Organophosphate esters (OPEs) are increasingly used as flame retardants and plasticizers in various products. Most of them are physically mixed rather than chemical bonded to the polymeric products, leading to OPEs being readily released into the surrounding environment. Due to their relatively high solubility and mobility, OPEs are ubiquitous in the aquatic environment and may pose potential hazards to human health and aquatic organisms. This review systematically summarized the fate and distribution of OPEs in the aquatic environment and the potential effects of OPEs on humans. Data analysis shows that the concentrations of OPEs vary widely in various types of aquatic environments, including surface water (range: 25–3671 ng/L), drinking water (4–719 ng/L), and wastewater (104–29,800 ng/L). The results of human exposure assessments via aquatic products and drinking water ingestion indicate that all OPEs pose low, but not negligible, risks to human health. In addition, the limitations of previous studies are summarized, and the outlook is provided. This review provides valuable information on the occurrence and distribution of OPEs in the aquatic environment.

In this study, pristine kiwi peel (KP) and nitric acid modified kiwi peel (NA-KP) based adsorbents were prepared and evaluated for selective removal of cationic dye. The morphology and chemical structure of KP and NA-KP were fully characterized and compared, and results showed nitric acid modification introduced more functional groups. Moreover, the adsorption kinetics and isotherms of malachite green (MG) by KP and NA-KP were investigated and discussed. The results showed that the adsorption process of MG onto KP followed a pseudo-second-order kinetic model and the Langmuir isotherm model, while the adsorption process of MG onto NA-KP followed a pseudo-first-order kinetic model and the Freundlich isotherm model. Notably, the Langmuir maximum adsorption capacity of NA-KP was 580.61 mg g⁻¹, which was superior to that of KP (297.15 mg g⁻¹). Furthermore, thermodynamic studies demonstrated the feasible, spontaneous, and endothermic nature of the adsorption process of MG by NA-KP. Importantly, NA-KP showed superior selectivity to KP towards cationic dye MG against anionic dye methyl orange (MO). When the molar ratio of MG/MO was 1:1, the separation factor (α_MG/MO) of NA-KP was 698.10, which was 5.93 times of KP. In addition, hydrogen bonding, π-π interactions, and electrostatic interaction played important roles during the MG adsorption process by NA-KP. This work provided a low-cost, eco-friendly, and efficient option for the selective removal of cationic dye from dyeing wastewater.