Influence of extracellular polymeric substances on the heteroaggregation between CeO2 nanoparticles and soil mineral particles

2022 ◽  
Vol 806 ◽  
pp. 150358
Author(s):  
Jun Zhao ◽  
Jun Tang ◽  
Tinghui Dang
Keyword(s):  
Extracellular Polymeric Substances ◽  
Ceo2 Nanoparticles ◽  
Soil Mineral ◽  
Mineral Particles

scholarly journals Physicochemical and Biological Effects on Activated Sludge Performance and Activity Recovery of Damaged Sludge by Exposure to CeO2 Nanoparticles in Sequencing Batch Reactors

2019 ◽  
Vol 16 (20) ◽  
pp. 4029 ◽  
Author(s):  
Qian Feng ◽  
Yaqing Sun ◽  
Yang Wu ◽  
Zhaoxia Xue ◽  
Jingyang Luo ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Extracellular Polymeric Substances ◽  
High Throughput Sequencing ◽  
Biological Effects ◽  
Recovery Period ◽  
Ceo2 Nanoparticles ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Key Enzymes ◽  
Activity Recovery

Recently, the growing release of CeO2 nanoparticles (CeO2 NPs) into sewage systems has attracted great concern. Several studies have extensively explored CeO2 NPs’ potential adverse impacts on wastewater treatment plants; however, the impaired activated sludge recovery potentials have seldom been addressed to date. To explore the physicochemical and biological effects on the activated sludge performance and activity recovery of damaged sludge by exposure to CeO2 NPs in sequencing batch reactors (SBRs), four reactors and multiple indicators including water quality, key enzymes, microbial metabolites, the microbial community structure and toxicity were used. Results showed that 10-week exposure to higher CeO2 NP concentration (1, 10 mg/L) resulted in a sharp decrease in nitrogen and phosphorus removal efficiencies, which were consistent with the tendencies of key enzymes. Meanwhile, CeO2 NPs at concentrations of 0.1, 1, and 10 mg/L decreased the secretion of tightly bound extracellular polymeric substances to 0.13%, 3.14%, and 28.60%, respectively, compared to the control. In addition, two-week recovery period assays revealed that the functional bacteria Proteobacteria, Nitrospirae and Planctomycetes recovered slightly at the phyla level, as analyzed through high-throughput sequencing, which was consistent with the small amount of improvement of the effluent performance of the system. This reflected the small possibility of the activity recovery of damaged sludge.

scholarly journals Colloid-bound and dissolved phosphorus species in topsoil water extracts along a grassland transect from Cambisol to Stagnosol

2017 ◽  
Vol 14 (5) ◽  
pp. 1153-1164 ◽  
Author(s):  
Xiaoqian Jiang ◽  
Roland Bol ◽  
Barbara J. Cade-Menun ◽  
Volker Nischwitz ◽  
Sabine Willbold ◽  
...  
Keyword(s):  
31P Nmr ◽  
Soil Mineral ◽  
Phosphorus Species ◽  
Dissolved Phosphorus ◽  
Water Extracts ◽  
Mineral Particles ◽  
Soil Fractions ◽  
P Fraction ◽  
Total P ◽  
Soil Colloids

Abstract. Phosphorus (P) species in colloidal and dissolved soil fractions may have different distributions. To understand which P species are potentially involved, we obtained water extracts from the surface soils of a gradient from Cambisol, Stagnic Cambisol to Stagnosol from temperate grassland in Germany. These were filtered to  <  450 nm, and divided into three procedurally defined fractions: small-sized colloids (20–450 nm), nano-sized colloids (1–20 nm), and dissolved P (<  1 nm), using asymmetric flow field-flow fractionation (AF4), as well as filtration for solution 31P-nuclear magnetic resonance (NMR) spectroscopy. The total P of soil water extracts increased in the order Cambisol  <  Stagnic Cambisol  <  Stagnosol due to increasing contributions from the dissolved P fraction. Associations of C–Fe/Al–PO43−/pyrophosphate were absent in nano-sized (1–20 nm) colloids from the Cambisol but not in the Stagnosol. The 31P-NMR results indicated that this was accompanied by elevated portions of organic P in the order Cambisol  >  Stagnic Cambisol  >  Stagnosol. Across all soil types, elevated proportions of inositol hexakisphosphate (IHP) species (e.g., myo-, scyllo- and D-chiro-IHP) were associated with soil mineral particles (i.e., bulk soil and small-sized soil colloids), whereas other orthophosphate monoesters and phosphonates were found in the dissolved P fraction. We conclude that P species composition varies among colloidal and dissolved soil fractions after characterization using advanced techniques, i.e., AF4 and NMR. Furthermore, stagnic properties affect P speciation and availability by potentially releasing dissolved inorganic and ester-bound P forms as well as nano-sized organic matter–Fe/Al–P colloids.

