Insight into the photodegradation and universal interactive products of 2,2′,4,4′–tetrabromodiphenyl ether on three microplastics

Photo-oxidation of Micro- and Nanoplastics: Physical, Chemical, and Biological Effects in Environments

“…Soil and sediment are major sinks of MNPs in aquatic and terrestrial ecosystems . As the primary life forms in soil and sediment systems, the microorganism is the main participator in many biogeochemical processes such as organic matter mineralization and nutrient cycling. , The greatest attention has focused on the effect of MNPs on the microbial community and function in soil and sediment systems, including microbial growth and viability, microbial activity and enzyme activity, , community structure, and function. − Indirect mechanisms of these impacts come from changes in soil physicochemical parameters, including bulk density, porosity, soil aggregation, − water-holding capacity, , and pH. , Direct interactions of MNPs with soil and sediment microorganisms are related to biofilm formation on MP surface, , plastic leachate impact, ROS-induced oxidative stress, and combined impacts with other chemicals. , The photo-oxidation of MNPs generally alters surface properties, leaching of toxic substances and DOC, , and ROS production, and subsequently changes their stability, , and mobility, , adsorption, , and transformations of contaminants . These effects of photoaged MNPs potentially lead to distinct alterations in microbial community and activity, although the specific response of soil characteristics and microorganisms to the photo-oxidation of MNPs remains largely unclear. , …”

“…The photolysis of 2,2′,4,4′tetrabromodiphenyl ether was inhibited by aged PS MPs compared with pristine ones as the aged PS caused more lightshielding effect, while aged PP and PE increased pollutant degradation because the fragmentation of aged MPs provided more contact surfaces for pollutants and light. 56 The photo-oxidation of MNPs can also mediate the oxidation or reduction of HMs (Table S4). Up to now, limited publications have studied the phototransformation of HMs in the presence of MPs.…”

“…192,193 The photo-oxidation of MNPs generally alters surface properties, 43 leaching of toxic substances and DOC, 45,169 and ROS production, 44 and subsequently changes their stability, 27,31 and mobility, 28,37 adsorption, 69,71 and transformations of contaminants. 56 These effects of photoaged MNPs potentially lead to distinct alterations in microbial community and activity, although the specific response of soil characteristics and microorganisms to the photo-oxidation of MNPs remains largely unclear. 47,194 For example, Liu et al reported the photoaged tire wear particles (TWPs) were more toxic than pristine TWPs, which is attributed to the increased adsorption of released heavy metals due to the increase in specific surface area and the transition of positive to negative charge after photooxidation.…”

“…The mechanism is direct photolysis and indirect phototransformation induced by environmental components, such as anions, cations, and DOM. The reactive intermediates such as 3 DOM* and ROS generated from this photosensitization process can participate in the photodegradation of OPs. − On the one hand, MNPs that usually show good optical absorption characteristics may compete for photons with OPs and thus inhibit the direct photolysis of OPs due to the light screening/shielding (see Table S4 for details on the role of MNPs in the phototransformation of pollutants). ,,, On the other hand, MNPs can also take part in the indirect phototransformation of OPs by generating ESPRs, ROS, and 3 MNPs* and by providing more surfaces for pollutant adsorption and photoreactions (Table S4). For example, Zhang et al reported that the degradation of sulfamethoxazole (SMX) was decreased in the presence PS MPs and even more so in the presence of aged PS MPs, as the optical absorption capacity of PS MPs gradually increased with the photoaging time after the formation of new chromophores, such as carbonyl groups and conjugated double bonds .…”

“…Currently, several reviews have summarized the weathering processes of MPs and corresponding effects on the environmental behavior of MPs, mainly considering the different weathering processes and mechanisms, and the effect of weathering on the properties, adsorption, and toxicity of MPs. ,− However, few of them have thoroughly considered the physical, chemical, and biological effects of photo-oxidation of MNPs in the environment. In the last two years, an increasing number of studies have focused on understanding the process of photo-oxidation and its impact on different types of MNPs, as well as the effect of environmental constituents on this process. ,,,− Furthermore, research on the influence of photo-oxidation of MNPs on the adsorption and photochemical transformation of other pollutants has gained more attention. − The biological effect of photo-oxidized MNPs on organism activity, especially microbial community composition and function has also become a subject of interest among scholars. ,, More importantly, the photo-oxidation process and the physical, chemical, and biological behavior of MNPs are mutually associated and inseparable. Thus, it is necessary to give a critical review of recent research on the physical, chemical, and biological effects of photoaged MNPs in aquatic and terrestrial environments.…”