scholarly journals Optimisation of the nanofiltration process of residual wastewater from table olives using synthetic solutions for the recovery of phenolic compounds

2021 ◽  
Author(s):  
Karem Y. Cazares-Carrión ◽  
Reinier Abreu-Naranjo
Keyword(s):  
Organic Material ◽  
Cross Flow ◽  
Oxygen Demand ◽  
Transmembrane Pressure ◽  
Table Olives ◽  
Total Polyphenol ◽  
Synthetic Solution ◽  
Cross Flow Velocity ◽  
Central Composite ◽  
Elaboration Process

Abstract Synthetic solution of ultrafiltration permeate from brine wastewater from the elaboration process of table olives was used to investigate the simulation and optimisation of the nanofiltration process with the aim of reducing the contents of salt and organic material, as well as maintaining the major phenolic content in the permeate of nanofiltration as a contribution to their possible recovery. The synthetic solution was elaborated by considering the main characteristics of the ultrafiltration permeate of residual brine from table olive fermentation. A response surface methodology – central composite design (RSM-CCD) was used. The efficiency of conductivity (Ec), total polyphenol content (TPC) and chemical oxygen demand rejections (RTPC and RCOD) were the response variables selected. Transmembrane pressure (TMP), cross-flow velocity (CFV) and nanomembrane type (NF270 and NF245) were the independent variables. The range for RTPC was from 0.59 to 3.34%, while the values for Ec were higher than the NF270 membrane, being between 13.63 and 24.13%. The RSM-CCD results indicate that the optimum that satisfies the objectives of the research were: nanomembrane (NF245), TMP (14.43 bar) and CFV (1.50 m/s). This allowed the permeate to keep 97.39% of polyphenol contents and reduce organic material and salts by 52 and 23%, respectively.

scholarly journals Operating Conditions Optimization via the Taguchi Method to Remove Colloidal Substances from Recycled Paper and Cardboard Production Wastewater

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 170 ◽  
Author(s):  
Mayko Rannany S. Sousa ◽  
Jaime Lora-García ◽  
María-Fernanda López-Pérez ◽  
Asunción Santafé-Moros ◽  
José M. Gozálvez-Zafrilla
Keyword(s):  
Taguchi Method ◽  
Flow Velocity ◽  
Cross Flow ◽  
Rejection Rate ◽  
Transmembrane Pressure ◽  
Optimal Conditions ◽  
Permeate Flux ◽  
Utility Concept ◽  
Cross Flow Velocity ◽  
Response Variables

Optimization of the ultrafiltration (UF) process to remove colloidal substances from a paper mill’s treated effluent was investigated in this study. The effects of four operating parameters in a UF system (transmembrane pressure (TMP), cross-flow velocity (CFV), temperature and molecular weight cut-off (MWCO)) on the average permeate flux (Jv), organic matter chemical oxygen demand (COD) rejection rate and the cumulative flux decline (SFD), was investigated by robust experimental design using the Taguchi method. Analysis of variance (ANOVA) for an L9 orthogonal array were used to determine the significance of the individual factors, that is to say, to determine which factor has more and which less influence over the UF response variables. Analysis of the percentage contribution (P%) indicated that the TMP and MWCO have the greatest contribution to the average permeate flux and SFD. In the case of the COD rejection rate, the results showed that MWCO has the highest contribution followed by CFV. The Taguchi method and the utility concept were employed to optimize the multiple response variables. The optimal conditions were found to be 2.0 bar of transmembrane pressure, 1.041 m/s of the cross-flow velocity, 15 °C of the temperature, and 100 kDa MWCO. The validation experiments under the optimal conditions achieved Jv, COD rejection rate and SFD results of 81.15 L·m−2·h−1, 43.90% and 6.01, respectively. Additionally, SST and turbidity decreased by about 99% and 99.5%, respectively, and reduction in particle size from around 458–1281 nm to 12.71–24.36 nm was achieved. The field-emission scanning electron microscopy images under optimal conditions showed that membrane fouling takes place at the highest rate in the first 30 min of UF. The results demonstrate the validity of the approach of using the Taguchi method and utility concept to obtain the optimal membrane conditions for the wastewater treatment using a reduced number of experiments.

