scholarly journals The removal of typical pollutants in secondary effluent by the combined process of powdered activated carbon–ultrafiltration

2017 ◽  
Vol 75 (6) ◽  
pp. 1485-1493 ◽  
Author(s):  
Lihua Sun ◽  
Ning He ◽  
Tianmin Yu ◽  
Xi Duan ◽  
Cuimin Feng ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Membrane Fouling ◽  
Filter Cake ◽  
Powdered Activated Carbon ◽  
Secondary Effluent ◽  
Moderate Amount ◽  
Combined Process ◽  
Membrane Flux ◽  
Initial Stage ◽  
Cake Layer

This paper focused on the effects of powdered activated carbon (PAC) dosage on ultrafiltration (UF) membrane flux caused by natural organic matter (NOM). Three model foulants, humic acid (HA), bovine serum albumin (BSA) and sodium alginate (SA), were adopted to represent different NOM fractions in secondary effluent treated by the combined process of PAC-UF. Moreover, the membrane fouling resistance and fouling mechanism were also analyzed. The results indicated that the best PAC dosage for the membrane flux variation was 20 mg/L for HA and SA, and 10 mg/L for BSA. SA caused the most serious membrane fouling, which was mainly reversible fouling. The membrane fouling caused by HA and BSA was mainly irreversible membrane fouling. The membrane fouling caused by organics happened mainly at the initial stage of filtration. Because the filter cake layer formed by a moderate amount of PAC could intercept organics, the membrane fouling, especially the irreversible fouling, could be reduced.

scholarly journals The membrane fouling mechanisms of the PAC/BPAC-UF combined process used to treat the secondary effluent from municipal wastewater treatment plant

2017 ◽  
Vol 77 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Lihua Sun ◽  
Ning He ◽  
Xi Duan ◽  
Bingbing Yang ◽  
Cuimin Feng ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Activated Carbon ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Membrane Surface ◽  
Treatment Plant ◽  
Powdered Activated Carbon ◽  
Combined Processes ◽  
Secondary Effluent

Abstract The combined processes of powdered activated carbon/biological powdered activated carbon- ultrafiltration (PAC/BPAC-UF) were used to treat secondary effluent. In this study, the effect of PAC and BPAC on membrane flux, membrane resistance and the removal of different molecular weight organic compounds were investigated. In addition, the structure characteristics of the microorganisms of the BPAC were analyzed. The results showed that the optimum dosage of PAC and BPAC was 10 mg/L and 40 mg/L respectively. The reversible membrane fouling resistance of BPAC-UF was higher than that of PAC-UF, and the two processes had the least irreversible resistance at the best dosage. The biodegradation of BPAC increased the concentration of small molecular weight organic matter up to 10,000 Da in the membrane effluent. So the dissolved organic carbon (DOC) removal effect of BPAC-UF process worsened. Microorganisms such as Proteobacteria, Bacteroidetes, Planctomycetes and other microorganisms on the surface of the BPAC enhanced the removal of organic matter in water. The results of scanning electron microscopy (SEM) scans showed that there was net mucus membrane on the UF membrane surface before the backwashing of the BPAC-UF process which increased the proportion of reversible pollution resistance. The physical flushing effect of BPAC-UF was better than that of direct UF and PAC-UF processes.

scholarly journals Alleviation of Ultrafiltration Membrane Fouling by ClO2 Pre-Oxidation: Fouling Mechanism and Interface Characteristics

Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Bin Liu ◽  
Meng Wang ◽  
Kaihan Yang ◽  
Guangchao Li ◽  
Zhou Shi
Keyword(s):  
Natural Water ◽  
Membrane Fouling ◽  
Interaction Force ◽  
Interfacial Free Energy ◽  
Fouling Control ◽  
Membrane Flux ◽  
Flux Decline ◽  
Interface Characteristics ◽  
Cake Layer ◽  
Free Energy Analysis

In order to alleviate membrane fouling and improve removal efficiency, a series of pretreatment technologies were applied to the ultrafiltration process. In this study, ClO2 was used as a pre-oxidation strategy for the ultrafiltration (UF) process. Humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA) were used as three typical organic model foulants, and the mixture of the three substances was used as a representation of simulated natural water. The dosages of ClO2 were 0.5, 1, 2, 4, and 8 mg/L, with 90 min pre-oxidation. The results showed that ClO2 pre-oxidation at low doses (1–2 mg/L) could alleviate the membrane flux decline caused by humus, polysaccharides, and simulated natural water, but had a limited alleviating effect on the irreversible resistance of the membrane. The interfacial free energy analysis showed that the interaction force between the membrane and the simulated natural water was also repulsive after the pre-oxidation, indicating that ClO2 pre-oxidation was an effective way to alleviate cake layer fouling by reducing the interaction between the foulant and the membrane. In addition, ClO2 oxidation activated the hidden functional groups in the raw water, resulting in an increase in the fluorescence value of humic analogs, but had a good removal effect on the fluorescence intensity of BSA. Furthermore, the membrane fouling fitting model showed that ClO2, at a low dose (1 mg/L), could change the mechanism of membrane fouling induced by simulated natural water from standard blocking and cake layer blocking to critical blocking. Overall, ClO2 pre-oxidation was an efficient pretreatment strategy for UF membrane fouling alleviation, especially for the fouling control of HA and SA at low dosages.

