We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Thermal stress suppresses methanogenesis while Fe(III) alters carbon-related responses during microplastic aging in landfill leachate.
AI summary Read the abstract
Researchers aged plastic particles (polyethylene, polystyrene, and polylactic acid) in landfill liquid waste for 90 days at two temperatures, with and without added iron. High heat reduced gas release linked to climate warming and reduced microbes that produce it, while iron changed how carbon and the plastics' surfaces behaved, with effects differing by plastic type.
Landfill leachate differs from many anaerobic aquatic environments because it combines darkness, oxygen limitation, high dissolved organic matter, reactive iron, plastic contamination, high ionic strength, and localized heat stress. These conditions may precondition microplastics (MPs), but whether MP aging in leachate promotes anaerobic greenhouse-gas production remains unclear. Here, polyethylene (PE), polystyrene (PS), and polylactic acid (PLA) MPs were incubated for 90 d in field-collected landfill leachate at 30 °C or 70 °C, with or without Fe(III) amendment. Temperature dominated the measured carbon-related responses: compared with 30 °C, 70 °C reduced headspace CO2C accumulation from 2.0 to 3.8 to 0.1-1.1 mg C and eliminated detectable headspace CH4. Under thermal stress, Fe(III) addition was associated with greater DOC depletion, lower filter-passing Fe concentrations, and increased filter-retained solid-phase C. MP aging was polymer dependent: PE mainly served as a scaffold for Fe-DOM coating, PS showed Fe-sensitive carbonyl-region changes and localized deposits, and PLA exhibited hydrolysis-associated disruption. Heat stress reduced microbial diversity and strongly diminished methanogenesis-associated archaea, whereas putative polymer-associated ASVs remained embedded within Fe-regulated and polymer-specific environments. These findings highlight polymer-specific surface alteration and concurrent changes in carbon fractions under thermal stress and Fe(III) amendment, with temperature exerting the dominant constraint on methanogenesis in the tested leachate system.
More Papers Like This
Zero-Valent Iron as a Sustainable Regulator for Anaerobic Digestion of MPs-Contaminated Organic Substrates: Performance Enhancement and Environmental Significance.
AI summary Read the abstract
Microplastics are everywhere, including in the organic waste processed to make biogas and fertilizer, and they can disrupt the helpful bacteria that break down this waste. This study found that adding iron particles to these systems restored microbial health and boosted methane production by nearly 75%, offering a cheap, practical way to keep waste recycling systems working despite microplastic contamination.
Microplastics trigger sediment organic carbon pools stabilization pathways: Evidence from microbial mediated DOM turnover
AI summary Read the abstract
Lab sediment mixed with two types of plastic (polyethylene and polylactic acid) for 100 days released more carbon dioxide and methane and changed the sediment's dissolved organic matter and microbial communities. Aged polylactic acid caused the biggest changes, increasing sediment oxidation and altering bacterial, fungal and archaeal community networks involved in carbon breakdown.
Deciphering the inhibitory mechanisms of polystyrene microplastics on thermophilic methanogens from the insights of microbial metabolite profiling and metagenomic analyses
AI summary Read the abstract
Researchers studied how polystyrene microplastics affect methane production during the thermophilic anaerobic digestion of food waste. They found that increasing microplastic concentrations reduced methane yield by up to 47.8%, driven by the accumulation of reactive oxygen species that inhibited key enzymes in the digestion process. Metagenomic analysis revealed that microplastics downregulated genes involved in methane metabolism, providing new insights into how plastic contamination can disrupt waste treatment systems.
Beyond simple inhibition: Unveiling the non-monotonic impact and multi-level mechanisms of aged microplastics on sludge anaerobic digestion
AI summary Read the abstract
Researchers used plasma treatment to precisely control polypropylene microplastic aging and tested its effects on anaerobic sludge digestion, finding that while unaged microplastics strongly inhibited methane production, optimally aged microplastics at a carbonyl index of 0.219 recovered methane yield to 83%.
Geochemical data on iron
AI summary Read the abstract
Scientists found that microplastics—tiny plastic bits polluting wetlands worldwide—can change how bacteria in soil process iron, a key nutrient cycle that keeps wetland ecosystems healthy. This matters because wetlands act like natural filters that clean our water, so if microplastics are disrupting their basic chemistry, it could affect water quality and the health of ecosystems we depend on. While this study focused on soil microbes rather than direct human health effects, it adds to growing evidence that plastic pollution is altering natural systems in ways scientists are still working to understand.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.