Sample records for biofiltration

  1. Active compost biofiltration of toluene. (United States)

    Matteau, Y; Ramsay, B


    Composting of leaves and alfalfa (i.e. active compost) was used for the biofiltration of toluene-contaminated air in a 6-L biofilter (initial bed height: 180 mm). During the thermophilic phase (45 to 55 degrees C), toluene biodegradation rates reached 110 g toluene.m-3.h-1 at an inlet concentration of about 5 g.m-3 and a gas residence time of 90 seconds. The highest rates were obtained in the thermophilic phase suggesting a microbial adaptation was occurring. Biodegradation rates decreased rapidly (50% in 48 h) in the cooling stage. Under mesophilic conditions, the maximum biodegradation rates that could be obtained by increasing the inlet toluene concentration were near 89 g toluene.m-3.h-1 which is similar to that reported in the literature for mature compost biofilters. No volatile by-product was detected by gas chromatherapy. Mineralization of 14C-toluene and benzene showed that they were completely degraded into CO2 and H2O under both thermophilic and mesophilic conditions. Bacteria isolated from late mesophilic stage had the capacity to degrade all BTEX compounds but were not able to transform chlorinated compounds. No organisms were isolated which could use toluene as their sole source of carbon and energy at 50 degrees C. Active compost biofiltration should be an excellent process for the treatment of gaseous BTEX by biofiltration. This is the first report of thermophilic biofiltration of toluene.

  2. Removal of Hydrogen Sulfide Gas using Biofiltration - a Review

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    Cheerawit RATTANAPAN


    Full Text Available Hydrogen sulfide (H2S is extremely toxic to living organisms and plants. H2S gas contamination may be treated by both chemical and physical methods but they have high capital costs, demand large energy inputs and result in the generation of secondary hazardous wastes. Biofiltration, a biological technique, has significant economic advantages over other air pollution control technologies. Biofiltration is a process by which contaminated gases pass through the biofilter and pollutants are transported into the biofilm where they are utilized by microbes as a carbon source, an energy source. Thiobacillus sp. is the most frequently used microbial species in H2S biofiltration and can degrade H2S for energy and produce sulfate or sulfuric acid. Moreover, media selection for biofiltration (combing both natural and synthetic media is an important step towards the development of a successful biofiltration operation. In addition, the optimization parameters of a biofiltration operation are found. First, optimal moisture content may vary from 20 to 60 wt%. Second, most microbial growths occur near neutral pH and wide deviation from these levels will impact the efficiency of the biofiltration. Third, the optimum temperature of biofiltration is near the optimum temperature for microbial inoculation based on removal efficiency. Finally, because nutrient supply is less critical as H2S removal requires few nutrients, commercial fertilizer or secondary effluent from wastewater treatment plants can be used for humid and nutrient supply. Many biofiltrations are designed for H2S control.Graphical abstract

  3. The effect of nitrate on ethylene biofiltration

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Hun, E-mail: [Department of Agricultural and Biological Engineering, Purdue University, 225 South University St., West Lafayette, 47907-2093 IN (United States); Li, Congna; Heber, Albert J. [Department of Agricultural and Biological Engineering, Purdue University, 225 South University St., West Lafayette, 47907-2093 IN (United States)


