scholarly journals Kinetic Modeling of VOC Photocatalytic Degradation Using a Process at Different Reactor Configurations and Scales

2016 ◽  
Vol 14 (1) ◽  
pp. 395-405 ◽  
Author(s):  
Aymen Amine Assadi ◽  
Bouzaza Abdelkrim ◽  
Wolbert Dominique
Keyword(s):  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Removal Rate ◽  
Pollutant Removal ◽  
Inlet Concentration ◽  
Operational Parameters ◽  
Flow Reactors ◽  
Photocatalytic Reactors ◽  
Continuous Flow Reactors

AbstractThis work investigated the performance of isovaleraldehyde (3-methylbutanal) removal from gas streams in photocatalytic reactors at room temperature. The feasibility of pollutant removal using the up-scaled reactor was systematically assessed by monitoring the removal efficiency at different operational parameters, such as geometries of reactor, air flow rate and inlet concentration. A proposal modeling for scaling up the photocatalytic reactors is described and detailed in this present study. In this context, the photocatalytic degradation of isovaleraldehyde (Isoval) in gas phase is studied. In fact, the removal rate has been compared at different continuous flow reactors: a photocatalytic tangential reactor (PTR), planar reactor and P5000 pilot. The effects of the inlet concentration, flow rate, geometries and size of reactors on the removal efficiency are also studied. A kinetic model taking into account the mass transfer step is developed. The modeling is done by introducing an equivalent intermediate (EI) formed by the photo-oxidation of Isoval. This new approach has substantially improved the agreement between modeling and experiments with a satisfactory overall description of the mineralization from lab to pilot scales.

Separation and Hydrodynamic Performance of Air-Kerosene-Water System by Bubble Column

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Abbas H. Sulaymon ◽  
Ahmed Abed Mohammed
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Bubble Column ◽  
Removal Rate ◽  
Air Flow ◽  
Bubble Diameter ◽  
Water Concentration ◽  
Hydrodynamic Performance ◽  
Air Flow Rate ◽  
Flotation Process

The separation of emulsified kerosene in water (concentration 250-750ppm) was investigated in a bubble column15.6 cm diameter and 120 cm height. The effective behaviors of bubble characteristics (bubble diameter, bubble rise velocity and air hold-up) on the removal efficiency were measured by electroresistivity probe. The effects of kerosene concentration, air flow rate,bubble diameter, liquid height, liquid viscosity, NaCl concentration, and alum on the removal rate were found. The experimental results showed that the removal efficiency increased with increasing air flow rate (1.09-2.6cm/s) and decreased with increasing CMC concentration. The results also showed that adding anionic surfactants (SLES and SDBS) leads to increase removal rate. The the flotation process was found to be first order kinetics. New correlations of air holdup and bubble diameter using dimensionless groups were derived.

Filtration Treatment of Pollutants in Urban Runoff Using Expanded Polypropylene Media

2007 ◽  
Vol 544-545 ◽  
pp. 573-576
Author(s):  
Sung Won Kang ◽  
Byung Cheol Lee ◽  
Young Im Kim ◽  
Sang Leen Yun ◽  
Yong Jin Park ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Best Management Practices ◽  
Urban Areas ◽  
Management Practices ◽  
Removal Rate ◽  
Stormwater Runoff ◽  
Expansion Ratio ◽  
Pollutant Removal ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Filter Media

