Treatment of agricultural wastewater and reuse

2002 ◽  
Vol 46 (11-12) ◽  
pp. 177-182 ◽  
Author(s):  
W. Reimann
Keyword(s):  
Membrane Separation ◽  
Membrane Surface ◽  
Pilot Scale ◽  
Wash Water ◽  
Coliform Bacteria ◽  
Permeate Flux ◽  
Log Reduction ◽  
Agricultural Wastewater ◽  
Inorganic Substances ◽  
Process Combination

The use of membrane separation technology, such as ultrafiltration (UF) and subsequent reverse osmosis (RO), for purifying different types of low-contaminated wash water of carrots (COD = 1,314 mg/l) and wash water of different kinds of vegetables (COD = 2,280 mg/l) was investigated on a pilot scale to determine its suitability for reuse in the process. In both membrane processes, UF and RO, the permeate flux first decreased with increasing fouling (deposition of organic and inorganic substances on the membrane surface and in its pores). After that the membrane permeability (permeate flux) and selectivity (rejection of COD) remained constant on a stable level in spite of a concentration with a volumetric concentration factor of up to 39. The tests showed that water can be obtained with a quality complying with the German regulations by applying a process combination of UF and RO. It was found that the membranes gave a 5-log reduction for total bacteria, and no coliform bacteria were present in the permeate after RO. Using UF and RO, part of the wastewater can be recovered for reuse in the process if drinking water is used for the last step of vegetable washing.

A Wall Film Model for Membrane Fouling

2018 ◽  
Author(s):  
Sina Jahangiri Mamouri ◽  
Volodymyr V. Tarabara ◽  
André Bénard
Keyword(s):  
Multiphase Flow ◽  
Membrane Fouling ◽  
Oil And Gas ◽  
Membrane Separation ◽  
Film Formation ◽  
Membrane Surface ◽  
Permeate Flux ◽  
Water Separation ◽  
Wall Film ◽  
Oil Water

Deoiling of produced or impaired waters associated with oil and gas production represents a significant challenge for many companies. Centrifugation, air flotation, and hydrocyclone separation are the current methods of oil removal from produced water [1], however the efficiency of these methods decreases dramatically for droplets smaller than approximately 15–20 μm. More effective separation of oil-water mixtures into water and oil phases has the potential to both decrease the environmental footprint of the oil and gas industry and improve human well-being in regions such as the Gulf of Mexico. New membrane separation processes and design of systems with advanced flow management offer tremendous potential for improving oil-water separation efficacy. However, fouling is a major challenge in membrane separation [2]. In this study, the behavior of oil droplets and their interaction with crossflow filtration (CFF) membranes (including membrane fouling) is studied using computational fluid dynamics (CFD) simulations. A model for film formation on a membrane surface is proposed for the first time to simulate film formation on membrane surfaces. The bulk multiphase flow is modeled using an Eulerian-Eulerian multiphase flow model. A wall film is developed from mass and momentum balances [3] and implemented to model droplet deposition and membrane surface blockage. The model is used to predict film formation and subsequent membrane fouling, and allow to estimate the actual permeate flux. The results are validated using available experimental data.

The Effect of Flow Pulsation on Ultrafiltration System Limiting Flux Behavior

2013 ◽  
Author(s):  
Chyouhwu Brian Huang ◽  
Hung-Shyong Chen
Keyword(s):  
Membrane Filtration ◽  
Concentration Polarization ◽  
Membrane Separation ◽  
Membrane Surface ◽  
Paper Industry ◽  
Surface Concentration ◽  
Permeate Flux ◽  
Filtration Time ◽  
Protection Systems ◽  
Oil Water

Ultrafiltration (UF) is an important industrial operation and is found in the food industry, separation of oil-water emulsions, treatment effluents from the pulp and paper industry, and environmental protection systems. Despite being widely used in these areas, UF systems exhibit a limiting flux behavior caused by concentration polarization on the membrane surface. Concentration polarization can be severe in macromolecular solutions due to low diffusivity on membrane separation and both mechanical and chemical methods have been used to reduce this phenomenon. This study introduces a new mechanical method that improves the performance of membrane separation and decreases concentration polarization. It involves pulsing the feed flow discontinuously and based on our results, feed flow velocity and solution bypass/membrane filtration time ratio are two vital factors when it comes to improving permeate flux. The proposed method is expected to find wide application, particularly in the processing of macromolecular solution.

