scholarly journals Membranes coupled with physico chemical treatment in water reuse

2010 ◽  
Vol 61 (2) ◽  
pp. 513-519 ◽  
Author(s):  
W. S. Guo ◽  
R. Zhang ◽  
S. Vigneswaran ◽  
H. H. Ngo ◽  
J. Kandasamy
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Membrane Filtration ◽  
Ion Exchange Resin ◽  
Transmembrane Pressure ◽  
Long Duration ◽  
Pre Treatment ◽  
Refractory Organic Pollutants ◽  
Treated Sewage Effluent ◽  
Magnetic Ion

In this study, short-term experiments were conducted with different configurations of membrane hybrid systems to treat biological treated sewage effluent containing refractory organic pollutants: (i) submerged hollow fiber microfiltration (SMF) alone; (ii) spiral flocculator (SF)-SMF without settling; (iii) SF-PAC-SMF without settling and (iv) SMF with magnetic ion exchange resin MIEX® pretreatment. The results indicated that the pre-flocculation of SF could improve the mitigation of membrane fouling significantly even when the system was operated at a high membrane filtration rate. The transmembrane pressure (TMP) of SF-PAC-SMF only increased marginally (0.8 kPa over 8 hours). SF-SMF without the addition of powdered activated carbon (PAC) also took a relatively long duration for the TMP to increase. The TMP only increased by 2.5 kPa over 8 hours. The SF-PAC-MF system resulted in a high dissolved organic carbon (DOC) removal of more than 96%. When used as pre-treatment to submerged membranes, the fluidized bed MIEX® contactor could remove a significant amount of organic matter in wastewater. This pre-treatment helped to reduce the membrane fouling and kept the TMP low during the membrane operation.

Removal of algogenic organic matter by magnetic ion exchange resin pre-treatment and its effect on fouling in ultrafiltration

2011 ◽  
Vol 11 (1) ◽  
pp. 15-22 ◽  
Author(s):  
C. Liu ◽  
W. Chen ◽  
V. M. Robert ◽  
Z. G. Han
Keyword(s):  
Organic Matter ◽  
Ion Exchange ◽  
Membrane Fouling ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Major Barrier ◽  
Treated Water ◽  
Fouling Control ◽  
Pre Treatment ◽  
Magnetic Ion

Natural organic matter (NOM) fouling continues to be the major barrier to efficient application of ultrafiltration (UF) in drinking water treatment. Algogenic organic matter (AOM), the main contributor to total NOM levels in raw waters characterised by elevated algae levels, is currently the subject of much investigation. In this study, the effect of AOM on fouling of ultrafiltration and the effectiveness of magnetic ion exchange resin (MIEX®) pre-treatment for AOM removal and membrane fouling control was evaluated. The results showed that, the main species of algae in raw water were Chlorella vulgaris, which accounted for 80% of total algae. AOM was predominantly hydrophilic (50% or more) with a low SUVA (1.7 Lm−1 mg−1). Coagulation alone could not remove AOM effectively (less than 20%), however, when combined with magnetic ion exchange resin pre-treatment, more than 60% of AOM was be removed; pre-treatment followed by coagulation was observed to be very effective in controlling membrane fouling by AOM. The application of magnetic ion exchange resin technology at a bed volume treatment rate (BVTR) of 800 was observed to effectively eliminate fouling of UF membrane. Careful analyses of the molecular weight (MW) distribution of AOM and UV absorbance of treated water revealed that the effectiveness in membrane fouling control was the result of the changes in AOM molecular characteristics in treated water, namely a change in MW due to the preferential removal of high molecular proteins by coagulation and magnetic ion exchange resin pre-treatment. The results demonstrate that magnetic ion exchange resin followed by coagulation might be a new membrane pre-treatment option for UF membrane fouling control.

scholarly journals Membrane Fouling Controlled by Adjustment of Biological Treatment Parameters in Step-Aerating MBR

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 553
Author(s):  
Dimitra C. Banti ◽  
Manassis Mitrakas ◽  
Petros Samaras
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Aeration Tank ◽  
Filamentous Bacteria ◽  
Membrane Performance ◽  
Low Concentrations ◽  
Fouling Reduction

