Sequential anaerobic/aerobic biodegradation of chlorinated hydrocarbons in activated carbon barriers

2002 ◽  
Vol 2 (2) ◽  
pp. 51-58 ◽  
Author(s):  
A. Tiehm ◽  
M. Gozan ◽  
A. Müller ◽  
H. Schell ◽  
H. Lorbeer ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Biological Activity ◽  
Activated Carbon ◽  
Vinyl Chloride ◽  
Reductive Dechlorination ◽  
Chlorinated Hydrocarbons ◽  
Aerobic Biodegradation ◽  
Anaerobic Conditions ◽  
Biological Activated Carbon ◽  
Batch Tests

The aim of this study is to develop a long lasting, sequential anaerobic/aerobic biological activated carbon barrier. In the biobarrier, pollutant adsorption on granular activated carbon (GAC) and biodegradation occur simultaneously. Trichloroethene (TCE), chlorobenzene (CB), and benzene were used as model pollutants. In the first barrier, that was operated under anaerobic conditions with sucrose and ethanol as auxiliary substrates, TCE was completely converted to lower chlorinated metabolites, predominantly cis-dichloroethene (cis-DCE). The reductive dechlorination process was stable for about 300 d, although the concomitant sulphate-reducing and methanogenic processes varied considerably. In the second barrier, that was operated with addition of hydrogen peroxide and nitrate, dechlorination was limited by a lack of oxygen and restricted mainly to CB biodegradation. Additional aerobic batch tests revealed that the metabolites of anaerobic TCE dechlorination, i.e. cis-DCE and vinyl chloride, were oxidatively dechlorinated in the presence of suitable auxiliary substrates such as ethene, CB, benzene, or sucrose and ethanol. During periods of low biological activity, elimination of TCE and CB occurred by adsorption in the GAC barriers. The pre-sorbed pollutants were available for subsequent biodegradation resulting in a bioregeneration of the activated carbon barriers.

scholarly journals Auxiliary Substrates for Elimination of Trichloroethene, Monochlorobenzene, and Benzene in a Sequential Anaerobic–Aerobic GAC Biobarrier

2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 68
Author(s):  
M. Gozan ◽  
A. Mueller ◽  
A. Tiehm
Keyword(s):  
Vinyl Chloride ◽  
Reductive Dechlorination ◽  
Biological Degradation ◽  
Anaerobic Conditions ◽  
Batch Studies ◽  
Second Stage ◽  
Competitive Reactions ◽  
Novel Concept ◽  
Tce Degradation ◽  
Granulated Activated Carbon

Sequential anaerobic-aerobic barrier is a novel concept for groundwater bioremediation. Trichloroethene (TCE), monochlorobenzene (MCB), and benzene (BZ) were used as model contaminants representing contaminant cocktails frequently found in the contaminated subsurface. The autochthonous microflora from a contaminated field was inoculated to eliminate model contaminants in a set of sequential anaerobic–aerobic granulated activated carbon (GAC) columns and batch studies. In the anaerobic column, the TCE was reductively dechlorinated through cis-dichloroethene (cis-DCE), vinyl chloride (VC), and ethene (ETH). Ethanol and sucrose as auxiliary substrates were added to donate electrons. In the second stage, MCB, BZ, and the lower chlorinated metabolites of TCE degradation, i.e. cis-Dichloroethene (cisDCE) and vinyl chloride (VC), were oxidatively degraded with addition of hydrogen peroxide and nitrate. This paper examines the influence of auxiliary substrates on the biological degradation of model pollutants. In the anaerobic barrier, the auxiliary substrates supply should be maintained low but stoichiometrically adequate for supporting reductive dechlorination. Supplying higher amount of auxiliary substrates provoked competitive reactions in anaerobic conditions, such as sulfate reduction and methanogenesis. If the auxiliary substrates are not utilized completely in the anaerobic phase, the remaining compounds flow into the aerobic phase. This led to unwanted conditions, i.e. oxidation of auxiliary substrates instead of pollutant elimination, and a higher consumption of electron acceptors. In the aerobic barrier, in particular, ethene proved to be a suitable auxiliary substrate for cometabolic degradation of cisDCE.

