scholarly journals Biodegradable dissolved organic carbon removal during biological filtration on granular actived carbon

2005 ◽  
Vol 5 ◽  
pp. 33-49 ◽  
Author(s):  
P. Bouillot ◽  
P. Servais ◽  
G. Billen ◽  
Y. Levi
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Contact Time ◽  
Treatment Plant ◽  
Bacterial Biomass ◽  
Distribution Networks ◽  
Microbial Colonization ◽  
Water Volume ◽  
Biological Filtration ◽  
Influent Water

In drinking water production, filtration on granular activated carton (GAC) is generally used in order to remove by adsorption the dissolved organic matter. Nevertheless, the adsorption capacity of GAC is rapidly saturated and it is so necessary to regenerate the GAC. An interesting alternate has been applied in some treatment plants. It consists to use GAC filtration without regeneration taking benefit of the activity of the microbial community which colonize the GAC particles (RITTMAN and HUCK, 1989). In fact, this biological filtration offers the advantage to specially remove the biodegradable fraction of the dissolved organic carbon (BDOC), which is responsible for the problem of bacterial growth into the distribution networks. The bacterial nature of the BDOC removal achieved by the biological filtration on GAC has been now clearly demonstrated (SERVAIS et al., 1991) and some important results of the functioning of these filters has been obtained in studies conducted on pilots filters (BOUILLOT et al., 1990; SERVAIS et al., 1992). These studies have for example shown that only a very small part of the bacterial biomass produced in the filter is exported with the outflow. In the present study, biological filtration has been investigated in a full scale treatment line at Choisy-le-Roi in the Parisian suburbs and the results compared with those gained on pilot filters. The working conditions of the three GAC filter studied are presented in table 1 and compared with those of pilot filters used in a previous study conducted al Neuilly-sur-Marne (table 2). The microbial colonization has been followed in two of the liners. If lasted roughly 3 months to reach biological equilibration, it corresponds to a water volume filtrated of 12 500 m3 per m3 of GAC. Efficiency of the removal during this period is presented in figure 2. Progressively, biological processes take turn with adsorption (fig. 1). As already demonstrated by SERVAIS et al. (1992), the efficiency of biological filtration, calculated in percentage of BDOC removal, increases with increasing contact time whatever the filtration velocity could be in the range 2 m/h to 18 m/h (fig. 3). However, the percentage of BDOC, at similar temperature, is higher in the GAC filters at Choisy-le-Roi than at Neuilly-sur-Marne. The fixed bacterial biomass is also higher at Choisy-le-Roi (average 7.5 µgC/cm3) than at Neuilly-sur-Marne (average 2 µC/cm3). Following during two years the functioning of the n° 56 and 38 filters (tables 3, 4 and fig. 5, 7), it seems that the global efficiency of filtration is better in 1990 than in 1989. This can be linked to the greater fluctuations in BDOC in the influent water in 1989 than in 1990, as shown on figure 8. Fluctuations in the quality of the influent water requires a period to reach the equilibrium during which the effluent is charchacterized by a lower quality (fig. 8). This period is longer at low temperature. The mathematical modal based on the kinetics of the basic microbiological processes involved in biological filtration (the CHABROL model) has been previously developed (BILLEN et al., 1992) in order la simulate the performances of the filtration. It can be used to simulate the vertical profiles of BDOC and bacterial biomass in the filters of the Choisy-le-Roi treatment plant, with modifying only one parameter in the model, the average bacterial mortality “kd” (fig. 4). BDOC decreases versus empty bed contact time (EBCT) calculated by the modal are presented on figure 6 for the Choisy-le-Roi and Neuilly-sur-Marne treatment plants and for two temperatures. From a management point of view, the minimum BDOC is reached for contact time between 15 and 20 minutes at Neuilly-sur-Marne, while at Choisy-le-Roi it is rather between 10 and 15 minutes. In conclusion, BDOC measurements and CHABROL modal constitute powerful tools for management and design of biological GAC filters.

