung thanks the Hong Kong Research Grants Council (HKBU 12303122) for the financial support. Catherine H.-H. Hor thanks Hong Kong Baptist University for the Seed Fund (SCI-21-22-CHEM-03) financial support.
Publisher Copyright:
© 2024 Elsevier B.V.
PY - 2024/12/1
Y1 - 2024/12/1
N2 - Using current water treatment systems, significant amounts of microplastics (MPs) are passing through and being released into the aquatic environment. However, we do not clearly know what effects disinfection processes have had on these particles. In this study, we applied inductively coupled plasma-mass spectrometry (ICP-MS) operating in time-resolved analysis (TRA) mode for quantifying changes in the chlorine (Cl) content of MPs under a variety of water treatment scenarios. Our results illustrated that time-resolved ICP-MS offers a potential method for sensitive and direct analysis of Cl content, including Cl mass and chlorine association (%Cl/C), of discrete particles in the MP suspension by the fast sequential measurements of signals from 35Cl1H2 and 12C1H. Our research, across various water treatment scenarios, also showed that polystyrene (PS) MPs exhibited greater reactivity to Cl disinfectant after being pre-disinfected with UV light and in mildly acidic to neutral pH environments. It is noteworthy that about half of the particles in MP suspension exposed to 10 mg Cl2/L, a typical Cl dose applied in water treatment, were chlorinated, and had a Cl content comparable to that of particles subjected to extreme conditions. Of even greater concern is the fact that our cell viability tests revealed that chlorinated MPs induced considerably higher rates of cell death in both human A549 and Caco-2 cells, and that the effects were Cl dose- and polymer type-dependent. Overall, this study demonstrates the potential of time-resolved ICP-MS as a valuable technique for quantifying the Cl content of MP particles, which is crucial to assessing the fate and transformation of MPs in our water supply and treatment systems.
AB - Using current water treatment systems, significant amounts of microplastics (MPs) are passing through and being released into the aquatic environment. However, we do not clearly know what effects disinfection processes have had on these particles. In this study, we applied inductively coupled plasma-mass spectrometry (ICP-MS) operating in time-resolved analysis (TRA) mode for quantifying changes in the chlorine (Cl) content of MPs under a variety of water treatment scenarios. Our results illustrated that time-resolved ICP-MS offers a potential method for sensitive and direct analysis of Cl content, including Cl mass and chlorine association (%Cl/C), of discrete particles in the MP suspension by the fast sequential measurements of signals from 35Cl1H2 and 12C1H. Our research, across various water treatment scenarios, also showed that polystyrene (PS) MPs exhibited greater reactivity to Cl disinfectant after being pre-disinfected with UV light and in mildly acidic to neutral pH environments. It is noteworthy that about half of the particles in MP suspension exposed to 10 mg Cl2/L, a typical Cl dose applied in water treatment, were chlorinated, and had a Cl content comparable to that of particles subjected to extreme conditions. Of even greater concern is the fact that our cell viability tests revealed that chlorinated MPs induced considerably higher rates of cell death in both human A549 and Caco-2 cells, and that the effects were Cl dose- and polymer type-dependent. Overall, this study demonstrates the potential of time-resolved ICP-MS as a valuable technique for quantifying the Cl content of MP particles, which is crucial to assessing the fate and transformation of MPs in our water supply and treatment systems.
KW - Characterization
KW - Chlorine disinfection
KW - Cytotoxicity
KW - Microplastics
KW - Time-resolved ICP-MS
UR - https://www.sciencedirect.com/science/article/pii/S0048969724062880?via%3Dihub
UR - http://www.scopus.com/inward/record.url?scp=85204689350&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2024.176132
DO - 10.1016/j.scitotenv.2024.176132
M3 - Journal article
C2 - 39260477
AN - SCOPUS:85204689350
SN - 0048-9697
VL - 954
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 176132
ER -