Macroplastic Storage and Remobilization in Rivers

Liro, Maciej; Emmerik, Tim van; Wyżga‬‬, Bartłomiej; Liro, Justyna; Mikuś, Paweł

doi:10.20944/preprints202007.0169.v1

Cited by 15 publications

(11 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…the trapping of macroplastic debris by riverine vegetation will be greater (and thus mean travel distances shorter) during the growing season (when vegetation density and cover are greater and vegetation structure is more complex; see Section 1.6.3). Liro et al (2020) suggest that the change in vegetation roughness caused by a seasonal change in vegetation characteristics and floristic composition favours plastic storage. Therefore, during the during the growing season, macroplastic debris is more likely to be trapped, relative to the non-growing season.…”

Section: Limitationsmentioning

confidence: 98%

Macroplastic Debris Transfer in Rivers: A Travel Distance Approach 

Newbould¹,

Powell²,

Whelan³

2021

Preprint

View full text Add to dashboard Cite

<p>Plastic accumulation in the marine environment is a major concern given the harmful effects and longevity of plastics at sea. Although rivers significantly contribute to flux of plastic to marine systems, plastic transport in rivers remains poorly understood and estimates of riverine plastic flux derived from field measurements and modelling efforts are highly uncertain. In this study, a new probabilistic model of plastic transport in rivers is presented which describes the main processes controlling displacement to predict the statistical distribution of travel distances for individual items of buoyant macroplastic debris. Macroplastic transport is controlled by retention in temporary stores (or traps) created by vegetation, bank roughness elements and other obstacles. The behaviour of these traps is represented in the model via a series of Bernoulli trials conducted in a Monte Carlo simulation framework. The probability of retention or release from traps is described using physical characteristics such as the type of vegetation, channel width or channel sinuosity index. The model was calibrated using a tracer experiment with six replicates, conducted in a small 1.1 km river reach. For each replicate, 90 closed air-filled plastic bottles were injected at the upstream end of the reach and the location of each bottle was recorded several times over a 24-hour period. Bottles were chosen as &#8216;model&#8217; macroplastic litter items given their high usage and littering volume. Travel distances were low (the average distance travelled over 24 hours was 231 m and no bottles travelled more than 1.1 km, the length of the study reach) and variable (the coefficient of variation for the replicates ranged between 0.54 and 1.41). The travel distance distributions were controlled by the location and characteristics of discrete traps. The numerical model described the observed travel distance distributions reasonably well (particularly the trapping effect of overhanging trees and flow separation at meander bends), which suggests that modelling plastic transport for longer reaches and even whole catchments using a stochastic travel distance approach is feasible. The approach has the potential to improve estimates of total river plastic flux to the oceans, although significant knowledge gaps remain (e.g. the rate and location of plastic supply to river systems, the transport behaviours of different types of plastic debris in rivers and the effectiveness of different traps in different types of river system).</p>

show abstract

Section: Limitationsmentioning

confidence: 98%

Macroplastic Debris Transfer in Rivers: A Travel Distance Approach 

Newbould¹,

Powell²,

Whelan³

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…During transportation, plastic interacts mechanically with water and river sediments, causing the particles to become mechanically fragmented [13]. When macroplastics are deposited for a long time, macroplastics will undergo biochemical degradation [14]. Any physical or chemical change in the polymer is caused by environmental factors, such as light, heat, humidity, chemical conditions or biological activity [15].…”

Section: % Compositionmentioning

confidence: 99%

Assessment of macro litter in Deli River Medan during pandemic COVID-19

Hasibuan

Salsabila

Perdana

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

View full text Add to dashboard Cite

This study identifies and quantifies floating macro litter and macro plastic from Deli River Medan during pandemic Covid-19. Macro litter transport consists of floating items at surface, suspended in water column and transport over on riverbed. Litter was collected from 5 location along 11.6 km using static trawls with a height of 150 cm and width of 300 cm with a square mesh size of 0.5 cm. Sampling was done in July, and during selection, 40 cm of net’s height was constantly submerged for one hour. This study found that macro litter was 19.26 kg/h with 65.2% as anthropogenic waste, 34.3% as macro plastic, 0.3% as metal, and 0.15% as medical waste. The composition of macro plastic has various variants, namely food containers, plastic bags, food packaging, sanitary packaging, and mineral water packaging with percentages of 10.21%, 67.89%, 8.35%, 4.36%, and 9.18%. The macro plastic abundance was obtained at 2,476 x 10-4 kg/m3. This study showed a significant increase in plastic consumption during the pandemic, especially plastic bags because it is dominated in all locations.

