Effect Of Solids Concentration Research Articles

Experimental investigation of the effects of various parameters on viscosity reduction of heavy crude by oil–water emulsion

The effects of water content, shear rate, temperature, and solid particle concentration on viscosity reduction (VR) caused by forming stable emulsions were investigated using Omani heavy crude oil. The viscosity of the crude oil was initially measured with respect to shear rates at different temperatures from 20 to 70 °C. The crude oil exhibited a shear thinning behavior at all the temperatures. The strongest shear thinning was observed at 20 °C. A non-ionic water soluble surfactant (Triton X-100) was used to form and stabilize crude oil emulsions. The emulsification process has significantly reduced the crude oil viscosity. The degree of VR was found to increase with an increase in water content and reach its maximum value at 50 % water content. The phase inversion from oil-in-water emulsion to water-in-oil emulsion occurred at 30 % water content. The results indicated that the VR was inversely proportional to temperature and concentration of silica nanoparticles. For water-in-oil emulsions, VR increased with shear rate and eventually reached a plateau at a shear rate of around 350 s−1. This was attributed to the thinning behavior of the continuous phase. The VR of oil-in-water emulsions remained almost constant as the shear rate increased due to the Newtonian behavior of water, the continuous phase.

Time after apple pressing and insoluble solids influence the efficiency of the UV treatment of cloudy apple juice

The effects of suspended insoluble solids (SIS) concentration and particle size, and the time after apple pressing on the efficiency of UV treatment of cloudy apple juice were evaluated. Clear model solutions (formulated to resemble physicochemical characteristics of apple juice) and commercial apple juice, containing different solids concentrations, were treated using a CiderSure reactor at 14 mJ cm−2 UV dose. Particle size effect was assessed on model solutions treated at 7 mJ cm−2 UV dose. The juice flow rate through the UV machine was determined. All samples were inoculated with Escherichia coli ATCC 25922 (106–107 CFU ml−1) and UV treated at 214.5 ml s−1 fixed flow rate. Log reductions were calculated. Increasing SIS concentrations did not significantly affect the juice flow rate (P > 0.05) but adversely affected the inactivation of E. coli (P < 0.05). For solutions treated at 7 mJ cm−2, a negative linear relationship between SIS and flow rate was observed and particle size significantly affected the flow rate (P < 0.05). A negative effect of time after apple pressing on the juice flow rate was observed and this effect was apple cultivar-dependent, thus UV efficiency would be improved if time after pressing is minimized.

Chemical Mechanical Polishing of Stainless Steel as Solar Cell Substrate

Recently, stainless steel has been widely used as the solar cell substrate. In this paper, chemical mechanical polishing technique was employed to prepare the ultra-smooth 316L stainless steel surface for such application. The effects of solid content, pH, H2O2 and benzotriazole (BTA) on the polishing performance of 316L stainless steel were investigated. The results indicated that, at pH 4.00, with the increase in the H2O2 concentration, the MRR first dramatically increases due to the fact that, with the addition of small amount of H2O2, a porous outer layer mainly consisting of iron-enriched oxides with relatively low mechanical strength of the bilayer-structure oxide film is rapidly formed on the surface. After reaching the maximum value, the MRR gradually decreases since the outer layer gradually grows compact by the transformation of γ-FeOOH into α-FeOOH and even into α-Fe2O3. With the addition of BTA, the MRR can be suppressed, which is probably attributed to the formation of BTA passivating film on the top surface. Finally, a two-step polishing method was proposed, by which the ultra-smooth 316L stainless steel surface with the surface roughness Ra about 2.0 nm can be achieved within 30 min and it can be subsequently used for thin-film solar cells.

Visualisation and Metering of Two Phase Counter-gravity Slurry Flow using ERT

Two-phase slurry flow is encountered in many industries such as petroleum, mining and related industries. The abrasiveness of slurry and interaction of solid particles with the carrier liquid make slurry flow measurement one of the most challenging applications in multi-phase flow metering. This paper presents a new method of solid-liquid flow metering, in which the Electrical Resistance Tomography (ERT) is used in combination with a commercial Electromagnetic Flow Meter (EMF) to measure the volumetric flow rate of each phase. A set of experiments were carried out using a mixture of sand particles and tap water as slurry. Two different sand types (coarse and medium), with a particle size range of 53-2330μm, were pumped through a 50mm inner-diameter pipeline. The range of throughput solids concentration used in the experiments was 5%-10% and operated the transport velocity was 2-5 m/s. The effect of solids concentration and solids velocity on the measurement scheme is discussed. The measurement results are compared to that of Coriolis mass flow meter and discharge flow measurement system (flow diversion system). The accuracy of the measurement results is assessed and the performance of the applicability of the proposed method is highlighted.