Aerobic Biodegradation of Aromatic and Chlorinated Hydrocarbons Commonly Detected in Landfill Leachates

1988 ◽  
Vol 23 (3) ◽  
pp. 460-475 ◽  
Author(s):  
Della J. Berwanger ◽  
James F. Barker
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Sediment ◽  
Chlorinated Hydrocarbons ◽  
Aerobic Biodegradation ◽  
Ethyl Benzene ◽  
Landfill Leachates ◽  
Toxic Level ◽  
Benzene Toluene ◽  
Hazardous Organics

Abstract Aromatic and chlorinated hydrocarbons are hazardous organics which persist in groundwater impacted by landfill leachate. Recent studies have indicated that the aromatics biodegrade readily under aerobic conditions. Similarly, methane-oxidizers are reported to metabolize trichloroethylene. This study investigates an in-situ biorestoration scheme involving stimulating aerobic biodegradation in a contaminated anaerobic, methane-saturated groundwater using hydrogen peroxide as an oxygen source. Batch biodegradation experiments were conducted with groundwater and core obtained from the Gloucester Landfill, Ottawa, Canada. Hydrogen peroxide, added at a non-toxic level, provided oxygen which promoted the rapid biodegradation of benzene, toluene, ethyl benzene, o-, m-, and p-xylene. Morphologically different methane-oxidizing cultures were obtained from Gloucester groundwater and a surface sediment. Both cultures degraded trichloroethylene in microcosms containing a mineral media and Gloucester core. Degradation was not observed when the mineral madia was replaced with Gloucester groundwater, or when other chlorinated hydrocarbons were added. Additional research is required to identify and overcome this inhibition to trichloroethylene biodegradation, before this remedial strategy can be employed.

Improvement of biodegradation of organic substance by addition of phosphorus in biological activated carbon

1997 ◽  
Vol 36 (12) ◽  
pp. 251-257 ◽  
Author(s):  
Wataru Nishijima ◽  
Eiji Shoto ◽  
Mitsumasa Okada
Keyword(s):  
Biological Activity ◽  
Activated Carbon ◽  
Bacterial Population ◽  
Phosphorus Concentration ◽  
Organic Substances ◽  
Biodegradation Rate ◽  
Phosphorus Addition ◽  
Biological Activated Carbon ◽  
Attached Bacteria ◽  
Rate Of Increase

The purposes of this study are to clarify the behavior of phosphorus in coagulation/sedimentation process, and to evaluate the effects of phosphorus addition into biological activated carbon (BAC) treatment on the biodegradation of organic substances. Conventional coagulation/sedimentation reduced phosphorus concentration to very low level, that is, 0.002–0.004 mgP.l−1 in water containing less than 0.063 mgP.l−1. In continuous experiment, the biodegradation rate of glucose in the BAC with adsorbed phosphorus before the start of operation was 5 times higher than that in the BAC without adsorbed phosphorus. The rate of increase in bacterial population was higher in the BAC with adsorbed phosphorus compared to the BAC without adsorbed phosphorus. The biodegradation rate of glucose in the BAC without adsorbed phosphorus increased significantly by addition of phosphorus into influent. Therefore, growth and biodegradation activity of attached bacteria on BAC was limited by phosphorus of low concentration in the influent treated by coagulation/sedimentation. Adsorption of phosphorus on activated carbon before the start of operation and/or addition of phosphorus in influent will be effective to improve the biological activity on BAC.

Study of natural adsorbent chitosan and derivatives for the removal of caffeine from water

2012 ◽  
Vol 47 (1) ◽  
pp. 80-90 ◽  
Author(s):  
Serena Sanford ◽  
Kripa S. Singh ◽  
Sahil Chaini ◽  
Gaetan LeClair
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Mesoporous Materials ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Chemical Modifications ◽  
High Affinity ◽  
Natural Adsorbent ◽  
Batch Tests

