The Efficiency of Carbon Dioxide and Hydrogen Sulphide Adsorption using Impregnated Granular Activated Carbon and Zeolite

Abstract. Four pilot (biological) granular activated carbon ((B)GAC) filters were operated to quantify the effects of ozonation and water temperature on the biodegradation of natural organic matter (NOM) in (B)GAC filters. Removal of dissolved organic carbon (DOC), assimilable organic carbon (AOC) and oxygen and the production of carbon dioxide were taken as indicators for NOM biodegradation. Ozonation stimulated DOC and AOC removal in the BGAC filters, but had no significant effect on oxygen removal and carbon dioxide production. The temperature had no significant effect on DOC and AOC removal, while oxygen removal and carbon dioxide production increased with increasing temperature. Multivariate linear regression was used to quantify these relations. In summer the ratio between oxygen consumption and DOC removal exceeded the theoretical maximum of 2.5 g O2·g C−1 and the ratio between carbon dioxide production and DOC removal exceeded the theoretical maximum of 3.7 g CO2·g C−1. Bioregeneration of large NOM molecules could explain this excesses and the non-correlation between DOC and AOC removal and oxygen removal and carbon dioxide production. However bioregeneration of large NOM molecules was considered not likely to happen, due to sequestration.

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Effects of ozonation and temperature on the biodegradation of natural organic matter in biological granular activated carbon filters

Drinking Water Engineering and Science ◽

10.5194/dwes-4-25-2011 ◽

2011 ◽

Vol 4 (1) ◽

pp. 25-35 ◽

Cited By ~ 11

Author(s):

L. T. J. van der Aa ◽

L. C. Rietveld ◽

J. C. van Dijk

Keyword(s):

Carbon Dioxide ◽

Organic Matter ◽

Oxygen Consumption ◽

Activated Carbon ◽

Organic Carbon ◽

Natural Organic Matter ◽

Granular Activated Carbon ◽

Carbon Dioxide Production ◽

Theoretical Maximum ◽

Assimilable Organic Carbon

Abstract. Four pilot (biological) granular activated carbon ((B)GAC) filters were operated to quantify the effects of ozonation and water temperature on the biodegradation of natural organic matter (NOM) in (B)GAC filters. The removal of dissolved organic carbon (DOC), assimilable organic carbon (AOC) and oxygen and the production of carbon dioxide were taken as indicators for NOM biodegradation. Ozonation stimulated DOC and AOC removal in the BGAC filters, but had no significant effect on oxygen consumption or carbon dioxide production. The temperature had no significant effect on DOC and AOC removal, while it had a positive effect on oxygen consumption and carbon dioxide production. Multivariate linear regression was used to quantify these relationships. In summer, the ratio between oxygen consumption and DOC removal was approximately 2 times the theoretical maximum of 2.6 g O2 g C−1 and the ratio between carbon dioxide production and DOC removal was approximately 1.5 times the theoretical maximum of 3.7 g CO2 g C−1. The production and loss of biomass, the degassing of (B)GAC filters, the decrease in the NOM reduction degree and the temperature effects on NOM adsorption could only partly explain these excesses and the non-correlation between DOC and AOC removal and oxygen consumption and carbon dioxide production. It was demonstrated that bioregeneration of NOM could explain the excesses and the non-correlation. Therefore, it was likely that bioregeneration of NOM did occur in the (B)GAC pilot filters.

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Anaerobic degradation of 2,4,6-trinitrotoluene in granular activated carbon fluidized bed and batch reactors

Water Science & Technology ◽

10.2166/wst.2001.0016 ◽

2001 ◽

Vol 43 (1) ◽

pp. 67-75 ◽

Cited By ~ 8

Author(s):

M. A. Moteleb ◽

M. T. Suoidan ◽

J. Kim ◽

J. L. Davel ◽

N. R. Adrian

Keyword(s):

Carbon Dioxide ◽

Activated Carbon ◽

Fluidized Bed ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Granular Activated Carbon ◽

Batch Reactors ◽

Serum Bottle ◽

Degradation Rates ◽

Water Waste

In this study, an anaerobic fluidized bed reactor (AFBR) was used to treat a synthetically produced pink water waste stream containing trinitrotoluene (TNT). The synthesized waste consisted of 95 mg/l-TNT, the main contaminant in pink water, which was to be co-metabolized with 560-mg/l ethanol. Granular activated carbon was used as the attachment medium for biological growth. TNT was reduced to a variety of compounds, mainly 2,4,6-triaminotoluene (2,4,6-TAT), 2,4-diamino-6-nitrotoluene (2,4-DA-6-NT), 2,6-diamino-4-nitrotoluene (2,6-DA-4-NT), 2-amino-4,6-dinitrotoluene (2-A-4,6-DNT), and 4-amino-2, 6-dinitrotoluene (4-A-2,6-DNT). These conversions resulted through the oxidation of ethanol to carbon dioxide under anoxic conditions, or reduction to methane under methanogenic conditions. The anaerobic reactor was charged with 1.0 kg of 16×20 U.S. Mesh Granular Activated Carbon (GAC) and was pre-loaded with 200g of TNT prior to the addition of the mixed seed culture. During the first three weeks of operation, ethanol was completely degraded and no methane was produced. Effluent inorganic carbon revealed stoichiometric conversion of the feed ethanol to dissolved inorganic carbon with accumulation of carbon dioxide in the headspace of the reactor. GAC extraction showed incremental reduction of the nitro groups to amino groups, with 2,4,6-TAT as the final product. After three weeks, the oxygen from the nitro groups was depleted and methane production commenced. The reproducibility of this phenomenon was confirmed by repeating the experiment in the same manner using an identical AFBR. Furthermore, serum bottle tests were conducted using TNT loading ratios of 0.2, 0.4, 0.8, 1.0 g-TNT/g-GAC as well as experiments in the absence of GAC. Similar behavior to that of the columns was observed, with degradation rates varying according to the particular condition. GAC greatly enhanced the degradation rates and the higher TNT loading resulted in slower degradation rates of ethanol.

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