    Highlights: Black-Right-Pointing-Pointer Ethylene biofiltration strongly depends on nitrate concentrations and media types. Black-Right-Pointing-Pointer We examine reduced N supply can increase ethylene removals in biofilters. Black-Right-Pointing-Pointer Perlite medium is better for ethylene biofiltration than activated carbon medium. - Abstract: This study investigated the effects of filter media types and nitrate (NO{sub 3}{sup -}) concentrations in nutrient solutions on C{sub 2}H{sub 4} biofiltration. A new nutrient solution with zero NO{sub 3}{sup -} concentration was supplied to two perlite-bed biotrickling filters, two perlite-bed biofilters, and two GAC (Granular Activated Carbon)-bed biofilters, while the other with 2 g L{sup -1} of NO{sub 3}{sup -} was used for the other two GAC biofilters. All reactors underwent a total test duration of over 175 days with an EBRT (Empty Bed Residence Time) of 30 s, inlet gas flow rate of 7 L min{sup -1}, and inlet C{sub 2}H{sub 4} concentrations of 20-30 mg m{sup -3}. NO{sub 3}{sup -} concentration and media type significantly affected the C{sub 2}H{sub 4} removal efficiencies in all types of biofiltration. The perlite media with no NO{sub 3}{sup -} achieved C{sub 2}H{sub 4} removal efficiencies 10-50% higher than the others. A NO{sub 3}{sup -} concentration as high as 2 g L{sup -1} in the original nutrient solution may act as an inhibitor that suppresses the growth or activity of C{sub 2}H{sub 4} degraders. In addition, the perlite media resulted in higher C{sub 2}H{sub 4} removal efficiencies than GAC media, because the hydrophilic surface of the perlite leads to a higher moisture content and thus to favorable microbial growth.

  4. Biofiltration of gasoline and diesel aliphatic hydrocarbons. (United States)

    Halecky, Martin; Rousova, Jana; Paca, Jan; Kozliak, Evguenii; Seames, Wayne; Jones, Kim


    The ability of a biofilm to switch between the mixtures of mostly aromatic and aliphatic hydrocarbons was investigated to assess biofiltration efficiency and potential substrate interactions. A switch from gasoline, which consisted of both aliphatic and aromatic hydrocarbons, to a mixture of volatile diesel n-alkanes resulted in a significant increase in biofiltration efficiency, despite the lack of readily biodegradable aromatic hydrocarbons in the diesel mixture. This improved biofilter performance was shown to be the result of the presence of larger size (C₉-C(12)) linear alkanes in diesel, which turned out to be more degradable than their shorter-chain (C₆-C₈) homologues in gasoline. The evidence obtained from both biofiltration-based and independent microbiological tests indicated that the rate was limited by biochemical reactions, with the inhibition of shorter chain alkane biodegradation by their larger size homologues as corroborated by a significant substrate specialization along the biofilter bed. These observations were explained by the lack of specific enzymes designed for the oxidation of short-chain alkanes as opposed to their longer carbon chain homologues.

  5. Formaldehyde biofiltration as affected by spider plant. (United States)

    Xu, Zhongjun; Qin, Na; Wang, Jinggang; Tong, Hua


    The kinetic process of formaldehyde biodegradation in a biofilter packed with a mixture of compost, vermiculite powder and ceramic particles was investigated in this study. The results showed that more than 60% of formaldehyde was removed by the first 5 cm high biofilter bed at 406 Lh(-1) flowrate within the range of 5-207 mgm(-3) inlet concentrations. A macrokinetic model was applied to describe the kinetic process of formaldehyde biodegradation and the experimentally determined elimination capacity for the biofilter agreed well with the model predicted values. The data on the effect of spider plant (Chlorophytum comosum L.) on formaldehyde removal indicated that formaldehyde biofiltration might be stimulated by spider plant since formaldehyde was assimilated by spider plant roots and microbial formaldehyde degradation was enhanced by the root exudates.

  6. Biofiltration with bicarbonate as dialysate buffer. (United States)

    Rizzelli, S; Alfonso, L; Corlianò, C; Patruno, P; Sozzo, E; Mastrangelo, F


    The biofiltration with bicarbonate as dialysate buffer (BiBF) was used in 10 patients on RDT: the patients were treated for 10 months on standard BF and for 10 months on BiBF. The amount of fluid infused varied between 3 and 5 liters and Na-bicarbonate (100 mEq/h) was infused during BF. The dialytic protocol was 3 hours every other day. Cardiovascular stability, waste molecules and acid-base balance were investigated. No differences in vascular stability and no significant changes in the waste-molecules concentrations were found. Both protocols correct the metabolic acidosis; however, in standard BF 50% of patients showed acute hypocapnia at the end of dialysis.