A promising solution for membrane fouling reduction in membrane bioreactors (MBRs) could be the adjustment of operating parameters of the MBR, such as hydraulic retention time (HRT), food/microorganisms (F/M) loading and dissolved oxygen (DO) concentration, aiming to modify the sludge morphology to the direction of improvement of the membrane filtration. In this work, these parameters were investigated in a step-aerating pilot MBR that treated municipal wastewater, in order to control the filamentous population. When F/M loading in the first aeration tank (AT1) was ≤0.65 ± 0.2 g COD/g MLSS/d at 20 ± 3 °C, DO = 2.5 ± 0.1 mg/L and HRT = 1.6 h, the filamentous bacteria were controlled effectively at a moderate filament index of 1.5–3. The moderate population of filamentous bacteria improved the membrane performance, leading to low transmembrane pressure (TMP) at values ≤2 kPa for a great period, while at the control MBR the TMP gradually increased reaching 14 kPa. Soluble microbial products (SMP), were also maintained at low concentrations, contributing additionally to the reduction of ΤΜP. Finally, the step-aerating MBR process and the selected imposed operating conditions of HRT, F/M and DO improved the MBR performance in terms of fouling control, facilitating its future wider application.

Effects of pre-treatment with magnetic ion exchange resins on coagulation/flocculation process

2008 ◽  
Vol 57 (1) ◽  
pp. 57-64 ◽  
Author(s):  
B. Sani ◽  
E. Basile ◽  
C. Lubello ◽  
L. Rossi
Keyword(s):  
Ion Exchange ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Ion Exchange Resin ◽  
Test Procedures ◽  
Aggregation State ◽  
Jar Test ◽  
Pre Treatment ◽  
Magnetic Ion

A new Magnetic Ion EXchange resin for DOC (Dissolved Organic Carbon) removal (MIEX®DOC Resin) has been evaluated as water pre-treatment at the Drinking Water Treatment Plant (DWTP) of Florence in order to reduce the oxidant demand and disinfection by-products (DBPs) formation potential. This pre-treatment leads to several effects on downstream treatment processes. In this experimental study the effects of MIEX® pre-treatment on clariflocculation process were evaluated with respect to coagulant demand reduction and characteristics of flocs formed. The analysis was conducted using traditional jar test procedures and a Photometric Dispersion Analyser (PDA2000) which provided continuous information about the aggregation state of particles during the jar tests. For a fixed turbidity goal in clarified water, ion exchange pre-treatment led to coagulant dosage reduction up to 60% and PDA results shown that flocs formed in pre-treated water were bigger and more resistant to shearing effects than those formed by conventional clariflocculation.

Characteristics of coagulation-flocculation of humic acid with effective performance of polymeric flocculant and inorganic coagulant

2003 ◽  
Vol 47 (1) ◽  
pp. 89-95 ◽  
Author(s):  
J. Yu ◽  
D.D. Sun ◽  
J.H. Tay
Keyword(s):  
Humic Acid ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Molecular Size ◽  
Aluminium Sulphate ◽  
Fouling Control ◽  
Effective Performance ◽  
Water And Wastewater ◽  
Pre Treatment ◽  
Flocculation Process

Ferric chloride and aluminium sulphate as coagulants and positive charged flocculants PDDMAC ((PDDMAC = poly (diallyldimethylammonium chloride) were used for pre-treatment of water and wastewater for removing humic substance prior to RO membrane filtration. It was found that a combination of flocculant and coagulant enhanced the coagulation-flocculation process and humic acid removal. The optimum conditions of coagulation-flocculation were established in reference to the ratio of humic acid and coagulant. Zeta potential and the ratio of E4/E6 were investigated to explore the possible micro-mechanisms of coagulation-flocculation. The ratios of E4/E6 show the molecular size variations using different coagulants and flocculants, which are expected to benefit membrane-fouling control.

