The Study Of New Brominated Flame Retardants (TBC?HBCDs) Adsorpted By Microplastics In Simulated Seawater

In recent years,microplastics in oceans have become a serious environmental problem and the focus of attention.TBC and HBCDs are two typical new brominated flame retardants,and they have the characteristics of toxicity,persistence,bioaccumulation,lipophilicity and hydrophobicity.Microplastics have adsorbability and can adsorb many harmful substances.In the present study,the sorption of TBC and HBCDs by microplastics in simulated seawater was studied.The effects of particle size,temperature,salinity,and concentration on the adsorption of TBC and HBCDs by microplastics were studied,and the adsorption kinetics and adsorption isotherm model were used to describe the results.The experimental results showed that the equilibrium time of TBC adsorption was about 15 hours,and the first-order adsorption kinetic model was more suitable than the pseudo-second-order kinetic model to describe adsorption.The adsorption capacity increased with the decreased in particle size.The adsorption capacity gradually increased at first and then decreased with the increased in salinity and temperature.When the temperature is 15 C and salinity is 14%,the adsorption capacity of microplastics reaches the maximum.Compared with the linear and Freundlich models,the Langmuir model was more suitable.This indicated that the main adsorption mechanism might be chemical adsorption.The adsorption equilibrium time of microplastics for HBCDs was about 10 h,and the first-order kinetics and the second-order kinetics both were suitable for described the adsorption change of microplastics for HBCDs.The adsorption capacity increased with the decreased in particle size.The adsorption capacity increased at first and then decreased with the increased of temperature,and the optimum temperature for adsorption was 15°C.With the increased of salinity,the adsorption capacity increased at first and then decreased.The maximum adsorption capacity was at 14% salinity.Compared with the linear and Freundlich models,the Langmuir model was more suitable.This indicated that the main adsorption mechanism might be chemical adsorption.