Changes in Particle Size Distributions on a Fixed Bed of Granular Activated Carbon

1986 ◽  
Vol 18 (1) ◽  
pp. 31-42 ◽  
Author(s):  
E. A. Shpirt ◽  
K. T. Alben
Keyword(s):  
New York ◽  
Particle Size ◽  
Activated Carbon ◽  
Average Particle Size ◽  
Fixed Bed ◽  
Treatment Plant ◽  
Granular Activated Carbon ◽  
Water Treatment Plant ◽  
Average Diameter ◽  
Average Particle

The particle size distribution at different bed depths of a fixed bed of granular activated carbon (GAC) has been monitored during 50 weeks of a pilot column run at the Waterford, New York potable water treatment plant. Initial backwashing resulted in significant stratification of GAC in the column: larger particles (average diameter 1.18 mm) settled in the bottom of the column (105 cm), and smaller particles (average diameter 0.97 mm) were concentrated near the top (24 cm), compared to samples of unstratified virgin Calgon F400 (average diameter 1.09 mm). During column loading and initial backwashing, more fines were created than were present in the virgin GAC (average 6.5% of GAC fines in the > 40 mesh fraction, compared to only 0.3% in the > 40 mesh fraction for virgin Calgon F400). After 50 weeks of service there was an overall trend toward a smaller average particle size (0.9 mm) with development of a more regular pattern of bed stratification (1.08 mm at the bottom and 0.75 mm at the top). These changes are attributed to breaking of large particles (12-20 mesh) and creation of intermediate size particles (20-30 and 30-40 mesh).

Cost-effective water treatment of polluted surface water by using direct filtration and granular activated carbon filtration

2002 ◽  
Vol 2 (1) ◽  
pp. 233-240 ◽  
Author(s):  
J. Cromphout ◽  
W. Rougge
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Process ◽  
Treatment Plant ◽  
Granular Activated Carbon ◽  
Cost Effective ◽  
Water Treatment Plant ◽  
Direct Filtration ◽  
Carbon Filtration ◽  
Effective Water

In Harelbeke a Water Treatment Plant with a capacity of 15,000 m3/day, using Schelde river water has been in operation since April 1995. The treatment process comprises nitrification, dephosphatation by direct filtration, storage into a reservoir, direct filtration, granular activated carbon filtration and disinfection. The design of the three-layer direct filters was based on pilot experiments. The performance of the plant during the five years of operation is discussed. It was found that the removal of atrazin by activated carbon depends on the water temperature.

scholarly journals Assessing biofilm on biofilter media (granular activated carbon and anthracite) from a pilot scale drinking water treatment plant

2021 ◽  
Author(s):  
Nick Dimas
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Granular Activated Carbon ◽  
Water Treatment Plant ◽  
Pilot Scale ◽  
Microbial Biofilms ◽  
Attachment Sites

Drinking Water Treatment Plants employ biofiltration systems to increase water quality through nutrient reduction. Microbial biofilms housed in biofilter media, are responsible for nutrient uptake and biodegradation. The purpose of this study was to re-evaluate the function and efficiency of biofilter media and investigate seasonal changes in the microbial populations. TOC and DO were more reduced in Granular Activated Carbon (GAC) media than in anthracite. Heterotrophic plate counts (HPC) were conducted to establish seasonal trends on microbial population. PCR-amplified 16S rRNA fragments were sequenced to compare microbial communities. Summer samples have higher HPC than winter samples. Summer samples yielded a reduction in microbial diversity and no detectable overlap with winter samples. Confocal microscopy conducted to qualitatively visualize the structure of biofilms was complemented by quantitative COMSTAT analysis showing GAC with double the biomass due to a greater level of attachment sites. GAC outcompetes anthracite in chemical adsorption and biological activity.

scholarly journals Development of sedimentation resistant water-acrylic titanium dioxide dispersions

2021 ◽  
Vol 4 (6(112)) ◽  
pp. 51-59
Author(s):  
Antonina Dyuryagina ◽  
Aida Lutsenko
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Deposition Rate ◽  
Sedimentation Rate ◽  
Average Particle Size ◽  
Average Diameter ◽  
Average Particle ◽  
Sodium Polyacrylate ◽  
Sedimentation Stability ◽  
Film Forming