Rheological characteristics of inulin solution at low concentrations: Effect of temperature and solid content.

The rheological properties of inulin solution was investigated at different solid content (Xs) ranging from 1 to 12% at wide range of temperatures ranging from 10 to 85°C. The rheological parameter shear stress was measured upto a shear rate of 300s(-1) using concentric cylinders attachment by controlled stress rheometer. The investigation showed that the inulin solution behaved like Newtonian liquid and viscosity (η) was in the range 2.0998 to 3.2439mPas depending upon the concentration and temperature studied. The temperature dependency of Newtonian viscosity of inulin solution was described by Arrhenius equation (r > 0.88, p < 0.05) and activation energy (Ea) for viscous flow was in the range 2.111 to 3.013kJ/mol depending upon the solid content studied. The flow activation energy (Ea) of inulin solution was significantly (p < 0.05) affected by solid content and described by exponential type equation (r = 0.9646, rmse% = 1.07, p < 0.001). Effect of solid content on Newtonian viscosity was described by linear as well as power law models depending upon the temperature studied. The combined effect of temperature and solid content on Newtonian viscosity of inulin solution was described by power law type equation and represented as η = 0.8835* (Xs)(0.0731) *Exp(296.410/T), (r = 0.9538, p < 0.001, rmse% = 0.15) Where η is Newtonian viscosity in mPa s, Xs is solid content in % and T is temperature in Kelvin (K).

Effects of volatile solid concentration and mixing ratio on hydrogen production by co-digesting molasses wastewater and sewage sludge.

Co-digesting molasses wastewater and sewage sludge was evaluated for hydrogen production by response surface methodology (RSM). Batch experiments in accordance with various dilution ratios (40- to 5-fold) and waste mixing composition ratios (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100, on a volume basis) were conducted. Volatile solid (VS) concentration strongly affected the hydrogen production rate and yield compared with the waste mixing ratio. The specific hydrogen production rate was predicted to be optimal when the VS concentration ranged from 10 to 12 g/l at all the mixing ratios of molasses wastewater and sewage sludge. A hydrogen yield of over 50 ml H2/g VS(removed) was obtained from mixed waste of 10% sewage sludge and 10 g/l VS (about 10-fold dilution ratio). The optimal chemical oxygen demand/ total nitrogen ratio for co-digesting molasses wastewater and sewage sludge was between 250 and 300 with a hydrogen yield above 20 ml H2/g VS(removed).

Fate and transport of uranium (VI) in weathered saprolite

Batch and column experiments were conducted to investigate sorption and transport of uranium (U) in the presence of saprolite derived from interbedded shale, limestone, and sandstone sequences. Sorption kinetics were measured at two initial concentrations (C0; 1, 10 μM) and three soil:solution ratios (Rs/w; 0.005, 0.25, 2 kg/L) at pH 4.5 (pH of the saprolite). The rate of U loss from solution (μmole/L/h) increased with increasing Rs/w. Uranium sorption exhibited a fast phase with 80% sorption in the first eight hours for all C0 and Rs/w values and a slow phase during which the reaction slowly approached (pseudo)equilibrium over the next seven days. The pH-dependency of U sorption was apparent in pH sorption edges. U(VI) sorption increased over the pH range 4–6, then decreased sharply at pH > 7.5. U(VI) sorption edges were well described by a surface complexation model using calibrated parameters and the reaction network proposed by Waite et al. (1994). Sorption isotherms measured using the same Rs/w and pH values showed a solids concentration effect where U(VI) sorption capacity and affinity decreased with increasing solids concentration. This effect may have been due to either particle aggregation or competition between U(VI) and exchangeable cations for sorption sites. The surface complexation model with calibrated parameters was able to predict the general sorption behavior relatively well, but failed to reproduce solid concentration effects, implying the importance of appropriate design if batch experiments are to be utilized for dynamic systems. Transport of U(VI) through the packed column was significantly retarded. Transport simulations were conducted using the reactive transport model HydroGeoChem (HGC) v5.0 that incorporated the surface complexation reaction network used to model the batch data. Model parameters reported by Waite et al. (1994) provided a better prediction of U transport than optimized parameters derived from our sorption edges. The results presented in this study highlight the challenges in defining appropriate conditions for batch-type experiments used to extrapolate parameters for transport models, and also underline a gap in our ability to transfer batch results to transport simulations.

