0
Article Tier 2 Environmental Sources Marine & Wildlife Policy & Risk Remediation Sign in to save

Microplastic Fibers Deteriorate Dewaterability of Waste Activated Sludge through Alteration of Extracellular Proteome and Extracellular Polymeric Substance Structures

AI summary Read the abstract

Researchers investigated how microplastic fibres affect the dewaterability of waste activated sludge (WAS) and found that fibres significantly deteriorated sludge dewatering performance by altering the extracellular proteome and modifying extracellular polymeric substance (EPS) structures. The study revealed that microplastic fibre exposure changed the protein composition and biophysical properties of EPS, creating a mechanistic link between fibre contamination and impaired sludge management in wastewater treatment.

Study Type Environmental

Microplastic fiber (MF) is a prevalent microplastic type in wastewater. However, its potential impact on waste-activated sludge (WAS) dewaterability remains unclear, posing challenges for sustainable wastewater management. This study revealed that MFs significantly deteriorate the sludge dewaterability, as evidenced by an increase in capillary suction time by 48.8% and a decrease in the total solids of the dewatered sludge cake by 14.1%. Proteomic analysis revealed that MFs altered extracellular protein profiles, notably reducing cation-binding proteins' abundance, leading to decreased organic binding metals content and increased hydrophilicity of extracellular polymeric substances (EPS). Meanwhile, the regulation of extracellular proteins by MFs also altered the spatial distribution of EPS, promoting a transformation from tightly bound EPS to loosely bound EPS, facilitating the retention of bound water. Further, XDLVO analysis indicated that MFs-induced changes in EPS compositions and structure enhanced the interparticle energy barrier so that sludge floc became more stable and more resistant to water release. The adverse effect of MFs on sludge dewaterability highlighted the importance of adjusting sludge conditioning strategies and controlling MFs' entry into wastewater/sludge to mitigate their impact. It also unveiled a previously overlooked mechanism that microplastics could regulate extracellular proteins and consequently reshape the structure and function of aquatic bioflocs.

More Papers Like This

Article Tier 2

Effects of chronic exposure to different sizes and polymers of microplastics on the characteristics of activated sludge

AI summary Read the abstract

Researchers studied how 60 days of exposure to different sizes and types of microplastics affected activated sludge at wastewater treatment plants. Millimeter-sized particles dramatically reduced sludge dewaterability by up to 47.7%, mainly through physical disruption of sludge flocs. Nano-sized particles also impaired sludge performance by inhibiting microbial activity and altering the composition of extracellular polymeric substances.

Article Tier 2

Leaching behavior of microplastics during sludge mechanical dewatering and its effect on activated sludge

AI summary Read the abstract

Researchers studied how mechanical dewatering of sewage sludge affects the microplastics embedded within it, including their physical changes and leaching behavior. They found that the dewatering process roughened microplastic surfaces, reduced particle sizes, and altered their chemical properties due to dewatering agents and mechanical forces. The study also showed that leachates from these processed microplastics could negatively affect activated sludge performance in treatment systems.

Article Tier 2

Impact of Polyethylene Terephthalate Microplastics on Aerobic Granular Sludge Structure and EPS Composition in Wastewater Treatment

AI summary Read the abstract

Researchers investigated how PET microplastics affect the structure and function of aerobic granular sludge used in wastewater treatment. Higher microplastic concentrations led to changes in granule size, altered the composition of extracellular polymeric substances, and shifted microbial community structure. The findings suggest that microplastic contamination in wastewater could compromise the stability and efficiency of biological treatment processes.

Article Tier 2

Role of extracellular polymeric substances in the acute inhibition of activated sludge by polystyrene nanoparticles

AI summary Read the abstract

Researchers investigated how extracellular polymeric substances — the sticky biofilm matrix produced by bacteria — affected the acute inhibition of activated sludge by microplastics, finding that these substances played a protective role by reducing microplastic toxicity in wastewater treatment systems.

Article Tier 2

Effects of polystyrene nanoplastics on extracellular polymeric substance composition of activated sludge: The role of surface functional groups

AI summary Read the abstract

Researchers investigated how three types of polystyrene nanoplastics with different surface functional groups affect activated sludge used in wastewater treatment. All three types significantly reduced total protein production in the sludge and caused cellular oxidative stress and membrane damage, with positively charged particles causing the most harm. The findings suggest that nanoplastic contamination in wastewater could impair the biological processes essential for effective sewage treatment.

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