show abstract

“…The high level of beaching in the composite simulation (Figure 4) and the sensitivity of model results to the three shoreline interaction options (Figure 8) suggest that the lack of beached particle remobilization (Liro et al, 2020) in the model is one of the most important limitations associated with particle transport. Indeed, Jalón-Rojas et al (2019) found their model results to be sensitive to the main remobilization parameter (there referred to as "washingoff "), which is the particle half-life on land.…”

Section: Model Limitationsmentioning

confidence: 99%

Estuaries as Filters for Riverine Microplastics: Simulations in a Large, Coastal-Plain Estuary

et al. 2021

View full text Add to dashboard Cite

Public awareness of microplastics and their widespread presence throughout most bodies of water are increasingly documented. The accumulation of microplastics in the ocean, however, appears to be far less than their riverine inputs, suggesting that there is a “missing sink” of plastics in the ocean. Estuaries have long been recognized as filters for riverine material in marine biogeochemical budgets. Here we use a model of estuarine microplastic transport to test the hypothesis that the Chesapeake Bay, a large coastal-plain estuary in eastern North America, is a potentially large filter, or “sink,” of riverine microplastics. The 1-year composite simulation, which tracks an equal number of buoyant and sinking 5-mm diameter particles, shows that 94% of riverine microplastics are beached, with only 5% exported from the Bay, and 1% remaining in the water column. We evaluate the robustness of this finding by conducting additional simulations in a tributary of the Bay for different years, particle densities, particle sizes, turbulent dissipation rates, and shoreline characteristics. The resulting microplastic transport and fate were sensitive to interannual variability over a decadal (2010–2019) analysis, with greater export out of the Bay during high streamflow years. Particle size was found to be unimportant while particle density – specifically if a particle was buoyant or not – was found to significantly influence overall fate and mean duration in the water column. Positively buoyant microplastics are more mobile due to being in the seaward branch of the residual estuarine circulation while negatively buoyant microplastics are transported a lesser distance due to being in the landward branch, and therefore tend to deposit on coastlines close to their river sources, which may help guide sampling campaigns. Half of all riverine microplastics that beach do so within 7–13 days, while those that leave the bay do so within 26 days. Despite microplastic distributions being sensitive to some modeling choices (e.g., particle density and shoreline hardening), in all scenarios most of riverine plastics do not make it to the ocean, suggesting that estuaries may serve as a filter for riverine microplastics.

show abstract

Macroplastic Storage and Remobilization in Rivers

Cited by 15 publications

References 58 publications

Macroplastic Debris Transfer in Rivers: A Travel Distance Approach

Macroplastic Debris Transfer in Rivers: A Travel Distance Approach

Assessment of macro litter in Deli River Medan during pandemic COVID-19

Estuaries as Filters for Riverine Microplastics: Simulations in a Large, Coastal-Plain Estuary

Contact Info

Product

Resources

About

Macroplastic Storage and Remobilization in Rivers

Cited by 15 publications

References 58 publications

Macroplastic Debris Transfer in Rivers: A Travel Distance Approach&#160;

Macroplastic Debris Transfer in Rivers: A Travel Distance Approach&#160;

Assessment of macro litter in Deli River Medan during pandemic COVID-19

Estuaries as Filters for Riverine Microplastics: Simulations in a Large, Coastal-Plain Estuary

Contact Info

Product

Resources

About

Macroplastic Debris Transfer in Rivers: A Travel Distance Approach

Macroplastic Debris Transfer in Rivers: A Travel Distance Approach