Pollutants such as heavy metals and PAHs (Polynuclear Aromatic Hydrocarbons) in stormwater runoff are a major problem in urban areas because these pollutants are discharged directly, in most cases without any treatment, into the receiving environments like river and lake. Since many of the pollutants are associated with suspended particulate materials in stormwater, SS (suspended solids) is of acknowledged importance in stormwater runoff treatment by BMPs (best management practices). Filtration, which is commonly used for removing particulate matter in stormwater structural BMPs, depends on various factors (e.g., filter media size, flow rate, bed depth, filter surface properties, etc). Especially, the characteristics of filter media are important factor affecting removal efficiency of pollutants and replacement period of filter media in filtration performance. In this study, EPM (expanded polypropylene media) as a filter media was manufactured at different expansion ratios (i.e., 5, 10, 15 times) and tested in the up-flow filtration for removing pollutants in urban stormwater runoff. The specific surface area of EPM10, EPM15, EPM30, EPM54 was 0.760 m2/g, 0.799 m2/g, 0.812 m2/g, 0.845 m2/g, respectively. The SS removal efficiency (64.1%) by EPM media was higher than that (44.2%) by sand media. In case of EPM10 media, it took 175min of removal rate of filtration system to be approached under 50% and EPM15 media was spent 110min. However, the SS removal efficiency of EPM15 was over 10% higher than that of EPM10. The CODCr removal efficiency of EPM media was also increased with increasing expansion rate. The experimental results in this work show that pollutant removal efficiency by EPM media was increased with increasing expansion ratio but replacement period of media was decreased. EPM media are expected to adsorb non-biological organics like PAHs owing to its hydrophobicity.

Kinetic Analysis of COD Removal from Actual Domestic Wastewater in an Expanded Granular Sludge Bed (EGSB) Reactor

2012 ◽  
Vol 610-613 ◽  
pp. 1691-1695
Author(s):  
Chun Juan Dong ◽  
Qing Ye Pan
Keyword(s):  
Low Temperature ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Experimental Studies ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Cod Removal ◽  
Utilization Rate ◽  
Cod Removal Efficiency ◽  
Pollutant Removal Rate

Treatment of actual domestic wastewater at ambient temperature, even low temperature is considered to be difficult by traditional systems. The present study is related to treatment of actual domestic wastewater in an EGSB reactor. The study showed the effectiveness of biological treatment of actual domestic wastewater involving appropriate microorganism and granules in an EGSB reactor. At 26°C, the reactor was operated at 18.7kg COD.m−3.d−1 of average organic loading and 83% high COD removal efficiency, and even at the highest loading rate of 57.12kgCOD.m−3.d−1, the COD removal efficiency still could attain to 68%. Varied influent flow need to supply varied optimal and thus to ensure the optimal removal effect. Low temperature would cause pollutant removal rate decrease. However, enhancing could optimize the contact of sludge and wastewater and thus strengthen the performance effect. Modified Stover–Kincannon model was applied to data obtained from experimental studies in EGSB reactor. Treatment efficiencies of the reactor were investigated at different hydraulic retention times (0.5-1.3h) and different operation temperature (15°C, 26°C). The modified Stover–Kincannon model was best fitted to the EGSB reactor, and the substrate utilization rate( ), saturation constant value( ), and actual pollutant removal rate( ) were found to be , , and for 26°C, , , and for 15°C( before increasing ), and , , and for 15°C(after increasing ). Low temperature could cause decrease and thus cause distinct decreasing of COD removal efficiency. However, increasing could increase and accordingly increase COD removal efficiency.

scholarly journals Factors Affecting the Simultaneous Removal of Nitrate and Reactive Black 5 Dye via Hydrogen-Based Denitrification

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 922
Author(s):  
Tippawan Singhopon ◽  
Kenta Shinoda ◽  
Suphatchai Rujakom ◽  
Futaba Kazama
Keyword(s):  
Flow Rate ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Textile Wastewater ◽  
Pollutant Removal ◽  
Bacterial Degradation ◽  
Reactive Black 5 ◽  
Simultaneous Removal ◽  
Removal Rates ◽  
Similar Treatment

