Solid-liquid Separation Method Research Articles

Optimized Solid–Liquid Separation of Phenolics from Lavender Waste and Properties of the Dried Extracts

Lavender distillation produces huge quantities of solid waste yearly. This waste is usually discarded, resulting in serious environmental issues. However, it still contains residual essential oil and other bioactive compounds. This research reports on the development and comparison of optimized solid–liquid separation methods, i.e., microwave- (MAE) and ultrasound-assisted extraction (UAE) of phenolic compounds from lavender distillation waste. The optimal pretreatment conditions, such as waste moisture content and particle size, were also determined. The extracts were spray- or freeze-dried and the resulting powders were characterized for their physicochemical properties. The majority of the original phenolic compounds in lavender were found in the leachate fraction after distillation (61%), whereas 43% was found in the solid waste. Drying of the solid waste before extraction affected the process efficiency. UAE led to a higher phenolic content and greater antioxidant properties compared to MAE. Drying (spray or freeze) the extracts did not significantly affect their phenolic content, whereas the use of maltodextrin as a drying agent improved the drying process yield, especially when using the freeze-drying method. It is concluded that valorization of lavender distillation wastes can be achieved via an integrated process consisting of a green extraction method and a consequent drying process that results in a stable bioactive powder.

Different manure management methods impact on nitrogen use efficiency - comparison of four dairy farms in Hokkaido Japan

Different manure management methods impact on nitrogen use efficiency - comparison of four dairy farms in Hokkaido Japan

Fabrication of polycaprolactone/heparinized nano fluorohydroxyapatite scaffold for bone tissue engineering uses

In this study, some polycaprolactone (PCL)/heparinized nano fluorohydroxyapatite (H-nFHA) scaffolds were fabricated with different amounts of H-nFHA using solid-liquid phase separation and freeze-drying methods. The scaffolds were characterized using Fourier transform infrared spectroscopy, x-ray diffraction, scanning electron microscopy techniques, and compressive test. Their biological behavior also was studied using Alkaline phosphatase activity and MTT assay. The results showed that adding H-nFHA to the PCL matrix improves MG-63 cells adhesion and proliferation and they also showed that heparinizing the nFHA particles improves the mechanical properties and dispersion of the nFHA particles in the PCL matrix for bone tissue engineering uses.

Polyethyleneimine/polydopamine-functionalized self-floating microspheres for caramel adsorption: Interactions and phenomenological mass transfer kinetics

A polyethyleneimine/polydopamine-functionalized self-floating microsphere (EHGM/PDA/PEI) bears an etched hollow glass microsphere as a support, polydopamine as an interfacial cross-linking “glue”, and polyethyleneimine as a functional monomer was fabricated and used as a decolorization sorbent for sugarcane juice. The advantages of EHGM/PDA/PEI for sugarcane juice decolorization were attributed to its richness of target polyethyleneimine monomers, well-connected and abundant three-dimensional network-like aperture structure, and nontoxicity. Moreover, EHGM/PDA/PEI has excellent self-floating performance to allow separation from the adsorption system after decolorization and may have a faster separation speed and lower energy consumption than conventional solid–liquid separation methods. Synthetic caramels were used as model colorants of sugarcane juice to assess EHGM/PDA/PEI performance. The adsorption capacity of EHGM/PDA/PEI for caramels was 18.36 mg/g with a removal efficiency of 91.80% in the adsorption equilibrium state. The interaction mechanisms revealed that the caramel adsorption on EHGM/PDA/PEI was mostly mediated by protonated amine groups, followed by electron sharing. Two layers of caramels adhered onto EHGM/PDA/PEI were mainly mediated by electrovalent bonds between carboxylate and protonated amine. On average, one caramel molecule can be shared by 3–4 protonated amine groups of EHGM/PDA/PEI, which suggests a parallel sorption orientation. Four phenomenological mass transfer models [external diffusion resistance (EXTDR), internal diffusion resistance (INTDR), EXTDR–INTDR mixed, and adsorption onto active sites (AOAS)] proposed new and unique insights into the dynamic properties of the adsorption process.