The adsorption of caffeine was evaluated using natural adsorbent chitosan and three derivates of the material. Raw, H2O2 pre-treated, and a chemically altered chitosan were compared to activated carbon. Activated carbon was found to have a high affinity for caffeine (98% removal) while raw chitosan performed poorly with an average adsorption of 15.9%. Batch tests in acidic and basic conditions as well as increasing dosage did not have an effect on the performance. Chemical modifications to chitosan included calcinated mesoporous materials and non-calcinated materials, both of which increased chitosan adsorption of caffeine to 29 and 40%, respectively. Hydrogen peroxide pre-treated chitosan performed best of chitosan-based adsorbents, and reached a 46% removal of caffeine in batch adsorption tests. The majority of the adsorbents had low correlation to the Langmuir, Freundlich, and Redlich–Peterson isotherm models. However, data were sufficient to compare adsorption capacity for caffeine among activated carbon, chitosan, and chitosan derivatives.

scholarly journals Effect of Hydrogen Peroxide and Phosphate Addition on Biopolymers Formation and Changes in Head Loss in Biological Activated Carbon Process

2020 ◽  
Vol 42 (12) ◽  
pp. 654-663
Author(s):  
Heejong Son ◽  
Eun-Young Jung ◽  
Hee-Young Kim ◽  
Sang-Goo Kim
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Water Temperature ◽  
Concentration Ratio ◽  
Extracellular Polymeric Substances ◽  
Head Loss ◽  
Efficient Operation ◽  
Biological Activated Carbon ◽  
Cell Counts ◽  
The Stability

Objectives:The purpose of this study was to suggest a more efficient operation condition for the BAC(biological activated carbon) process by evaluating the change in the concentration of biopolymers in the effluent of the BAC process and the head loss of the BAC filter layer according to phosphate (PO4-P) and hydrogen peroxide (H2O2) input.Methods:During the experiment period (Feb. to Aug. 2020), the O3 dosage was fixed at 1 mg･O3/mg･DOC. Four columns with an inner diameter of 20 cm and a height of 250 cm were prepared. Empty bed contact time (EBCT) was fixed at 20 minutes and backwash was performed once a week. The four BAC columns are conventional BAC(control-BAC), enhanced BAC with hydrogen peroxide (H2O2+BAC), enhanced BAC with phosphate (PO4-P+BAC), and enhanced BAC with phosphate and hydrogen peroxide together (PO4-P+H2O2+BAC). In the case of enhanced BAC with PO4-P added, PO4-P was added with a concentration of 0.010 mg/L in the influent, and in BAC with H2O2, H2O2 was added with a concentration of 1 mg/L to the influent.Results and Discussion:According to the change of water temperature, the average head loss in control-BAC was 4.4 (25~28℃)~7.7 cm(8~12℃). In addition, PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC were 3.9~5.8 cm, 2.5~3.5 cm, and 2.6~3.5 cm, respectively. The head loss was reduced by the input of PO4-P and H2O2. During the low water temperature period, in control-BAC, the effluent biopolymers (BP) concentration was higher than the influent concentration, indicating that a large amount of EPS (extracellular polymeric substances) was produced and released from the attached biofilm. In PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC processes, the BP concentration ratio (Cout/Cin) was about 36~57% lower than that of the control-BAC during the low water temperature period. The BP concentration ratio was high when the water temperature (8~12℃) was low, and the BP concentration ratio gradually decreased as the water temperature increased. These results were very similar to those of the head loss change in the control-BAC process and the enhanced BAC process, and the BP concentration ratio and the head loss showed a very high correlation (r2=0.82~0.87). To evaluate the stability of the biofilm during the operation period, the total cell counts (TCC) in BAC treated waters were investigated. In control-BAC, PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC process, the average TCC was 46.8×106 cells, 30.3×106 cells, 21.8×106 cells, and 18.8×106 cells, respectively. Compared to the control-BAC, it was found to be 35~60% lower in the enhanced BAC processes. In addition, live cell count (LCC) ratio (LCC/TCC) was 0.84~0.89 in the enhanced BAC processes compared to 0.53 in the control-BAC. These results indicate that the biofilm stability of the enhanced BAC processes is higher than that of control-BAC.Conclusions:During the experiment, compared to the conventional BAC process, the enhanced BAC processes in which PO4-P and H2O2 were added showed a clear effect of reducing the head loss. In particular, the effect of reducing the head loss was higher when H2O2 was added than when PO4-P was added. A rapid head loss increase occurred in the conventional BAC process compared to the enhanced BAC processes in the low water temperature season is the result of the production of large amounts of EPS in the attached biofilm. The input of PO4-P or H2O2 reduces the head loss by improving the stability of the attached biofilm and reducing EPS production.

