Suspended Particle Size Research Articles

Impact of EO chain length of dodecanol ethoxylates (C12En) on the rheological properties and physical stability of pesticide suspension concentrate

Rheological measurement can provide not only the shear-induced but also strain-induced microstructural changes, as well as transient network formation and subsequent recovery with time. It has been explored as a useful tool for probing the interparticle interactions which govern the physical stability of concentrated suspension. However, its application in pesticide formulation is rarely investigated. Herein, the rheological properties of 25% mancozeb suspension concentrate stabilized with nonionic surfactants dodecanol ethoxylates (C12En, n = 3, 7, 9, 15, 20) were studied. The steady-state shear measurement showed that all the 25% mancozeb suspension concentrate displayed shear-thinning flow. The experimental flow behavior followed prediction of Herschel–Bulkley model with the correlation coefficients greater than 0.99. Oscillatory shear measurements showed the viscoelastic response of 25% mancozeb suspension concentrate transformed from solid-like to gel-like viscoelasticity with the addition of C12En. As the EO chain length of C12En increased, the apparent viscosity and elastic modulus decreased initially, followed by an increase behavior. The thixotropic response of mancozeb formulations was evaluated by applying a three-step test. It turned out that the addition of C12En changed the mancozeb suspension concentrate from normal viscoelastic fluid to inelastic thixotropic material, and the recovery of viscosity gradually decreased as the EO chain length increased. Besides, the influence of C12En on suspension rate and particle size of 25% mancozeb suspension concentrate was investigated. The results showed that C12E9 performed best in improving the physical stability of the formulations before and after thermal storage. From SEM imagines of mancozeb particles, it was found that the aggregation was inhibited by C12E9, which was also responsible for the best dispersibility, minimum apparent viscosity and elastic modulus of 25% mancozeb suspension concentrate with the addition of C12E9.

Practical Method to Screen Contaminated Holograms of Flocs Using Light Intensity

Submergible digital holographic camera can measure the in situ size and shape of suspended particles, such as complex flocs and biological organisms, without disturbance. As the number of particles in the water column increases, overlapping concentric rings (interference patterns) can contaminate the holographic images. Using light intensity (LI), this study proposes a practical method to assess the degree of contamination and screen out contaminated images. The outcomes from image processing support that LI normalized on a gray scale of 0 (black) to 255 (white) can be a reliable criterion for defining the contamination boundary. Results found that as LI increased, the shape of the particle size distribution shifted from a positively skewed to a normal distribution. When LI was lower than approximately 80, owing to the distortion of particle properties, the settling velocities derived from the contaminated holograms with mosaic patterns were underestimated compared to those from the uncontaminated holograms. The proposed method can contribute to a more accurate estimation of the transport and behavior of cohesive sediments in shallow estuarine environments.

Ultrasonic-Assisted Removal of Undesirable Submicron-Sized Particulates To Realize Sustainable and Eco-Friendly Circulation of Drilling Fluid

SummaryRemoval of useless and submicrometer-sized solids from drilling fluid, which exert significant effects on drilling performance, is a crucial part of sustainable and eco-friendly circulation in drilling operations. However, current solid-control methods for drilling-fluid reuse and recirculation, such as electronic-adsorption and chemical-flocculation methods, are associated with high cost and low efficiency and/or pollution of drilling fluid. In this study, a novel method using ultrasonic waves has been proposed to remove unwanted submicrometer-sized solids from polysulfonate drilling fluids. The results show that the suspension stability, viscosity, and particle size can all be significantly reduced, while the solid-separation ratio of the drilling fluid can be greatly enhanced by ultrasonic-wave treatment. The parameters of ultrasonic waves are optimized to be power of 3 kW, treating time of 30 minutes, treating frequency of 20 kHz, and ventilation (i.e., air) for 5 minutes in a laboratory scale. The scanning electron microscope (SEM) analysis shows that solid particles exhibit more obvious crystal morphology after ultrasonic-wave treatment, indicating that the breaking of gel-structure of drilling fluid due to the cavitation, mechanical, and heat effects of ultrasonic waves is the main mechanism for decreasing the suspension stability. Thus, the proposed ultrasonic-assisted technique has a high potential for removing undesirable solids from drilling fluid and fulfilling its recirculation in a cost-effective and environmentally friendly manner. This new technology has been successively applied to 12 wells, and good results were obtained.

