We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Source-specific quantification of microplastic-derived dissolved organic matter in sludge liquor using δ13C-labeled sludge and isotopic fingerprinting under varying conditioning treatments
AI summary Read the abstract
Source-specific dissolved organic matter released by microplastics was quantified and characterized, revealing that different polymer types leach distinct chemical profiles into water. These leachates can alter aquatic chemistry and microbial communities in ways specific to the plastic source.
Microplastics (MPs) have emerged as persistent pollutants in wastewater treatment plants (WWTPs), accumulating in sludge and releasing microplastic-derived dissolved organic matter (MP-DOM) during sludge processing. This study presents the first source-specific quantification of MP-DOM in sludge liquor using C-labeled sludge and a stable carbon isotope tracing approach. Aerobic digestion experiments with C-labeled activated sludge, with and without polyethylene (PE) MPs, were conducted, followed by sludge conditioning treatments (Fenton oxidation, hydrothermal, and KMnO oxidation). MP addition significantly increased dissolved organic carbon (DOC) release and shifted DOM quality toward more labile, protein-like fractions. Stable isotope analysis showed slower C depletion in the biomass and delayed C enrichment in the liquid phase of MP-amended systems compared to control, suggesting a possible retarding effect of MPs on microbial carbon turnover. Using a two-end-member isotope mixing model, MP-DOM was found to contribute 11.5 % of DOC in untreated sludge liquor, 19.4 % under Fenton oxidation, 13.5 % under KMnO oxidation, and 5.6 % under hydrothermal treatment. These results suggest that oxidative treatments, particularly Fenton, promote MP-DOM mobilization, while hydrothermal treatment primarily enhances biomass-derived DOM release. Conventional techniques using optical and molecular weight measurements captured overall DOM transformation but lacked source specificity. This study demonstrates the utility of isotope-based source apportionment for identifying hidden contributions of MPs to sludge liquor DOM and underscores the implications for treatment performance, carbon cycling, and sludge reuse strategies in WWTPs.
More Papers Like This
Continuous long-term monitoring of leaching from microplastics into ambient water – A multi-endpoint approach
AI summary Read the abstract
Researchers conducted continuous long-term monitoring of leaching from 16 types of microplastics into water, finding that most released significant dissolved organic carbon and various chemicals, with leaching patterns varying by polymer type and environmental conditions.
Advancing understanding of microplastics-derived dissolved organic matter release: From source-dependent behavior to micro-interfacial processes
AI summary Read the abstract
Researchers compared dissolved organic matter released by microplastics from river-collected versus newly purchased plastics under UV aging, finding that environmentally pre-aged plastics released chemically more oxidized DOM while fresh plastics preferentially shed higher-molecular-weight, aromatic humic-like compounds — with salinity amplifying these source-dependent differences in seawater conditions.
Microplastic-derived dissolved organic matter and its biogeochemical behaviors in aquatic environments: A review
AI summary Read the abstract
This review examines how microplastics release dissolved organic matter (MP-DOM) as they break down in water, and how these released chemicals affect water ecosystems. MP-DOM can interact with other pollutants and alter carbon cycling in natural waters, with the type and amount varying based on plastic composition and weathering conditions. Understanding what microplastics release into water as they degrade is important because these dissolved chemicals may have their own toxic effects on aquatic life and water quality.
Microplastic-Derived Dissolved Organic Matter: Release Pattern, Chemical Properties, Environmental Risk, and Impact on Carbon Cycling
AI summary Read the abstract
This review examines microplastic-derived dissolved organic matter (MPs-DOM), which plastic debris releases at an estimated 23,600 tons annually into surface waters, covering its chemical properties, release patterns, and interactions with metals, microorganisms, and the carbon cycle. MPs-DOM represents a largely overlooked secondary pollution pathway through which microplastics extend their environmental impact well beyond the particles themselves.
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.