scholarly journals Permeate Flux in Ultrafiltration Membrane: A Review

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
A. Beicha ◽  
R. Zaamouch ◽  
N. M. Sulaiman
Keyword(s):  
Membrane Filtration ◽  
Membrane Separation ◽  
Size Range ◽  
Membrane Surface ◽  
Separation Performance ◽  
Permeate Flux ◽  
Predictive Capability ◽  
Separation Processes ◽  
Ultrafiltration Pressure ◽  
Rate Limiting

Membrane processes exist for most of the fluid separations encountered in industry. The most widely used is membrane ultrafiltration, pressure driven process which is capable of separating particles in the approximate size range of 0.001 to 0.1 μm. The design of membrane separation processes, like all other processes, requires quantitative expressions relating material properties to separation performance. The factors controlling the performance of ultrafiltration are extensively reviewed. There have been a number of seminal approaches in this field. Most have been based on the rate limiting effects of the concentration polarization of the separated particles at the membrane surface. Various rigorous, empirical and intuitive models exist, which have been critically assessed in terms of their predictive capability and applicability. The decision as to which of the membrane filtration models is the most correct in predicting permeation rates is a matter of difficulty and appears to depend on the nature of the dispersion to separated.

Factors causing PAC cake fouling in PAC–MF (powdered activated carbon-microfiltration) water treatment systems

2005 ◽  
Vol 51 (6-7) ◽  
pp. 231-240 ◽  
Author(s):  
P. Zhao ◽  
S. Takizawa ◽  
H. Katayama ◽  
S. Ohgaki
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Membrane Surface ◽  
Pilot Scale ◽  
Powdered Activated Carbon ◽  
Raw Water ◽  
Permeate Flux ◽  
Void Space ◽  
High Concentration ◽  
Cake Layer

Two pilot-scale powdered activated carbon–microfiltration (PAC–MF) reactors were operated using river water pretreated by a biofilter. A high permeate flux (4 m/d) was maintained in two reactors with different particle sizes of PAC. High concentration (20 g/L) in the PAC adsorption zone demonstrated 60–80% of organic removal rates. Analysis on the PAC cake fouling demonstrated that attached metal ions play more important role than organic matter attached on PAC to the increase of PAC cake resistance. Effects of factors which may cause PAC cake fouling in PAC-MF process were investigated and evaluated by batch experiments, further revealing that small particulates and metal ions in raw water impose prominent influence on the PAC cake layer formation. Fe (II) precipitates after being oxidized to Fe (III) during PAC adsorption and thus Fe(III) colloids display more significant effect than other metal ions. At a high flux, PAC cake layer demonstrated a higher resistance with larger PAC due to association among colloids, metals and PAC particles, and easy migration of small particles in raw water into the void space in the PAC cake layer. Larger PAC possesses much more non-uniform particle size distribution and larger void space, making it easier for small colloids to migrate into the voids and for metal ions to associate with PAC particles by bridge effect, hence speeding up and intensifying the of PAC cake fouling on membrane surface.

scholarly journals INFLUENCE OF CHITOSAN MOLECULAR WEIGHT AND DEGREE OF DEACETYLATION ON MEMBRANE PHYSICOCHEMICAL AND SEPARATION PROPERTIES IN ETHANOL DEHYDRATION BY THE VAPOUR PERMEATION PROCESS

2020 ◽  
Vol XXV ◽  
pp. 79-93
Author(s):  
Małgorzata Gnus
Keyword(s):  
Molecular Weight ◽  
Contact Angle ◽  
Membrane Separation ◽  
Membrane Surface ◽  
Selectivity Coefficient ◽  
Permeate Flux ◽  
Ethanol Dehydration ◽  
Degree Of Deacetylation ◽  
Molecular Weights ◽  
Surface Contact Angle

Membranes were prepared using three chitosans with different molecular weights and degrees of deacetylation. The influence of chitosan features on membrane physicochemical properties, i.e. degree of swelling, contact angle and tensile strength, as well as membrane separation properties in ethanol dehydration by the vapour permeation process are discussed. The conducted experiments showed that an increase in the chitosan molecular weight led to an increase in the membrane surface contact angle concomitant with a decrease in the material selectivity coefficient. On the other hand, an increase in the chitosan degree of deacetylation caused a reduction in ethanol and improved the water permeate flux. There was greater selectivity in the test process for membranes prepared from chitosan with the lowest molecular weight.

