Effect of operational modes on the removal of a synthetic organic chemical by powdered activated carbon during ultrafiltration

2001 ◽  
Vol 1 (5-6) ◽  
pp. 39-47
Author(s):  
Y. Matsui ◽  
A. Yuasa ◽  
F. Colas
Keyword(s):  
Activated Carbon ◽  
Cross Flow ◽  
Powdered Activated Carbon ◽  
Organic Chemical ◽  
Filtration Cycle ◽  
Dead End ◽  
Synthetic Organic Chemical ◽  
The Cross ◽  
Short Time ◽  
Operational Modes

The effects of operational modes on the removal of a synthetic organic chemical (SOC) in natural water by powdered activated carbon (PAC) during ultrafiltration (UF) were studied, through model simulations and experiments. The removal percentage of the trace SOC was independent of its influent concentration for a given PAC dose. The minimum PAC dosage required to achieve a desired effluent concentration could quickly be optimized from the C/C0 plot as a function of the PAC dosage. The cross-flow operation was not advantageous over the dead-end regarding the SOC removal. Added PAC was re-circulated as a suspension in the UF loop for only a short time even under the cross-flow velocity of gt; 1.0 m/s. The cross-flow condition did not contribute much to the suspending of PAC. The pulse PAC addition at the beginning of a filtration cycle resulted in somewhat better SOC removal than the continuous PAC addition. The increased NOM loading on PAC which was dosed in a pulse and stayed longer in the UF loop could possibly further decrease the adsorption rate.

Drinking water production by coagulation-microfiltration and adsorption-ultrafiltration

1998 ◽  
Vol 37 (10) ◽  
pp. 135-146 ◽  
Author(s):  
Akira Yuasa
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Hollow Fiber ◽  
Cross Flow ◽  
Ceramic Membranes ◽  
Cellulose Acetate Membrane ◽  
Water Recovery ◽  
Dead End ◽  
Iron Manganese ◽  
Gac Adsorption

Microfiltration (MF) and ultrafiltration (UF) pilot plants were operated to produce drinking water from surface water from 1992 to 1996. Microfiltration was combined with pre-coagulation by polyaluminium chloride and was operated in a dead-end mode using hollow fiber polypropylene and monolith type ceramic membranes. Ultrafiltration pilot was operated in both cross-flow and dead-end modes using hollow fiber cellulose acetate membrane and was combined occasionally with powdered activated carbon (PAC) and granular activated carbon (GAC) adsorption. Turbidity in the raw water varied in the range between 1 and 100 mg/L (as standard Kaolin) and was removed almost completely in all MF and UF pilot plants to less than 0.1 mg/L. MF and UF removed metals such as iron, manganese and aluminium well. The background organics in the river water measured as KMnO4 demand varied in the range between 3 and 16 mg/L. KMnO4 demand decreased to less than 2 mg/L and to less than 3 mg/L on the average by the coagulation-MF process and the sole UF process, respectively. Combination of PAC or GAC adsorption with UF resulted in an increased removal of the background organics and the trihalomethanes formation potential as well as the micropollutants such as pesticides. Filtration flux was controlled in the range between 1.5 and 2.5 m/day with the trans-membrane pressure less than 100 kPa in most cases for MF and UF. The average water recovery varied from 99 to 85%.

p-Nitrophenol removal by combination of powdered activated carbon adsorption and ultrafiltration – comparison of different operational modes

2008 ◽  
Vol 42 (15) ◽  
pp. 4117-4124 ◽  
Author(s):  
Ivana Ivančev-Tumbas ◽  
Ralph Hobby ◽  
Benjamin Küchle ◽  
Stefan Panglisch ◽  
Rolf Gimbel
Keyword(s):  
Activated Carbon ◽  
Powdered Activated Carbon ◽  
Activated Carbon Adsorption ◽  
Carbon Adsorption ◽  
Operational Modes

Adjoint sensitivity and optimal perturbations of the low-speed jet in cross-flow

2019 ◽  
Vol 877 ◽  
pp. 330-372
Author(s):  
Marc A. Regan ◽  
Krishnan Mahesh
Keyword(s):  
Shear Layer ◽  
Time Horizon ◽  
Cross Flow ◽  
Adjoint Equations ◽  
Low Speed ◽  
Time Horizons ◽  
Jet In Cross Flow ◽  
Jet Nozzle ◽  
The Cross ◽  
Short Time