  7. Phosphorus limitation in biofiltration for drinking water treatment

    Institute of Scientific and Technical Information of China (English)


    Bacterial growth potential(BGP) method and two parallel pilot-scale biofilters were used to investigate phosphorus limitation and itseffect on the removal of organic matters in biofiltration for drinking water treatment. Addition of phosphorus can substantially increase the BGPsof the samples. Its effect was equivalent to that of addition of a mixture of various inorganic nutrients including phosphorus. The biofilter withphosphate added into its influent performed a higher biological stability of the effluent and a higher CODMn removal than the control filter. Theseresults suggested that phosphorus was the limiting nutrient in the biofiltration and the removal efficiency of organic matters could be improved byadding phosphate into the influent.

  8. Biofiltration of air contaminated with methanol and toluene

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    Pakamas Chetpattananondh


    Full Text Available Biofiltration of air contaminated with VOCs is inexpensive compared with the conventional techniques and very effective for treating large volumes of moist air streams with low concentrations of VOCs. In this study, biofiltration for the purification of polluted air from methanol, a hydrophilic VOC, and toluene, a hydrophobic VOC, was investigated. The experiments were operated using three separated stainless steel biofilters, for methanol, toluene, and a mixture of methanol and toluene, respectively. Biofilter consisted of a mixture of palm shells and activated sludge as a filter-bed material. Only the indigenous microorganisms of the bed medium without any addition of extra inoculum were used throughout the whole process. The polluted air inlet concentration was varied from 0.3-4.7 g/m3 with flow rates ranging from 0.06-0.45 m3/h, equivalent to the empty bed residence times of 9-71 sec. Polluted air was successfully treated by biofiltration, 100% removal efficiencies would be obtained when the air flow rate was lower than 0.45 m3/h. The presence of toluene did not affect the removal rate of methanol while the removal rate of toluene was decreased with the presence of methanol in air stream according to the competition phenomenon.

  9. Effect of ozone on biopolymers in biofiltration and ultrafiltration processes. (United States)

    Siembida-Lösch, Barbara; Anderson, William B; Wang, Yulang Michael; Bonsteel, Jane; Huck, Peter M


    The focus of this full-scale study was to determine the effect of ozone on biopolymer concentrations in biofiltration and ultrafiltration (UF) processes treating surface water from Lake Ontario. Ozonation was out of service for maintenance for 9 months, hence, it was possible to investigate ozone's action on biologically active carbon contactors (BACCs) and UF, in terms of biopolymer removal. Given the importance of biopolymers for fouling, this fraction was quantified using a chromatographic technique. Ozone pre-treatment was observed to positively impact the active biomass in biofilters. However, since an increase of the active biomass did not result in higher biopolymer removal, active biomass concentration cannot be a surrogate for biofiltration performance. It was evident that increasing empty bed contact time (EBCT) from 4 to 19 min only had a positive effect on biopolymer removal through BACCs when ozone was out of service. However, as a mass balance experiment showed, ozone-free operation resulted in higher deposition of biopolymers on a UF membrane and slight deterioration in its performance.

  10. The Use of Inorganic Packing Materials during Methane Biofiltration

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    Josiane Nikiema


    Full Text Available The objective behind this study is to select a suitable inorganic packing material for methane biofiltration. Three packing materials are to be compared: two rock materials (average particles' sizes: 2 and 5 mm and one porous clay particles (average particle size of 7 mm. The main parameter used to assess the efficiency of the packing material is the methane elimination capacity. The study reveals that the rock material having an average particle size around 2 mm is to be preferred. This result is probably due to its high specific surface area and to its good surface properties as compared to the other 2 tested porous materials. The influence of the nonirrigation with the nutrient solution of the biofilter is also investigated. It has been found that nonirrigation of biofilter causes the biofilter performance to decrease significantly (e.g., 45% decrease in 1 week even with the humidification of the gas phase prior to its introduction into the biofilter.

