Filtration of lake natural organic matter: Adsorption capacity of a polypropylene microfilter

2005 ◽  
Author(s):  
M KOH ◽  
M CLARK ◽  
K HOWE
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Natural Organic Matter

scholarly journals Facile synthesis of graphene wool doped with oleylamine-capped silver nanoparticles (GW-αAgNPs) for water treatment applications

2021 ◽  
Vol 11 (11) ◽  
Author(s):  
Adedapo O. Adeola ◽  
Gugu Kubheka ◽  
Evans M. N. Chirwa ◽  
Patricia B. C. Forbes
Keyword(s):  
Silver Nanoparticles ◽  
Organic Matter ◽  
Adsorption Capacity ◽  
Natural Organic Matter ◽  
Elevated Temperatures ◽  
Maximum Adsorption Capacity ◽  
Facile Synthesis ◽  
Gram Positive ◽  
Gram Negative ◽  
Process Economics

AbstractThe facile synthesis of graphene wool doped with oleylamine-capped silver nanoparticles (GW-αAgNP) was achieved in this study. The effect of concentration, pH, temperature and natural organic matter (NOM) on the adsorption of a human carcinogen (benzo(a)pyrene, BaP) was evaluated using the doped graphene wool adsorbent. Furthermore, the antibacterial potential of GW-αAgNP against selected drug-resistant Gram-negative and Gram-positive bacteria strains was evaluated. Isotherm data revealed that adsorption of BaP by GW-αAgNP was best described by a multilayer adsorption mechanism predicted by Freundlich model with least ERRSQ < 0.79. The doping of graphene wool with hydrophobic AgNPs coated with functional moieties significantly increased the maximum adsorption capacity of GW-αAgNP over GW based on the qmax and qm predicted by Langmuir and Sips models. π-π interactions contributed to sorbent-sorbate interaction, due to the presence of delocalized electrons. GW-αAgNP-BaP interaction is a spontaneous exothermic process (negative $$\Delta H^\circ$$ Δ H ∘ and $$\Delta G)$$ Δ G ) , with better removal efficiency in the absence of natural organic matter (NOM). While GW is more feasible with higher maximum adsorption capacity (qm) at elevated temperatures, GW-αAgNP adsorption capacity and efficiency is best at ambient temperature, in the absence of natural organic matter (NOM), and preferable in terms of energy demands and process economics. GW-αAgNP significantly inhibited the growth of Gram-negative Pseudomonas aeruginosa and Gram-positive Bacillus subtilis strains, at 1000 mg/L dosage in preliminary tests, which provides the rationale for future evaluation of this hybrid material as a smart solution to chemical and microbiological water pollution.

scholarly journals Effect of Changes in Physical Properties of Granular Activated Carbon (GAC) on the Adsorption of Natural Organic Matter (NOM) with Increasing the Number of Thermal Regeneration: Pore Size and NOM Molecular Weight

2021 ◽  
Vol 43 (7) ◽  
pp. 537-546
Author(s):  
Heejong Son ◽  
Sangki Choi ◽  
Byungryul An ◽  
Hyejin Lee ◽  
Hoon-Sik Yoom
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Activated Carbon ◽  
Pore Structure ◽  
Adsorption Capacity ◽  
Natural Organic Matter ◽  
Volume Ratio ◽  
The Other ◽  
Low Molecular Weight ◽  
Thermal Regeneration

Objectives : The purpose of this study was to evaluate the effect of increasing the number of regeneration of granular activated carbon (GAC) on the adsorption capacity of natural organic matter (NOM), and to suggest the technical process options associated the limit number of regeneration and the efficient use of regenerated GAC.Methods : The physicochemical properties of virgin and thermally regenerated GAC were analyzed. To evaluate the NOM adsorption capacity of virgin- and regenerated-GAC, five laboratory-scale columns packed with virgin- and regenerated-GAC were used for treating effluent from pilot-scale drinking water treatment facility. The NOM concentration in the influent and the effluent treated by each column was analyzed by LC-OCD (liquid chromatography-organic carbon detector) to evaluate the adsorption capacity of each NOM fractions (humic substances (HS), building blocks (BB), low molecular weight organics (LMWs)).Results and Discussion : Due to the change in the pore structure of GAC by thermal regeneration, the volume of micropores (< 2 nm) decreased, while the volume of mesopores (> 2 nm) increased. The volume ratio of micropore in virgin-GAC was about 60%, but it gradually decreased as the number of regenerations increased, resulting that the volume ratio of micropore in the 5th-regenerated (5th-Re) GAC decreased to 23%. On the other hand, the volume ratio of mesopore increased in proportion to the number of regenerations from 40% of the virgin GAC to 77% of the 5th-Re-GAC. The DOC adsorption capacities of the regenerated GACs were higher than that of virgin GAC, and the DOC adsorption capacity increased as the number of regenerations increased. As a result of comparing the adsorption capacity of virgin- and regenerated-GAC by NOM fractions, the adsorption capacity of high molecular weight NOM, such as HS, increased by 1.5 to 1.7 times as the number of regenerations increased. In contrast, the adsorption capacity of low molecular weight NOM, such as BB and LMWs, decreased by 78% and 48% as the number of regeneration increased. The limit number of regeneration was evaluated based on that the adsorption capacity (qe) of each NOM fractions keep over than 70% relative to its virgin GAC. As a result, the adsorption capacity for low molecular weight NOM was greatly reduced in GAC regenerated over than 3rd time, so that the 2nd-Re-GAC was valid to keep 70% removal of whole NOM fractions. Low adsorption of low molecular weight NOM (BB and LMWs) by 3rd-Re-GAC could be complemented by using together with virgin-GAC, and low adsorption of high molecular NOMs (HS) could be compensated as well.Conclusions : Due to the change in the pore structure of GAC by thermal regeneration, the DOC adsorption capacity was higher in regenerated GAC than its virgin-GAC, and the adsorption capacity of DOC and high molecular weight NOM (HS) was enhanced as the number of regenerations increased. On the other hand, the pore volume of micropore was reduced by regenerations, and in more than 3rd times regenerations, the adsorption capacity of low molecular weight NOMs (BB and LMWs) was reduced by less than 70% compared to its virgin GAC, so that 2nd-Re-GAC was suggested for suitable GAC. When using a mixture of virgin- and 3rd-Re-GAC, low adsorption of low molecular weight NOM (BB and LMWs) by 3rd-Re-GAC could be complemented by using together with virgin-GAC, and low adsorption of high molecular NOMs (HS) could be compensated as well.

