Vibratory Shear Enhanced Processing Research Articles

Evaluation of vibratory shear-enhanced processing module-integrated three-dimensional printed spacers for enhanced wastewater ultrafiltration.

The article evaluates the effectiveness of two new designed module-integrated three-dimensional (3D) printed spacers in enhancing wastewater ultrafiltration efficiencies using vibratory shear-enhanced processing (VSEP). The study investigates the star-shaped spacer filled module channel (star spacer) and the column-shaped herringbone spacer filled module channel with the same position as the flow direction (column spacer) and with the opposite position as the flow direction (rev column spacer). It compares the VSEP module-integrated spacers with membrane module vibration (module vibration) and empty membrane module channel (control) configurations. The results show that the module integration of the 3D printed spacers can greatly improve the specific, average, and constant permeate fluxes and can contribute to reducing the total, reversible and irreversible resistance values, and specific energy consumption of the ultrafiltration membrane separation experiments. Overall, this study provides valuable insights into improving the performance of wastewater ultrafiltration systems and fouling mitigation through the module integration of 3D printed spacers and membrane module vibration. PRACTITIONER POINTS: Vibratory shear-enhanced processing (VSEP) ultrafiltration module-integrated 3D printed spacers were successfully fabricated and evaluated for improved wastewater treatment. Two spacer designs, a star-shaped and a column-shaped herringbone, were compared with an empty membrane module channel with and without vibration. Two configurations of the column-shaped spacer, in the same and reversed flow direction, were tested. Specific energy consumption was calculated and compared for all configurations. Significant improvements in ultrafiltration performance were observed with the use of spacers compared with an empty module channel, including enhanced permeate fluxes and reductions in both total and reversible, as well as irreversible, resistance.

Application of Vibrating Reverse Osmosis Technology for Nutrient Recovery from Pig Slurry in a Circular Economy Model.

The rapid growth of the livestock sector in some areas of Europe has caused an imbalance between the generation of livestock manure and the availability of agricultural soil for its direct application as a fertilizer. Since the transport of pig slurry to other areas with nutrient-deficient soils is costly from an economic point of view due to its high water content, the application of new technologies for the concentration of this waste is considered key for reducing management costs. Consequently, the main objective of this study was to demonstrate the potential of vibratory shear enhanced processing (VSEP) operated with reverse osmosis membranes to recover nutrients from the liquid fractions of pig slurry (LF-pig slurry) and digestate (LF-digestate) and obtain concentrated fertilizing products. Use of the VSEP unit permitted reductions in the water contents of the LF-pig slurry and LF-digestate, around 77% and 67%, respectively. Both VSEP concentrates were characterized by their significant nutrient contents and showed a nitrogen fertilizer replacement value similar to that of mineral fertilizer as demonstrated in a barley crop pot-test, although the salinity of the digestate concentrate was identified as a key limitation, negatively impacting the agronomic yield of the test crop.

Assessment of vibration amplitude and transmembrane pressure on vibratory shear enhanced membrane filtration for treating dairy wastewater

AbstractIn this study, statistical analysis was performed to investigate the influence of operational parameters based on experimental results. The research aimed to know whether a long-term discontinuous module vibration operation is possible without adversely affecting filtration efficiency. Polymer membranes were compared by surface characteristics with contact angle measurements and selected for further membrane filtration experiments for dairy wastewater treatment. The effect of the main operational parameters, membrane module vibration amplitude (Avibr.) and transmembrane pressure (TMP), was investigated using a vibratory shear enhanced processing (VSEP) module with ultrafiltration (UF) and nanofiltration (NF) membranes. Components of the permeates, including chemical oxygen demand (COD), were measured, and membrane rejections were calculated to compare with threshold limit values. The results suggest that proper combination of Avibr. and TMP could mitigate membrane fouling. However, discontinuous module vibration resulted in more clogged membrane with lower fluxes, but slightly higher rejections. We conclude that investigating the significance of operational parameters is necessary for a wider, more energy and environment-friendly application in wastewater treatment.