Organic Stabilization and Nitrogen Removal in Membrane Separation Bioreactor for Domestic Wastewater Treatment

1992 ◽  
Vol 25 (10) ◽  
pp. 231-240 ◽  
Author(s):  
C. Chiemchaisri ◽  
Y. K. Wong ◽  
T. Urase ◽  
K. Yamamoto
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Hollow Fiber ◽  
Membrane Separation ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Aeration Tank ◽  
Intermittent Aeration ◽  
Permeate Flux ◽  
Fiber Membrane

In this study, organic stabilization and nitrogen removal were investigated using a household type hollow fiber membrane separation bioreactor of 6 2 1 volume. The process employed direct solid-liquid separation by hollow fiber membrane inside an activated sludge aeration tank. By providing highly turbulent conditions within the separation zone in conjunction with Jet aerating installation inside the membrane module, sludge accumulation on the membrane surface and inside the module can be reduced. Permeate flux obtained after 330 days of operation was 0.2 m/d under intermittent suction. High degree of organic stabilization was obtained in the system by operation without sludge wastage except for sampling purposes. Continuous and intermittent aeration modes were investigated in the study. The average effluent COD concentration of 20.8 and 16.5 mg/l were observed during continuous and intermittent aerating application respectively. Degree of nitrification depended upon DO concentration of mixed liquor during aeration period. Introduction of intermittent aeration enhanced total nitrogen removal up to 80% or more by simultaneous nitrification and denitrification, resulting in average of 4.9 mg/l of total nitrogen in the effluent. Increase in DO in aeration period from 1.5–2 mg/l to 4–5 mg/l improved percentage of nitrogen removal to more than 90%. Rejection of 4–6 log virus concentration by gel layer formed on the membrane surface was also observed.

Process combination of nanofiltration and adsorption: optimisation of an air and back flushing procedure

2003 ◽  
Vol 3 (5-6) ◽  
pp. 367-372
Author(s):  
J. Meier ◽  
T. Neymann ◽  
T. Melin
Keyword(s):  
Landfill Leachate ◽  
Cross Flow ◽  
Pilot Scale ◽  
Experimental Results ◽  
Permeate Flux ◽  
Leachate Treatment ◽  
Side Pressure ◽  
New Process ◽  
Major Factors ◽  
Process Combination

A new process combination integrating adsorption on powdered adsorbent into a nanofiltration process is applied to landfill leachate treatment on a pilot scale. Lab scale experiments have shown that the permeate flux is significantly increased by the application of a flushing procedure combining permeate back flushing and feed and air cross flow flushing. In this paper an optimisation strategy for the flushing procedure is described and first experimental results are presented. These results indicate that the cross flow flushing velocity and the number of permeate side pressure pulses are the major factors of the flushing procedure.

Pilot scale nanofiltration membrane separation for waste management in textile industry

2001 ◽  
Vol 43 (10) ◽  
pp. 233-240 ◽  
Author(s):  
I. Koyuncu ◽  
E. Kural ◽  
D. Topacik
Keyword(s):  
Membrane Fouling ◽  
Textile Industry ◽  
Membrane Separation ◽  
Transport Model ◽  
Pilot Scale ◽  
Operating Pressure ◽  
Nanofiltration Membrane ◽  
Permeate Flux ◽  
Feed Concentration ◽  
Mass Transport Model