scholarly journals Powdered Activated Carbon Exacerbates Fouling in MBR Treating Olive Mill Wastewater

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2498 ◽  
Author(s):  
Noya Ran ◽  
Jack Gilron ◽  
Revital Sharon-Gojman ◽  
Moshe Herzberg
Keyword(s):  
Activated Carbon ◽  
Membrane Permeability ◽  
Membrane Fouling ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Powdered Activated Carbon ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Permeate Flux ◽  
Wastewater Treatment Process

Membrane fouling is a major obstacle in membrane bioreactors (MBRs) that treat wastewater. The addition of powdered activated carbon (PAC) is commonly suggested as a way to improve the MBR wastewater treatment process with respect to membrane fouling and effluent quality. Integrating the PAC addition into the MBR may also improve the stability of the acclimated microbial community for biodegrading the recalcitrant organic compounds that can also enhance membrane fouling. In this study, the ability of the MBR-PAC system to decrease membrane fouling was evaluated. Two pilot-scale reactors were operated: one reactor was supplemented with suspended PAC, and one was operated under similar conditions, without PAC. The feed to the reactors comprised domestic and olive oil mill wastewater. Surprisingly, the permeate flux and the membrane permeability decreased faster in the MBR supplemented with PAC compared to the control reactor. Corroborating these MBR fouling results, soluble microbial products (SMPs), originating from the PAC-supplemented reactor, were found to be more adhesive to an ultrafiltration membrane mimetic surface (polyether sulfone) as analyzed in a quartz crystal microbalance with dissipation monitoring (QCM-D). While the PAC had almost no effect on the dissolved organic carbon in the MBR, it altered the molecular weight distribution of the organic molecules in the SMP as observed with gel permeation chromatography: The fractions of 577–789 kDa and the one bigger than 4 × 103 kDa, were elevated and reduced, respectively, by the addition of PAC. A biofilm formation analysis using a confocal laser scanning microscopy showed a higher amount of biofilm on the membrane taken from the PAC reactor, but this membrane showed no traces of PAC particles when analyzed with a scanning electron microscope (SEM). Taken together, altering the composition of the dissolved organic matter in the MBR by PAC addition promoted its adhesion to the membrane, induced biofilm formation, and more prominently, decreased membrane permeability.

scholarly journals Pilot Studies and Cost Analysis of Hybrid Powdered Activated Carbon/Ceramic Microfiltration for Controlling Pharmaceutical Compounds and Organic Matter in Water Reclamation

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 33 ◽  
Author(s):  
Rui M. C. Viegas ◽  
Elsa Mesquita ◽  
Margarida Campinas ◽  
Maria João Rosa
Keyword(s):  
Organic Matter ◽  
Activated Carbon ◽  
Cost Analysis ◽  
Free Water ◽  
Pharmaceutical Compounds ◽  
Powdered Activated Carbon ◽  
Production Costs ◽  
Secondary Effluent ◽  
Total Production ◽  
Water Reclamation

This paper addresses the enhanced removal of pharmaceutical compounds (PhCs), a family of contaminants of emerging concern, and effluent organic matter (EfOM) in water reclamation by powdered activated carbon/coagulation/ceramic microfiltration (PAC/cMF). Four chemically diverse PhCs are targeted: ibuprofen (IBP), carbamazepine (CBZ), sulfamethoxazole (SMX) and atenolol (ATN). Pilot assays (100 L/(m2 h), 10 mg Fe/L) run with PhC-spiked sand-filtered secondary effluent and 15 mg/L PAC dosed in-line or to a 15-min contactor. They showed no PAC-driven membrane fouling and +15 to +18% added removal with PAC contactor, reaching significant removals of CBZ and ATN (59%–60%), SMX (50%), colour (48%), A254 (35%) and dissolved organic carbon (DOC, 28%). Earlier long-term demo tests with the same pilot proved PAC/cMF to consistently produce highly clarified (monthly median < 0.1 NTU) and bacteria-free water, regardless of the severe variations in its intake. A detailed cost analysis points to total production costs of 0.21 €/m3 for 50,000 m3/day and 20 years membrane lifespan, mainly associated to equipment/membranes replacement, capital and reagents.

scholarly journals Combination of Coagulation, Adsorption, and Ultrafiltration Processes for Organic Matter Removal from Peat Water

