Microplastics and nanoplastics in water: Improving removal in wastewater treatment plants with alternative coagulants
Abstract
Due to growing concerns of plastic pollution release into water bodies, it is imperative to understand and assess the removal of nanoplastics and microplastics during wastewater treatment processes. Although earlier studies have shown high removal of plastic contaminants during coagulation, flocculation and settling, a limited number of experiments have examined the removal of nanoplastics in relevant water chemistries including higher pH values and in the presence of organics. In this study, the removal of nanoplastics and microfibers is assessed using conventional (alum) and alternative coagulants including aluminum chlorohydrate (ACH) and cationic polyamines (pDADMAC) in a synthetic wastewater matrix for pH conditions between 7 and 8.6. Our results show that plastic removal is considerably reduced at higher pH values when alum is used as a coagulant. At the shorter settling time of 30 s, removal of pristine and aged nanoplastics declined from 64 ± 3% and 76 ± 3% respectively (pH 7) to less than 20% at pH values higher than 7.8. Similarly, polyester microfiber removal was observed to decline from 97 ± 1% at pH 7 to 85 ± 3% at pH 8.6 for samples collected after 3 min of settling. Replacing alum with polynuclear aluminum coagulants resulted in greater plastic contaminant removal at pH values above 8 with a maximum observed microfiber removal of 95 ± 1% (ACH; pH 8.6; 3 min settling time) and a maximum observed nanoplastic removal of 71 ± 5% (ACH+pDADMAC; pH 8.2; 30 s settling…
Read the paper
Related studies
- Green Chemistry: A Framework for a Sustainable Future
- Nano/micro-plastic, an invisible threat getting into the brain
- Emerging contaminants antibiotic resistance genes and microplastics in the environment: Introduction to 21 review articles published in CREST during 2018–2022
- Water Resources and Sustainable Development
- Nano- and microplastics in the workplace
- Water Enclosure and World-Literature: New Perspectives on Hydro-Power and World-Ecology
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.