Single- and multi-stage dairy wastewater treatment by vibratory membrane separation processes

Before discharge into sewage or living waters, dairy effluents need to be effectively treated to meet the requirements defined by environmental protection regulations. In addition to the commonly used technologies, membrane separation might offer a novel solution with many remarkable advantages. Although membrane fouling often limits its industrial scale application, module vibration can reduce membrane fouling. In this study, multi-stage membrane separations with ultrafiltration (UF), as pre-filtration, and nanofiltration (NF) were investigated. On the one hand, our aim was to separate the wastewater to reach the cleanest permeate possible, on the other hand to achieve the highest organic content in the smallest volume for further energetic utilization. Firstly, with one-stage separations the effects of Vibratory Shear Enhanced Processing (VSEP) on shear rate, fluxes and rejections were investigated. These tests revealed that vibration has a positive effect on fluxes and rejections. Secondly, two types of multi-stage UF/NF separation experiments were carried out and membrane fluxes, COD rejections and flux decreasing rates were examined. In type 1, permeates of nanofiltered UF permeates achieved the lowest organic load in purified wastewater to meet European environmental threshold limits for living waters. In type 2, concentrates of nanofiltered UF concentrates reached the highest possible volume reduction ratio (VRR) resulting in higher organic content in a smaller volume, which could increase the efficiency of biogas production as an alternative post-treatment for waste management.

UTEP–EPW university–utility partnership: Concentrate enhanced–recovery reverse osmosis process for high water recovery from silica‐saturated desalination concentrates

Since the 1970s, The University of Texas at El Paso and El Paso Water have had a synergistic university-utility partnership, and in 2002, we began a sequence of investigations of enhanced recovery of water from silica-saturated reverse osmosis concentrate: (a) two-pass nanofiltration (NF) and reverse osmosis (RO) treatment, (b) lime softening for silica removal, (c) vibratory shear enhanced processing (VSEP), (d) continuous-flow seawater RO treatment of brackish RO concentrate, and finally (e) high-recovery concentrate enhanced-recovery reverse osmosis (CERRO) process. Studies funded by El Paso Water, Texas Water Development Board, U.S. Bureau of Reclamation, and WateReuse Research Foundation were conducted at the Kay Bailey Hutchison (KBH) Plant in ElPaso and the Brackish Groundwater National Desalination Research Facility in Alamogordo, NM, and showed that as much as 88% of the water could be recovered from silica-saturated KBH concentrate using the CERRO process. Full-scale implementation of the CERRO process at well sites in El Paso has resulted in 70%-75% recovery of RO concentrate with a specific energy consumption of 1.23kWh/m3 (4.6kWh/kgal) and total estimated cost of approximately $0.59/m3 ($2.25/kgal). Cost-effective high-recovery desalination technologies such as CERRO are essential for drought-proof water supply in arid cities such as El Paso. PRACTITIONER POINTS: This two-decade UTEP-EPW research partnership was sustained by a long-term commitment to research and consistent financial support from EPW. Universities can collaborate to leverage utility funding toward larger external grant funding to advance research and development in a win-win partnership. The high-recovery CERRO process was developed through multiple phases of concentrate management research, which would not have been possible without long-term research commitment and risk tolerance from EPW. CERRO systems are being implemented at full scale in El Paso to recover water from silica-saturated RO concentrate at an estimated specific energy consumption of 1.23kWh/m3 (4.6kWh/kgal) and total amortized cost of $0.59/m3 ($2.25/kgal).

Treatment of Tannery Wastewater with Vibratory Shear-Enhanced Processing Membrane Filtration

The performance of a vibratory shear-enhanced process (VSEP) combined with an appropriate membrane unit for the treatment of simulated or industrial tannery wastewaters was investigated. The fundamental operational and pollution parameters were evaluated, i.e., the membrane type, the applied vibration amplitude, as well as the removal rates (%) of tannins, chemical oxygen demand (COD), Ntotal, turbidity and color. Regarding the system’s treatment efficiency, specific emphasis was given towards the removal of organics (expressed as COD values), suspended solids (SS), conductivity (as an index of dissolved solids’ presence) and total nitrogen. The removal of organic matter in terms of COD exceeded 75% for all the examined cases. The quality of treated wastewater was affected not only by the membrane specific type (i.e., the respective pore diameters), but also by the applied vibration amplitude. Furthermore, an average 50% removal rate, regarding the aforementioned parameters, was observed both for the simulated and the industrial tannery wastewaters during the microfiltration (MF) experiments. That removal rate was further increased up to 85%, when ultrafiltration (UF) was applied, and up to 99% during the Reverse Osmosis (RO) experiments, considering the maximum applied vibration amplitude (31.75 mm).