Extraction Behavior of Some Elements from Leaching Solution of Simulated Nuclear Fuel

The crush-leach process was investigated as a method to treat GEN IV simulated ceramic-coated reactor fuel. Simulated ceramic-coated fuel was prepared using fine carbon as a coating and surrogate elements for fuel, the method retained the bulk of the carbon components in elemental form, which is favorable for achieving waste reduction goals. Simulated ceramic-coated fuel was crushed and nitric acid was added to the fines as slurry that led to rapid and effective leaching of the heavy metal. The leaching process of simulated crushed ceramic-coated fuel and extraction behavior of the separated leaching solution was tested at the laboratory scale. Results showed that carbon used in the preparation of stimulated fuel was difficult to be separated by filtered, indicating the need to carefully control particle size and/or use alternative solid-liquid separation methods. Foams or emulsions was not observed during the solvent extraction step, which indicated that measurement of the distribution ratios for actinides elements were slightly larger than predicted by previous models. This increase may be due to small concentrations of organics; however the experimental results are not conclusive. Although the results do not strongly indicate effects by a contaminating organic agent, the organic species may exist in small concentrations. Such an organic species could affect the extraction behavior of the solvent if it accumulates over time.

A rigid body dynamics model to predict the combined effects of particle size and shape on pressure filtration

• Developed a novel computational workflow for simulating pressure filtration. • Rigid body dynamics used to simulate cake formation with various particle shapes. • A “local” Ergun equation developed to capture spatial variations in cake structure. • Platelet-shaped particles predicted to generate low porosity and poor filterability. • Large and small particle mixtures predicted to generate spatial heterogeneities. Many theoretical studies have focused on the effects of spherical particle size on pressure filtration, a solid-liquid separation method commonly used in pharmaceutical manufacturing and other industries. While experimental studies have demonstrated the importance of particle shape as well as size on the filterability of non-spherical particles commonly produced from pharmaceutical crystallization, process models that mechanistically capture how particle morphology affects the microscopic properties of the particle cake are lacking. The objective of this study was to investigate the combined effects of particle shape and size on pressure filtration performance using rigid body dynamics simulation, a powerful method for predicting porous cake structure based on the properties of the constituent particles. Once a detailed cake structure was generated, the Ergun equation was used to predict the macroscopic flow behavior of the filtration process. This workflow was validated by comparing model predictions with filtrate flow measurements from a series of dead-end filtration experiments using spherical particles with heterogeneous size. By simulating cylindrical particles over a wide range of aspect ratios, we showed that particle shape can have a dramatic effect on cake porosity and filtrate flow with disk-shaped particles predicted to be particularly difficult to filter. Rigid body simulation allowed the prediction of local as well as average cake properties. We predicted that heterogeneously sized particles with small or large aspect ratios such as disks or needles could produce highly asymmetric cake structures characterized by densely packed and low porosities near the filter medium. A modified Ergun equation based on local particle size and porosity was developed and shown to predict substantially different filtrate flows than the standard Ergun equation based on spatially-averaged properties, especially for cylindrical particles with high aspect ratio.

Simulation of particles screening in pulsating negative pressure shale shaker by coupling CFD and DEM

PurposeThe purpose of this paper is to obtain the combination of working parameters suitable for pulsating negative pressure shale shaker through simulation, which is conducive to efficient recovery of clean drilling fluid and relatively dry cuttings.Design/methodology/approachShale shaker is still one of the main equipment in solid–solid and solid–liquid separation processes in drilling industry. This research is based on a new drilling fluids circulation treatment device, namely pulsating negative pressure shale shaker. In this work, a numerical study of particle flow and separation in the pulsating negative pressure shale shaker is carried out by coupling computational fluid dynamics/discrete element method (CFD-DEM). The effect of vibration parameters and negative pressure parameters are studied in terms of conveyance velocity and percent through screen.FindingsThe results show that, conveyance velocity of particle is mainly affected by vibration parameters, negative pressure in pulsating form can effectively prevent cuttings from sticking to the screen. Vibration parameters and pulsating airflow velocity peak have great influence on percent through screen, while vibration frequency and screen slope have influence on the time when the percent through screen reaches stability.Originality/valueIn this paper, the authors put forward a new kind of drilling waste fluid treatment equipment, and focused on the study of particle movement law. The results have important guiding significance for the selection of structural design parameters and rational use of equipment. In addition, the new device provides a new idea for solid–liquid separation method, which is one of the hot topics in current research.

