0
Article Tier 2 Remediation Sign in to save

Pretreatment as a Microplastics Generator during Household Biogenic Waste Treatment

Engineering 2023 12 citations

AI summary Read the abstract

Mechanical pretreatment of household biogenic waste generates substantial quantities of microplastics — up to 33,000 billion particles annually in the feedstock fed to anaerobic digesters in the studied facilities — primarily from crushers, shredders, and biohydrolysis reactors. The study found that pre-sorting and depackaging waste at the household level before collection can reduce microplastic generation by up to 72%, highlighting source separation as a critical intervention point for preventing microplastic contamination of compost and digestate applied to farmland.

Mechanical pretreatment is an indispensable process in biological treatment plants that remove plastics and other impurities from household biogenic waste (HBW). However, the imperfect separation of plastics in these pretreatment methods has raised concerns that they pose a secondary formation risk for microplastics (MPs). To validate this presumption, herein, quantities and properties of plastic debris and MPs larger than 50 μm were examined in the full chain of three different pretreatment methods in six plants. These facilities received HBW with or without prior depackaging at the source. The key points in the secondary formation of MPs were identified. Moreover, flux estimates of MPs were released, and an analysis of MPs sources was provided to develop an overview of their fate in HBW pretreatment. Pretreated output can contain a maximum of (1673 ± 279) to (3198 ± 263) MP particles per kilogram of wet weight (particles·kg−1 ww) for those undepackaged at source, and secondary MPs formation is primarily attributed to biomass crushers, biohydrolysis reactors, and rough shredders. Comparatively, HBW depackaged at the source can greatly reduce MPs by 8%–72%, regardless of pretreatment processes. Before pretreatment, 4.6–205.6 million MP particles were present in 100 tonnes of HBW. MPs are produced at a rate of 741.11–33 124.22 billion MP particles annually in anaerobic digester feedstock (ADF). This study demonstrated that HBW pretreatment is a competitive source of MPs and emphasized the importance of implementing municipal solid waste segregation at the source. Furthermore, depackaging biogenic waste at the source is recommended to substantially alleviate the negative effect of pretreatment on MPs formation.

More Papers Like This

Article Tier 2

Occurrence of macroplastics and microplastics in biogenic waste digestate: Effects of depackaging at source and dewatering process

AI summary Read the abstract

Researchers investigated plastic debris in digestate from anaerobic digestion of biogenic waste, finding that both preprocessing and dewatering steps significantly influence the quantity of macroplastics and microplastics in the resulting material used as a soil conditioner.

Article Tier 2

Microplastics generation and concentration during mechanical-biological treatment of mixed municipal solid waste

AI summary Read the abstract

Researchers found that mechanical-biological treatment of mixed municipal solid waste generates and concentrates microplastics across multiple processing stages, with the stabilized organic output containing significant microplastic loads — raising concerns about the use of this material as compost or soil amendment.

Article Tier 2

Microplastic Behavior in Sludge Pretreatment and Anaerobic Digestion: Impacts, Mechanistic Insights, and Mitigation Strategies

AI summary Read the abstract

This review examines how microplastics behave during sludge pretreatment and anaerobic digestion, finding that microplastics frequently persist through these processes and can affect methane production and microbial communities when present at elevated concentrations, calling for mitigation strategies in wastewater treatment.

Article Tier 2

Microplastics and impurities in digestates and compost: A comparative study of waste-derived soil amendments

AI summary Read the abstract

Researchers analyzed five types of compost and digestate from organic waste treatment facilities over three months, finding microplastics in all samples at concentrations comprising 30–65% of total plastic content, with fibers, films, and fragments of polyethylene, polypropylene, and PET being most common — highlighting how even properly managed biowaste streams can introduce plastics into agricultural soils.

Article Tier 2

Distribution characteristics of microplastics in typical organic solid wastes and their biologically treated products

AI summary Read the abstract

Researchers extracted and characterized microplastics from food waste, livestock manure, sludge, and their composted or digested products, finding MPs in all organic waste types with concentrations varying by matrix. The study highlights organic waste management pathways as an understudied route for microplastic transfer to agricultural soils.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper