scholarly journals Ultrafiltration membrane process for produced water treatment: experimental and modeling

2013 ◽  
Vol 3 (3) ◽  
pp. 249-259 ◽  
Author(s):  
Ramin Badrnezhad ◽  
Ali Heydari Beni

Produced water has been a big issue of water and environmental pollution. In this research, results of an experimental and modeling study on the separation of oil and salts from produced water using a rectangular flat sheet polyacrylonitrile (PAN) ultrafiltration (UF) membrane (nominal pore size of 10 nm) were analyzed. The effects of transmembrane pressure (TMP) (1, 2, 3 and 5 bar) on permeation flux of UF membranes for treatment of produced water were investigated. The results show that the average removal of chemical oxygen demand (COD) and total organic carbon (TOC) during the experiments were 94 and 83%, respectively. The UF membrane showed high potential for application in industry for produced water reusing purposes. The experimental results showed that oil retentions of almost all the membranes were over 99% and oil concentrations in the permeate were below 0.2 mg L–1. In addition, the fouling mechanism involved in UF processing of produced water was investigated by modeling. Experimental results of permeation flux were compared to the results of the fouling models. After the cake filtration model, the intermediate pore blocking model was found to predict the experimental data very well.

Author(s):  
N. Chin ◽  
S. O. Lai ◽  
K. C. Chong ◽  
S. S. Lee ◽  
C. H. Koo ◽  
...  

The study was concerned with the treatment of tank dewatering produced water using hybrid microfiltration (MF) and ultrafiltration (UF) processes. The pre-treatment MF membrane was fabricated with polyethersulfone (PES), n-methyl-2-pyrrolidone (NMP) and polyvinylpyrrolidone (PVP). The UF membranes meanwhile contained additional component, i.e., titanium dioxide (TiO2) nanoparticles in the range of zero to 1.0 wt.%. The membrane performances were analysed with respect to permeate flux, oil removal and flux recovery ratio. An increase in TiO2 nanoparticles enhanced the pore formation, porosity and pure water permeability due to improved hydrophilicity. The permeate flux of UF membranes increased with the increase of TiO2 nanoparticles and pressure. The oil removal rate by MF process was only 52.35%, whereas the oil rejection efficiency was between 82.34% and 95.71% for UF process. It should be highlighted that the overall oil removal rate could achieve as high as 97.96%. Based on the results, the PES membrane incorporated with 1.0 wt.% TiO2 was proved to be the most promising membrane at a transmembrane pressure of 3 bar. Although 1.0 M NaOH solution could be used as cleaning agent to recover membrane water flux, it is not capable of achieving good results as only 52.18% recovery rate was obtained.


2013 ◽  
Vol 67 (3) ◽  
pp. 477-484 ◽  
Author(s):  
X. S. Yi ◽  
S. L. Yu ◽  
W. X. Shi ◽  
S. Wang ◽  
L. M. Jin ◽  
...  

In the present study, nano-sized TiO2/Al2O3 modified polyvinylidene fluoride (PVDF) membranes (MM) were fabricated and then utilized for oil/water emulsion separation. The results showed that, compared with PVDF membrane (OM), the contact angle of MM decreased and hydrophilicity increased. The ultrafiltration (UF) of oil in water emulsions with transmembrane pressure (TMP) increasing results in a sharp fall in relative flux with time. The cake filtration models did not always predict the performance over the complete range of filtration times very well. In the initial 30 min, all the four cake models can simulate this UF process to a certain extent, and the suitability was: cake filtration > intermediate pore blocking > standard pore blocking > complete pore blocking models. However, they were no longer adapted well with UF time extent to 60 min, but only cake filtration (R2 = 0.9535) maintained a high adaptability. Surface and cross-sectional morphology of the membrane was investigated by SEM to make an advanced certificate of this UF mechanism.


2013 ◽  
Vol 68 (4) ◽  
pp. 799-806 ◽  
Author(s):  
Vasileios I. Diamantis ◽  
Konstantinos Anagnostopoulos ◽  
Paraschos Melidis ◽  
Spyridon Ntougias ◽  
Alexander Aivasidis

A household-scale wastewater treatment system was operated with domestic sewage. The system could recover gardening/irrigation water from raw sewage or secondary effluent by low pressure ultrafiltration (UF). The UF membranes (surface area = 3.5 m2, pore size = 0.04 μm) were operated at constant transmembrane pressure (0.13 bar). The proposed technology was examined for approximately 2 months without membrane cleaning. Membrane operation was performed periodically (one or two times per week), simulating water usage for gardening irrigation. During raw sewage filtration (chemical oxygen demand (COD) total = 242 ± 71 mg L–1, COD soluble = 105 ± 51 mg L−1, suspended solids = 188 ± 58 mg L−1), low permeate COD was achieved (52 ± 25 mg L−1), whereas nitrogen and phosphorus were recovered in the permeate. The water recovered during 1 h of operation displayed a gradual decrease from 42 to 22 L m−2h−1 during the 50-d time period. For the secondary effluent filtration, the UF module achieved consistently a recovery rate of 39.6 ± 8.0 L m−2h−1, with an average permeate COD of 37 mg L−1. In this case, the fouling layer (cake layer) was completely reversible after the relaxation period, rendering the process suitable for unattended household applications.