2021 ◽  
Vol 14 (1) ◽  
pp. 370
Author(s):  
Muthia Elma ◽  
Amalia Enggar Pratiwi ◽  
Aulia Rahma ◽  
Erdina Lulu Atika Rampun ◽  
Mahmud Mahmud ◽  
...  
Keyword(s):  
Organic Matter ◽  
Activated Carbon ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Aluminum Sulfate ◽  
Adsorption Process ◽  
Powdered Activated Carbon ◽  
Organic Matter Removal ◽  
Water Borne

The high content of natural organic matter (NOM) is one of the challenging characteristics of peat water. It is also highly contaminated and contributes to some water-borne diseases. Before being used for potable purposes, peat water must undergo a series of treatments, particularly for NOM removal. This study investigated the effect of coagulation using aluminum sulfate coagulant and adsorption using powdered activated carbon (PAC) as a pretreatment of ultrafiltration (UF) for removal of NOM from actual peat water. After preparation and characterization of polysulfone (Psf)-based membrane, the system’s performance was evaluated using actual peat water, particularly on NOM removal and the UF performances. The coagulation and adsorption tests were done under variable dosings. Results show that pretreatment through coagulation–adsorption successfully removed most of the NOM. As such, the UF fouling propensity of the pretreated peat water was substantially lowered. The optimum aluminum sulfate dosing of 175 mg/L as the first pretreatment stage removed up to 75–78% NOM. Further treatment using the PAC-based adsorption process further increased 92–96% NOM removals at an optimum PAC dosing of 120 mg/L. The final UF-PSf treatment reached NOM removals of 95% with high filtration fluxes of up to 92.4 L/(m2.h). The combination of three treatment stages showed enhanced UF performance thanks to partial pre-removal of NOM that otherwise might cause severe membrane fouling.

Ammonia oxidation at low temperature in a high concentration powdered activated carbon membrane bioreactor

2002 ◽  
Vol 2 (2) ◽  
pp. 169-176 ◽  
Author(s):  
G. Seo ◽  
S. Takizawa ◽  
S. Ohgaki
Keyword(s):  
Activated Carbon ◽  
Water Temperature ◽  
Membrane Bioreactor ◽  
Ammonia Oxidation ◽  
Hollow Fiber Membrane ◽  
Powdered Activated Carbon ◽  
Carbon Membrane ◽  
High Concentration ◽  
Filtration Resistance ◽  
Cake Layer

In this study, a membrane bioreactor (MBR) with high concentration of powdered activated carbon was investigated to enhance the oxidation of ammonia at a water temperature lower than 4°C. A semi-pilot scale submersed suction type MBR was operated with a hollow fiber membrane module having a nominal pore size of 0.1μm and an effective filtration area of 0.05 m2. A powder activated carbon (PAC) concentration of 40 g/L was maintained in the reactor and the PAC was not replaced during the experiment. A control reactor without PAC was also operated for comparison. Water temperature of both reactors was controlled at 25, 10, 4 and 2°C. At a water temperature of 4°C, the influent ammonia nitrogen of 10 mg/L was removed completely in the reactor with PAC. On the other hand, the effluent concentration of the control reactor was fluctuated in a range of 3-6 mg/L. In addition, nitrite nitrogen was detected in the control reactor up to a maximum concentration of 6 mg/L at the same temperature. Still high removal efficiency was obtained in the reactor with PAC even at 2°C, but almost no ammonia oxidation was observed in the control reactor. The average ammonia oxidation rate of the powdered activated carbon reactor was 1.3-3.2 mg/L.h, which is 4.5 times higher than that of the control (0.51-0.63 mg/L.h). Filtration resistance was 2.45 × 1012m-1 for the reactor with PAC, which is one order lower than that of the control reactor (1.64 × 1013m-1). The microbial cake layer on the membrane surface caused the larger filtration resistance for the control reactor. Only one chemical cleaning was conducted for the membrane in the PAC reactor at the flux of 0.4-0.7 m/d while 3 times cleaning was required for that of the control.

Effect of low dosages of powdered activated carbon on membrane bioreactor performance

2012 ◽  
Vol 65 (5) ◽  
pp. 954-961 ◽  
Author(s):  
Maxime Remy ◽  
Hardy Temmink ◽  
Wim Rulkens
Keyword(s):  
Activated Carbon ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Membrane Bioreactors ◽  
Powdered Activated Carbon ◽  
Filtration Time ◽  
Sludge Flocs ◽  
Operational Costs ◽  
Long Term Effect

Previous research has demonstrated that powdered activated carbon (PAC), when applied at very low dosages and long SRTs, reduces membrane fouling in membrane bioreactors (MBRs). This effect was related to the formation of stronger sludge flocs, which are less sensitive to shear. In this contribution the long-term effect of PAC addition was studied by running two parallel MBRs on sewage. To one of these, PAC was dosed and a lower fouling tendency of the sludge was verified, with a 70% longer sustainable filtration time. Low PAC dosages showed additional advantages with regard to oxygen transfer and dewaterability, which may provide savings on operational costs.

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