Production of dulce de leche: The effect of starch addition

This study evaluated the effect of addition of modified starch on the characteristics of dulce de leche, being conducted in two phases. In the initial phase, starches were evaluated for their ability to provide viscosity in model solutions representing the composition of dulce de leche during processing, thus evaluating the effect of solid concentration, which occurs during production, on the ability of starches to increase viscosity in simulated conditions of heat treatment and agitation promoted by Rapid Visco Analyser (RVA). It has been chosen 2 starches and 2 concentrations of soluble solids from the results of the initial phase, being employed as a criterion of choice starches with the highest viscosities at each solid concentration processing phase. In the second stage, 6 treatments were applied in triplicate, in which it's been determined the chemical composition, the instrumental color, texture profile and yield. Analyses were performed on crystallization of lactose during storage. According to the established conditions of the experiment, the starch configures itself as an important optional ingredient for the production of dulce de leche providing then longer shelf life without change in texture, composition, yield and sensory characteristic.

Optimization of Rougher Flotation Parameters of the Sarcheshmeh Copper Ore Using a Statistical Technique

Response surface plots showing the effect of two variables on recovery of copper (other two variables are held at center level): (a) pH and solid content and (b) pH and ratio Z11 to mercaptobenzothiazole when tap water was used in flotation tests.The performance of rougher flotation of the Sarcheshmeh copper ore was studied by a series of batch flotation tests. The D-optimal experimental design was employed to evaluate the effects of the main parameters including pH, solid content, water type, and ratio of Z11 collector to mercaptobenzothiazole on the recovery of copper into the concentrate. A response surface model was also fitted to results for the recovery of copper, which showed that the linear effects of solid percentage and ratio of collectors, the quadratic effect of pH, the interaction effect of solid concentration and pH, and the quadratic effect of water type and ratio of collectors were statistically significant. Using Design Expert software, it was shown that within the range of parameters investigated a copper recovery of 85.03% with a Cu grade of 8.28% could be obtained. The optimized values of the parameters were verified on feed samples and compared with the actual regime in the pilot plant.

Wastewater sludge as raw material for microbial oils production

Biodiesel is a promising alternative energy source as it is renewable, biodegradable, and environmental friendly. This study deals with oils production from wastewater sludge. Primary, secondary, and mixed municipal sludge and pulp and paper secondary sludge collected in Québec City, Canada has 5–11% oil content (based on weight) in initial sludge. The oil content is in the order of pulp and paper secondary sludge>municipal primary sludge>municipal mixed sludge>municipal secondary sludge. Different types of sludge were also used for lipid production by Pichia amethionina sp., Galactomyces sp., and Trichosporon oleaginosus. The results showed that maximum lipid content was obtained in municipal secondary sludge among all types. Further, the effect of initial sludge suspended solids concentration (10–30g/L) on lipid accumulation was investigated. The maximum lipid content of 30.17% and 32.42% w/w dry weight, was reached by P.amethionina sp. and Galactomyces sp., respectively, at 25g/L suspended solids concentration, and that of 37.69% w/w dry weight by T.oleaginosus at 30g/L suspended solids concentration all with municipal secondary sludge. The results showed that carbon to nitrogen ratio had more obvious effect on lower suspended solids concentration (10g/L) than on the higher one (30g/L) in lipid accumulation of the three strains.

Preparation of Stable ZrB2-SiC-B4C Aqueous Suspension for Composite Based Coating: Effect of Solid Content and Dispersant on Stability

ZrB2-SiC-B4C aqueous suspension has been prepared using poly(ethyleneimine) as a dispersant. Since increasing the solid content of suspension leads to high compaction and consequently low porosities through final coat, the effect of solid content has been studied. The dispersant and solid content were changed in the range of 0.3–1.5 wt.% and 45–55 vol.%, respectively, to assess the optimal conditions effect on stability and characteristics of suspension. Results of zeta potential measurements and rheological analysis at pH 7.8 showed that the composite suspension including 45 vol.% solid content and 1.5 wt.% dispersant was in stable state.