Biodegradability of Danube bank filtrate and its enhancement by ozonation

2007 ◽  
Vol 7 (3) ◽  
pp. 139-144
Author(s):  
V.Z. Cukic ◽  
V.L. Knezic
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Distribution Networks ◽  
Organic Content ◽  
Low Risk ◽  
Danube River ◽  
Source Water ◽  
Transformation Processes ◽  
By Products

The reduction of organic content through transformation processes in the Danube aquifer along a studied area, biodegradability of Danube bank filtrate and its enhancement by ozonation have all been examined in a study carried out in order to assess amenability of Danube bank filtrate for bio-filtration. As determined during the study period Dissolved Organic Carbon (DOC) varied from 4.6–6.5 mgC/L and from 2.8–3.7 mgC/L in Danube River and Danube bank filtrate respectively. As determined 11.2% of Danube bank filtrate DOC was bio-degradable. A substantial enhancement of biodegradability has been observed after the application of Ozone dosages ranging from 0.45 to 0.9 mgO3/ mgC. It was concluded that Danube bank filtrate itself is not amenable for bio-filtration but an enhancement of its bio-degradability by ozonation could make bio-filtration a reasonable and economical option for reducing of DOC content to the levels that provide low risk of excessive disinfection by-products formation and prevent bacterial re-growth in distribution networks of cities using Danube bank filtrate as the source water.

scholarly journals Seasonal variations in concentration and lability of dissolved organic carbon in Tokyo Bay

2015 ◽  
Vol 12 (1) ◽  
pp. 269-279 ◽  
Author(s):  
A. Kubo ◽  
M. Yamamoto-Kawai ◽  
J. Kanda
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
River Water ◽  
Seasonal Variations ◽  
Relative Concentration ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Tokyo Bay ◽  
Chl A

Abstract. Concentrations of recalcitrant and bioavailable dissolved organic carbon (DOC) and their seasonal variations were investigated at three stations in Tokyo Bay, Japan, and in two freshwater sources flowing into the bay. On average, recalcitrant DOC (RDOC), as a remnant of DOC after 150 days of bottle incubation, accounted for 78% of the total DOC in Shibaura sewage treatment plant (STP) effluent, 67% in the upper Arakawa River water, 66% in the lower Arakawa River water, and 78% in surface bay water. Bioavailable DOC (BDOC) concentrations, defined as DOC minus RDOC, were lower than RDOC at all stations. In freshwater environments, RDOC concentrations were almost constant throughout the year. In the bay, RDOC was higher during spring and summer than in autumn and winter because of freshwater input and biological production. The relative concentration of RDOC in the bay derived from phytoplankton, terrestrial, and open-oceanic waters was estimated to be 8–10, 21–32, and 59–69%, respectively, based on multiple regression analysis of RDOC, salinity, and chl a. In addition, comparison with previous data from 1972 revealed that concentrations of RDOC and BDOC have decreased by 33 and 74% at freshwater sites and 39 and 76% in Tokyo Bay, while the ratio of RDOC to DOC has increased. The change in DOC concentration and composition was probably due to increased amounts of STP effluent entering the system. Tokyo Bay exported mostly RDOC to the open ocean because of the remineralization of BDOC.

scholarly journals Preliminary investigation into the claims of the IBROM system

2020 ◽  
Vol 55 (2) ◽  
pp. 198-208
Author(s):  
Zahra Vojdani ◽  
Beata Gorczyca
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Preliminary Investigation ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Biodegradable Dissolved Organic Carbon ◽  
Reverse Osmosis Membranes

Abstract Membrane filtration is commonly applied to reduce dissolved organic carbon (DOC) to control the formation of trihalomethanes (THMs); however, high levels of DOC can cause severe fouling of reverse osmosis membranes. The integrated biological and reverse osmosis membrane (IBROM) process is a combination of biological filters and reverse osmosis membranes. The IBROM process claims to remove biodegradable dissolved organic carbon (BDOC), which apparently should result in reduced membrane fouling. The goal of this research was to conduct a preliminary investigation into the claims of the IBROM system, using water collected from the Herbert water treatment plant (Saskatchewan). The plant is utilizing the IBROM for the treatment of a dugout and groundwater blend (DOC of 17.5–22.7 mg/L). The results demonstrated that BDOC concentrations did not change significantly throughout the plant. Optimized laboratory-scale coagulation with polyaluminium chlorohydrate achieved 58% removal of BDOC. Oxidation with permanganate increased the concentration of BDOC (from 5.7 to 8.8 mg/L). Overall, BDOC was effectively removed by optimized coagulation rather than the IBROM system. Moreover, the results show an inverse relationship between BDOC and THMs formation potential (THMFP) in both coagulated and oxidized water. For all concentrations, more biodegradable DOC had less tendency to form THMs based on the lower THMFP.