Empirical Approach Using Acoustic Doppler Current Profilers for Determining Particle Size Distributions in Estuaries with Highly Concentrated Suspended Matter

The backscatter strength provided by multifrequency acoustic systems is frequently used to characterize suspended elements in water courses in the entire water column on a short time scale with high temporal and spatial resolution. However, in estuarine waters with highly concentrated suspended matter, sound attenuation may hinder the ability of the acoustic method to obtain grain size profiles. This article presents a novel acoustic technique to overcome this limitation by estimating the sound attenuation caused by both fine and coarse suspended matter fractions through an iterative process that starts by introducing discrete values of suspended particle concentration and size obtained from a conventional diffractometer. Results were compared with those obtained by the traditional two frequency method to highlight the substantial improvement achieved. The main advantage of the proposed methodology is the rapid detection of changes in the concentration and size profiles, which remain hidden when measurements are made with instruments that provide discrete values and require longer times. The technique was applied to obtain the particle size and concentration distributions along a cross section of an estuary characterized by zones where a massive convective process of sedimentation occurs.

Experimental Research on Size Distribution of Suspended Particles in water Based on Mie Scattering Theory

With the rapid development of social economy, it has brought serious environmental pollution problems. This thesis mainly summarizes the measurement methods of particle size and distribution of suspended particles. We have analyzed the relationship between scattering coefficient and concentration of different wavelengths at each scattering angle; the relationship between scattering coefficient and concentration of different scattering angles at each wavelength; and the relationship between scattering coefficient and wavelength of different concentrations at each scattering angle. The result shows that particle size and distribution of suspended particles can be accurately reversed when scattering angle is 15 degree, denoising factor is 200 and wavelength range is 450 nm-500 nm. The analysis can effectively filter out suspended particles in water, which is essential to resolve air pollution and purify water quality.

Detachment of Submicron Particles from Substrates Using the Suspension-Assisted Ultrasonic Method

A protocol for the detachment of solid samples deposited on flat substrates and their collection in aqueous samples is proposed based on a suspension-assisted ultrasonic method. As samples, combustion-synthesized magnesium oxide aggregates in the submicron size range were deposited in the gas phase onto three kinds of substrates: a silicon wafer and coarse and fine alumina-coated resin sheets. To enhance the sample particle detachment, a solid–liquid suspension made of candle combustion soot particles was selected as an ultrasound propagation medium, which is different from the usual liquid medium, such as water, a surfactant solution, or a solvent. Preliminary detachment experiments were performed using low-power (42 kHz and 35 W) ultrasonication, and the substrates and suspensions were analyzed using scanning electron microscopy (SEM) images and particle size distributions based on dynamic light scattering, respectively. The detachment efficiency, defined as the fraction of cleaned area on a substrate, was determined from the SEM images and indicates that the detachment using the medium with soot had a higher efficiency compared to that without soot, and there was an optimum soot concentration for particle detachment for all three substrates. The suspension particle size distribution after ultrasonication showed good dispersion of the sample particles in the soot suspension.

Sedimentation rate of microfluidized sugarcane juice

Sugarcane juice contains unstable particles that readily undergo agglomeration and sedimentation. In this work, microfluidization was used as a processing tool to generate a possible solution to the sedimentation problem in sugarcane juice for the first time. Stoke's law was used to determine the particle sedimentation rate. Experiments were devised to explore the majority of the pressure range of microfluidization (50–200 MPa) with variation in processing cycles (1–7). Particle size and apparent viscosity of sugarcane juice were determined. Microscopic analysis was also carried out to visualize the effect of microfluidization on the particles in the juice. Microfluidization in the pressure range of 50-150 MPa with less than 7 cycles of processing reduced the size of suspended juice particles successfully. Results revealed that 150 MPa pressure with 5 cycles was suitable for sugarcane juice processing as it generates the lowest particle size (~437 nm) and minimum particle sedimentation rate (4.91 × 10−2 mm/day).

Estimation of the Sizes of Suspended Organic Particles from Light-Scattering Phase Functions and Their Relationship to the Water Trophic State

Average sizes of organic particles suspended in water are calculated from measurements of light-scattering phase functions. Their correlation with the sizes of phytoplankton cells, visually determined with the use of a microscope, is derived. The relationship between the size of suspended organic particles and the water trophic state is studied. It is ascertained that the average size of suspended organic particles increases with a decrease in the water productivity (trophic state). Taking into account the correlation between the average size of organic particles suspended in water and the average size of phytoplankton cells, it was concluded that the size of phytoplankton cells increased in oligotrophic waters (low trophic state) as compared to eutrophic waters (high trophic state).