Performance of airlift MBR for on-site treatment of slaughterhouse wastewater in urban areas of Vietnam

2016 ◽  
Vol 74 (9) ◽  
pp. 2245-2251 ◽  
Author(s):  
Anh Tien Do ◽  
Dung Quang Bach ◽  
Uan Khac Do ◽  
Ana Prieto ◽  
Huynh Thi Lan Huong
Keyword(s):  
Surface Waters ◽  
Urban Areas ◽  
Membrane Bioreactor ◽  
Cross Flow ◽  
Oxygen Demand ◽  
Cost Effective ◽  
Air Flow Rate ◽  
Slaughterhouse Wastewater ◽  
Membrane Flux ◽  
Cross Flow Velocity

In many cities in Vietnam, wastewater generated in slaughterhouses is normally discharged directly into surface waters without treatment. Management of slaughterhouse wastewater (SHWW) is difficult due to the lack of infrastructure for conveyance to centralized facilities. On-site treatment presents one cost-effective way of managing SHWW compared to mass improvement of infrastructure. This study evaluates the application of an airlift membrane bioreactor (AL-MBR) for on-site treatment of SHWW. The concentrations of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total nitrogen (TN) and NH4+-N in the simulated SHWW were 1,697 ± 317 mg/L, 891 ± 137 mg/L, 246 ± 65 mg/L and 171 ± 4.2 mg/L, respectively. The mixed-liquor volatile suspended solids in the aerobic and anoxic tanks were maintained at 5,000–6,000 mg/L. Air flow rate and cross flow velocity were maintained at 0.2 L/min and 0.8 m/s, respectively, to keep the trans-membrane pressure (TMP) stable at 0.8 bar and the membrane flux at 15–18 L/m2 h bar (LMH/bar). The removal efficiencies of COD and TN were 95 ± 1.9% and 70 ± 3.3%, respectively, at a hydraulic retention time (HRT) of 2.5 days. This study shows that GL-MBR is a promising on-site solution for SHWW treatment.

scholarly journals Fouling Behaviour During Cross Flow Ultrafiltration of Cassava Starch Hydrolysate Using Polyacrylonitrile Membrane

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
I. N. Widiasa ◽  
I. G. Wenten
Keyword(s):  
Flow Velocity ◽  
Cross Flow ◽  
Cassava Starch ◽  
Alkaline Condition ◽  
Transmembrane Pressure ◽  
Permeate Flux ◽  
Promising Alternative ◽  
Glucose Syrup ◽  
Cross Flow Velocity ◽  
Starch Hydrolysate

Ultrafiltration (UF) is considered as a promising alternative to the traditional clarification techniques in the sugar industries. In this work, a hollow fiber UF membrane (polyacrylonitrile, MWCO 100 kDa) was used for clarification of cassava starch hydrolysate. The influence of various operating parameters, such as transmembrane pressure (TMP), cross flow velocity and pH hydrolysate on the membrane fouling was assessed. The results showed that TMP higher than 1.0 bar was not effective to improve flux. Increasing cross flow velocity was virtually effective to reduce permeate flux decline. The steady state flux, Jssincreased significantly when pH of the feed was adjusted to alkaline condition; however, this resulted in dark brown clarified glucose syrup. Operating at natural pH of 4.5, the membrane selectivity was close to 100%. Evaluation of hydraulic resistance indicated that concentration polarization and pore blocking were beyond approximately 50 and 40% of the total filtration resistance, respectively. Moreover, scanning electron microscopy showed that extensive fouling layer was deposited on the membrane surface. Finally, the developed cleaning procedure could restore membrane performance approximately 45% of its initial performance.

Parametric Study of Ultrafiltration

2009 ◽  
Author(s):  
Nina Zhou ◽  
A. G. Agwu Nnanna
Keyword(s):  
Flow Velocity ◽  
Suspended Solids ◽  
Cross Flow ◽  
Transmembrane Pressure ◽  
High Flux ◽  
Permeate Flux ◽  
Membrane Performance ◽  
Cross Flow Velocity ◽  
High Concentrations ◽  
Cleaning Methods

