Pesticides carried by cotton fiber are potential risk for production workers and consumers. Dissipation behaviour of a commonly used cotton pesticide profenofos in cotton fiber during growing period and scouring treatment was investigated. The results showed that profenofos in the fiber from the pre-opened and post-opened bolls both decreased to undetectable amounts 21 days after pesticide application. However, a minority of profenofos was converted to a strongly irritant compound, 4-bromo-2-chlorophenol and retained a non-negligible amount in cotton fiber even after 28 days. Profenofos and its degradation product could be completely removed during the conventional cotton scouring process. The degradation half-time of profenofos in scouring bath was only 3.0 min, and the degradation product was also 4-bromo-2-chlorophenol. Cotton products made of profenofos-carrying fiber are safe; however, the scouring waste should be detoxicated before discharge due to the accumulation of 4-bromo-2-chlorophenol in the scouring bath. These results could be useful for evaluating the risk of cotton fiber from the profenofos applied fields.
Jin Liu,Cong Hu,Xiaoyan Meng,Ying Sun,Bo Zhao,Zian Lin
Phenolic compounds are a kind of persistent organic pollutants (POPs), which are always a threat to human and environment due to their strong toxicity and low biodegradability. Therefore, developing a reliable method to simultaneously detect phenolic pollutants is of great importance to environmental safety and human health. Herein, we combined the advantages of metal organic frameworks (MOFs) and covalent organic frameworks (COFs) to prepare two cyclic trinuclear unit-based metal covalent organic framework (MCOFs, denoted as Cu 3 -TDH COF and Cu 3 -BDU COF) with large specific surface area, good stability and excellent laccase-like activity. Their oxidative degradation ability toward phenolic pollutants was verified, and a dual-channel nanozyme sensor array based on Cu 3 -TDH COF and Cu 3 -BDU COF was constructed for the identification of six phenolic pollutants. Notably, the sensor array can accurately distinguish between different concentrations of phenolic pollutants and different types of phenolic pollutants at the same concentration, even at levels as low as 1 μM. Moreover, three real water samples (rainwater, tap water and wastewater) and 18 unknown samples were also distinguished and differentiated by the sensor array. This study opens up a potential avenue for the design of MCOFs-based nanozyme sensor arrays to simultaneously realize identification and detection of multiple phenolic pollutants.