Adsorptive fouling of a polypropylene microfiltration membrane with dissolved natural organic matter: do membranes possess an adsorption capacity?

2006 ◽  
Vol 6 (2) ◽  
pp. 25-30 ◽  
Author(s):  
M. Koh ◽  
M.M. Clark ◽  
K.P. Ishida
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Natural Waters ◽  
Uv Light ◽  
Attenuated Total Reflectance ◽  
Infrared Spectrometry ◽  
Flux Decline ◽  
Aromatic Ether

Rejection by membrane adsorption has been observed and widely reported. However, little is known about whether membranes possess an adsorption capacity. Experimental data showed that when a hydrophobic polypropylene (PP) microfilter was used to filter a large volume of particle-free surface water containing dissolved natural organic matter (NOM), later batches of microfiltration (MF) permeate caused more flux decline to a fresh 20K-Dalton polyethersulfone (PES) ultrafilter. This suggests that membranes can have an adsorption capacity for foulants. In this research, the gradual increase in absorbance of ultraviolet (UV) light by subsequent batches of MF permeate was observed, and supports the findings from previous studies, that only a small fraction of NOM causes membrane fouling. Attenuated total reflectance Fourier transform infrared spectrometry and energy dispersive spectroscopy of fouled PP and PES membranes suggests foulants containing amide, aromatic, ether, hydroxyl and silicate functional groups. Silicates appear to participate in membrane fouling, and its removal with the small fraction of fouling NOM can reduce the fouling potential of water. These data improve our understanding of membrane fouling by natural waters, and have implications for the design of membrane plants that filter natural waters.

Micropollutant removal with saturated biological activated carbon (BAC) in ozonation–BAC process

1997 ◽  
Vol 36 (12) ◽  
pp. 283-298 ◽  
Author(s):  
Hang Kim Woo ◽  
Wataru Nishijima ◽  
Aloysius U. Baes ◽  
Mitsumasa Okada
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Natural Organic Matter ◽  
The Other ◽  
Sand Filters ◽  
Reservoir Water ◽  
Sand Filter ◽  
Biological Activated Carbon ◽  
Long Period ◽  
Micropollutant Removal

The objective of this study is to evaluate the adsorption capacity of BAC saturated with natural organic matter (NOM) for micropollutant removal which intermittently enter into water sources and to compare this to sand filtration that has no adsorbability but has biodegradability. The removal of intermittently applied micropollutants was examined with two BAC and sand filters. Two BAC filters which have been operated for 6 and 20 months and a sand filter being used for 6 months for the treatment of reservoir water were used in this experiment. EBCT of these BAC and sand filter were 15 minutes. Bromophenol (highly adsorbable but refractory) and phenol (adsorbable and biodegradable) were used instead of targeted micropollutants. Bromophenol and phenol of about 200 μg·l−1 were applied for 24 hours. The BAC 1, which was used for 20 months had already lost its adsorbability because it was saturated with NOM. BAC 2 filter which was used for 6 months had small adsorption capacity for NOM. As a result, either BAC 2 or BAC 1 removed bromophenol (160 μg·l−1) completely for 24 hours spike, but sand filter did not removed at all. Bromophenol can be removed only by adsorption, therefore bromophenol might be removed through adsorption by BAC. On the other hand, phenol (220 μg·l−1) whose adsorbability is lower than bromophenol, was removed completely by both BAC 1 and BAC 2. These results indicate that micropollutants with similar adsorbability as that of phenol and bromophenol can be removed by BAC even after a long period of operation and saturation with NOM.

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

Characterization and isolation of natural organic matter from a eutrophic reservoir

2000 ◽  
Vol 49 (5) ◽  
pp. 269-280 ◽  
Author(s):  
Cheng-Nan Chang ◽  
Ying-Shih Ma ◽  
Guor-Cheng Fang ◽  
Fang-Fong Zing
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Eutrophic Reservoir

Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Water Production ◽  
Cellulose Acetate Membranes ◽  
Wide Range ◽  
Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

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