Intensification of solid–liquid separation by thermal sedimentation in pressure oxidative leaching process of chromite

In the leaching process of chromite, how to quickly separate sodium chromate from leaching slurry is a key issue. In this paper, a simple method, named thermal sedimentation, was firstly introduced into the solid–liquid separation of sodium chromate. The results shown that the thermal sedimentation can respectively shorten the separation time (h) by 71.9% and 53.9% when compared to dilution filtration and centrifugation separation. In terms of processing unit volume of leaching slurry, the power consumption of thermal sedimentation was 6.48 × 103 J, which was the lowest in the investigated separation methods. Meanwhile, the alkali solution after the separation of thermal sedimentation can be directly reused. When sedimentation temperature was 150 °C, sedimentation efficiency was higher. In addition, the relationship between slurry viscosity and sedimentation velocity was consistent with Coe-Clevenger method and Stokes formula. The thermal sedimentation can be regarded as an effective solid–liquid separation method for liquid phase oxidative leaching system of chromite.

Study on Control of pH-Modulation Crystallization Utilizing Concept of Dissociation Equilibrium.

Crystallization by pH adjustment, as a type of reaction crystallization, is a solid-liquid separation method widely used in the area of pharmaceutical and pharmaceutical intermediate manufacturing. On the other hand, 3-alkenyl cephem compound is a typical zwitterionic pharmaceutical intermediate that possesses both an amino group and a carboxylic acid group. Such structure affords three main pH regions in solution and results in difficulties using crystallization by pH adjustment for isolation. As a consequence, 3-alkenyl cephem compound is usually crystallized at the point away from the solubility curve, causing unrestricted nucleation and flocculation behavior for the deposited particles which is difficult to filtrate. In this study, the pKa of 3-alkenyl cephem compound was intensively investigated to inhibit the nucleation. An optimal pH level point was also sought to make monodisperse particles. In particular, during crystallization by pH-modulation operation, the key point was identified to be the number of primary particles aggregated in the secondary particles. It was revealed that the increment number of primary particles led to the generation of larger monodisperse particles. This investigation, combined with solid-liquid equilibrium, enabled the acquisition of target species with good operability for filtration process. This present investigation becomes the prosperity in the zwitterion compound production that it has hardships to crystallize and filtrate.

Innovative composite material for efficient and highly selective Pb(II) ion capturing from wastewater

In the present study, highly porous composite material (PCM) was fabricated by novel ligand immobilization onto the silica monolith for Pb(II) ion detection and adsorption from wastewater by the solid-liquid separation method. The material was systematically characterized to know the material morphology and functional group. In addition, the Pb(II) capturing performance of PCM toward Pb(II) in aqueous media was explored. The PCM was enhanced the color upon addition of different concentration Pb(II) ion. The low-level limit detection was determined, and the value was 0.33 μg/L, which was lower than the permissible limit of Pb(II) ion in water. Factors affecting the adsorption of Pb(II) ion such as solution acidity, reaction time, initial Pb(II) concentration, competing ion and regeneration were investigated systematically in batch mode by the PCM. The solution pH was played the key role both in the detection and adsorption of Pb(II) ion. The pH dependent was exhibited due to the complexation bonding ability. The kinetic performance was rapid as the Pb(II) ion adsorption was equilibrated within short time, and this was confirmed the chemisorption process. The adsorption isotherm of Pb(II) onto PCM was well fitted to the Langmuir isotherm models as expected from the material homogeneity. In addition, the maximum monolayer adsorption capacity was 204.34 mg/g. The competing ions were not affected the Pb(II) detection or adsorption, and this were evident to the high selectivity toward the Pb(II) ion at the optimum condition. The adsorbed Pb(II) from PCM was desorbed with 0.15 M HCl and then simultaneously regenerated for next Pb(II) capturing process. Therefore, the proposed PCM can be considered as a potential material for Pb(II) ion detection and adsorption from the wastewater sample.