Abstract PO040: Chemoprevention and regression of estrogen-induced atypical endometrial hyperplasia by oral SHetA2 in a rat model

Abstract Introduction: The purpose was to evaluate the chemoprevention efficacy of SHetA2 (NSC 726189) in a rat model of atypical endometrial hyperplasia (AEH). Methods: Female Sprague Dawley rats were ovariectomized, rested for 2 weeks, and subcutaneously implanted with placebo or slow-release estrogen (E2; 1.5 mg/90-day) pellets on the lateral side of the neck. The rats were randomly divided for two studies: 1) AEH prevention, in which SHetA2 treatment was started one day after E2 pellet implantation; 2) AEH regression, in which SHetA2 treatment was started after AEH development (12 weeks after E2 pellet implantation) and continued for 4 weeks. SHetA2 was orally given as a suspension at three different doses of 30, 60 or 90 mg/kg/day. The suspension was prepared by first micronizing SHetA2 powder to < 63 µm and then ultrahomogenizing it in aqueous 30% Kolliphor HS15 until the size of drug particles in suspension was < 20 µm. The presence of AEH in H&E stained uterine sections was evaluated by two pathologists as the study endpoint by the presence of abnormal cells (nuclear enlargement, nuclear membrane irregularities, prominent nucleoli, nuclear hyperchromasia, nuclear pleomorphism, mitotic activity and/or loss of axial polarity) within tissue areas that exhibit at least one of the following features: increased gland to stroma ratio of >1:1, glandular complexity including irregular contours, and cribriform/papillary configurations. Results: E2-treated animals had reduced body weight gain compared to placebo-implanted animals (Repeated Measures ANOVA, p<0.0001). There were no effects of SHetA2 on rat body weights. In the prevention study, uterine to body weight ratios were significantly higher in E2-treated animals compared to placebo (Repeated Measures ANOVA, p<0.0001) and significantly reduced by 30 and 60 mg/kg/day SHetA2 doses (Repeated Measures ANOVA, p=0.0193 and 0.0108, respectively). Also, SHetA2 caused a dose-responsive decrease in AEH incidence in E2-implanted animals from 86.7% (13/15) in the untreated control to 53.3% (8/15), 26.7% (4/15) and 26.7% (4/15) in the 30, 60 and 90 mg/kg/day SHetA2 treatment groups, respectively (Chai Square Analysis p<0.0022). In the regression study, there were no significant differences in uterine to body weight ratios across all groups. Also, SHetA2 caused dose-responsive regression of AEH to normal histology in E2-implanted animals observed by lack of AEH in 18.2% (2/11) of the untreated control group and 83.3% (10/12), 81.8% (9/11) and 75% (9/12) in the 30, 60 and 90 mg/kg/day SHetA2 treatment groups, respectively (Chai Square Analysis p<0.0025). Conclusions: AEH can be induced by implantation of slow-release E2 pellets in ovariectomized rats. SHetA2 significantly prevented AEH development and caused AEH regression to normal endometrium histology in a dose-dependent manner. Further study is warranted to explore the mechanistic chemoprevention action of SHetA2 and translate these findings toward clinical trials. Funding: NCI PREVENT Program Contract HHSN26100008. Citation Format: Vishal Chandra, Rajani Rai, Stan S. Lightfoot, Manolya Kukut Hatipoglu, Lucila Garcia-Contreras, Doris M. Benbrook. Chemoprevention and regression of estrogen-induced atypical endometrial hyperplasia by oral SHetA2 in a rat model [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PO040.

Experimental Study on the Effect of Nanoparticle Migration on the Convective Heat Transfer Coefficient of EG/Water-based Al2O3 Nanofluids

In this paper, the effect of nanoparticle migration on the convective heat transfer characteristics of EG/water-based Al2O3 nanofluids flowing through a simple round tube with constant heat flux in a fully developed turbulent flow regime was investigated experimentally. Homogenous EG/water-based Al2O3 nanofluids were mass-produced using a modified two-step method with both a dispersion with a nanodisperser and centrifugal decanting. The suspension stability, particle size, thermal conductivity, and viscosity of the nanofluids were systematically measured. To observe the effect of nanoparticle migration, the convective heat transfer coefficient of the nanofluids was experimentally measured according to NBT values, which indicates the ratio of the Brownian diffusivity to thermophoretic diffusivity. The convective heat transfer coefficients of nanofluids increased by at least 12.4% and up to 22.7% depending on the NBT values at the fixed Reynolds number. Moreover, the convective heat transfer coefficient of the nanofluids decreased by 7.7% (low NBT value) or increased by approximately 13.2% (high NBT value) under constant pumping power. These results indicate that the convective heat transfer coefficients of EG/water-based Al2O3 nanofluids under each condition are strongly dependent on the NBT values.