Textile wastewater (TW) contains toxic pollutants that pose both environmental and human health risks. Reportedly, some of these pollutants, including NO3-, NO2- and reactive black 5 (RB-5) dye, can be removed via hydrogen-based denitrification (HD); however, it is still unclear how different factors affect their simultaneous removal. This study aimed to investigate the effect of H2 flow rate, the sparging cycle of air and H2, and initial dye concentration on the TW treatment process. Thus, two reactors, an anaerobic HD reactor and a combined aerobic/anaerobic HD reactor, were used to investigate the treatment performance. The results obtained that increasing the H2 flow rate in the anaerobic HD reactor increased nitrogen removal and decolorization removal rates. Further, increasing the time for anaerobic treatment significantly enhanced the pollutant removal rate in the combined reactor. Furthermore, an increase in initial dye concentration resulted in lower nitrogen removal rates. Additionally, some of the dye was decolorized during the HD process via bacterial degradation, and increasing the initial dye concentration resulted in a decrease in the decolorization rate. Bacterial communities, including Xanthomonadaceae, Rhodocyclaceae, and Thauera spp., are presented as the microbial species that play a key role in the mechanisms related to nitrogen removal and RB-5 decolorization under both HD conditions. However, both reactors showed similar treatment efficiencies; hence, based on these results, the use of a combined aerobic/anaerobic HD system should be used to reduce organic/inorganic pollutant contents in real textile wastewater before discharging is recommended.

Removal of Zn (II) from Aqueous Solution by Copolymer of Grafting Acrylic Acid onto Deacetylated Konjac Glucomannan

2009 ◽  
Vol 620-622 ◽  
pp. 611-614
Author(s):  
Feng Liu ◽  
Xue Gang Luo ◽  
Xiao Yan Lin
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Removal Efficiency ◽  
Adsorption Process ◽  
Removal Rate ◽  
Konjac Glucomannan ◽  
Operational Parameters ◽  
Effective Removal ◽  
Isotherm Adsorption ◽  
Solid Liquid Interface

Removal of Zn (II) from aqueous solution by copolymer of grafting acrylic acid onto deacetylated konjac glucomannan (GADKGM) was evaluated in a bath adsorption system. Operational parameters such as pH, time, temperature and initial concentration were studied in present work. The adsorption process was relatively fast and highly effective. Removal efficiency for Zn(II) solution at the concentration of 100 mg/L was 98% at optimum operational pH of 6. The removal rate for Zn(II) on GADKGM was very fast and the removal efficiency can attain about 90% within 5 min. Isotherm adsorption data were described by Langmuir model with monolayer adsorption capacity of 125 mg/g. The negative values of thermodynamic parameters of △Go and △So indicated that adsorption process was a spontaneous process and randomness at the solid/liquid interface was decreased during the adsorption process.

scholarly journals UV Light-Irradiated Photocatalytic Degradation of Coffee Processing Wastewater Using TiO2 as a Catalyst

Environments ◽  
2020 ◽  
Vol 7 (6) ◽  
pp. 47 ◽  
Author(s):  
Gurudev Sujatha ◽  
Subramaniam Shanthakumar ◽  
Fulvia Chiampo
Keyword(s):  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Ultraviolet C ◽  
Catalyst Dosage ◽  
Uv C ◽  
Experimental Runs

The coffee industry generates a significant amount of wastewater that is rich in organic loads and is highly acidic. The present study investigates the potential of the heterogeneous photocatalytic oxidation process to reduce the pollutant load in coffee processing wastewater. The experimental runs were conducted to evaluate the effect of operative parameters such as pH, catalyst dosage, intensity of UV light irradiation, and addition of oxidant on Chemical Oxygen Demand (COD) and colour reduction. Significant results for COD and colour removal, 67%, and 70% respectively, were achieved at a pH of 4 with titanium dioxide (TiO2), and a catalyst dosage of 500 mg/L, using four ultraviolet-C (UV-C) lamps of 16 W each. With the addition of hydrogen peroxide (H2O2) as an oxidant, the removal efficiency increased to 84% and 75% for COD and colour, respectively. Finally, the best results obtained by photocatalytic degradation using UV light were compared to those using solar light. Based on the investigation, it was inferred that the pollutant removal efficiency in coffee pulping wastewater was also considerably high under sunlight. These findings may have relevance in terms of application in countries where coffee processing is carried out and where sunlight irradiance is usually strong: the technique could be exploited to decrease the pollutant content of this wastewater sustainably.