Non-chromatographic purification of Teriparatide with a pH-responsive CspB tag

Cell surface protein B (CspB) from Corynebacterium glutamicum is used as a pH-responsive peptide tag to enable a simple solid–liquid separation method for isolating a CspB fusion protein. Here we demonstrate the first application of a CspB tag for the purification of Teriparatide, which is a biologic drug that is prescribed for osteoporosis. The Teriparatide was constructed as CspB50TEV-Teriparatide, comprising 50 amino acid residues of CspB, the cleavage site of TEV protease, and Teriparatide. CspB50TEV-Teriparatide was expressed in a culture supernatant by C. glutamicum secretion system at 3.0 g/L (equivalent to approximately 1.2 g/L Teriparatide). The CspB50TEV-Teriparatide was precipitated by reducing the pH of the culture supernatant, and the precipitate was then dissolved in a neutral buffer. A TEV protease treatment was applied to cleave the Teriparatide from the CspB50TEV-Teriparatide. Then, the remaining digested CspB50TEV, undigested CspB50TEV-Teriparatide, and TEV protease were precipitated in an acidic pH, whereas the soluble Teriparatide remained in the supernatant. The process had a yield of 96.5% and resulted in Teriparatide with a purity of 98.0% and productivity of 1.1 g/L of C. glutamicum culture. Thus, tag-free Teriparatide was successfully purified from the CspB fusion protein using only pH changes, centrifugation, and protease digestion without the need for chromatography. This versatile purification protocol is expected to be applicable to various proteins from laboratory to industrial scales.

Studies on a new solid–liquid Cs separation using the ionic liquid extraction system in comparison with the conventional adsorption

The process characteristics of a new solid–liquid Cs+ separation from the radioactive liquid waste using a crown ether dicyclohexano-18-crown-6 as an extractant and an ionic liquid of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were studied. The physicochemical properties of the precipitate containing Cs+ which is an solid–liquid extraction product were investigated to identify the solid–liquid phase separability and Cs+ loading. The Cs+ separation process performances were compared experimentally with those of the conventional adsorption system for pretreatment requirement and the amount of Cs+ waste. It was observed that the solid–liquid separation method using ILs has high Cs+ separation performance especially in the low Cs+ concentration.

Comparison of nutrient solubilisation and dewatering by freeze/thaw processing of sludge from Biological Nutrient Removal (BNR) and Non-BNR wastewater treatment plants.

Natural freeze/thaw processing is a simple, practical and low-cost solid-liquid separation method, which can effectively dewater wastewater sludge in Northern Canadian communities located in cold climate conditions. This method is especially effective when used in small treatment plants in remote and cold regions as typical dewatering methods require complex and expensive equipment, skilled operators and special maintenance. The objective of this research was to evaluate freeze/thaw processing as a method for dewatering, nutrient solubilisation and organics separation of wastewater sludge originating from two different wastewater treatment facilities: a Biological Nutrient Removal (BNR) plant and non-BNR plant. The results of experiments showed the effectiveness of this method for sludge dewatering and solubilisation of organics and nutrients. The sludge solid content increased approximately 10-fold after freeze/thaw processing. The treatment solubilised 15.2%, 33.5% and 21.5% of the initial total nitrogen, total phosphorus and total chemical oxygen demand, respectively for the non-BNR sludge. These values were 6.3%, 80.0% and 16.5%, respectively for the BNR sludge. The released phosphorus and nitrogen in the water can be recovered and used as fertilizer for agricultural purposes, supporting northern food production.