scholarly journals A Decontamination Process to Remove Metals and Stabilise Montreal Sewage Sludge

2002 ◽  
Vol 2 ◽  
pp. 1121-1126 ◽  
Author(s):  
G. Mercier ◽  
J.F. Blais ◽  
F. Hammy ◽  
M. Lounes ◽  
J.L. Sasseville
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Treatment Plant ◽  
Average Concentration ◽  
Filter Press ◽  
High Rate ◽  
Organic Polymer ◽  
Production Plant ◽  
Set Up ◽  
Sludge Production

The Montreal Urban Community (MUC) treatment plant produces approximately 270 tons of dry sludge daily (tds/day) during physicochemical wastewater treatment. The sludges are burned and contribute to the greenhouse effect by producing atmospheric CO2. Moreover, the sludge emanates a nauseating odour during its thermal stabilisation and retains unpleasant odours for the part (25%) that is dried and granulated. To solve this particular problem, the treatment plant authorities are currently evaluating an acidic chemical leaching (sulfuric or hydrochloric acid) process at a pH between 2 and 3, using an oxidizing agent such as ferric chloride or hydrogen peroxide (METIX-AC technology, patent pending; [20]). They could integrate it to a 70 tds/day granulated sludge production process. Verification of the application of METIX-AC technology was carried out in a pilot plant set up near the sludge production plant of the MUC. The tests showed that METIX-AC technology can be advantageously integrated to the process used at the MUC. The residual copper (274 ± 58 mg/kg) and cadmium (5.6 ± 2.9 mg/kg) concentrations in the treated sludge meet legislation standards. The results have also shown that odours have been significantly eliminated for the dewatered, decontaminated, and stabilized biosolids (> 97%) compared to the non-decontaminated biosolids. A high rate of odour elimination also was obtained for the liquid leached biosolids (> 93%), compared to the untreated liquid biosolids. The fertilising value (N and P) is well preserved by the METIX-AC process. Dissolved organic carbon measurements have showed that little organic matter is brought in solution during the treatment. In fact, the average concentration of dissolved organic carbon measured in the treated liquid phase is 966 ± 352 mg/l, whereas it is 1190 ± 325 mg/l in untreated sludge. The treated sludge was first conditioned with an organic polymer and a coagulant aid. It was successfully dewatered with various dehydration equipments (filter press, rotary press, centrifuge).

Impact of operational parameters on biofiltration performance: organic carbon removal and effluent turbidity

2016 ◽  
Vol 16 (6) ◽  
pp. 1683-1692 ◽  
Author(s):  
Vivek A. Nemani ◽  
Lizbeth Taylor-Edmonds ◽  
Nicolas M. Peleato ◽  
Robert C. Andrews
Keyword(s):  
Energy Consumption ◽  
Surface Water ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Contact Time ◽  
Lake Ontario ◽  
Pilot Scale ◽  
Operational Parameters ◽  
Turbidity Removal ◽  
The Impact

The objectives of this pilot-scale study were to optimize backwash frequency and empty bed contact time (EBCT) of biofilters treating ozonated surface water from Lake Ontario. Performance was benchmarked in terms of the reduction of turbidity, dissolved organic carbon (DOC), disinfection by-product (DBP) precursors, and ultrafiltration foulants (biopolymers). Increasing the EBCT from 4 to 8 min resulted in a higher reduction of DOC (5%), trihalomethane (THM4) and haloacetic acid (HAA9) precursors (∼12%) without negatively impacting effluent turbidity (consistently below 0.4 NTU), while biopolymer removal remained unaffected (2%). The impact of varying backwash frequency (5, 10, and 25 day intervals) was also compared for biofilters operated at an EBCT of 4 min. Results showed no impact of extended run times (up to 25 days) on DOC or DBP precursor removal; however turbidity removal was affected beyond 15 days of operation. Backwashing biofilters at 10 vs 5 day intervals would result in a reduction of backwash water, energy consumption and amount to nearly $17,000 in savings for the utility.

scholarly journals Estimation of Biochemical Oxygen Demand Based on Dissolved Organic Carbon, UV Absorption, and Fluorescence Measurements

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Jihyun Kwak ◽  
Bumju Khang ◽  
Eunhee Kim ◽  
Hyunook Kim
Keyword(s):  
Wastewater Treatment ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
River Water ◽  
Biochemical Oxygen Demand ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Fluorescence Measurements ◽  
Wwtp Effluent ◽  
Software Sensors