Fate of steroid hormone micropollutant estradiol in a hybrid magnetic ion exchange resin-nanofiltration process

2019 ◽  
Vol 16 (8) ◽  
pp. 630
Author(s):  
Alessandra Imbrogno ◽  
Prantik Samanta ◽  
Andrea I. Schäfer
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Ion Exchange ◽  
Membrane Fouling ◽  
Exchange Resin ◽  
Environmental Concern ◽  
Steroid Hormone ◽  
Ion Exchange Resin ◽  
Feed Water ◽  
Magnetic Ion

Environmental contextContamination of surface water by micropollutants is a major environmental concern because of their high persistence and toxicity. Micropollutants are only partially removed in nanofiltration water treatment systems, encouraging the investigation of more complex systems involving partitioning with membrane materials, organic matter and ion exchange resins. This study elucidates the micropollutant partitioning mechanisms in this complex water treatment system. AbstractThe accumulation of micropollutants, such as steroid hormones, in magnetic ion exchange resin-nanofiltration (MIEX-NF) poses a risk to the environmental contamination of surface water where the treated water is discharged. In this study, the partitioning of the steroid hormone estradiol (E2) with humic acid (HA), MIEX and the membrane is investigated at different feed water conditions (e.g. pH and presence of calcium). The transport and adsorption of E2 in NF is not affected significantly by the E2-HA interaction. Indeed, E2 partitions with HA between 8% and 25% at different pH. This is attributed to the presence of calcium ions, which reduces the number of HA molecules available to interact with E2 molecules. The calcium interference is evident especially at pH>10, where calcite and HA precipitate to result in irreversible membrane fouling. In the hybrid MIEX-NF process, the E2-MIEX interaction occurs at all pH conditions. Approximately 40% of the E2 total mass partitions with MIEX. This is significantly higher than E2 accumulation in NF. Since the partitioning is at least partially reversible, this poses a risk for accidental E2 release into the process streams.

scholarly journals In-line coagulation assessment for ultrafiltration fouling reduction to treat secondary effluent for water reuse

2020 ◽  
Author(s):  
Samia A. Aly ◽  
William B. Anderson ◽  
Peter M. Huck
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Hollow Fiber Membrane ◽  
Secondary Effluent ◽  
Membrane Performance ◽  
Coagulant Dosage ◽  
Pre Treatment ◽  
Uf Membranes ◽  
Fouling Reduction ◽  
The Impact

Abstract Low pressure membranes are attracting attention for their potential to improve secondary effluent quality, but membrane fouling can limit their widespread applicability. In this study, in-line coagulation as pre-treatment to ultrafiltration (UF) was investigated using a bench-scale hollow fiber membrane at a constant flux of 33 L/m2 h. Membrane fouling was monitored by observing change in trans-membrane pressure when the membrane was fed with secondary effluent and in-line coagulated secondary effluent over a 24-h period. The impact of four coagulants at different dosages on reversible and irreversible membrane fouling and permeate quality was studied. It was found that in-line coagulation improved UF performance to varying degrees depending on coagulant type and dosage. Generally, higher reduction of fouling was achieved by increasing coagulant dosage within the 0.5–5.0 mg/L range investigated. Ferric-based coagulants were better than aluminum-based coagulants with respect to improving membrane performance for the secondary effluent investigated, even at low dosages (0.5 mg/L). Further investigations are required to determine how in-line coagulation affects removal of organic compounds through UF membranes.

An integrated wastewater reuse concept combining natural reclamation techniques, membrane filtration and metal oxide adsorption

2008 ◽  
Vol 57 (6) ◽  
pp. 909-914 ◽  
Author(s):  
A. Sperlich ◽  
X. Zheng ◽  
M. Jekel ◽  
M. Ernst
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Membrane Filtration ◽  
Sodium Hydroxide Solution ◽  
Wastewater Reuse ◽  
Ferric Hydroxide ◽  
Operation Time ◽  
Pilot Scale ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration

In a Sino-German research project, a sustainable water reclamation concept was developed for different applications of municipal water reuse at the Olympic Green 2008 in Beijing, China. Results from pilot-scale experiments in Beijing and Berlin show that selective nutrient removal by adsorption onto granular ferric hydroxide (GFH) after a membrane bioreactor (MBR) can maintain a total phosphorus concentration of <0.03 μg L−1 P, thus preventing eutrophication of artificial lakes. Operation time of GFH adsorption columns can be extended by regeneration using sodium hydroxide solution. A subsequent ultrafiltration (UF) membrane after bank filtration creates an additional barrier for pathogens and allows for further urban reuse applications such as toilet flushing. Short term bank / bio-filtration prior to UF is shown to effectively remove biopolymers and reduce membrane fouling.

