Occurrence, toxicity, ecological risk, and remediation of diclofenac in surface water environments: a review with a focus on China.

Diclofenac (DCF) is a nonsteroidal anti-inflammatory drug commonly used in health care, livestock, and pharmaceuticals and widely detected in surface water environments globally. Here, we reviewed the occurrence characteristics, migration pathways, and aquatic toxicity of DCF in surface water environments. Asian and African populations are exposed to high concentrations of DCF (> 8,000 ng L-1). Wastewater discharge, livestock, and industrial pollution are the primary factors influencing the concentration and distribution of DCF. Diclofenac can cause acute toxicity, oxidative stress, and other toxic effects on aquatic organisms. We focused on China and analyzed the ecological risks of DCF in surface water environments and found low risk in the south and high risk in the north, as well as low risk during the rainy season and high risk during the dry season. Finally, we discuss the removal methods for DCF and propose the potential of metal-organic frameworks as a new material to replace conventional methods for DCF removal. This study comprehensively reveals the pollution status of DCF and the ecological risk it poses to surface water environments, providing a reference for the environmental management of DCF.