  11. A demonstration of biofiltration for VOC removal in petrochemical industries. (United States)

    Zhao, Lan; Huang, Shaobin; Wei, Zongmin


    A biotrickling filter demo has been set up in a petrochemical factory in Sinopec Group for about 10 months with a maximum inlet gas flow rate of 3000 m3 h(-1). The purpose of this project is to assess the ability of the biotrickling filter to remove hardly biodegradable VOCs such as benzene, toluene and xylene which are recalcitrant and poorly water soluble and commonly found in petrochemical factories. Light-weight hollow ceramic balls (Φ 5-8 cm) were used as the packing media treated with large amounts of circulating water (2.4 m3 m(-2) h(-1)) added with bacterial species. The controlled empty bed retention time (EBRT) of 240 s is a key parameter for reaching a removal efficiency of 95% for benzene, toluene, xylene, and 90% for total hydrocarbons. The demo has been successfully adopted and practically applied in waste air treatments in many petrochemical industries for about two years. The net inlet concentrations of benzene, toluene and xylene were varied from 0.5 to 3 g m(-3). The biofiltration process is highly efficient for the removal of hydrophobic and recalcitrant VOCs with various concentrations from the petrochemical factories. The SEM analysis of the bacterial community in the BTF during VOC removal showed that Pseudomonas putida and Klebsiella sp. phylum were dominant and shutdown periods could play a role in forming the community structural differences and leading to the changes of removal efficiencies.

  12. Improving bioretention/biofiltration performance with restorative maintenance. (United States)

    Brown, Robert A; Hunt, William F


    One of the most popular Stormwater Control Measures is bioretention, or biofiltration. Anecdotal evidence suggests that well-designed bioretention cells are often not adequately installed and that maintenance is lacking, leading to less-than-adequate water storage volume and/or surface infiltration rates post-construction. In March 2009, two sets of bioretention cells were repaired by excavating the top 75 mm of fill media, increasing the bioretention surface storage volume by nearly 90% and the infiltration rate by up to a factor of 10. Overflow volume decreased from 35 and 37% in the pre-repair state for two different sets of cells, respectively, to 11 and 12%. Nearly all effluent pollutant loads exiting the post-repair cells were lower than their pre-repair conditions. The bioretention systems employed two different media depths (0.6 and 0.9 m). The deeper media cells discharged less outflow volume than the shallower cells, with 10-11% more runoff volume leaving as exfiltration from the 0.9-m than from the 0.6-m media depth cells. This study showed that maintenance is both critical and beneficial to restore otherwise poorly performing bioretention. Moreover, while deeper media cells did outperform the shallower systems, the improvement in this case was somewhat modest vis-à-vis additional construction costs.

  13. The effect of nutrient supplementation on the biofiltration removal of butanal in contaminated air

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Vriens, L.; Verachtert, H.


    Butanal is one of the odorous compounds produced in the animal-rendering and food-processing industries and also in sewage-treatment plants. It shows the necessity for complementing such plants with systems for off-gas treatment. Biofiltration using simple packing material was tested for the removal

  14. Mussel biofiltration effects on attached bacteria and unicellular eukaryotes in fish-rearing seawater (United States)

    Voudanta, Eleni; Monchy, Sebastién; Delegrange, Alice; Vincent, Dorothée; Genitsaris, Savvas; Christaki, Urania