Influence of bubble diameter and solids concentration on bubble stability: Development of a novel analytical approach

The properties and thickness of the bubbles in the froth control the flotation process. There is no work showing how to measure bubble film composition and thickness by a straightforward manner. In this work, a novel approach, a custom-designed bubble cell associated with layer interferometry (in the UV-vis region) and FT-IR spectroscopy was used to investigate the effect of solid particle type (hydrophilic vs hydrophobic), concentration and bubble diameter on stability of a bubble blown in air. Stability was quantified by measuring bubble lifetime and hydrated film thickness. Kerosene with silicone oil as a foaming agent was used to evaluate the impact of bubble diameter (test series I). Frother solutions (MIBC, Dowfroth 250, Hexanol and F-150) were used for the solid type concentration experiments (test series II). In the first series of experiments, it was determined that as the diameter of a bubble increased from 10 to 25 mm, so did the hydrated film thickness from 350 to 1000 nm. In the second series, as the silica concentration increased (0 to 10%), an increase in bubble lifetime and hydrated film thickness was resulted (130%–250%). An impact of solid hydrophobicity was found but to a lesser degree than expected. It is possible that the small particle size (<0.1 m) of silica was responsible for this behavior. The findings are used to interpret the effect of solids in flotation froth.

Experimental investigation of coarse particles-water mixture flow in horizontal and inclined pipes

Abstract The effect of solid concentration and mixture velocity on the flow behaviour, pressure drops, and concentration distribution of coarse particle-water mixtures in horizontal, vertical, and inclined smooth stainless steel pipes of inner diameter D = 100 mm was experimentally investigated. Graded basalt pebbles were used as solid particles. The study revealed that the coarse-grained particle-water mixtures in the horizontal and inclined pipes were significantly stratified. The solid particles moved principally in a layer close to the pipe invert; however for higher and moderate flow velocities, particle saltation became the dominant mode of particle conveyance. Frictional pressure drops in the horizontal pipe were found to be markedly higher than in the vertical pipe, while the frictional pressure drops in the ascending pipe increased with inclination angle up to about 30°.

Transportation Performance of Highly Concentrated Coal-Water Slurries Prepared from Indian Coals

The rheological behaviour of concentrated coal-water slurries prepared from three different Indian coals were investigated using an Anton Paar rheometer. The perspective was laid in to study the effect of solids concentration on the rheological behaviour of coal water slurry. It was observed that coal water slurry exhibited non-Newtonian pseudoplastic fluid behaviour at concentrations above 30 % by weight. The apparent viscosity varied with the amount of coal in the slurry. The rheological data were utilized to predict the pressure drop characteristics of coal water slurry flowing through a 53 mm diameter slurry pipeline using ANSYS Fluent 14.0 computational fluid dynamics code.

Regime transition in viscous and pseudo viscous systems: A comparative study

A comprehensive quantitative study on the effect of liquid viscosity (1 ≤ µL ≤ 1149 mPa‐s) on the local flow phenomena of the gas phase in a small diameter bubble column is performed using ultrafast electron beam X‐ray tomography. The internal dynamic flow structure and the bubble size distribution shows a dual role of the liquid viscosity on the hydrodynamics. Further, the effect of solid concentration (Cs = 0.05, 0.20) on the local flow behavior of the gas phase is studied for the pseudo slurry viscosities similar to the liquid viscosities of the gas–liquid systems. The effects of liquid and pseudo slurry viscosities on flow structure, bubble size distribution, and gas phase distribution are compared. The bubble coalescence is significantly enhanced with the addition of particles as compared to the system without particles for apparently same viscosity. The superficial gas velocity at which transition from homogeneous bubbly to slug flow regime occurs is initiated by the addition of particles as compared to the particle free system for apparently same viscosity. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3079–3090, 2014

Upflow anaerobic sludge blanket-hollow centered packed bed (UASB-HCPB) reactor for thermophilic palm oil mill effluent (POME) treatment

Upflow anaerobic sludge blanket-hollow centered packed bed (UASB-HCPB) reactor was developed with the aim to minimize operational problems in the anaerobic treatment of Palm Oil Mill Effluent (POME) under thermophilic conditions. The performance of UASB-HCPB reactor on POME treatment was investigated at 55 °C. Subsequent to start-up, the performance of the UASB-HCPB reactor was evaluated in terms of i) effect of hydraulic retention time (HRT); ii) effect of organic loading rate (OLR); and iii) effect of mixed liquor volatile suspended solid (MLVSS) concentration on thermophilic POME treatment. Start-up up of the UASB-HCPB reactor was completed in 36 days, removing 88% COD and 90% BOD respectively at an OLR of 28.12 g L−1 d−1, producing biogas with 52% of methane. Results from the performance study of the UASB-HCPB reactor on thermophilic POME treatment indicated that HRT of 2 days, OLR of 27.65 g L−1 d−1 and MLVSS concentration of 14.7 g L−1 was required to remove 90% of COD and BOD, 80% of suspended solid and at the same time produce 60% of methane.