Influence of solid-liquid separation method parameters employed in soil leaching tests on apparent metal concentration

Soil leaching tests are commonly used to evaluate the leachability of hazardous materials, such as heavy metals, from the soil. Batch leaching tests often enhance soil colloidal mobility and may require solid-liquid separation procedures to remove excess soil particles. However, batch leaching test results depend on particles that can pass through a 0.45μm membrane filter and are influenced by test parameters such as centrifugal intensity and filtration volume per filter. To evaluate these parameters, we conducted batch leaching experiments using metal-contaminated soils and focused on the centrifugal intensity and filtration volume per filter used in solid-liquid separation methods currently employed in standard leaching tests. Our experiments showed that both centrifugal intensity and filtration volume per filter affected the reproducibility of batch leaching tests for some soil types. The results demonstrated that metal concentrations in the filtrates significantly differed according to the centrifugal intensity when it was 3000 g for 2h or less. Increased filtration volume per filter led to significant decreases in filtrate metal concentrations when filter cakes formed during filtration. Comparison of the filtration tests using 0.10 and 0.45μm membrane filters showed statistically significant differences in turbidity and metal concentration. These findings suggest that colloidal particles were not adequately removed from the extract and contributed substantially to the apparent metal concentrations in the leaching test of soil containing colloidal metals.

Mechanical performance of Nano‐Al2O3‐modified composites at cryogenic and room temperatures

Mechanical properties of fiber‐reinforced plastic composites at room temperature can be enhanced by adding nanoparticles. However, the damage mechanisms of nanocomposites at low temperatures are still not understood. In this article, different contents of nano‐Al2O3 particles were added on fiber surface by solid–liquid separation method, and vacuum‐assisted resin injection was adopted to manufacture composites laminates. A comparative study on the mechanical behavior of nano‐Al2O3‐filled composite at room and low temperatures was presented. Effect of nano‐Al2O3 particle contents (0, 0.5, 1, and 2 wt%) on the mechanical properties of glass fiber‐reinforced vinyl ester resin (GF/vinyl ester) composite laminates at different temperatures was investigated. The damage mechanism of these composite laminates in various environments was studied. The results showed that to a certain extent, nanoparticles could improve the mechanical properties of composites at 25 and −60°C. With assistance of scanning electron microscope (SEM) observation, the damage mechanisms of the composite laminates in various temperature conditions were further analyzed. POLYM. COMPOS., 39:3006–3012, 2018. © 2017 Society of Plastics Engineers

Tissue Reaction to a Novel Bone Substitute Material Fabricated With Biodegradable Polymer-Calcium Phosphate Nanoparticle Composite.

The aim of this study was to evaluate the effectiveness of a novel bone substitute material fabricated using a biodegradable polymer-calcium phosphate nanoparticle composite. Porous structured poly-L-lactic acid (PLLA) and hydroxyapatite (HA) nanoparticle composite, which was fabricated using solid-liquid phase separation and freeze-drying methods, was grafted into bone defects created in rat calvarium or tibia. Rats were killed 4 weeks after surgery, and histological analyses were performed to evaluate new bone formation. Scanning electron microscopic observation showed the interconnecting pores within the material and the pore diameter was approximately 100 to 300 μm. HA nanoparticles were observed to be embedded into the PLLA beams. In the calvarial implantation model, abundant blood vessels and fibroblastic cells were observed penetrating into pores, and in the tibia model, newly formed bone was present around and within the composite. The PLLA-HA nanoparticle composite bone substitute developed in this study showed biocompatibility, elasticity, and operability and thus has potential as a novel bone substitute.

Characterization of Tensile Mechanical Behavior of MSCs/PLCL Hybrid Layered Sheet.

A layered construct was developed by combining a porous polymer sheet and a cell sheet as a tissue engineered vascular patch. The primary objective of this study is to investigate the influence of mesenchymal stem cells (MSCs) sheet on the tensile mechanical properties of porous poly-(l-lactide-co-ε-caprolactone) (PLCL) sheet. The porous PLCL sheet was fabricated by the solid-liquid phase separation method and the following freeze-drying method. The MSCs sheet, prepared by the temperature-responsive dish, was then layered on the top of the PLCL sheet and cultured for 2 weeks. During the in vitro study, cellular properties such as cell infiltration, spreading and proliferation were evaluated. Tensile test of the layered construct was performed periodically to characterize the tensile mechanical behavior. The tensile properties were then correlated with the cellular properties to understand the effect of MSCs sheet on the variation of the mechanical behavior during the in vitro study. It was found that MSCs from the cell sheet were able to migrate into the PLCL sheet and actively proliferated into the porous structure then formed a new layer of MSCs on the opposite surface of the PLCL sheet. Mechanical evaluation revealed that the PLCL sheet with MSCs showed enhancement of tensile strength and strain energy density at the first week of culture which is characterized as the effect of MSCs proliferation and its infiltration into the porous structure of the PLCL sheet. New technique was presented to develop tissue engineered patch by combining MSCs sheet and porous PLCL sheet, and it is expected that the layered patch may prolong biomechanical stability when implanted in vivo.