    Mussel biofiltration is a widely used approach for the mitigation of aquaculture water. In this study, we investigated the effect of mussel biofiltration on the communities of particle-associated bacteria and unicellular eukaryotes in a sea bass aquaculture in southern North Sea. We assessed the planktonic community changes before and after biofiltration based on the diversity of the 16S and 18S rRNA genes by using next generation sequencing technologies. Although there was no overall reduction in the operational taxonomic units (OTU) numbers between the control (no mussels) and the test (with mussels) tanks, a clear reduction in the relative abundance of the top three most dominant OTUs in every sampling time was observed, ranging between 2–28% and 16–82% for Bacteria and Eukarya, respectively. The bacterial community was dominated by OTUs related to phytoplankton blooms and/or high concentrations of detritus. Among the eukaryotes, several fungal and parasitic groups were found. Their relative abundance in most cases was also reduced from the control to the test tanks; a similar decreasing pattern was also observed for both major higher taxa and functional (trophic) groups. Overall, this study showed the effectiveness of mussel biofiltration on the decrease of microbiota abundance and diversity in seawater fueling fish farms. PMID:27069786

  15. Biofiltration of gasoline and ethanol-amended gasoline vapors. (United States)

    Soares, Marlene; Woiciechowski, Adenise L; Kozliak, Evguenii I; Paca, Jan; Soccol, Carlos R


    Assuming the projected increase in use of ethanol as a biofuel, the current study was conducted to compare the biofiltration efficiencies for plain and 25% ethanol-containing gasoline. Two biofilters were operated in a downflow mode for 7 months, one of them being compost-based whereas the other using a synthetic packing material, granulated tire rubber, inoculated with gasoline-degrading microorganisms. Inlet concentrations measured as total hydrocarbon (TH) ranged from 1.9 to 5.8 g m(-3) at a constant empty bed retention time of 6.84 min. Contrary to the expectations based on microbiological considerations, ethanol-amended gasoline was more readily biodegraded than plain hydrocarbons, with the respective steady state elimination capacities of 26-43 and 14-18 gTH m(-3) h(-1) for the compost biofilter. The efficiency of both biofilters significantly declined upon the application of higher loads of plain gasoline, yet immediately recovering when switched back to ethanol-blended gasoline. The unexpected effect of ethanol in promoting gasoline biodegradation was explained by increasing hydrocarbon partitioning into the aqueous phase, with mass transfer being rate limiting for the bulk of components. The tire rubber biofilter, after a long acclimation, surpassed the compost biofilter in performance, presumably due to the 'buffering' effect of this packing material increasing the accessibility of gasoline hydrocarbons to the biofilm. With improved substrate mass transfer, biodegradable hydrocarbons were removed in the tire rubber biofilter's first reactor stage, with most of the remaining poorly degradable smaller-size hydrocarbons being degraded in the second stage.

  16. Effects of Operational Conditions on the Performance of Triethylamine Biofiltration

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    A Torkian, H Keshavarzi Shirazi, A Azimi


    Full Text Available Nitrogen compounds such as triethylamine are odorants generally found in chemical plants and foundries in which cold-box cores are made. In this study, the efficiency of biofiltration of triethylamine (TEA vapor was evaluated. Experiments were conducted in two 6-L biofilters arranged in three stages and packed with inoculated compost - wood chips (40:60v/v as the filter medium. The seed inoculum was obtained from municipal activated sludge. Tests were made to compare effects of initial temperature (30±1°C, biofilter A and (23±2 °C, biofilter B on the performance of the biofilter. TEA elimination rate pattern was evaluated by changing loading rates (6-138 gm-3h-1 and hydraulic retention times (40-60 s while operating at constant temperature and humidity at 50-55%. Results showed that organic loading rates (OLR of up to 114.4 gm-3h-1 (biofilter A and 90.56 gm-3h-1 (biofilter B could be handled without any apparent indication of maximum elimination capacity and substrate inhibition. The elimination capacity of biofilters could reach up to 72 gm-3h-1 (biofilter A and 61.5 gm-3h-1(biofilter B. When the loading of TEA exceeded the critical values, substrate inhibition occurred and the elimination capacity decreased. However, the requirement of keeping the pressure drop below 4 cm water gauge per meter of bed height to avoid operational problems warranted lower than maximum capacity operation. The optimal OLR values of 90±14 gm-3h-1 are suggested for hydraulic retention time value of 48 s and temperature of 30±1°C. Under these conditions, elimination capacity of 71±3 gm-3h-1and removal efficiency of 81±14% was achieved.