According to the results of the research, the effect of stabilization of dispersions of titanium dioxide in water-acrylic compositions was established. It was proved that in aqueous-acrylic suspensions at all variations of film-forming agent (from 0 to 5 g/dm3), the maximum of stabilizing activity of the surfactants under study is achieved at CSAS=0.25 g/dm3. The minimum deposition rate of titanium dioxide dispersions at a dosing of 0.25 g/dm3 of sodium polyacrylate was at the level of 0.097 10-3 g/s at any content of film-forming agent (Cff=0.5÷5 g/dm3) in suspensions. At the introduction of the same concentration (CSAS=0.25 g/dm3) of the polyether siloxane copolymer, a decrease in sedimentation rate to 0.053 10-3 g/s in suspensions with a limited acryl content (C≤1 g/dm3) was recorded. At an increase in the concentration of a film-forming agent (C>1 g/dm3) in suspensions, sedimentation stability decreased, which is proved by an increase in the sedimentation rate of TiO2 to 0.110∙10-3 g/s at Cff=5.0 g/dm3. It was found that in aqueous-acrylic suspensions with the film-forming content from 0.5 to 1 g/dm3, the minimum average diameter was 2.64÷3.1 μm CSAS=0.25 g/dm3. Further concentration of acryl (Cff=4÷5 g/dm3) at the same dosage of polyether siloxane copolymer was accompanied by an increase in the average particle size up to 4.30÷4.61 μm. The maximum of wedging activity of sodium polyacrylate (CSAS=0.25 g/dm3) corresponds to the same minimum of the average diameter (2–3 μm).

scholarly journals High-performance Removal of Anti-inflammatory Using Activated Carbon from Water Treatment Plant Sludge: Fixed-bed and Batch Studies

2021 ◽  
Author(s):  
Alaor Valério Filho ◽  
Luana Vaz Tholozan ◽  
Aline Lemos Arim ◽  
André Ricardo Felkl de Almeida ◽  
GABRIELA SILVEIRA DA ROSA
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Adsorption Capacity ◽  
High Performance ◽  
Fixed Bed ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Maximum Adsorption Capacity ◽  
Continuous Adsorption ◽  
Anti Inflammatory

Abstract Activated carbon from water treatment sludge (WASC) was employed as adsorbent material to remove the anti-inflammatory Nimesulide (NM) from aqueous solutions. NM adsorption was performed in batch and fixed-bed systems, evaluating pH, adsorbent dosage, adsorption kinetics, equilibrium isotherm, continuous adsorption, and simulated effluents. The kinetic data were best fitted to the Elovich model and Intraparticle diffusion reaching the equilibrium at 120 min. Langmuir model presented a better description of the equilibrium data with the maximum adsorption capacity (qmax) of 274.99 mg g− 1 from NM adsorption by WASC. The adsorbent was tested in two simulated hospital effluents and proved to be an excellent adsorbent for removing NM from an aqueous solution with the presence of salts, sugars, and other inorganics. Finally, WASC was applied in fixed-bed NM adsorption obtaining the adsorption capacity of 217.28 mg g− 1.

The Preparation and Research of PVA Embedding Zr-AC Phosphorus Adsorbent

2011 ◽  
Vol 90-93 ◽  
pp. 2438-2443
Author(s):  
Jian Min Zhang ◽  
Hong Ji Li ◽  
Zhan Yao Gao ◽  
Ni Li
Keyword(s):  
Particle Size ◽  
Activated Carbon ◽  
Boric Acid ◽  
Sodium Alginate ◽  
Phosphorus Removal ◽  
Mass Concentration ◽  
Orthogonal Experiment ◽  
Average Particle Size ◽  
Average Particle ◽  
Preparation Conditions

The hydration ZrOH was loaded in the powdered activated carbon（PAC）,the aim to modify activated carbon, then the mixed liquor including poval(PVA) and sodium alginate tech grade (SV) , as the embedding agent ,embedded the modified PAC.The main investigation were that the hydration ZrOH concentration,the ratio of embedding agent composition and Curing liquid ingredient etc. influence the phosphorus removal . The orthogonal experiment determined the optimum prepared conditions of embedding adsorbent. The experimental results showed that : the optimum loaded conditions were that PAC average particle size was 0.5-1.0mm, hydration ZrOH concentration was 0.04mol/L;the optimum embedded preparation conditions were PVA mass concentration for 8%，SV mass concentration for 1.2%; the optimum cured conditions were the curing liquid ingredient was saturated boric acid with 2% CaCl2. The adsorption of phosphorus removal efficiency was 99.27%.