Use of vibratory shear enhanced processing to treat magnetic ion exchange concentrate: A techno-economic analysis

Disposal of waste generated by inland water treatment technologies is highly expensive. The introduction of vibratory shear enhanced processing (VSEP) to treat waste produced from magnetic ion exchange (MIEX) shows benefits in terms of performance and economics. A small VSEP unit fitted with a nanofiltration (NF) membrane is capable of treating up to 15kL of MIEX waste per day, is able remove more than 97% of dissolved organic compounds as well as recover over 80% of waste in the form of permeate. The reuse of permeate to makeup brine has seen significant reductions in salt consumption and waste disposal at Wanneroo Groundwater Treatment Plant (GWTP). During the first year of VSEP operation, salt consumption reduced by 42% and waste disposal was projected to reduce by 23.9%. Further improvements in both cost categories were observed in the second year of operation and considering the same trend is followed, the payback period of the project will occur between the 6th and 7th year of operation for discounted analysis and has a positive net present value.

Performance of a vibratory shear membrane filtration system during the treatment of magnetic ion exchange process concentrate

The performance of a vibratory shear enhanced processing (VSEP) unit used to treat waste generated from a magnetic ion exchange (MIEX) process is assessed. The unit was fitted with a NF-270 membrane (97% nominal rejection of MgSO4) with an internal membrane surface area of 37m2. The vibration amplitude of the module was set at 12.7mm. The system removes greater than 97% dissolved organic carbon as well as 70−85% multivalent solutes (Mg2+, Ca2+, SO42−) from the MIEX waste. The permeate generated was high in salt and was successfully recycled to reduce the brine requirement for MIEX resin bead regeneration. Early operation in recirculating batch mode examined the effect of volumetric recoveries (in the permeate) ranging from 75–85%. Higher recovery had no significant influence on the performance of the system. System chemical cleaning was carried out every 14–16 batches. Batch durations generally extended in each subsequent cycle prior to cleaning, with the last batches taking up to five times longer than the first batch. The installation of VSEP has resulted in a reduced frequency of waste disposal from the facility and has also reduced the amount of make-up brine required for resin regeneration by 78%.

Reverse osmosis membranes for treatment of produced water: a process analysis

AbstractThe purpose of this paper was to develop and present a process suitable for the purification of the so-called produced waters, a by-product of crude oil extraction, by devising a treatment train aimed at industrial and agricultural water reuse. If compared to municipal wastewaters, produced waters have a very high salinity that requires specific attention for designing and managing the specific treatment device. Membranes, commonly used in the production of desalted water, appear to be a suitable technique to deal with these issues. In this paper, we propose a comprehensive process scheme for produced water treatment train: A Vibratory Shear Enhanced Processing (VSEP) membrane system is in charge of the secondary treatment, whereas a reverse osmosis (RO) unit realizes the tertiary treatment. Material and energy balances are carried out on the whole process, while the RO process is simulated by the IMSDesign Software by Hydranautics. We analyzed three different scenarios, at increasing produced wat...

Economics of Ion Exchange versus Vibratory Shear Enhanced Processing for Minimization of Reverse Osmosis Concentrate Volume

AbstractAchieving a supply-demand water balance in Arizona depends on full utilization of the regional allotment of Central Arizona Project (CAP) water. The total dissolved solids (TDS) concentration at the CAP turnout to Cortaro Marana Irrigation District (CMID) in Tucson, Arizona (∼790 mg/L), is more than three times that of native groundwater. As a consequence, 200,000 t/year of salt accumulates, creating a major long-term issue. Reverse osmosis (RO) was evaluated for salt management. Pilot-scale studies indicated that scaling limits water recovery to 75–80% during conventional RO desalination of CAP water. To increase water recovery (1) ion exchange (IX) pretreatment of the RO influent and (2) posttreatment of RO brine using vibratory shear enhanced processing (VSEP) were evaluated. When scale-forming cations, barium and calcium, are removed via IX pretreatment, the expected maximum water recovery is >95% based on solubility product calculations. Alternatively, the water lost as brine can be reduced...

Hydrodynamic Techniques to Enhance Membrane Filtration

This article reviews the use of various techniques for membrane filtration, such as Dean and Taylor vortices, pulsatile flows, and dynamic filtration, which can generate high shear rates more efficiently than cross-flow filtration. In dynamic filtration, shear rates are generated not by a pump, but by moving parts or by vibrations. The most successful application of Taylor vortices has been plasma collection from donors in transfusion centers by microfiltration (MF), using small rotating cylindrical filters. Industrial dynamic filtration modules consist of metal disks with vanes or blades rotating between circular flat membranes or rotating ceramic membrane disks. These systems can be operated at high rotation speeds in order to produce very high permeate fluxes, or they can be operated at low speeds and save energy as compared with cross-flow filtration for the same flux. Vibrating modules (i.e., vibratory shear-enhanced processing) consist of a stack of circular membranes oscillating around a vertical shaft at its resonant frequency. While instabilities created by Dean vortices and pulsatile flows are mostly efficient in laminar flow and in MF and ultrafiltration, the benefits of high shear dynamic filtration are even more impressive in nanofiltration and reverse osmosis, as the reduction in concentration polarization not only increases permeate flux as compared with cross-flow filtration, but also decreases microsolute transmission.