The performance of cross flow hollow fiber ultrafiltration (UF) membrane with molecular weight cut off (MWCO) 100 kDaltons was studied in order to effectively remove suspended solids in wastewater. Experiments were carried out to investigate the influence of the several factors such as cross flow velocity, transmembrane pressure (TMP), water temperature, and concentration of suspended solids on the membrane performance. Several cleaning methods were applied to remove the fouling. The experimental results showed that increasing TMP, temperature and cross flow velocity all resulted in increasing permeate flux. It is observed that high TMP aggravated the fouling while high cross flow velocity alleviated the fouling. High concentrations of suspended solids led to the reduction of permeate flux. It is also found that both combination of chemical, back- and forward-washing as well as soaking cleaning methods effectively removed fouling and achieved high flux recovery. The suspended solids were effectively removed by our UF system, and the water quality is significantly improved after ultrafiltration.

scholarly journals Effect of Gas Sparging on Fouling and Fouling Mechanism During Microfiltration of Pineapple Juice and Coconut Water

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
A. Laorko ◽  
W. Youravong ◽  
S. Tongchitpakdee
Keyword(s):  
Hollow Fiber Membrane ◽  
Gas Injection ◽  
Cross Flow ◽  
Coconut Water ◽  
Transmembrane Pressure ◽  
Cake Filtration ◽  
Pineapple Juice ◽  
Fouling Mechanism ◽  
Gas Sparging ◽  
Cross Flow Velocity

Flux reduction due to fouling is the major problem during microfiltration. This study aimed to investigate the role of gas sparging, an effective technique for flux enhancement, on fouling and fouling mechanism during microfiltration pineapple juice and coconut water. A hollow fiber membrane was used and the experiments were performed at cross flow velocity (CFV) of 1.5 m/s, transmembrane pressure (TMP) of 0.7 bar for pineapple juice and CFV of 1.6 m/s, TMP of 0.6 bar for coconut water, as varying gas injection factors (e). It was found that the fouling mechanism during microfiltration of pineapple juice and coconut water began with complete blocking, followed by an intermediate blocking and finally cake filtration. The use of gas sparging did not affect the sequence of fouling mechanism but affected both intensity duration of these fouling mechanisms. The duration of complete blocking stage was about 5-6 min at the beginning of the microfiltration for both feed. The initial points of defined cake filtration stages reduced from 1.3 to 0.9 h for pineapple juice and 1.0 to 0.67 h for coconut water when the e was varied from 0 to 0.35. Regarding fouling resistance analysis, increase in gas injection factor could significantly reduce the reversible fouling, external irreversible fouling but internal irreversible fouling.

scholarly journals The concentrating of alizarin using a reverse osmosis process

2005 ◽  
Vol 70 (1) ◽  
pp. 107-114 ◽  
Author(s):  
S.S. Madaeni ◽  
H. Daneshvar
Keyword(s):  
Flow Velocity ◽  
Reverse Osmosis ◽  
Cross Flow ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Transmembrane Pressure ◽  
Reverse Osmosis Membrane ◽  
Cross Flow Velocity ◽  
Membrane Technologies ◽  
Madder Root

Membrane technologies in general and reverse osmosis in particular have been employed for the concentrating of solutions. In this study, the concentrating of a heat sensitive alizarin extracted from madder root was realized using an FT30 reverse osmosis membrane. The effects of cross flow velocity, transmembrane pressure and pH on the flux and rejection were studied. Increasing the transmembrane pressure increased the flux while the rejection was constant. At pH 7-8, the highest flux was achieved. This study showed that reverse osmosis is the process of choice for the concentrating of alizarin solutions. The optimum operating conditions were 1.0 m/s cross flow velocity, 16 bars transmembrane pressure and pH 7. The system was tested for 12 h without severe fouling problems.

DYNAMIC MEMBRANE TECHNOLOGY FOR PRINTING WASTEWATER REUSE

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1943-1948
Author(s):  
LIN LIU ◽  
XUJIE LU ◽  
JIHUA CHEN
Keyword(s):  
Flow Velocity ◽  
Tap Water ◽  
Sewage Treatment ◽  
Cross Flow ◽  
Oxygen Demand ◽  
Economic Benefits ◽  
Effluent Treatment ◽  
Dynamic Membrane ◽  
Treated Effluent ◽  
Cross Flow Velocity