This paper presents the pilot scale membrane separation studies on dyehouse effluents of textile industry. Nanofiltration (NF) membranes which have 2 m2 of surface area were evaluated for membrane fouling on permeate flux and their suitability in separating COD, color and conductivity in relation to operating pressure and feed concentration from textile industry dyehouse effluents. Successive batch runs demonstrated that any serious membrane fouling was not experienced for NF membrane tested in treating this type of wastewater. The permeate flux was found to increase significantly with operating pressure. Flux decreased with increasing recovery rate. The overall removal efficiencies of COD, color and conductivity were found as greater than 97%. COD was lower than 10 mg/l at 12 bar pressures. Permeate COD was also increased with increasing recovery and COD was 30 mg/l with recovery of 80%. Almost complete color removal was achieved with nanofiltration membrane. Color value was also decreased from 500 Pt-Co to 10 Pt-Co unit. This significant reduction in color and COD makes possible the recycle of the permeate in the dyehouse. Permeate conductivity was decreasing with increasing pressure and retention of conductivity increases with increasing pressures. This phenomenon is expected from the analysis of conductivity mass transport model. Economical analysis have been done and the total estimated cost will be 0.81 $/m3 based on 1000 m3/day of and this value is very economical for Istanbul City due to increasing industrial water supply tariffs.

scholarly journals Sonicated membrane separation

2018 ◽  
Vol 14 (s1) ◽  
pp. 89-99
Author(s):  
Balázs Lemmer ◽  
Szabolcs Kertész ◽  
Gábor Keszthelyi-Szabó ◽  
Kerime Özel ◽  
Cecilia Hodúr
Keyword(s):  
Membrane Fouling ◽  
Membrane Separation ◽  
Fermentation Broth ◽  
Membrane Surface ◽  
Permeate Flux ◽  
Separation Processes ◽  
Xylanase Enzyme ◽  
Stirred Cell ◽  
Hydrolysis Of

Membrane separation processes are currently proven technologies in many areas. The main limitation of these processes is the accumulation of matter at the membrane surface which leads to two phenomena: concentration polarization and membrane fouling. According to the publications of numerous authors permeate flux could be increased by sonication. Our work focuses on separation of real broth by sonicated ultrafiltration. The broth was originated from hydrolysis of grounded corn-cob by xylanase enzyme. The filtration was carried out in a laboratory batch stirred cell with a sonication rod sonicator. In our work the effect of the stirring, the intensity of sonication and the membrane-transducer distance was studied on the efficiency of the ultrafiltration and on the quality of separated enzymes. Results reveal that xylanase enzyme can be effectively separated from real fermentation broth by ultrafiltration and enzymes keep their activity after the process. Enzyme activity tests show that low energy sonication is not harmful to the enzyme.

scholarly journals Synthesizing Various Organic Polyacid Compounds for Modifying Forward Osmosis Membranes to Enhance Separation Performance

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 597
Author(s):  
Yi-Li Lin ◽  
Bharath Samannan ◽  
Kuo-Lun Tung ◽  
Jeyabalan Thavasikani ◽  
Cheng-Di Dong ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Membrane Separation ◽  
Membrane Surface ◽  
Forward Osmosis ◽  
Solute Flux ◽  
Separation Performance ◽  
The Novel ◽  
Permeate Flux ◽  
Membrane Selectivity ◽  
Surface Morphologies

In order to overcome the challenges of low permeate flux (Jp) and the accompanying reverse solute flux (JS) during the forward osmosis (FO) membrane separation process, we synthesized four hybrid materials of polyacid-based organic compounds and incorporated them into the selective polyamide (PA) layer to make novel thin-film nanocomposite (TFN) FO membranes. The Jp and JS of each membrane were evaluated and used along with membrane selectivity (Jp/JS) as indicators of membrane separation performance. The fabricated and modified membranes were also characterized for ridge and valley surface morphologies with increasing hydrophilicity and finger-shaped parallel channels in the PSf substrate. Moreover, two highly hydrophilic nanoparticles of graphene oxide (GO) and titanium oxide (TiO2) were introduced with the hybrid materials for PA modification, which can further enhance the Jp of the TFN membranes. The highest Jp of the TFN membranes achieved 12.1 L/m2-h using 0.1% curcumin-acetoguanamine @ cerium polyacid (CATCP) and 0.0175% GO. The characteristic peaks of the hybrid materials were detected on the membrane surface using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, evidencing successful incorporation of the hybrid materials during membrane modification. Here, we present the novel TFN membranes using hybrid materials for separation applications. The reactions for synthesizing the hybrid materials and for incorporating them with PA layer are proposed.

Sign in / Sign up

Export Citation Format

Share Document