RO brine treatment and disposal methods

More than 50 percent of countries in the world will likely face water stress or water shortages by 2025, and by 2050, as much as 75 percent of the world’s population could face water scarcity. Desalination technologies, particularly the reverse osmosis (RO) process, have increasingly been adopted to produce freshwater from alternative sources such as seawater and brackish water due to water scarcity. However, desalination applications have always been limited by the disposal costs of RO brine and the adverse impact of brine on the receiving environment. The scope of this paper is to identify technically and commercially RO brine disposal and treatment methods such as deep well injection, discharge into the sea, sanitary sewers, evaporation ponds, forward osmosis (FO), vacuum membrane distillation (VMD), vacuum-enhanced direct contact membrane distillation (VEDCMD), RO–NF Integrated system, bipolar membrane electrodialysis (BMED), electrodialysis (ED), Electrodialysis reversal (EDR), vibratory shear enhanced processing (VSEP), capacitive deionisation (CDI) and so on. In this paper, as a part of our desalination research package, to achieve profitable and environmental solutions, we assess advantages and disadvantages of mentioned methods through a comprehensive review of worldwide laboratory, pilot and industrial scale experiments.

Dairy wastewater purification by vibratory shear enhanced processing

This study investigated the performance of a Vibratory Shear Enhanced Processing (VSEP) using ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membrane system for decreasing of chemical oxygen demand (COD) from dairy wastewater. Three commercially available membranes having different pore sizes were used to compare their relative efficiency for COD decreasing. Permeate flux and membrane rejection of COD were measured as well as mean shear rates and the specific energy demands of vibrated and non-vibrated methods were calculated and compared. Furthermore, flux and COD rejection were also studied increasing by transmembrane pressure (TMP) and vibration amplitude. Concentration test were performed by UF, NF and RO.

Fate of Macronutrients in Water Treatment of Digestate Using Vibrating Reversed Osmosis

In the transition from a fossil to a bio-based economy, it has become an important challenge to maximally recuperate and recycle valuable nutrients coming from manure and digestate processing. Mem- brane filtration is a suitable technology to separate valuable nutrients in easily transportable concentrates which could potentially be re-used as green fertilizers, in the meantime producing high quality water. However, traditional membrane filtration systems often suffer technical problems in waste stream treatment. The aim of this study was to evaluate the performance of vibratory shear enhanced processing (VSEP) in the removal of macronutrients (N, P, K, Na, Ca, Mg) from the liquid fraction of digestates, reducing their concentrations down to dischargeable/ re-usable water. In addition, the re-use potential of VSEP-concentrates as sustainable substitutes for fossil-based mineral fertilizers was evaluated. Remov- al efficiencies for N and P by two VSEP filtration steps were high, though not sufficient to continuously reach the Flemish legislation criteria for discharge into surface waters (15 mg N l �1 and 2 mg P l �1 ). Additional purification can occur in a subsequent lagoon, yet further optimization of the VSEP filtration system is advised. Furthermore, concentrates pro- duced by one membrane filtration step showed potential as N-K fertilizer with an economic value of €6.3±1.1 t �1 fresh weight (FW). Further research

Effect of shear rate on fouling in a Vibratory Shear Enhanced Processing (VSEP) RO system

Membrane fouling due to formation of inorganic scales limits the application of reverse osmosis (RO) technology for desalination. This study continued our investigation of the performance of RO membranes in a Vibratory Shear Enhanced Processing (VSEP) system during the treatment of a simulated brackish water source and a brine. Increasing vibration amplitude decreased membrane fouling, increased rejection of most solutes and changed the morphology of the scales from a tightly packed layer to a more scattered distribution of particles that is easier for water to permeate. Decreasing pH reduced fouling slightly, and the presence of natural organic matter displayed no substantial effect. When all but a thin ring of the membrane surface was sealed by impermeable epoxy resin, fouling decreased as the shear rate increased. In these tests, the fouling rate was almost identical in paired tests in which the same average shear rate was achieved by different combinations of ring radius and vibration amplitude. The shear rate appears to control fouling by determining the structure of the scale deposit that forms early in a filtration run.