scholarly journals Effect of Phosphate and Hydrogen Peroxide on Bacterial Community and Removal Efficiency of Biological Activated Carbon (BAC) Process for Enhanced Biofiltration

2021 ◽  
Vol 43 (1) ◽  
pp. 20-31
Author(s):  
Eun-Young Jung ◽  
Byungryul An ◽  
Heejong Son
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Bacterial Community ◽  
Distribution System ◽  
Residual Chlorine ◽  
Organic Substrates ◽  
Biological Activated Carbon ◽  
Supply And Distribution ◽  
Attached Bacteria ◽  
Wide Range

Objectives:The correlation between the organic material removal ability of the enhanced BAC process injected by the phosphate (PO4-P) and/or hydrogen peroxide (H2O2) and attached bacterial community was evaluated.Methods:As pilot plant for the purification of raw water downstream of Nakdong river, 4 acrylic columns with an inner diameter of 20 cm and a height of 250 cm were operated at an empty bed contact time of 20 minutes. The four BAC columns are as followed; conventional BAC (control-BAC), enhanced BAC with phosphorus (PO4-P+BAC), enhanced BAC with hydrogen peroxide (H2O2+BAC), and enhanced BAC with phosphorus and hydrogen peroxide (PO4-P+H2O2+BAC). 0.01 mg/L of PO4-P and 1 mg/L of H2O2 were added in influent in the enhanced BAC, respectively. After 18 months of operation, activated carbon was collected from the top of each BAC column and 16S rRNA amplicon sequence analysis was performed.Results and Discussion:The long-term addition of PO4-P and H2O2 contributes the increase of biomass and activity of attached bacteria, respectively. In the attached bacterial community of conventional and enhanced process, Proteobacteria phylum is the most dominant specie and both α-Proteobacteria class and β-Proteobacteria class are also highly present. Each enhanced BAC exhibits very high bacterial community similarity based on the composition of various genera but it is completely different with conventional BAC. In particular, Bradyrhizobium, Sphingomonas, Methylobacterium, Sphingobium, Belnapia, Burkholderia, Polaromonas, and Desulfuromonas, which have excellent metabolism functions for a wide range of organic substrates, are highly dominated in the enhanced BAC process. The concentration of Biodegradable Dissolved Organic Carbon (BDOC) is obtained close to 0.15 mg/L for conventional BAC and less than 0.15 mg/L for enhanced BAC process, respectively. In general, the higher BDOC concentration can result in reducing biostability in water supply and distribution system when the residual chlorine concentration does not meet requirements. As result, less than 0.15 mg/L BDOC accomplished by PO4-P and H2O2 enhances the biostability.Conclusions:Compared to the conventional BAC process, the biomass and activity of attached bacteria and the ratio of the organization composition of the bacteria insides (genus) are considerably higher in the enhanced BAC process. These results achieve higher water quality and improve biostability.

New Biology for Advanced Wastewater Treatment

1999 ◽  
Vol 40 (4-5) ◽  
pp. 137-144 ◽  
Author(s):  
K. Miserez ◽  
S. Philips ◽  
W. Verstraete
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Organic Carbon ◽  
Genetically Modified Organisms ◽  
New Technologies ◽  
Chemical Oxidation ◽  
Advanced Treatment ◽  
Biological Activated Carbon ◽  
Catabolic Potential ◽  
New Biology

A number of new technologies for the advanced treatment of wastewater have recently been developed. The oxidative cometabolic transformation by methanotrophs and by nitrifiers represent new approaches in relation to organic carbon. The Biological Activated Carbon Oxidative Filters characterized by thin biofilms are also promising in that respect. Moreover, implementing genetically modified organisms with improved catabolic potential in advanced water treatment comes into perspective. For very refractory effluents chemical support techniques, like e.g. strong chemical oxidation, can be lined up with advanced biology.

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