Fate and removal of silver nanoparticles during sludge conditioning and their impact on soil health after simulated land application
Autor: | Dina Schwertfeger, Juliska Princz, Zainab Abdulsada, Richard Kibbee, Maria C. DeRosa, Banu Örmeci |
---|---|
Rok vydání: | 2021 |
Předmět: |
Environmental Engineering
Silver Biosolids Polyacrylamide Metal Nanoparticles 02 engineering and technology 010501 environmental sciences Wastewater 01 natural sciences Silver nanoparticle chemistry.chemical_compound Soil Waste Management and Disposal 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering Soil health Sewage Chemistry Alum Ecological Modeling 021001 nanoscience & nanotechnology Pollution 6. Clean water Environmental chemistry Soil water Sewage treatment 0210 nano-technology |
Zdroj: | Water research. 206 |
ISSN: | 1879-2448 |
Popis: | The growing use of silver nanoparticles (AgNPs) in personal care products and clothing has increased their concentrations in wastewater and subsequently in sludge raising concerns about their fate and toxicity during wastewater treatment and after land application of sludge. This research investigated the fate and removal of AgNPs during chemical conditioning of anaerobically digested sludge and their impact on soil bacteria and health after land application. Ferric chloride (FeCl3), alum (Al2 (SO4)3 • (14–18) H2O), and synthetic (polyacrylamide) polymer were used for sludge conditioning. All conditioners effectively removed AgNPs from the liquid phase and concentrated them in sludge solids. Concentration analyses showed that out of 53.0 mg/L of silver in the sludge, only 0.1 to 0.003 mg/L of silver remained in the sludge supernatant after conditioning and 12 to 20% of this value were particulates. Morphological analyses also showed that AgNPs went through physical, chemical, and morphological changes in sludge that were not observed in nanopure water and the resulting floc structures and the incorporation of nanoparticles were different for each conditioner. The impact of conditioned AgNPs on the biological activities of soil was evaluated by investigating its impact on the presence of five important phyla (Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria). The results showed that AgNPs at a concentration of 20 mg AgNPs/g soil had a minimal impact on the presence and diversity of the assessed phyla. Also, using different chemicals for sludge conditioning resulted in different growth behavior of studied phyla. This study provides new insight into how the presence of AgNPs and different chemicals used for sludge conditioning might impact the soil biological activities and hence plant growth. The study also provides a solid basis for further research in the risk assessment of nanoparticle toxicity in biosolids amended soils. |
Databáze: | OpenAIRE |
Externí odkaz: |