Study on Cu2+ Removal from Water via an Cation Exchange Membrane

2012 ◽  
Vol 253-255 ◽  
pp. 954-959
Author(s):  
De Hua Xie
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Potassium Ions ◽  
Inlet Concentration ◽  
Experimental Conditions ◽  
External Voltage ◽  
Initial Concentration ◽  
Exchange Membrane

The removal of Cu2+ in water via an ion-exchange membrane under no external voltage condition was studied in the research, and effects such as Cu2+ concentration, concentration of compensation potassium ions, water stirring speed, temperature and hydraulic retention time (HRT) on the removal efficiency of Cu2+ were also investigated. The results showed that when the initial concentration of bivalent ion Cu2+ was 0.0787mmol/L （5mg/L）, under the experimental conditions of the water temperature at 25 °C , the HRT was 6h, the hydraulic mixing speed was 600±25rpm, and the concentration of the compensation ion K+ was 10 times as that of Cu2+, and the removal efficiency of Cu2+ could be achieved 85%. In addition, using the same equipments, when the inlet concentration of Cu2+ increased to 0.787mmol/L (50mg/L), the removal efficiency would be decreased to 76%; while the ratio of concentration of compensation potassium ions to that of inlet Cu2+ is larger than 20, the removal efficiency would not change significantly as the ratio continued increasing; the removal efficiency would be decreased to 60% when lowering the stirring speed to 300±25rpm; the removal efficiency would be decreased to 68% when lowering the temperature to 15+1 °C; the removal rate was no significant change when the hydraulic retention time (HRT) from 6h to 12h.

scholarly journals Selective Adsorption of Vitamin E from Palm Fatty Acid Distillate on Silica-Packed Fixed-Bed Columns

2009 ◽  
Vol 5 (5) ◽  
Author(s):  
Boon-Seang Chu ◽  
Badlishah Sham Baharin ◽  
Yaakob B. Che Man ◽  
Siew-Young Quek
Keyword(s):  
Fatty Acid ◽  
Vitamin E ◽  
Flow Rate ◽  
Service Time ◽  
Fixed Bed ◽  
Inlet Concentration ◽  
Operational Parameters ◽  
Column Temperature ◽  
Bed Height ◽  
Palm Fatty Acid Distillate

Understanding the behavior of vitamin E adsorption during chromatographic separation was useful for a better control of the process. In this study, a pre-concentrated vitamin E fraction from palm fatty acid distillate (PFAD) was subjected to a normal phase silica-packed fixed-bed column for further purification. The effect of various operational parameters i.e. column bed height, vitamin E inlet concentration, column temperature and flow rate on column performance were detailed. It appeared that the breakthrough curves of all systems showed a typical S-shaped profile. The service time of the column increased when increasing the column bed height, or reducing the inlet concentration, column temperature and flow rate. It was found that column efficiency in terms of adsorbent usage rate could be improved by decreasing the inlet concentration and flow rate. Decreasing the column temperature resulted in higher column capacity, suggesting that the adsorption of vitamin E on silica was an exothermic process. The Bed Depth Service Time (BDST) model described the adsorption process well, with coefficient of determination ranging from 0.92 to 0.99 and low residual sum of square (< 0.28) and standard error (< 0.35). The model could explain the characteristic operational parameters well except for the effect of flow rate in this study.

Uniformity of Particle Removal by Aerosol Spray

2012 ◽  
Vol 187 ◽  
pp. 149-152
Author(s):  
Xiu Mei Xu ◽  
Antoine Pacco ◽  
Masayuki Wada ◽  
Leonardus Leunissen ◽  
Herbert Struyf ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Dwell Time ◽  
Removal Rate ◽  
Process Conditions ◽  
Particle Removal ◽  
Time Profiles ◽  
Temporal Decay ◽  
Aerosol Spray ◽  
Typical Process

In this work the dynamics of particle removal by aerosol spray is investigated. Local dwell time of spray cleaning is calculated numerically from the process conditions, and some striking topological similarities between the particle removal efficiency and dwell time profiles are observed. The particle removal rates, defined as the normalized speed of particle removal, are not constant during a typical process, with the highest removal rate for the first tens of milliseconds and a temporal decay as time elapses. Increasing N2flow rate results in an enhancement in both the particle removal efficiency and the particle removal rate.

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