The tri-global stability and sensitivity of the low-speed jet in cross-flow are studied using the adjoint equations and finite-time horizon optimal disturbance analysis at Reynolds number $Re=2000$, based on the average velocity at the jet exit, the jet nozzle exit diameter and the kinematic viscosity of the jet, for two jet-to-cross-flow velocity ratios $R=2$ and $4$. A novel capability is developed on unstructured grids and parallel platforms for this purpose. Asymmetric modes are more important to the overall dynamics at $R=4$, suggesting increased sensitivity to experimental asymmetries at higher $R$. Low-frequency modes show a connection to wake vortices. Adjoint modes show that the upstream shear layer is most sensitive to perturbations along the upstream side of the jet nozzle. Lower frequency downstream modes are sensitive in the cross-flow boundary layer. For $R=2$, optimal analysis reveals that for short time horizons, asymmetric perturbations dominate and grow along the counter-rotating vortex pair observed in the cross-section. However, as the time horizon increases, large transient growth is observed along the upstream shear layer. When $R=4$, the optimal perturbations for short time scales grow along the downstream shear layer. For long time horizons, they become hybrid modes that grow along both the upstream and downstream shear layers.

scholarly journals PENINGKATAN KINERJA MEMBRAN ULTRAFILTRASI ALIRAN DEAD-END PADA PENYISIHAN BAHAN ORGANIK DALAM EFLUEN IPAL DOMESTIK DENGAN PRA-PERLAKUAN ADSORPSI

2020 ◽  
Vol 2 (2) ◽  
pp. 23-28
Author(s):  
Anisa Yuliani ◽  
Mahmud Mahmud ◽  
Chairul Abdi
Keyword(s):  
Activated Carbon ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Powdered Activated Carbon ◽  
Dead End ◽  
Modified Fouling Index

Salah satu kendala yang membatasi kinerja membran ultrafiltrasi (UF) yaitu fouling membran.   Keberadaan Bahan Organik (BO) merupakan salah satu penyebab utama terjadinya fouling membran pada air efluen IPAL Domestik.  Oleh karena itu, perlu dilakukan pra-perlakuan adsorpsi karbon aktif untuk mengurangii foulingi dani meningkatkani performai membrani UF. Penelitian ini bertujuan untuk mengetahui proses pengolahan air efluen dengan kondisi terbaik pada proses hibrid adsorpsi dan Ultrafiltrasi (UF) selulosa asetat (SA), serta menganalisis terbentuknya fouling membran pada proses hibrid adsorpsi dan UF-SA.  Karbon aktif yang digunakan pada rencana penelitian ini adalah Powdered Activated Carbon (PAC) dengan interval variasi dosis 25 mg/L pada rentang 25 mg/L-200mg/L serta pH 4.  Metode yang digunakan pada proses pra-perlakuan adsorpsi menggunakan sistem batch dengan pengadukan adsorpsi 180 rpm selama 240 menit.   Kemudian, dialirkan pada membran UF-SA menggunakan sistem aliran dead-end dengan variasi tekanan operasi 1-3 bar dengan interval 0,5 bar pada pH 4 selama 120 menit.   Selanjutnya dicari kondisi terbaik proses hibrid adsorpsi dan UF-SA dengan cara mengatur dosis optimum (dinaikkan maupun diturunkan), sehingga didapatkan tiga variasi dosis.   Analisis kandungan BO dilakukan melalui pengukuran parameter Dissolved Organic Carbon (DOC), UV254, E4/E6  , dan UV456 menggunakan TOC Analyzer dan Spektrofotometer UV serta karakterisasi membran dengan permeabilitas.   Hipotesis dari penelitian ini adalah pra-perlakuani adsorpsii karboni aktifi berpengaruh untuki mereduksii foulingi pada membrani UF-SA, dan model Modified Fouling Index (MFI) dapat menggambarkan pembentukan fouling pada proses hibrid adsorpsi dan UF-SA pada penyisihan air efluen.

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