Effects of microplastics on DBPs formation under the chlorination of natural organic matters

Microplastics have attracted extensive attention and concern because they inflict damage on human beings and the environment. When the microplastics enter the water system, they inevitably flow into the water treatment system and encounter disinfectants during the disinfection procedure. Chlorine can react with microplastics to form different kinds of disinfection byproducts (DBPs). O-containing functional groups on the surface of microplastics may play a major role in DBP formation. Without O-containing functional groups, microplastics can also form DBPs but with totally different mechanisms. Reactive oxygen species (ROS, i.e., •OH) and reactive chlorine substances (RCS, i.e., Cl• and ClO•) may attack the microplastics and form DBP precursors. With relatively low surface area and very little pore volume, microplastics cannot affect the DBP formation between Suwannee River fulvic acid (SRFA) and chlorine. When SRFA exists, microplastics with few O-containing functional groups can hardly form DBPs because of the inhibition of ROS and RCS.