As environmental regulations become rigid and the cost of freshwater increases, wastewater is considered as a major resource in China. The paper presented a study on the implementation of the advanced treatment process using dynamic membrane (DM) in reusing of printing wastewater. The DM was well formed by circulating 1.5g/L of PAC in 20 minutes, the trans-membrane pressure of 200 kPa and the cross-flow velocity of 0.75m/s. The printing effluents were treated in effluent treatment plants comprising a physicochemical option followed by biological process. The treated effluent contained chemical oxygen demand (COD), color and turbidity in the range of 45-60 mg/L, 0.030-0.045 (absorbance at 420 nm) and 3-5 NTU. The results showed that the COD, color and turbidity removal efficiencies of the DM permeate were 84%, 85% and 80%, respectively. The wastewater treated by DM was reused as process water and the final concentrated retentate could be discharged directly into sewage treatment works with no additional treatments. Cleaning and regeneration of DM were very convenient if necessary. The proper process was that the polluted DM was cleaned with tap water at high cross-flow velocity. When irreversible pollutants accumulate, it would be rinsed with chemicals tested and the membrane flux would be restored up to 95%. The result showed that DM was considered as a promising method for purification aimed at reuse of printing wastewater, resulting in direct environmental and economic benefits.

Effects of alternating elliptical chamber on jet impingement heat transfer in vane leading edge under different cross-flow conditions

2021 ◽  
pp. 1-17
Author(s):  
K. Xiao ◽  
J. He ◽  
Z. Feng
Keyword(s):  
Heat Transfer ◽  
Velocity Ratio ◽  
Cross Flow ◽  
Leading Edge ◽  
Longitudinal Vortices ◽  
Impingement Jet ◽  
Flow And Heat Transfer ◽  
Impingement Heat Transfer ◽  
Cross Flow Velocity ◽  
The Cross

ABSTRACT This paper proposes an alternating elliptical impingement chamber in the leading edge of a gas turbine to restrain the cross flow and enhance the heat transfer, and investigates the detailed flow and heat transfer characteristics. The chamber consists of straight sections and transition sections. Numerical simulations are performed by solving the three-dimensional (3D) steady Reynolds-Averaged Navier–Stokes (RANS) equations with the Shear Stress Transport (SST) k– $\omega$ turbulence model. The influences of alternating the cross section on the impingement flow and heat transfer of the chamber are studied by comparison with a smooth semi-elliptical impingement chamber at a cross-flow Velocity Ratio (VR) of 0.2 and Temperature Ratio (TR) of 1.00 in the primary study. Then, the effects of the cross-flow VR and TR are further investigated. The results reveal that, in the semi-elliptical impingement chamber, the impingement jet is deflected by the cross flow and the heat transfer performance is degraded. However, in the alternating elliptical chamber, the cross flow is transformed to a pair of longitudinal vortices, and the flow direction at the centre of the cross section is parallel to the impingement jet, thus improving the jet penetration ability and enhancing the impingement heat transfer. In addition, the heat transfer in the semi-elliptical chamber degrades rapidly away from the stagnation region, while the longitudinal vortices enhance the heat transfer further, making the heat transfer coefficient distribution more uniform. The Nusselt number decreases with increase of VR and TR for both the semi-elliptical chamber and the alternating elliptical chamber. The alternating elliptical chamber enhances the heat transfer and moves the stagnation point up for all VR and TR, and the heat transfer enhancement is more obvious at high cross-flow velocity ratio.

scholarly journals Data-driven Modelling of Microfiltration Process with Embedded Static Mixer for Steepwater from Corn Starch Industry

2017 ◽  
Author(s):  
Laslo Šereš ◽  
Ljubica Dokić ◽  
Bojana Ikonić ◽  
Dragana Šoronja-Simović ◽  
Miljana Djordjević ◽  
...  
Keyword(s):  
Corn Starch ◽  
Desirability Function ◽  
Specific Energy Consumption ◽  
Cross Flow ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Static Mixer ◽  
Permeate Flux ◽  
Experimental Conditions ◽  
Starch Industry

Cross-flow microfiltration using ceramic tubular membrane was applied for treatment of steepwater from corn starch industry. Experiments are conducted according to the faced centered central composite design at three different transmembrane pressures (1, 2 and 3 bar) and cross-flow velocities (100, 150 and 200 L/h) with and without the usage of Kenics static mixer. For examination of the influence of the selected operating conditions at which usage of the static mixer is justified, a response surface methodology and desirability function approach were used. Obtained results showed improvement in the average permeate flux by using Kenics static mixer for 211 % to 269 % depending on experimental conditions when compared to the system without the static mixer. As a result of optimization, the best results considering flux improvement as well as reduction of specific energy consumption were obtained at low transmembrane pressure and lower feed cross-flow rates.

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