Influence of Piezoelectric Properties on the Ultrasonic Dispersion of TiO2 Nanoparticles in Aqueous Suspension.

In this study, the soft-type and hard-type lead zirconate titanate (PZT) ceramics were compared in order to create an optimal system for ultrasonic dispersion of nanoparticles, and sound pressure energy for each PZT ceramic was analyzed and closely examined with ultrasonic energy. TiO2 was water-dispersed using the soft-type and hard-type PZT transducer, possessing different characteristics, and its suspension particle size and distribution, polydispersity index (PDI), zeta potential, and dispersion were evaluated for 180 days. Furthermore, it was confirmed that the particles dispersed using the hard-type PZT transducer were smaller than the particles dispersed using the soft-type PZT by 15 nm or more. Because the hard-type PZT transducer had a lower PDI, uniform particle size distribution was also confirmed. In addition, by measuring the zeta potential over time, it was found that the hard-type PZT transducer has higher dispersion safety. In addition, it was confirmed that the ultrasonically dispersed TiO2 suspension using a hard-type PZT transducer maintained constant particle size distribution for 180 days, whereas the suspension from the soft-type PZT aggregated 30 days later. Therefore, the hard-type PZT is more suitable for ultrasonic dispersion of nanoparticles.

Stabilization of Palygorskite Aqueous Suspensions Using Bio-Based and Synthetic Polyelectrolytes.

Palygorskite is a natural fibrous clay mineral that can be used in several applications, for which colloidal stability in aqueous suspensions is a key point to improve its performance. In this study, methods of magnetic stirring, high-speed shearing, and ultrasonication, as well as different chemical dispersants, combined with these methods, namely carboxymethylcellulose, alginate, polyphosphate, and polyacrylate, were used to improve the dispersibility and the formation of stable suspensions of palygorskite in different conditions of pH. The stability and particle size of suspensions with a low concentration of palygorskite were evaluated by visual inspection, optical and electron microscopy, dynamic light scattering, and zeta potential measurements. Moreover, the palygorskite used in this work was initially characterized for its mineralogical, chemical, physical, and morphological properties. It was found that more stable suspensions were produced with ultrasonication compared to the other two physical treatments, with magnetic stirring being inefficient in all tested cases, and for higher pH values (pH of 12 and pH of 8, the natural pH of the clay) when compared to lower pH values (pH of 3). Remarkably, combined with ultrasonication, carboxymethylcellulose or in a lesser extent polyphosphate at near neutral pH allowed for the disaggregation of crystal bundles of palygorskite into individualized crystals. These results may be helpful to optimize the performance of palygorskite in several domains where it is applied.

Acoustic scattering characteristics and inversions for suspended concentration and particle size above mixed sand and mud beds

The majority of reported field studies, using acoustic backscattering, for the measurement of nearbed suspended sediment processes, have been focussed on field sites with sand size fractions and unimodal size distributions. However, in many sedimentary environments, and particularly for estuaries and rivers, sands and muds coexist in the bed sediment substrate, forming a size regime that is often bimodal in nature. To examine the interaction of sound in these more complex sedimentary environments a numerical study is presented based on observations of sediment size distributions measured in the Dee estuary, UK. The work explores the interpretation of the backscatter signal from a mixed sediment composition in suspension, with mud-sand fractions varying with height above the bed. Consideration is given to the acoustical scattering properties and the inversion of the backscatter signal to extract information on the suspension. In common with most field deployments, the scenarios presented here use local bed sediments for the acoustic inversion of the backscattered signal. The results indicate that in general it is expected that particle size and concentration will diverge from what is actually in suspension, with the former being overestimated and the latter underestimated.

