Biodegradable Microplastics Affect the Wheatgrass Traits, Fe Plaque Development Involved in Sb Accumulation, and Microbial Community Functions in Antimony-Contaminated Riparian Wetlands

Abstract

Alternative biodegradable plastics have been the primary protocols to alleviate traditional plastic pollution in terrestrial systems. However, few studies have investigated the risks of biodegradable microplastics (MPs) and their combination with antimony (Sb) in wetlands. In this study, polyhydroxyalkanoate (PHA), polylactic acid (PLA), and poly(butyleneadipate-co-terephthalate) (PBAT) MPs (0.5 and 2.5 wt %) and Sb(III)/Sb(V) were individually or jointly exposed to wheatgrass in waterlogged riparian wetland sediments. Results showed that root/shoot lengths and root branches were more sensitive to coexposure of Sb(III) with PLA/PHA MPs. Coexposure of Sb(III) and PLA MPs led to a plummet, but coexposure of Sb(V) with PLA presented a significant promotion on microbial activities. PLA and PHA (2.5 wt %) MPs presented a great impact on Fe plaque development, and their combination with Sb significantly increased Sb accumulation in roots. Meanwhile, PBAT MPs promoted transfer factors and bioaccumulation factors of Sb in wheatgrass shoots under Sb(V) amendment. In addition, except for single Sb(V) exposure, the treatments of MPs with Sb led to a stimulation on carbon utilization by microbes in flooded wetland soil. In summary, this study provided information for evaluating potential threats of biodegradable plastics and MPs if present in high concentrations in Sb-or other heavy-metal-contaminated riparian wetlands.

Understanding the Impact of Biodegradable Microplastics on Living Organisms Entering the Food Chain: A Review

“…Here, the toxicity was attributed to the release of toxic substances during the decomposition of particles, which alter the symbiotic microbial community with possible risks to soil-plant systems. Different effects of the influence of PLA and PBAT were found in the publication by Cao et al [32]. At a concentration of 2.5 wt%, PLA reduced the root length of wheatgrass (Triticum aestivum) by 39% and PBAT increased it by 72%.…”

“…At the time of writing this review (May 2023), 22 research articles have been identified from the Scopus and Web of Science databases investigating the interaction between biodegradable plastic particles and plants [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. The survey methodology included queries in the Scopus and Web of Science databases for “biodegradable microplastics and plants”.…”

Molybdenum Trioxide Nanoparticles as Promising Stimulators for Facilitating Phytoremediation by Cd Hyperaccumulator Solanum nigrum L

“…After 60 days of cultivation, the plants were harvested, weighed, and then divided into several parts for further analysis. About 50 mg of plant leaves was weighed and applied for photosynthetic pigment measurements (chlorophyll a/b and carotenoid). , Specifically, the fresh leaves were cut into small pieces, extracted with 5 mL of an extractant of acetone and 95% ethyl alcohol (1:1, v/v) in the dark for 8 h, and finally determined via a UV–vis spectrophotometer (UV-1800, Shimadzu, Japan). The oxidative stress levels in plant tissue indicated by the hydrogen peroxide (H 2 O 2 ) and malondialdehyde (MDA) contents were determined using ammonium molybdate and thiobarbituric acid methods via spectrophotometry .…”

Adsorption of copper by naturally and artificially aged polystyrene microplastics and subsequent release in simulated gastrointestinal fluid

“…1–3 Microplastics are generally considered to be plastic particles less than 5 mm in diameter, which are formed due to weathering and breakdown of plastics. 4,5 Due to the small size and poor degradation rate, microplastics can be mistakenly considered as food and ingested by a wide range of organisms with adverse biological effects. 6,7…”