Membrane performance in combined processes including ozonation or advanced oxidation, powdered activated carbon and coagulation — Investigations in pilot scale

Advanced treatment of wastewater is currently being discussed throughout Europe in an effort to reduce emissions to surface waters and protect drinking water resources. In this study the combination of adsorption onto powdered activated carbon (PAC) and coagulation/filtration was investigated as a single advanced treatment step for simultaneous removal of organic micropollutants (OMPs) and phosphorus from domestic secondary effluent. Two pilot-scale dual-media filters were operated in parallel for a period of 4 months to investigate the influence of PAC addition on filtration parameters and determine removal of 14 selected OMPs. OMP abatement in the PAC filter was compared to batch tests and correlated with relative removal of UV254 absorption (UVA254). Stable operation with an average PAC dose of 8 mg/L and a removal >90% of total suspended solids was possible for filtration cycles of 24 h. The results show that PAC dosing does not negatively affect either filtration resistance or removal of phosphorus by precipitation. Concentrations of benzotriazole and carbamazepine were reduced by >70%, while sulfamethoxazole and diclofenac were removed to the extent of 40–60% (median values). Relative OMP removal showed only minor fluctuations despite occasionally strong changes of influent concentrations. Moreover, the results indicate that contact times were not sufficient for complete PAC exhaustion before separation and that further adsorption onto embedded PAC in the filter significantly contributes to overall OMP removal.

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Inline dosing of powdered activated carbon and coagulant prior to ultrafiltration at pilot-scale – Effects on trace organic chemical removal and operational stability

Chemical Engineering Journal ◽

10.1016/j.cej.2021.128801 ◽

2021 ◽

Vol 414 ◽

pp. 128801

Author(s):

Christoph Schwaller ◽

Grit Hoffmann ◽

Christian X. Hiller ◽

Brigitte Helmreich ◽

Jörg E. Drewes

Keyword(s):

Activated Carbon ◽

Scale Effects ◽

Pilot Scale ◽

Powdered Activated Carbon ◽

Operational Stability ◽

Organic Chemical ◽

Trace Organic

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Nitrosamine removal: Pilot-scale comparison of advanced oxidation, nanofiltration, and biological activated carbon processes

Chemosphere ◽

10.1016/j.chemosphere.2021.130249 ◽

2021 ◽

pp. 130249

Author(s):

Hye J. Kang ◽

Jeongeem Ahn ◽

Hyeona Park ◽

Kwang-Ho Choo

Keyword(s):

Activated Carbon ◽

Advanced Oxidation ◽

Pilot Scale ◽

Biological Activated Carbon

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A hybrid fluidized-bed reactor (HFBR) based on arrayed ceramic membranes (ACMs) coupled with powdered activated carbon (PAC) for efficient catalytic ozonation: A comprehensive study on a pilot scale

Water Research ◽

10.1016/j.watres.2020.115536 ◽

2020 ◽

Vol 173 ◽

pp. 115536 ◽

Cited By ~ 2

Author(s):

Kajia Wei ◽

Zhuo Wang ◽

Changpei Ouyang ◽

Xiaoxin Cao ◽

Peng Liang ◽

...

Keyword(s):

Activated Carbon ◽

Fluidized Bed ◽

Fluidized Bed Reactor ◽

Ceramic Membranes ◽

Pilot Scale ◽

Catalytic Ozonation ◽

Powdered Activated Carbon ◽

Comprehensive Study

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

Water Science & Technology ◽

10.2166/wst.2005.0642 ◽

2005 ◽

Vol 51 (6-7) ◽

pp. 231-240 ◽

Cited By ~ 23

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.

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

Water Science & Technology ◽

10.2166/wst.2017.518 ◽

2017 ◽

Vol 77 (1) ◽

pp. 211-219 ◽

Cited By ~ 2

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.

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