Investigation of vibratory shear-enhanced processing system

In this study the performance of a vibratory shear-enhanced processing system (VSEP) for the concentration of cheese whey was assessed and compared with a classical, cross-flow, plate and frame membrane configuration system (3DTA) with the same membrane (i.e. a C30F UF regenerated cellulose UF membrane with a 30 kDa molecular weight cutoff). The temperature and pressure dependences of the permeate flux, the permeate flux reduction ratio, the resistances and the rejection values were investigated. Comparison of the two systems revealed a definite advantage for the VSEP system equipped with the same membrane and operated at the same pressure and temperature. The VSEP system yielded a permeate protein retention of 99.7% vs. 74.5% for the 3DTA system, together with a higher average flux: 54 L m −2 h −1 vs. 44.2 L m −2 h −1 . The flux reduction ratio ( J/J0 ) was 0.60 vs. 0.42, and the total resistances 2.87*10 +13 m −1 vs. 4.54*10 +13 m −1 for the VSEP and 3DTA system, respectively.

Comparison of 3DTA and VSEP systems during the ultrafiltration of sweet whey

Whey, a side-product of the cheese-making and casein industry, is a nutritious protein source. The nutritional, biological and functional properties of whey proteins make them attractive and explain why an active whey industry has been developing over the last 30 years. The preconcentration of whey at its production site is the major field of application of membrane separation. The high salt content of whey (8–20% dry matter) gives rise to numerous processing difficulties, a low lactose crystallization rate, and fouling in microfiltration (MF) and ultrafiltration (UF) performed to produce whey protein concentrates. In order to improve UF performance, it is advisable to limit fouling of the membranes by selecting an appropriate flux or shear stress ratio [1]. In this study, the performance of a vibratory shear-enhanced processing system (VSEP) for the concentration of cheese whey was assessed and compared with a classical, cross-flow, plate and frame membrane configuration system (3DTA) with the same membr...

Removal of non-biodegradable compounds from stabilized leachate using VSEPRO membrane filtration

In this paper, the technical applicability of the vibratory shear-enhanced processing reverse osmosis (VSEPRO) membrane system for the treatment of stabilized leachate from the NENT landfill in Hong Kong was studied using both 99 and 96% NaCl rejection membranes. The performance of VSEPRO for NH 3-N and COD removal was evaluated and compared to the performances of other individual and/or combined treatments from other studies. Without any pH adjustment, it was found that the rejection rates of VSEPRO were 96% for COD and 98% for NH 3-N with initial COD and/or NH 3-N concentrations of 8000 and 2620 mg/L, respectively. It was evident that pH adjustment of raw leachate to acidic conditions (pH 6.0) slightly improved the rejection rates for COD (97%) and NH 3-N (99.6%). These results were satisfactory compared to other physicochemical treatments. It is important to note that the treatment of leachate using VSEPRO was able to meet the local effluent limit for COD of lower than 200 mg/L and for NH 3-N of less than 5 mg/L. This result suggests that VSEPRO is technically applicable and appealing for the treatment of stabilized leachate.

An hydrodynamic investigation of microfiltration and ultrafiltration in a vibrating membrane module

The performance of a vibratory shear-enhanced processing (VSEP) vibrating laboratory module was investigated in microfiltration (MF) of yeast suspensions and in ultrafiltration (UF) of bovine albumin solutions. The membrane displacement ( d) was measured as a function of radius and vibration frequency with an accelerometer and its maximum amplitude was found to be 30 mm at the resonant frequency of 60.75 Hz. The shear rate at the membrane γ w was calculated as a function of frequency, displacement and fluid viscosity in the limit of large Reynolds numbers. When the frequency is lowered, d drops rapidly to 5.7 mm at 59 Hz (81%), while the permeate flux dropped by 46% in the case of yeast MF and by 48% in the case of albumin UF. The variation of permeate flux with shear rate was investigated by varying the frequency. In the case of yeast MF the permeate flux was found to be proportional to γ w 0.19 at a frequency below 59.7 Hz and to γ w 0.50 at higher frequency. In UF of albumin, the permeate flux was proportional to γ w 0.426 at all frequencies. The radial distribution of permeate flux was determined in the case of yeast MF using modified annular membranes. The local flux was found to be constant when the radius r was less than 7.5 cm and increased as r 2.4 at larger radii. In concentration tests the device was able to reach a yeast concentration of 330 g l −1. In UF of albumin, the permeate flux varied linearly with the logarithm of concentration, predicting a gel concentration of 300 g l −1 in accordance with the literature.