Effect of solids content and oil load on the microencapsulation process of rosemary essential oil

Microencapsulation by spray-drying is widely used in the preparation of flavors in the food industry. This study sought to evaluate the influence of oil load and wall material ratios on the properties of rosemary essential oil microencapsulated by spray-drying, using maltodextrin and modified starch as carriers. Increasing the oil load of the emulsion, the obtained particles presented higher moisture content, lower hygroscopicity and higher total oil content. The increased wall material content lengthened the wettability time. This research further suggested that the optimal wall concentration and oil load conditions are 20.9% and 29.4%, respectively. The encapsulated oil composition proved to be quite similar to pure oil. The mean particle size was 12.2μm and the analysis of the particles revealed surfaces with some depressions, however without fissures.

Effect of solids concentration on particle size distribution of deagglomerated barium titanate in stirred media mills

The effect of solids concentration on particle size distribution of a suspension of barium titanate in toluene/ethanol solvent, deagglomerated in a re-circulating stirred media mill, has been examined by experimentation. The effect on the particle size distribution curves was recorded for solids concentrations ranging from 10% to 85% by weight and for impeller tip velocities of 4m/s, 6m/s and 8m/s. Lower D50 (median) particle sizes were found at both low and high concentrations. Additionally the span of the distribution curves was found to be widest at both the lower and higher concentrations. At low concentrations high specific energies per pass of product through the grinding chamber were measured and this was as a result of high calculated stress numbers indicating high numbers of successful contact between particles and media. At high concentrations, high specific energies per pass were also measured and this was due to the increased density and viscosity of the suspension which had the effect of increasing residence time, reducing the number of passes. Thus an optimum range for solids concentration was determined which gave the narrowest spans of the particle size distribution curve, an important characteristic for deagglomeration of barium titanate for MLCC manufacture.

Solid effect in solvent extraction treatment of pre-treated oily sludge

Oil recovery from oily sludge generated from the petroleum industry has been investigated by solvent extraction using four organic solvents, cyclohexane, n-hexanol, n-butanol and kerosene. Special emphasis was placed on the effect of sludge (solid) concentration (CS) on the oil recovery efficiency (RO) and partition coefficient (KD). The KD was found to vary with CS. This phenomenon can be described as the “solid concentration effect” or “solid effect” (CS-effect). The CS-effect can be explained using the surface component activity (SCA) model that we developed previously. In this model, the activity coefficient of solid surface sites (fS) was proposed as a function of CS rather than unity because of interactions among solid particles. Based on the SCA model, we provide a CS-dependent function of partition coefficient (termed the SCA-partition coefficient function), in which the intrinsic (or thermodynamic) partition coefficient KD0 independent of CS can be simulated from extraction experimental data and can be used to characterize the extraction equilibrium. It was confirmed that the SCA-partition coefficient function could describe the CS-effect observed in our solvent extraction experiments accurately. In addition, the fS of the sludge was independent of the solvent in our tests and decreased with increasing temperature.

Impact of Irradiation Time on the Hydrolysis of Waste Activated Sludge by the Dielectric Heating of Microwave

The effects of initial solid concentration and microwave irradiation (MWI) time on the hydrolysis of waste activated sludge (WAS) were investigated. MWI time strongly influenced WAS hydrolysis for all initial solid concentrations of 8.20, 31.51, and 52.88 g VSS/L. For all WAS, the volatile suspended solids (VSS) solubilization degree ranged from 35.6% to 38.4% during a total MWI time of 10 min. Soluble chemical oxygen demand (SCOD) concentration increased at a rate proportional to the decrease of VSS during the MWI. However, the clearly different VSS solubilization patterns that were observed during the MWI were explained by the 2-step hydrolysis of WAS, consisting of the initial disintegration of the easily degradable part of the sludge, followed by the subsequent disintegration of the hardly degradable part of the sludge. WAS hydrolysis rates for 3 to 6 min of MWI were significantly lower than those for less than 3 min, or more than 6 min. From these results, 3 min MWI time and WAS of 31.51 g VSS/L (centrifugal thickener WAS) showed the most efficient hydrolysis of WAS at 36.0%. The profiles of total nitrogen (T-N) concentrations corresponded well to the SCOD increases in terms of the empirical formula of bacterial cell mass (C5H7O2N). The negligible T-N increase and pH decrease during WAS hydrolysis by MWI will allow the application of this process to subsequent biological processes, such as anaerobic digestion.