A unified modelling framework for type I (discrete) settling and rising of microplastics in primary sedimentation tanks

Long-term presence of microplastics in aerobic and anaerobic sequential batch reactors: Effect on treatment, microbial diversity, and microplastics morphology

Sewage treatment plants (STPs) are identified as the significant sink and source of microplastics (MPs) in aquatic bodies and terrestrial systems. A major fraction of MPs gets retained in STPs for a longer duration, and their potentiality for secondary MPs generation and additives leaching remain under investigated. Therefore, this study focussed on the effect of long-term exposure of aerobic and anaerobic biological sewage treatment units on MPs, along with the effect of MPs on treatment efficiency and microbial consortium. A mixture of polyvinyl chloride, polystyrene, and nylon MPs at 262 MPs/L was spiked in the aerobic and anaerobic sequential batch reactors (SBRs) for 120 days at the start of study. The study revealed a release of noteworthy fraction of secondary MPs into the reactors from spiked MPs. At the end of 120th day, the presence of secondary generated MPs was estimated as 1000 ± 71 MPs/L and 650±141 MPs/L in aerobic and anaerobic SBRs respectively. Most of the observed secondary MPs were of size < 300 µm. Leaching of additives, i.e. cyclohexylamine, cyclotetradecane, octadecanol, pipericine etc., into the SBR effluents were also observed. The depuration capacities of the reactors were not affected with the presence of MPs during the study. While the microbial diversity and abundance were negatively impacted in aerobic SBRs, no such impacts were observed in anaerobic SBRs due to MPs. These results do suggest such exposures to potentially cause secondary MPs and chemical pollution in receiving matrices for the treated effluent, as well as effect on the native microbial community.

Exposure to Polystyrene Microplastics Promotes the Progression of Cognitive Impairment in Alzheimer's Disease: Association with Induction of Microglial Pyroptosis

We focused on investigating the effects and mechanisms of polystyrene (PS) microplastics in Alzheimer's disease (AD). PS could promote the cognitive impairment in mice and antagonize the action of PS. Meanwhile, it could promote microglial pyroptosis and aggravate neuroinflammation. In vitro results also showed that PS induced pyroptosis of BV2 and RAW264.7, after GSDMD silencing, such pyroptosis was inhibited. Our study found that PS aggravated neuroinflammation by inducing microglial pyroptosis, thereby promoting the progression of cognitive impairment in AD. This finding offers new support and reference for the induction of AD progression by environmental factors.