Use of fouling resistant nanofiltration and reverse osmosis membranes for dyeing wastewater effluent treatment

2005 ◽  
Vol 51 (6-7) ◽  
pp. 159-164 ◽  
Author(s):  
S.-W. Myung ◽  
I.-H. Choi ◽  
S.-H. Lee ◽  
I.-C. Kim ◽  
K.-H. Lee
Keyword(s):  
Surface Roughness ◽  
Surface Charge ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Water Reuse ◽  
Effluent Treatment ◽  
Poly Vinyl Alcohol ◽  
Dyeing Wastewater ◽  
Pre Treatment

Dyeing wastewater was post-treated by using nanofiltration (NF) and reverse osmosis (RO) membranes. To reduce membrane fouling, poly (vinyl alcohol) (PVA) with a neutral charge was coated on NF and RO membranes. The effect of surface charge and surface roughness on membrane fouling was investigated. Dyeing wastewater was pre-treated by using coagulation, activated sludge process, and MF process to investigate the effect of the pre-treatment on the membrane fouling. It is demonstrated that the extent of fouling is significantly influenced by the surface roughness and the surface charge on the NF and RO membranes. A membrane with a smooth and neutral surface was fouled less. The pre-treatment was essential for avoiding NF and RO membranes fouling. The quality of the final permeate was acceptable for water reuse.

Capillary nanofiltration coupled with powdered activated carbon adsorption for high quality water reuse

2009 ◽  
Vol 60 (1) ◽  
pp. 251-259 ◽  
Author(s):  
C. Kazner ◽  
J. Meier ◽  
T. Wintgens ◽  
T. Melin
Keyword(s):  
Activated Carbon ◽  
Water Reuse ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Powdered Activated Carbon ◽  
Transmembrane Pressure ◽  
Municipal Wastewater Treatment ◽  
High Quality ◽  
Quality Water

Direct capillary nanofiltration was tested for reclamation of tertiary effluent from a municipal wastewater treatment plant. This process can be regarded as a promising treatment alternative for high quality water reuse applications when combined with powdered activated carbon for enhanced removal of organic compounds. The nanofiltration was operated at flux levels between 20 and 25 L/(m2 h) at a transmembrane pressure difference of 2–3 bar for approximately 4,000 operating hours. The study was conducted with PAC doses in the range from 0 to 50 mg/L. The plant removal for DOC ranged from 88–98%. The sulfate retention of the membrane filtration process was between 87 and 96%. The process provided a consistently high permeate quality with respect to organic and inorganic key parameters.

Influence of extracellular polysaccharides (EPS) produced by two different green unicellular algae on membrane filtration in an algae-based biofuel production process

2014 ◽  
Vol 69 (9) ◽  
pp. 1919-1925 ◽  
Author(s):  
Takaki Matsumoto ◽  
Hiroshi Yamamura ◽  
Jyunpei Hayakawa ◽  
Yoshimasa Watanabe ◽  
Shigeaki Harayama
Keyword(s):  
Green Algae ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Specific Growth ◽  
Biofuel Production ◽  
Extracellular Polysaccharides ◽  
Transmembrane Pressure ◽  
Unicellular Algae

In the present study, two strains of green algae named S1 and S2, categorized as the same species of Pseudo-coccomyxa ellipsoidea but showing 99% homology, were cultivated under the same conditions and filtrated with a microfiltration membrane. On the basis of the results of the extracellular polysaccharides (EPS) characteristics of these two green algae and the degree of fouling, the influence of these characteristics on the performance of membrane filtration was investigated. There was no difference in the specific growth rate between the S1 and S2 strains; however, large differences were seen in the amount and quality of EPS between S1 and S2. When the S1 and S2 strains were filtered with a membrane, the trend in the increase in transmembrane pressure (TMP) was quite different. The filtration of the S1 strain showed a rapid increase in TMP, whereas the TMP of the filtration of the S2 strain did not increase at all during the operation. This clearly demonstrated that the characteristics of each strain affect the development of membrane fouling. On the basis of the detailed characterization of solved-EPS (s-EPS) and bound-EPS (b-EPS), it was clarified that s-EPS mainly contributed to irreversible fouling for both operations and the biopolymer-like organic matter contained in b-EPS mainly contributed to reversible fouling.

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