Removal of Ammonium and 4-Methylphenol from Synthetic Wastewater by Cell-Free Extracts of Nitrifying Sludge

Fluoroquinolone antibacterial agents (FQs) are the most commonly detected antibiotics in soil/groundwater which cause chronic effects on human beings as well as aquatic ecosystems. The current situation of the regulation, occurrence, fate, and sources of FQs in soil/groundwater was systematically analyzed in this paper. And then, the important factors affecting milligram per liter concentration of FQs sorption in soil, such as pH, cation exchange, clay minerals, organic content, surface complexation, and microbial degradation or transformation, were summarized. Actually, nanogram-microgram per liter concentration is detected frequently in soil/groundwater by far. Due to the extensive application of FQs and its relatively stable physicochemical characteristics, the higher concentration in soil/groundwater would appear in the coming decades which may exert a threat to freshwater and human beings. To the knowledge of the authors, no full-scale fate, occurrence, spatial, and temporal variations of FQs in soil/groundwater have been reported in the scientific literature. Therefore, it is recommended that more comprehensive studies are required to fill knowledge gaps in low-concentration transport, fate and occurrence, spatial, and temporal variations of FQs in soil/groundwater and their potential risk assessment to human and ecosystem.