A5025768200- Microplastics and Plastic Pollution
- Marine and coastal ecosystems
- Oil Spill Detection and Mitigation
- Toxic Organic Pollutants Impact
- Atmospheric and Environmental Gas Dynamics
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Recycling and Waste Management Techniques
- biodegradable polymer synthesis and properties
- Microbial Community Ecology and Physiology
- Petroleum Processing and Analysis
- Marine Biology and Environmental Chemistry
- Mercury impact and mitigation studies
- Effects and risks of endocrine disrupting chemicals
- Marine Biology and Ecology Research
- Arctic and Russian Policy Studies
- Atmospheric chemistry and aerosols
- Indigenous Studies and Ecology
- Sustainable Supply Chain Management
- Hydrocarbon exploration and reservoir analysis
- Environmental Impact and Sustainability
- Polymer Foaming and Composites
- Water Quality Monitoring Technologies
- Water Quality Monitoring and Analysis
- Ocean Acidification Effects and Responses
Woods Hole Oceanographic Institution
2018-2025
Woodwell Climate Research Center
2020-2024
University of Michigan
2014-2022
Ann Arbor Center for Independent Living
2014
The Ohio State University
1997-2010
Carbon in thawing permafrost soils may have global impacts on climate change; however, the factors that control its processing and fate are poorly understood. The dominant of dissolved organic carbon (DOC) released from to inland waters is either complete oxidation CO2 or partial river export oceans. Although both processes most often attributed bacterial respiration, we found photochemical exceeds rates respiration accounts for 70 95% total DOC processed water column arctic lakes rivers. At...
Numerous international governmental agencies that steer policy assume polystyrene persists in the environment for millennia. Here, we show is completely photochemically oxidized to carbon dioxide and partially dissolved organic carbon. Lifetimes of complete partial photochemical oxidation are estimated occur on centennial decadal time scales, respectively. These lifetimes orders magnitude faster than biological respiration thus challenge prevailing assumption Additives disproportionately...
In sunlit waters, photochemical alteration of dissolved organic carbon (DOC) impacts the microbial respiration DOC to CO2. This coupled and biological degradation is especially critical for budgets in Arctic, where thawing permafrost soils increase opportunities oxidation CO2 surface thereby reinforcing global warming. Here we show how why sunlight exposure draining soils. Sunlight significantly increases or decreases depending on whether photo-alteration produces removes molecules that...
Photochemical degradation of dissolved organic matter (DOM) to carbon dioxide (CO2) and partially oxidized compounds is an important component the cycle in Arctic. Thawing permafrost soils will change chemical composition DOM exported arctic surface waters, but molecular controls on photodegradation remain poorly understood, making it difficult predict how inputs thawing may alter its photodegradation. To address this knowledge gap, we quantified susceptibility draining shallow mat deeper...
Dissolved black carbon is more susceptible to photooxidation than particulate carbon, and partial of dissolved a important degradation pathway complete photooxidation.
Following the Deepwater Horizon (DWH) blowout in 2010, oil floated on Gulf of Mexico for over 100 days. In aftermath blowout, substantial accumulation partially oxidized surface was reported, but pathways that formed these residues are poorly constrained. Here we provide five quantitative lines evidence demonstrating oxidation by sunlight largely accounts oil. First, residence time sunlit sea surface, where photochemical reactions occur, strongest predictor partial oxidation. Second,...
Plastic pollution is one of the most visible and complex environmental issues today.Interested concerned parties include researchers, governmental agencies, nongovernmental organizations, industry, media, general public.One key assumption behind issue public outcry that plastics last indefinitely in environment, resulting chronic exposure harms animals humans.But data supporting this are scant.An accurate understanding persistence plastic goods environment critical for many...
Sunlight exposure is a control of long-term plastic fate in the environment that converts into oxygenated products spanning polymer, dissolved, and gas phases. However, our understanding how formulation influences amount composition these photoproducts remains incomplete. Here, we characterized initial formulations resulting dissolved four single-use consumer polyethylene (PE) bags from major retailers one pure PE film. Consumer contained 15–36% inorganic additives, primarily calcium...
In May 2021, the M/V X-Press Pearl cargo ship caught fire 18 km off west coast of Sri Lanka and spilled ∼1680 tons spherical pieces plastic or "nurdles" (∼5 mm; white in color). Nurdles are preproduction used to manufacture a wide range end products. Exposure combustion, heat, chemicals led agglomeration, fragmentation, charring, chemical modification plastic, creating an unprecedented complex spill visibly burnt unburnt nurdles. These span continuum colors, shapes, sizes, densities with...
