Session Chairs: Hrissi K. Karapanagioti, Department of Chemistry, University of Patras; Ioannis Kalavrouziotis, Hellenic Open University

 This session is dedicated to researchers, operators, stakeholders, and regulators on the results of monitoring studies in wastewater treatment plants and best management practices.

 Most of the microplastic particles and synthetic fibers can be effectively removed by the different WWTP processes depending on their density. However, more efficient methods such as microfiltration should be employed to protect the environment. Despite the high efficient removal rates of microplastics achieved by WWTPs when dealing with such a large volume of effluent even a modest amount of microplastics being released per litter of effluent could result in significant amounts of microplastics entering the environment. In most cases, microplastics and synthetic fibers concentration was higher in the WWTP effluent compared to the receiving body of water. This indicates that WWTPs may operate as a route for microplastics entering the sea. WWTPs can act as a primary source for beached microplastics.

WWTP operators should be informed and educated on how to address this issue regulators should prohibit the use of microplastics in personal care products and consumer decision should be based on common sense practices. Studies dealing with monitoring, good practices, educating and informing operators and manager will be welcomed to present. WWTPs is a totally preventable route for microplastics to the sea and should be eliminated. The specific intent of the session is to bring WWTP operators to a marine debris conference that will allow them to understand the marine debris problem, allow them to understand what is microplastic and its chemistry, find ways to monitor microplastics and motivate them to eliminate this point source of microplastic to the sea. Marine debris community will learn about this preventable source and be motivated to stop this input to the sea since it is preventable.




Microplastics in Wastewater Treatment Plants

presenting: Nikolaos Mourgkogiannis (Department of Chemistry, University of Patras, Greece); authors: Hrissi Karapanagioti (University of Patras, Greece), Ioannis K. Kalavrouziotis (School of Science and Technology, Hellenic Open University), Hrissi K. Karapanagioti (Department of Chemistry, University of Patras)

Marine pollution by microplastics, plastic particles in the size range 1 nm to 5 mm, is a recognized emerging issue. Wastewater treatment plants (WWTPs) although they remove the solid waste arriving to their screens, they are not designed to remove microplastics. There are a few studies measuring the concentration of microplastics in the effluent. It seems that the concentrations are low but the actual amount ending up in the sea is quite significant. The present study is an extensive study surveying 101 WWTPs in various areas throughout Greece. Based on the results, the total amount of solid waste arriving to these 101 WWTPs is calculated equal to 3.7 108 L per week. This amount is collected by screens but 94% of the WWTPs have screens with gaps larger than 5 mm. This suggests that microplastics are passing through preatreatment to the main WWTP. Indeed, 89% of the WWTP managers observed microplastics anywhere in the plant. Cotton swabs are identified as the most common microplastic found in WWTPs and the surrounding marine and coastal areas of the effluent pipes. Informing the public as well as operators and engineers about this problem is necessary.


Microplastic Particle Morphology and Categorization: Implications for Managing Sources to the Great Lakes

presenting: Paul Helm (Ontario Ministry of the Environment and Climate Change, Canada); authors: Paul Helm (Ontario Ministry of the Environment and Climate Change, Canada), Erin Nicholls (Ontario Ministry of the Environment), Courtney Miller (Ontario Ministry of the Environment and Climate Change)

Contamination by microplastic particles (MPPs) is well-documented in marine, and more recently, freshwater environments. Sampling in urban streams, wastewater effluents, and nearshore waters of the Great Lakes has shown that there are numerous types of MPPs entering the lakes. Typical reporting of MPP research and monitoring results includes the listing of abundances (counts per unit area, volume, or mass) and grouping of types of MPPs into broad categories such as fragments, film, foam, fibers, and pellets/beads. However, such broad categories may be insufficient for directing management actions for MPPs reductions and to measure the success of such actions. We present morphological characteristics of MPPs which can be used to expand their source-type categorization/classification. For example, rigid plastic particles resembling shavings, cuttings, and trimmings clearly generated by mechanical means, normally categorized as “fragments”, are indicative of commercial plastic activities. These “commercial fragments” comprised a significant portion (>50%) of the up to 19 million MPPs / sq. km found in Humber Bay along the waterfront of Toronto, Canada. Our 2015 sampling of nearshore waters, streams and wastewater effluents in this region of the Great Lakes demonstrates the influence of more specific sources when detailed categories are used to characterize MPP profiles. Emissions of MPPs, likely from plastic product manufacture and recycling, are indicated to be a significant source to western Lake Ontario, and these findings form the basis for advice to resource managers regarding strategies to reduce to the occurrence of MPPs in the Great Lakes.