Determination of 5-d biochemical oxygen demand (BOD5) is the most commonly practiced test to assess the water quality of surface waters and the waste loading. However, BOD5is not a good parameter for the control of water or wastewater treatment processes because of its long test period. It is very difficult to produce consistent and reliable BOD5results without using careful laboratory quality control practices. This study was performed to develop software sensors to predict the BOD5of river water and wastewater. The software sensors were based on the multiple regression analysis using the dissolved organic carbon (DOC) concentration, UV light absorbance at 254 nm, and synchronous fluorescence spectra. River water samples and wastewater treatment plant (WWTP) effluents were collected at 1-hour interval to evaluate the feasibility of the software sensors. In short, the software sensors developed in this study could well predict the BOD5of river water (r=0.78) and for the WWTP effluent (r=0.90).

scholarly journals The effect of Iron Ion on Removal Efficiency of Dissolved Organic Carbon (DOC) Using UV/TiO2

2016 ◽  
Vol 18 (2) ◽  
pp. 392-401 ◽  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Removal Efficiency ◽  
Ferric Chloride ◽  
Contact Time ◽  
Ph Value ◽  
Pearson Correlation ◽  
Complex Mixture ◽  
Iron Ion ◽  
Quasi Experimental

<div> <p>Most of water sources throughout the world contain natural organic matter (NOM), which is the best description as a complex mixture of organic compounds. The effect of iron ion on removal efficiency of dissolved organic carbon (DOC) using UV/TiO<sub>2</sub> photo catalytic oxidation (TiO<sub>2</sub>) was examined. In this quasi-experimental study, the different variables such as pH value, contact time, various concentrations of TiO<sub>2</sub>, FeCl<sub>2</sub> on the removal efficiency of DOC by the UV/TiO<sub>2</sub> on raw water of Zayandehroud in Isfahan were studied. The results were analyzed by using Pearson correlation coefficient test and SPSS software. Removal efficiency DOC improved as the amount of catalyst was increased. Maximum removal efficiency was achieved during acidic conditions (pH=3) within 60 minutes of contact time. The removal efficiency of DOC by the UV/TiO<sub>2</sub> decreased with increase of contact time. The presence of iron ions increased the rate of DOC removal by the UV/TiO<sub>2</sub>. Removal efficiency of dissolved organic carbon increased when ionic strength and initial concentration of Ferric Chloride was increased. Also, by adding particles of Ferric Chloride, Removal of dissolved organic carbon increased to 98% in comparison with absence of iron ion (78%).</p> </div> <p>&nbsp;</p>

Zooplankton responses to freshwater inflows and organic-matter pulses in a wave-dominated estuary

2016 ◽  
Vol 67 (9) ◽  
pp. 1374 ◽  
Author(s):  
James N. Hitchcock ◽  
Simon M. Mitrovic ◽  
Wade L. Hadwen ◽  
Ivor O. Growns ◽  
Ann-Marie Rohlfs
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Critical Role ◽  
River Estuary ◽  
Bacterial Biomass ◽  
Assemblage Structure ◽  
Freshwater Inflow ◽  
Structure Density ◽  
Freshwater Inflows ◽  
Zooplankton Communities

Freshwater inflow events play a major role in structuring estuarine zooplankton communities. Freshwater inflow events affect zooplankton directly through advective forcing and changes in salinity, and indirectly through changes to resources by the delivery of organic carbon and nutrients that can stimulate microbial and primary production. Here, we investigate changes to estuarine zooplankton assemblage structure, density and δ13C stable isotopes during a period of highly variable freshwater inflow in the Bega River estuary, Australia. High inflows resulted in a reduction of salinity and a shift in the zooplankton assemblage structure from purely estuarine taxa towards freshwater taxa. The density of select genera of rotifers, cladocera and, in the upper estuary, copepods, increased following inflows, concurrent with increases in the concentration of dissolved organic carbon and bacterial biomass. Redundancy analysis found that environmental variables including discharge, dissolved organic carbon, salinity and bacterial biomass explained 66–73% of zooplankton variation. Stable isotope results indicated that all copepod and cladocera species tested were predominantly supported by allochthonous carbon from terrestrial sources. The present results have provided important evidence that freshwater inflows play a critical role in structuring zooplankton assemblages and supporting increased production through the delivery of allochthonous organic carbon.

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