Comparison of Hydrometer Analysis and Laser Diffraction Method for Measuring Particle and Floc Size Distribution Applied to Fine Coal Refuse

Abstract Traditional grain size distribution measurement techniques assume that the measured particle diameters are of individual grains. However, for suspended particulate materials, particles may be dispersed or associated in flocs. Further, particle-level associations depend on the surrounding fluid chemistry, which may change over time. The purpose of this study is to compare two different methods of grain size analysis for detecting particle and floc sizes in suspensions of fine coal refuse (FCR): hydrometer analysis, the well-known traditional method, and laser diffraction, a lesser known method. The influence of background solution—flocculant, dispersant, or distilled water—on the apparent grain size of FCR was also investigated. Analogous slurry suspensions made from a well-characterized kaolin were analyzed for comparison. Results from the grain/floc size analysis indicate that there are several advantages of laser diffraction over hydrometer analysis including a short measurement period, small sample size requirement, and the ability to measure a wide range of particle sizes in the same analysis. Moreover, this study highlights the ability of the particle size analyzer (PSA) to accurately measure changes in apparent particle size over time for the same suspension and thereby indicate the presence of flocs. Finally, the PSA has the capability of capturing dynamic particle interactions—flocculation and deflocculation—in real time.

Quality parameters and bioactive compound bioaccessibility changes in probiotics fermented mango juice using ultraviolet-assisted ultrasonic pre-treatment during cold storage

Ultrasound can be applied in fruit juice fermentation as an innovative non-thermal sterilisation method with product quality-promoting potential. In this study, the qualities changes in fermented mango juice (UFJ) pre-treated by ultraviolet-assisted ultrasound (US-UV) during the 30-days of cold storage (4 °C) were evaluated. The essential qualities of UFJ were enhanced compared with the fresh juice and traditional fermented juice (thermal pre-treatment). Additionally, UFJ showed better performances concerning physical features (suspension stability, particle size, viscosity, and colour), pH and acidity, as well as bioactive compounds stability (soluble dietary fibre, carotenoids, total phenols, and ascorbic acid) than fresh juice during storage, revealing that the higher qualities of fermented mango juice were improved by US-UV pre-treatment. More importantly, the in vitro simulated gastrointestinal digestion validated that the bioactive compounds in UFJ had better stability and bioaccessibility than fresh juice during various storage periods, and lead to better antioxidant performance. As an effective and novel non-thermal technology, US-UV pretreatment can be considered a promising alternative method to thermal sterilisation in the juice industry.

The effect of potato starch ultrasonic modification on its functional and structural properties and the particle size

Nowadays, starch is widely used in the food industry as an additive that can improve product quality due to its characteristics. Starch can have a significant effect on the texture of a food product, and works as a thickener, stabilizer, filler and ingredient that locks in moisture well. Different types of starch are used in production, depending on the purpose of their application. Starch properties mainly depend on its physical and chemical characteristics, amylose/amylopectin ratio, and also on the average granule size and percentage ratio of different granule size groups. Currently, the innovation approaches with the use of so-called "green technologies" have been the priorities of food industry development not only in Russia but also all over the world. This paper deals with the possibility of producing modified starches using ultrasonic exposure methods. It was found that the properties of the modified starch suspensions undergo significant changes when exposed to low-frequency ultrasound. In particular, the temperature of starch gelatinization decreases by an average of 17° C, the output of amylose from the starch grain increases by 2.8–3.5 times relative to the native starch. The size of particles in the starch suspensions varies. On the basis of the carried out research it has been established that increase of ultrasonic exposure duration leads to equalizing of particle sizes. The native sample has no particles less than 400 nm in size but there are particles larger than 3,000 nm, while the size of particles exposed to ultrasound (630 W, 10 min) is mostly (426 ± 10) nm (35.5%) and (678 ± 5) nm (24.8%). Thus, the use of ultrasound for starch modification makes it possible to produce a substance with new properties and this significantly expands the possibility of using modified starch in the food industry.)

The effect of rare earth element (Er, Yb) doping and heat treatment on suspension stability of Y2O3 nanoparticles elaborated by sol-gel method

Sol–gel processing was used to fabricate undoped and rare-earth (Er, Yb) doped very fine Y2O3 nanoparticles under supercritical drying conditions of ethanol using an autoclave and annealed at 500 °C and 800 °C for 2 h. The Er and/or Yb concentration is fixed at 5 mol % for doped and co-doped nanoparticles. The as-synthesized Y2O3 nanopowder was characterized by the X-ray diffraction, scanning electron microscopy and thermogravimetric analysis (TGA) coupled with differential thermal calorimetry (DTA). The effects of solvent, heat treatment and the doping on the suspension stability of yttrium oxide (Y2O3) nanoparticles doped rare-earth elements (Er and Yb) were evaluated by UV-Visible spectroscopy, zeta potential measurement and particle size in suspension, thus, Hamaker 2 software. During this work, the particle analysis showed that the resulting nanoparticles had a pure cubic structure and nano-sized crystallites of about 8–38 nm. The heat treatment of the nanopowders causes a rapid decantation of the suspensions and the Er doped nanoparticles suspension had a good stability.