A wastewater utility’s attempt to optiomize extraction and identification of microplastics in secondary Waste Water Treatment Plant (WWTP) effluent

presenting: Artem Dyachenko (EBMUD, United States); authors: Artem Dyachenko (EBMUD, United States), Nirmela Arsem (EBMUD)

A regional effort to optimize sampling, extraction, identification and quantitation of microplastic particles in secondary Wastewater Treatment Plant (WWTP) effluent is presented. The study found that wastewater samples require special handling in order to remove inherent organic material-related interferences. Sequential wet peroxide oxidation (WPO) digestion leads to cleaner extracts with significantly reduced amounts of major wastewater related interferences such as cellulose and fatty acids. An attempt to count and type microparticles extracted from secondary wastewater effluent has been made and results were extrapolated using WWTP’s average daily flow rates. Findings reveal significant discrepancy in microparticle count in extracts obtained from 2-hour sampling at peak flow and 24-hour composite sampling events. The vast majority of microparticles could be categorized as fragments whereas pellets or beads appear to contribute less than 10 % of the overall microparticle count. Many microplastic particles in wastewater are not homogenous with traces of other compounds present and visual microscopic identification alone is not sufficient in determining microplastics presence which should be confirmed with an appropriate spectroscopic technique (e.g. micro-FTIR). Normal handling of some microplastic particles during analysis led to fragmentation which could bias the final results. The need for a robust screening and quantitation of micorplastics with the tools accessible to wastewater laboratories and challenges of current methodologies are discussed.


A new analytical approach for the detection of micro-sized fibers from textile laundry

presenting: Jasmin Haap (Hohenstein Insitut für Textilinnovation, Germany); authors: Jasmin Haap (Hohenstein Insitut für Textilinnovation, Germany), Edith Classen (Hohenstein Insitut für Textilinnovation)

The abundance of microplastic in freshwater environments and marine habitats, its sources as well as the pathways are not fully known to date. However, micro-sized synthetic fibers released from textile laundry are known to contribute to the microplastic problem. In fact, there is still a gap of knowledge regarding the extend of fiber discharge and the main influence factors. Detailed investigations on the release of micro-sized fibers require precise and reproducible analytic methods. Frequently used analytics for microplastic fiber detection in wastewater are often based on filtration combined with subsequent visual analysis of the particles (e.g. microscopy). This workflow is time consuming and prone to human errors. Due to the non-spherical shape of the fibers or the turbidity of the wastewater, commonly applied particle detection systems (e.g. light scattering, laser diffraction) are limited.

This study highlights the application of a new analytical approach to wastewater samples from laundry. Dynamic image analysis is utilized to analyze suspended textile fibers and particles in the wastewater. This optical detection system allows for a fast and non-destructive measurement of fibers and particles covering a broad range of particle dimensions (10 – 3500 µm) without the need of a pretreatment. Furthermore, it enables statistical analysis regarding various fiber characteristics like diameter, length and shape. In addition, this system provides quantitative information on the number of fibers per wash load and the corresponding size distribution. For the distinction of synthetic and natural fibers, dynamic image analysis is a promising tool regarding the chemical fiber identification of mixed laundry loads or blended fabrics.