While plastic pollution threatens ecosystems and human health, the use of products continues to increase. Limiting its harm requires design strategies for informed by threats that plastics pose environment. Thus, we developed a sustainability metric ecodesign with low environmental persistence uncompromised performance. To do this, integrated degradation rate into established material selection strategies, deriving indices persistence. By comparing impact on-the-market proposed alternatives,...
Nonpersistence in natural environments with benign degradation products is a growing design criterion for consumer plastics. However, data on their biodegradation rates and environmental lifetimes the coastal ocean are lacking, limiting informed engineering regulatory decisions. Single-use drinking straws, common marine litter relevant to key stakeholders, exemplify this. To fill this knowledge gap, commercial straws made of cellulose diacetate (CDA), polyhydroxyalkanoates (PHA), paper,...
Abstract Once thawed, up to 15% of the ∼1,000 Pg organic carbon (C) in arctic permafrost soils may be oxidized dioxide (CO 2 ) by 2,100, amplifying climate change. However, predictions this amplification strength ignore oxidation C CO surface waters (photomineralization). We characterized wavelength dependence dissolved (DOC) photomineralization and demonstrate that iron catalyzes old DOC (4,000–6,300 a BP) derived from soil lignin tannin. Rates production are twofold higher than for modern...
The photodegradation rates of floating marine plastics govern their environmental lifetimes, but the controls on this process remain poorly understood. Photodegradation these materials has so far been studied under ideal conditions in absence factors such as biofouling, which may slow photochemical transformation through light screening. To investigate interaction, we incubated different continuous flow seawater mesocosms to follow (i) extent biofilm growth samples and (ii) decreases...
Abstract Many challenges remain before we can fully understand the multifaceted role that natural organic matter (NOM) plays in soil and aquatic systems. These despite considerable progress has been made understanding NOM’s properties reactivity using latest analytical techniques. For nearly 4 decades, International Humic Substances Society (IHSS, which is a non-profit scientific society) distributed standard substances adhere to strict isolation protocols reference materials are collected...
About half of the surface oil floating on Gulf Mexico in aftermath 2010 Deepwater Horizon spill was transformed into oxygenated hydrocarbons (OxHC) within days to weeks. These OxHC persist for years oil/sand aggregates nearshore and beach environments, there is concern that these might represent a long-term source toxic compounds. However, because this fraction continuum transformation products are not well chemically characterized, it included current fate effect models. This challenges an...
In sunlit waters, photodegradation of dissolved organic matter (DOM) yields completely oxidized carbon (i.e., CO2) as well a suite partially compounds formed from oxygen incorporation partial photo-oxidation). Of these two groups DOM photo-products, more studies focus on CO2 (a greenhouse gas) than DOM, which is likely diverse group with poorly constrained roles in aquatic cycling or biogeochemistry. The objective this study to address knowledge gaps the prevalence, products, and pathways...
Oxygenation reactions initiated by sunlight can transform insoluble components of crude oil at sea into water-soluble products, a process called photo-dissolution. First reported half century ago, photo-dissolution has never been included in spill models because key parameters required for rate modeling were unknown, including the wavelength and photon dose dependence. Here, we experimentally quantified as function dose, making possible sensitivity analysis environmental variables...
Chemical dispersants are one of many tools used to mitigate the overall environmental impact oil spills. In principle, break up floating into small droplets that disperse water column where they subject multiple fate and transport processes. The effectiveness typically decreases as weathers in environment. This decrease is often attributed evaporation emulsification, with contribution photochemical weathering assumed be negligible. Here, we aim test this assumption using Macondo well...
Microbes and sunlight convert terrigenous dissolved organic matter (DOM) in surface waters to greenhouse gases. Prior studies show contrasting results about how biological photochemical processes interact contribute the degradation of DOM. In this study, DOM leached from layer tundra soil was exposed natural or kept dark, incubated dark with microbial community, analysed for gene expression chemical composition. Microbial (metatranscriptomics) light treatments diverged substantially after 4...
The persistence of cellulose diacetate (CDA), a biobased plastic used in textiles and single-use consumer products, the ocean is currently unknown. Here, we probe disintegration degradation CDA-based materials (25 μm films, 510 foam, 97 g/m2 fabric) by marine microbes continuous flow seawater mesocosm. Photographic evidence mass loss measurements demonstrate that disintegrate months. Disintegration marked increasing esterase cellulase activity biofilm community, suggesting degrade CDA....
Arguably, the largest knowledge gap in aquatic photochemistry discipline is wavelength dependence of sunlight-driven reaction rates surface waters. Here, we introduce a new light-emitting diode (LED)-based approach to directly quantify photochemical rates. The LEDs generate narrow-banded, spatially uniform light at five wavelengths (275, 309, 348, 369, and 406 nm), with irradiances that are stable easily adjusted desired levels. Strong agreement was observed between irradiance measurements...