Determination of large microplastics: wet-sieving of dewatered digested sludge, co-substrates, and compost

Abstract

Dewatered digested sludge and compost may act as a conduit for microplastics (<5 mm) in terrestrial and subsequently aquatic systems. However, standardized methods for microplastics analyses are lacking. Thus, the aim is to demonstrate the applicability of wet-sieving as a way to quantify large microplastic particles (MPP, 1–5 mm) in dewatered digested sludge and compost. Additionally, we investigated the organic fraction of municipal solid waste, expired drinks and slaughterhouse waste used as co-substrate for anaerobic digestion at wastewater treatment plants (WWTP). Therefore, we collected samples from six WWTP and two biogas plants. These were then wet-sieved and potential MPP analysed via attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). In dewatered digested sludge the amount of microplastics ranged from 0 to 326 MPP/kg TS (total solids) while compost contained 39–102 MPP/kg TS. Our results show that with 0–36 MPP/kg TS co-substrates are not necessarily a source of microplastics in WWTP. Furthermore, we found film to be the most abundant shape in the biogas plant samples, whereas, in WWTP samples film, fragments and fibers were detected the most. ATR-FTIR revealed that polyvinyl chloride, polyester, polypropylene, and polyethylene were the most abundant materials found across all samples.

Investigation of Global Trends of Pollutants in Marine Ecosystems around Barrang Caddi Island, Spermonde Archipelago Cluster: An Ecological Approach

“…It is estimated that exposure to contaminants from the GTP group around BCI will increase in the future due to the island's status as part of the Marine Tourism Area (MTA), meaning that it is visited by many tourists, which is seen as a potential factor contributing to the pollutant component, especially the pollutant types MP and PAH [65,69,80]. BCI is adjacent to the city of Makassar, which has a beach length of ± 7.5 km.…”

“…Based on the functional groups, the type of MP can be predicted. Seven types of MP pollutants may be present in a sample, among which the most common are polypropylene, polyethylene, polystyrene, and polycarbonate [69,70].…”

Investigation of Microplastic Exposure to Marine Fish in the Marine Tourism Area of Makassar City

“…The connected software is used to read the resulting spectrum from microplastics and then matched it with a standard spectrum from a polymer database using Euclidean Distance, aiming to determine the type of polymer in the sample. Spectrum recorded over the range of 500-4000 cm -1 at a resolution of 2 cm -1 (Schwinghammer, Krause, & Schaum, 2020;Putrawan, Natan, & Syakuron, 2020). The results of the identification of the type of microplastic in the sample using FTIR Spectroscopy will be displayed in the form of a microscopic wavenumber chromatogram.…”

Panacea for the nanoplastic surge in Africa: A state-of-the-art review

“…The toxicity of plastics is associated with its component chemicals including solvents, monomers, catalysts, plasticizers and additive dyes, Tetrabrobisphenol A and tetrabromobisphenol A bis(2-hydroxyethyl) ether [ 134 , 135 , 136 , 137 ]. Some low molecular weight additives leach out into the water bodies [ 138 ]. These additives cause numerous toxicities to the water bodies, soil, air and its inhabitant organisms.…”