Micro plastic and fibres in the marine environment of Svalbard, Norway

presenting: Dorte Herzke (NILU, Norway); authors: Dorte Herzke (NILU, Norway), Jan H. Sundet (IMR, Institute of Marine Research), Maria Jenssen (IMR, Institute of Marine Research)

Due to the great connectivity between the Arctic Ocean and adjacent seas through the Fram Strait and the Bering Strait, the problem of plastic litter most likely extends into the Arctic Ocean, but is highly understudied in this region. To understand the distribution of plastic litter in the Arctic, knowledge of local sources within the Arctic is as important as an understanding of the transport pathways from more densely populated areas further south. Besides the five known ‘great garbage patches’ of the world oceans, a sixth litter patch is predicted for the Barents Sea, based on calculations from drifter buoy data (van Sebille et al., 2012), but to date this accumulation of debris has not been observed in situ. Besides these litter patches, a large number of coastal areas and inland waters suffer a high plastic pollution, also in the Arctic (OSPAR, 2014).

Between 2015 and 2017, IMR and NILU sampled wastewater effluent, sediment, seawater and filter feeders in several locations along the coast of Svalbard, including Longyearbyen, Adventfjorden, with the aim to establish a baseline of micro plastic abundance in the Norwegian Arctic. The first year of the project was used to establish a method for sampling and sample treatment as well as to assess the impact of a major settlement on Svalbard to the marine emissions. In the second year, we sampled locations along the western coast of Svalbard to assess the abundance of micro plastic reaching Svalbard from long distances. In 2017 we investigated the fibre emissions caused by the waste water effluent more closely, including the effect of a fibre reducing device. Micro plastic and fibres were found in all years and the results will be presented at the conference.


Microplastic distribution in environmental matrices (water-sediment) in Todos Santos Bay, Mexico.

presenting: Nancy Ramírez-Álvarez (Instituto de Investigaciones Oceanológicas-UABC, Mexico); authors: Nancy Ramírez Álvarez (Instituto de Investigaciones Oceanológicas-UABC, Mexico), Lorena Margarita Rios-Mendoza (University of Wisconsin Superior), José Vinicio Macías-Zamora (Instituto de Investigaciones Oceanologicas-UABC), Arturo Álvarez-Aguilar (Instituto de Investigaciones Oceanológicas-UABC), Lucero Oregel-Vázquez (Facultad de Ciencias Marinas-UABC), Félix Augusto Hernández-Guzmán (Instituto de Investigaciones Oceanológicas-UABC), José Luis Sánchez-Osorio (Instituto de Investigaciones Oceanológicas -UABC), Charles J. Moore (Algalita Marine Research Foundation), Hortencia Silva-Jiménez (Instituto de Investigaciones Oceanológicas-UABC), Luis Felipe Navarro-Olache (Instituto de Investigaciones Oceanológicas-UABC)

Microplastics (MP) represent a great threat to the marine environment because evidence suggests its ubiquity. In Mexico, this line of investigation is emerging and, therefore, also the knowledge of them in coastal zones. The goal of this research is to evaluate the impact of MP in Todos Santos Bay (TSB) by analyzing the type of synthetic polymers found in surface waters and sediments, as well as evaluating one of its main sources, the Wastewater Treatment Plants (WWTPs) effluents. Eleven surface water samples were collected by Manta trawl, as well as nine samples of sediment with a Van Veen grab (0.1 m²). Also, four samples were collected in each WWTP effluents (n = 3) with discharges in TSB. Preliminaries results showed that MP in surface waters in TSB were 0.01 to 0.65 plastic particles per m³, with a high presence of fibers in the samples (40 – 80%). In the sediment, MP were counted between 850 to 20,000 plastic particles per m², with a mean value of 22% of fibers. A preliminary estimate suggests that the effluents from the WWTPs could introduce 18 × 10⁶ to 47 × 10⁶ plastic particles per day in TSB. The incidence of the plastic fibers in the WWTP effluents were between 60 to 90% in the samples. The main synthetic polymers of MP found in the surface waters (approximately 10% of each sample) were polyethylene, polyethylene-propylene, polypropylene co-polymer, and polypropylene. Currently, we are determining the type of MP polymers present in the sediments and the effluent WWTPs samples. According to the preliminary results, we found that there is a greater accumulation of MP in the sediments than in the surface waters from TSB, which could interact with organisms such as macro invertebrates. Finally, the WWTP effluents are an important source of MP in TSB.