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 461
Author(s):  
Fu Yang ◽  
Zhengkun Huang ◽  
Jun Huang ◽  
Chongde Wu ◽  
Rongqing Zhou ◽  
...  

Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.


Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract


Author(s):  
Katsumasa Miyazaki ◽  
Kunio Hasegawa ◽  
Koichi Saito ◽  
Bostjan Bezensek

The fitness-for-service code requires the characterization of non-aligned multiple flaws for the flaw evaluation, which is performed using a flaw proximity rule. Worldwide almost all codes provide own proximity rule, often with unclear technical bases of the application of proximity rule to ductile fracture. To clarify the appropriate proximity rule for non-aligned multiple flaws in fully plastic fracture, fracture tests on flat plate specimen with non-aligned multiple through wall flaws were conducted at ambient temperature. The emphasis of this study was put on the flaw alignment rule, which determines whether non-aligned flaws are treated as independent or aligned onto the same plane for the purpose of flaw evaluations. The effects of the flaw separation and flaw size on the maximum load were investigated. The experimental results were compared with the estimations of the collapse load using the alignment rules in the ASME Section XI, BS7910 and API 579-1 codes. A new estimation procedure specific to the fully plastic fracture was proposed and compared with the comparison with the experimental results.


2013 ◽  
Vol 67 (9) ◽  
Author(s):  
Karina Michalska ◽  
Stanisław Ledakowicz

AbstractThis work studies the influence of the alkali pre-treatment of Sorghum Moench — a representative of energy crops used in biogas production. Solutions containing various concentrations of sodium hydroxide were used to achieve the highest degradation of lignocellulosic structures. The results obtained after chemical pre-treatment indicate that the use of NaOH leads to the removal of almost all lignin (over 99 % in the case of 5 mass % NaOH) from the biomass, which is a prerequisite for efficient anaerobic digestion. Several parameters, such as chemical oxygen demand, total organic carbon, total phenolic content, volatile fatty acids, and general nitrogen were determined in the hydrolysates thus obtained in order to define the most favourable conditions. The best results were obtained for the Sorghum treated with 5 mass % NaOH at 121°C for 30 min The hydrolysate thus achieved consisted of high total phenolic compounds concentration (ca. 4.7 g L−1) and chemical oxygen demand value (ca. 45 g L−1). Although single alkali hydrolysis causes total degradation of glucose, a combined chemical and enzymatic pre-treatment of Sorghum leads to the release of large amounts of this monosaccharide into the supernatant. This indicates that alkali pre-treatment does not lead to complete cellulose destruction. The high degradation of lignin structure in the first step of the pre-treatment rendered the remainder of the biomass available for enzymatic action. A comparison of the efficiency of biogas production from untreated Sorghum and Sorghum treated with the use of NaOH and enzymes shows that chemical hydrolysis improves the anaerobic digestion effectiveness and the combined pre-treatment could have great potential for methane generation.


2005 ◽  
Vol 51 (1) ◽  
pp. 39-46 ◽  
Author(s):  
C.M. Sheridan ◽  
F.F. Bauer ◽  
S. Burton ◽  
L. Lorenzen

Wine production in South Africa is delocalised, with numerous small-to-medium sized producers within several regions within the Western Cape. Whilst adapting to new technological changes, producers have to respond to pressure from consumers and governments regarding the environmental consequences of winemaking, especially water usage and pollution. To date, no systematic analysis integrating the various aspects of winemaking in South Africa has been done. This study assessed both physical inputs and outputs. A detailed questionnaire was developed to broadly assess these parameters and was submitted to all cellars in South Africa. Case studies were performed at three cellars during the 2002 harvest season to validate the questionnaires and collect missing information. Based on this, and a cocurrent project, the following parameters were correlated to the tons of grapes presses per annum: effluent parameters which include chemical oxygen demand, suspended solids, total dissolved solids, sodium adsorption ratio, quantity of effluent; wine produced, water consumed, and electricity consumed. These parameters were used to develop an input/output model. This model may be used by wineries to predict their water and electrical consumption, wine produced and effluent characteristics provided they know the tonnage of grapes pressed per year.


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