A review on sludge dewatering indices.

Dewatering of sludge from sewage treatment plants is proving to be a significant challenge due to the large amounts of residual sludges generated annually. In recent years, research and development have focused on improving the dewatering process in order to reduce subsequent costs of sludge management and transport. To achieve this goal, it is necessary to establish reliable indices that reflect the efficiency of sludge dewatering. However, the evaluation of sludge dewaterability is not an easy task due to the highly complex nature of sewage sludge and variations in solid-liquid separation methods. Most traditional dewatering indices fail to predict the maximum cake solids content achievable during full-scale dewatering. This paper reviews the difficulties in assessing sludge dewatering performance, and the main techniques used to evaluate dewatering performance are compared and discussed in detail. Finally, the paper suggests a new dewatering index, namely the modified centrifugal index, which is demonstrated to be an appropriate indicator for estimating the final cake solids content as well as simulating the prototype dewatering process.

Optimization of physicochemical process for pre-treatment of fine suspension by flocculation prior to dewatering

In the design of process reactors, it is often necessary to tailor the separation technique to the dynamics and characteristics of the working slurry. This study reports the results of physicochemical optimization tests conducted on a model system prior to its pre-treatment in a Taylor-Couette device. The assessment of the flocculation performance was carried out on the basis of surrogate indicators such as sludge volume index ISV and supernatant turbidity; which were chosen on the strength of a preliminary investigation and the particular solid–liquid separation method employed in this study. The results of this investigation showed that the lowest sludge volume index ISV of 4.2 and residual turbidity of 7.27 NTU were obtained at the optimum polymer dose of 2 kg/t TS in single conditioning and 4 kg/t in dual additions. Theoretical charge neutralization of 48.4, 37.8, and 49.1% for the single conditioning and 32.1, 25.1, and 32.6% for the dual additions were recorded at the optimum conditions. The optimum dosage values confirmed polymer bridging as the primary flocculation mechanism. The analysis provides information on the slurry polymer dose response and will serve as a guide for polymer selection and subsequent performance optimization of the pre-treatment devices under development.

Solid–liquid separation method governs the in vitro bioaccessibility of metals in contaminated soil-like test materials

An in vitro gastrointestinal model was used to explore the role of solid–liquid separation method on the bioaccessibility of trace elements in a smelter-impacted soil (NIST-2711) from Helena, MT and a mine overburden from an open-pit gold and silver mine in Mount Nansen, YK (YK-OVB). Separation methods studied included centrifugation (5000g, 12000g), syringe microfiltration (0.45μm), and ultrafiltration (1000kDa, 50kDa, 30kDa, 10kDa, 3kDa). Results indicated that the use of syringe microfiltration generally yields the same bioaccessibility as the use of centrifugation and that the speed of centrifugation does not typically affect metal bioaccessibility. However, ultrafiltration consistently yields a significantly lower bioaccessibility than the use of centrifugation and syringe microfiltration. There are rarely any differences between bioaccessibility estimates generated using a low-resistance (1000kDa) and a high-resistance (3kDa) ultrafiltration membrane; therefore, under the in vitro gastrointestinal conditions modeled herein, negligible quantities of trace elements are complexed to small molecules between 3 and 1000kDa. The primary exceptions to these trends were observed for Pb in NIST-2711 (5000g>12000g>0.45μm>ultrafiltration) and for Tl in NIST-2711 and YK-OVB (5000g∼12000g>0.45μm>ultrafiltration). These results provide valuable information to researchers attempting to expand the use of in vitro bioaccessibility beyond soil Pb and As.