Influence of CeO2 nanoparticles on viscoelastic properties of sludge: Role of extracellular polymeric substances

2018 ◽  
Vol 167 ◽  
pp. 34-41 ◽  
Author(s):  
Guoxiang You ◽  
Peifang Wang ◽  
Jun Hou ◽  
Chao Wang ◽  
Lingzhan Miao ◽  
...  
Keyword(s):  
Viscoelastic Properties ◽  
Extracellular Polymeric Substances ◽  
Ceo2 Nanoparticles

scholarly journals Colloid-bound and dissolved phosphorus species in topsoil water extracts along a grassland

2016 ◽  
Author(s):  
Xiaoqian Jiang ◽  
Roland Bol ◽  
Barbara J. Cade-Menun ◽  
Volker Nischwitz ◽  
Sabine Willbold ◽  
...  
Keyword(s):  
Temperate Grassland ◽  
Soil Types ◽  
Soil Mineral ◽  
Stagnant Water ◽  
Phosphorus Species ◽  
Dissolved Phosphorus ◽  
Water Extracts ◽  
Mineral Particles ◽  
P Fraction ◽  
Soil Colloids

Abstract. Stagnant water conditions may release phosphorus (P) in soil solution that was formerly bound to Fe oxides. To understand which P species are potentially involved, we obtained water extracts from the surface soils of a gradient from Cambisol, Stagnic Cambisol to Stagnosol from temperate grassland, Germany. These were filtered to Stagnosol. Across all soil types, elevated proportions of inositol hexakisphosphate species (e.g. myo-, scyllo-, and D-chiro-IHP) were associated with soil mineral particles (i.e. bulk soil and small-sized soil colloids) whereas other orthophosphate monoesters and phosphonates were found in the ‘dissolved’ P fraction. We conclude that stagnic properties affect P speciation and availability by potentially releasing dissolved inorganic and ester-bound P forms as well as nano-sized organic matter-Fe/Al-P colloids.

scholarly journals Experimental Study on the Effect of Freeze—Thaw Cycles on the Mineral Particle Fragmentation and Aggregation with Different Soil Types

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 913
Author(s):  
Jinbang Zhai ◽  
Ze Zhang ◽  
Andrey Melnikov ◽  
Mingyi Zhang ◽  
Linzhen Yang ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Soil Types ◽  
Silty Clay ◽  
Soil Mineral ◽  
Freeze Thaw ◽  
Fine Grained ◽  
Mineral Particles ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

The freeze–thaw cycle can change the size and shape of soil particles, that is, cause fragmentation and aggregation of soil mineral particles, thereby affecting the soil structure, which, in turn, affects the soil properties. In addition, the process of soil mineral fragmentation and aggregation, as an event closely related to the cold climate, plays an irreplaceable role in reconstructing the climatic conditions of a certain area and a certain period of time and has important referential significance for the restoration of historical permafrost boundaries and the study of climate change. Therefore, in order to better study the effect of freeze–thaw cycles on the fragmentation and aggregation of soil mineral particles, four soil specimens were selected for this study; the freeze–thaw cycle tests were carried out 0, 3, 6, 9, 50, and 100 times, respectively, and the test results were analyzed. The results of these experiments indicate that (1) after freeze–thaw cycles, the changes in grain-size distribution are different in various soil types, and the changes are mainly concentrated in 0.001–0.1 mm; (2) the coarse particle size particles (sand, silt) can be fragmented into relatively fine-grained particles (silt, clay). The fine-grained particles (clay) cannot undergo fragmentation, and the decrease in clay is due to its aggregation; (3) with the increase in freeze–thaw cycles, the fraction change trend of four specimens is parallel to the x-axis, which means the fragmentation and aggregation of soil mineral particles are in a state of equilibrium or balance; (4) the increase in the Kvar value indicates the change in grain-size distribution, which means aggregation and fragmentation of soil mineral particles. After the 100th cycle, the Kvar value of four specimens is <0.1, which belongs to a low-intensity area; (5) the freeze–thaw cycle will change the type of soil, and after 100 freeze–thaw cycles, the soil type of specimen (H) changes from silty clay loam to silty clay; (6) during the freeze–thaw process, different types of soil have different situations of aggregation and fragmentation.

Influence of Bacteria Pseudomonas fluorescens on the Properties of Latvian Clay

2014 ◽  
Vol 604 ◽  
pp. 208-211
Author(s):  
Maris Rundans ◽  
Ingunda Sperberga ◽  
Gaida Sedmale ◽  
Dagnija Vecstaudza ◽  
Olga Muter
Keyword(s):  
Soil Properties ◽  
Rheological Properties ◽  
Pseudomonas Fluorescens ◽  
Extracellular Polymeric Substances ◽  
Clay Soil ◽  
Atterberg Limits ◽  
Mineral Particles ◽  
Ft Ir ◽  
Growth Of Bacteria

Wide varieties of bacteria are able to produce extracellular polymeric substances (EPS) which are mostly composed of polysaccharides. It is suggested that EPS substances can alter certain clay soil properties due to their ability to adhere to the surface of mineral particles. Most common used microorganisms by the researchers for this purpose are of either genus Bacillus or genus Pseudomonas. In this study growth of bacteria P. fluorescens AM PS11 culture in locally obtained clay is studied for the purpose of establishing their influence on rheological properties of clay. An attempt to evaluate it has been made using FT-IR and XRD. Change in plasticity of clay using Atterberg limits method and coefficient of drying sensitivity has also been determined.

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