Comparison of nickel oxide and palladium nanoparticle loaded on activated carbon for efficient removal of methylene blue

2014 ◽  
Vol 34 (2) ◽  
pp. 153-169 ◽  
Author(s):  
S Arabzadeh ◽  
M Ghaedi ◽  
A Ansari ◽  
F Taghizadeh ◽  
M Rajabi
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Particle Size ◽  
Activated Carbon ◽  
Nickel Oxide ◽  
High Surface ◽  
Average Particle Size ◽  
High Surface Area ◽  
Average Particle ◽  
Efficient Removal

Palladium nanoparticles (Pd-NPs) and nickel oxide nanoparticles (NiO-NPs) were synthesized and loaded on activated carbon (AC). This novel material successfully used for the removal of methylene blue (MB) dye from aqueous medium. Full characterization of both material using X-ray diffraction, transmission electron microscopy, scanning electron microscopy and Brunauer–Emmet–Teller analyses for Pd-NP show their high surface area (>1340 m2/g) and low pore size (<20 Å) and average particle size lower than 45 Å and for NiO-NP show their high surface area (>1316.1554 m2/g) and low pore size (<20 Å) and average particle size lower than 46 Å in addition to high reactive atom and presence of various functional groups. These unique properties make them possible for efficient removal of MB. In batch experimental set-up, optimum conditions for maximum removal of MB by both adsorbents were attained following searching effect of variables such as central composite design. The Langmuir isotherm was found to be highly recommended for fitting the experimental equilibrium data. The kinetic of adsorption of MB on both adsorbents strongly can be fitted by a combination of pseudo-second order and intraparticle diffusion pathway. The experimental result achieved in this article shows the superiority of Pd-NP-AC for MB removal than NiO-NP-AC, so the maximum adsorption capacities of Pd-NP-AC and NiO-NP-AC were 555.5 mg/g and 588.2 mg/g, respectively.

scholarly journals Assessing biofilm on biofilter media (granular activated carbon and anthracite) from a pilot scale drinking water treatment plant

2021 ◽  
Author(s):  
Nick Dimas
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Granular Activated Carbon ◽  
Water Treatment Plant ◽  
Pilot Scale ◽  
Microbial Biofilms ◽  
Attachment Sites

Drinking Water Treatment Plants employ biofiltration systems to increase water quality through nutrient reduction. Microbial biofilms housed in biofilter media, are responsible for nutrient uptake and biodegradation. The purpose of this study was to re-evaluate the function and efficiency of biofilter media and investigate seasonal changes in the microbial populations. TOC and DO were more reduced in Granular Activated Carbon (GAC) media than in anthracite. Heterotrophic plate counts (HPC) were conducted to establish seasonal trends on microbial population. PCR-amplified 16S rRNA fragments were sequenced to compare microbial communities. Summer samples have higher HPC than winter samples. Summer samples yielded a reduction in microbial diversity and no detectable overlap with winter samples. Confocal microscopy conducted to qualitatively visualize the structure of biofilms was complemented by quantitative COMSTAT analysis showing GAC with double the biomass due to a greater level of attachment sites. GAC outcompetes anthracite in chemical adsorption and biological activity.

scholarly journals Rietveld refinement on XRD and TEM study of nanocrystalline PbZr0:5Ti0:5O3 ceramics prepared with a soft chemistry route

2015 ◽  
Vol 33 (1) ◽  
pp. 18-24 ◽  
Author(s):  
T.K. Mandal
Keyword(s):  
Particle Size ◽  
Rietveld Refinement ◽  
Average Particle Size ◽  
Average Diameter ◽  
Average Particle ◽  
Soft Chemistry ◽  
Hexagonal Symmetry ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Bet Method

AbstractPbZr0:5Ti0:5O3 nanopowders (~27 nm) have been prepared by a controlled reconstructive thermal decomposition and crystallization from an amorphous polymeric precursor with polyvinyl alcohol (PVA) and sucrose at 400 to 700 °C in air. The Rietveld refinement of the XRD profiles which were recorded at room temperature for the PbZr0:5Ti0:5O3 powder prepared by a thermal treatment at 700 °C for 2 h, confirmed the P4mm tetragonal crystal structure of the as prepared PbZr0:5Ti0:5O3 nanopowders, with a = 0.4036 nm and c = 0.4147 nm. A hexagonal symmetry (R3c), with a = 0.5774 nm and c = 1.4212 nm, was also detected from Rietveld refinement analysis. Thus, tetragonal and hexagonal phases were found to coexist with the as prepared PbZr0:5Ti0:5O3 nanopowders. The average particle size (D) of the PbZr0:5Ti0:5O3 powders, estimated with the help of the specific surface area, measured by BET method, was 26.1 nm. Average D value, calculated by D2θ1/2 in the XRD peaks with the Debye-Scherrer relation was ~24 nm. TEM study made it possible to measure the particle size of PbZr0:5Ti0:5O3 powders with an average diameter of 27 nm.

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