Kaolin/silica/mullite fiber multilayer membranes for high-efficiency gas filtration

At present, the ultra-fine particulate matter (UPM) with diameter less than 1 μm cannot be filtered efficiently and precisely by the current filtration materials, which leads to the UPM being the main source of air pollution. Here, we prepared Kaolin/silica/mullite fiber multilayer membranes (KSFMs) by a simple vacuum filtration. The UPM filtration efficiency has been significantly improved by the nanoporous kaolin layer coated on the support body constructed by Si-sol bonded mullite fiber. By controlling the size and amount of kaolin particles in the mixed suspension, the structure and filtration efficiency and filtration resistance of the multilayer membranes are optimized. The multilayer membranes exhibit high UPM filtration efficiency with 99% for 0.3 μm and low filtration resistance (lower than 70 Pa at 0.3 m/s).

Influence of the hydrophilic moiety of polymeric surfactant on their surface activity and physical stability of pesticide suspension concentrate

Polymeric surfactant has explored as an efficient dispersant for improving the physical stability of pesticide suspension concentrate. However, the influence of the hydrophilic monomer on the surface-active property of polymeric surfactant and its application performance in pesticide formulation is rare investigated. Herein, three kinds of random polymers were designed and synthesized via polymerization reaction of styrene (St), methacrylic acid (MAA) with 2-hydroxyethyl acrylate (HEA), 2-hydroxypropyl acrylate (HPA) and vinyl sulfonate sodium (VS), respectively. A series of surface-active parameters, including critical aggregation concentration (CMC), saturation surface excess concentration (Γmax), minimum area per molecule (Amin) and standard Gibbs free energy ΔGm0 values were obtained from surface tension measurement. The results showed that CMC increased and ΔGm0 decreased with the increase of the hydrophilicity of the third monomer. The results of foamability measurement indicated that the polymeric surfactant with VS as the third monomer had the best foam producing ability and foam stability. When HPA served as the third monomer, the surfactant had the lowest hydrophile lipophile balance (HLB) value and the O/W emulsion prepared by it had the worst stability. Besides, the influence of synthesized polymeric surfactants as dispersant on zeta potential, viscosity and suspension rate of 430 g/L tebuconazole suspension concentrate were investigated. The results showed that poly(styrene-co-methacrylic acid-co-2-hydroxypropyl acrylate) performed best in improving the physical stability of the formulations. From SEM imagines of tebuconazole particle, it was found the increase of particle size in tebuconazole suspension concentrate were caused by aggregation or Ostwald ripening after thermal storage.

Effect of water-sediment regulation operation on sediment grain size and nutrient content in the lower Yellow River

The Yellow River (YR) is famous for its high sediment concentration. The Xiaolangdi dam (XLD), the most downstream dam on the mainstream of the YR, plays an integral role in siltation mitigation, flood defence, agriculture, and hydropower generation. To alleviate siltation of the Xiaolangdi Reservoir (XLDR) and riverbed uplift of the lower reaches of the YR and strengthen flood control safety downstream, the XLDR began to implement water-sediment regulation in 2002. Water-sediment regulation (WSR) has significantly changed the hydrological processes, erosion and deposition, and sediment transport in the downstream channel, and the downstream water environmental conditions have also changed. In this study, 10 sections in the Lower Yellow River (LYR, from the XLDR to the Lijin section) and 4 sections in the soft floodplain area were sampled in the field to analyse their surface sediment grain size composition and nutrient content. At the same time, data on the average annual median particle sizes (D50) of channel sediments and suspended particles in 7 typical sections in the LYR from 2004 to 2015 were statistically analysed. The results show that the channel sediment grain size in the LYR decreased along the river course, and the D50 ranged from 0.20 mm in the HYK section to 0.08 mm in the LJ section. Moreover the D50 of the suspended sediment was less than 0.05 mm. The D50 of the channel and suspended sediment were both ranked as follows: non-flood season > flood season > WSR period. After WSR, fine silt particles with diameters of 0.01–0.05 mm were deposited on the soft floodplain. The channel sediment size was mainly coarse particles with diameters of 0.05–0.20 mm due to channel erosion. The suspension of fine silt particles due to flood scouring led to the total organic carbon (TOC) and total nitrogen (TN) absorbed in the particles to also be resuspended in the water. As a result, the TOC and TN contents in the channel sediments decreased by approximately 40% after WSR.