Biopolymer Assisted Remediation of Microplastics from Fresh and Saline Water Environments using an Integrated Technology of Coagulation-Ultrasonication/Cavitation

Project Information

MinusMicro

Grant agreement ID: 897736

DOI

10.3030/897736

Project closed

EC signature date 11 March 2020

Start date 2 November 2020

End date 1 November 2022

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 224 933,76

EU contribution

€ 224 933,76

Coordinated by

UNIVERSITY OF LEEDS
United Kingdom

Periodic Reporting for period 1 - MinusMicro (Biopolymer Assisted Remediation of Microplastics from Fresh and Saline Water Environments using an Integrated Technology of Coagulation-Ultrasonication/Cavitation)

Reporting period: 2020-11-02 to 2022-11-01

Summary of the context and overall objectives of the project

Problem Statement: An extensive use of protective face coverings is an outcome of SARS-CoV-2, a type of coronavirus which is transmitted largely by the respiratory route and has recently led to COVID-19 pandemic. An additional pressure on the waste management systems has led to inappropriate management practices such as direct landfills and local burnings. However, an uncontrolled management of even 1% of face masks could correspond to 10 million pieces leading to generating 30-40 tons of waste. Moreover, COVID-19–related plastic has been observed in marine environments, forming a potential new source of oceanic microplastics. A detailed analyses performed by researchers from the University of Portsmouth, UK showed a constant increase in the proportion of face mask as compared to wipes and gloves during the period May 2020 to October 2020. The data on the proportionality to the total litter (%) generated for a period between March 2020 to October 2020 for countries namely showed a consistent increase in the proportion of face masks to the total litter collected (%) in UK as compared to countries such as France, Spain, Germany, Canada and Belgium.
There is a considerable amount of scientific evidence on the microplastic (microfibers in particular) leaching from face masks. Disposable face masks (DFMs) have a direct correlation with increasing the burden of plastic wastes. Being made of non-woven material, DFMs are composed of synthetic polymer materials such as polyethylene (PE), polypropylene (PP),polyurethane (PU), polyacrylonitrile (PAN), polystyrene (PS), polycarbonate (PC), and polyethylene terephthalate (PET). Microfibers released as a result of processes such as shearing, weathering and leaching from these synthetic textile materials have been recognized as an emerging pollutant and currently receiving global attention owing to their widespread nature and potential adverse impacts. The significant release of microfibers from synthetic non-woven materials.

Importance to society: The research conducted under the project of Minusmicro could have significant impacts on the society as the work has been done in multidimensional aspects to tackle microplastic pollution. Coagulation technique has been pursued towards the remediation of microplastics from aqueous environment (both freshwater and marinewater). A formulation has been developed using chitosan and xanthan gum as oppositely charged biopolymers. The functional aspects of these biopolymer have been effectively modified to improve the microplastic remediation efficiency. Additionally, the user-friendly fluorescence based strategy developed for microplastic sensing could be very beneficial for microplastic detection under different aqueous environments. As a vital part of the research, a strategy was also developed to upcycle microfiber wastes into macrofungus based biomaterials to be effectively used as packaging materials. This could be helpful to develop alternatives of polystyrene materials.

The objectives of the present research are:

(1) To characterize microfibers leached from face mask samples and develop a portable sensing technique for its assessment under different aqueous environments

(2) Develop and characterize various functionalized forms of chitosan by implementing technologies namely hydrodynamic cavitation and electrospinning

(3) Generate a two-way evaluation system for coagulation potential (based on pseudo-wastewater model prepared in laboratory) with suitable monitoring and response parameters

(4) Develop suitable collaborations with industry for developing a strategy towards effective upcycling of microplastic laden sludge material

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

‘Overview of the main results and their exploitation and dissemination: -
As an outcome of our work the main results obtained are as follows: -
(1)Result: Microplastics (in particular, microfibers leached from face masks) could be well detected using a pyrene based fluorescent dye. The detection was enabled using a pocket photometer. Based on thorough characterization and validation studies (using portable photometer, benchtop spectrofluorometer, FTIR and fluorescence microscope), it was noted that the dye could bind microplastics based on their polymeric nature and shape.

Dissemination- Water samples were collected from different coastal areas (Whitby, Scarborough, Saltburn, Robin Hood's Bay, Sandsend) and freshwater areas (River Aire, Leeds, Wharfadale, Windermere, Loch Ness-Scotland). The samples were analysed using the detection technique developed in the lab. We could identify microplastics (up to 14 microfibers/mL) in samples collected from River Aire (Leeds) Scarborough, Saltburn, Robin Hood's Bay, Sandsend).

(2) Result: A polyelectrolyte complex was formulated for the removal of the microplastics. The polyelectrolyte complex comprised of chitosan (a positively charged biopolymer) and xanthan gum (a negatively charged biopolymer) in the molar ratio 1:1. We initially employed three variants of chitosan and their molecular weights were determined to be 1.66±0.87x105 Da (4.1 CPS), 2.59±0.00x105 Da (6.4 CPS) and 3.29±0.06x105 Da (10.7 CPS) respectively. We noted that the chitosan variant with maximum value of molecular weight exhibited the higher microplastic removal efficiency. The corresponding values of microplastic removal efficiencies were noted to be 72.5%, 76.1% and 64.7% respectively.
Dissemination: We could finally formulate and assess the quality of polyelectrolyte complex developed by us and compare the efficiency of the bioflocculant with that of commercial flocculants (polyaluminium chloride and polyacrylamide). We found that, the developed polyelectrolyte complex exhibited upto 76% microfiber removal. However, the commercial flocculants could remove upto 60% microfibers. As a part of dissemination, manuscripts are in progress
As a step towards initiating collaboration with Industry, we have established a connectivity with Biopower Technology, Tring to pursue hydrodynamic cavitation as a technology to enhance the properties of the biopolymers chitosan and xanthan gum for enhancement of flocculation. Further, we have established a collaboration with StudioOsmose UK to upcycle the microplastic laden sludge material into zero-carbon products.
Dissemination activities such as conference talks is scheduled in 2024 (after completion of publishing the manuscripts)’

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

We could confidently mention that we have achieved way beyond promised! The research was started with a major intention towards remediation of microplastics. However, we found that the phenomena of interaction between positively and negatively charged biopolymers could lead to interesting insights beyond just the remediation. This included the fluorescence based sensing, which enabled us to design and develop a portable and user friendly technique for detection of microplastics. Further, we could also design novel matrices for enabling the growth of macrofungus towards development of suitable and sustainable alternatives of polystyrene.
We believe that the results could have relevant and significant impact on the society with respect to environmental pollutant clean up, sensing and upcycling as a whole. Additionally, there is also a route established towards upcycling and biomaterial development using microfibers that could have beneficial impacts on environment hinting at carbon neutrality.

image.png