  17. Removal of gasoline vapors from air streams by biofiltration

    Energy Technology Data Exchange (ETDEWEB)

    Apel, W.A.; Kant, W.D.; Colwell, F.S.; Singleton, B.; Lee, B.D.; Andrews, G.F.; Espinosa, A.M.; Johnson, E.G.


    Research was performed to develop a biofilter for the biodegradation of gasoline vapors. The overall goal of this effort was to provide information necessary for the design, construction, and operation of a commercial gasoline vapor biofilter. Experimental results indicated that relatively high amounts of gasoline vapor adsorption occur during initial exposure of the biofilter bed medium to gasoline vapors. Biological removal occurs over a 22 to 40{degrees}C temperature range with removal being completely inhibited at 54{degrees}C. The addition of fertilizer to the relatively fresh bed medium used did not increase the rates of gasoline removal in short term experiments. Microbiological analyses indicated that high levels of gasoline degrading microbes are naturally present in the bed medium and that additional inoculation with hydrocarbon degrading cultures does not appreciably increase gasoline removal rates. At lower gasoline concentrations, the vapor removal rates were considerably lower than those at higher gasoline concentrations. This implies that system designs facilitating gasoline transport to the micro-organisms could substantially increase gasoline removal rates at lower gasoline vapor concentrations. Test results from a field scale prototype biofiltration system showed volumetric productivity (i.e., average rate of gasoline degradation per unit bed volume) values that were consistent with those obtained with laboratory column biofilters at similar inlet gasoline concentrations. In addition, total benzene, toluene, ethyl-benzene, and xylene (BTEX) removal over the operating conditions employed was 50 to 55%. Removal of benzene was approximately 10 to 15% and removal of the other members of the BTEX group was much higher, typically >80%.

  18. Removal of gasoline vapors from air streams by biofiltration

    Energy Technology Data Exchange (ETDEWEB)

    Apel, W.A.; Kant, W.D.; Colwell, F.S.; Singleton, B.; Lee, B.D.; Andrews, G.F.; Espinosa, A.M.; Johnson, E.G.


    Research was performed to develop a biofilter for the biodegradation of gasoline vapors. The overall goal of this effort was to provide information necessary for the design, construction, and operation of a commercial gasoline vapor biofilter. Experimental results indicated that relatively high amounts of gasoline vapor adsorption occur during initial exposure of the biofilter bed medium to gasoline vapors. Biological removal occurs over a 22 to 40[degrees]C temperature range with removal being completely inhibited at 54[degrees]C. The addition of fertilizer to the relatively fresh bed medium used did not increase the rates of gasoline removal in short term experiments. Microbiological analyses indicated that high levels of gasoline degrading microbes are naturally present in the bed medium and that additional inoculation with hydrocarbon degrading cultures does not appreciably increase gasoline removal rates. At lower gasoline concentrations, the vapor removal rates were considerably lower than those at higher gasoline concentrations. This implies that system designs facilitating gasoline transport to the micro-organisms could substantially increase gasoline removal rates at lower gasoline vapor concentrations. Test results from a field scale prototype biofiltration system showed volumetric productivity (i.e., average rate of gasoline degradation per unit bed volume) values that were consistent with those obtained with laboratory column biofilters at similar inlet gasoline concentrations. In addition, total benzene, toluene, ethyl-benzene, and xylene (BTEX) removal over the operating conditions employed was 50 to 55%. Removal of benzene was approximately 10 to 15% and removal of the other members of the BTEX group was much higher, typically >80%.

  19. Ozone and biofiltration as an alternative to reverse osmosis for removing PPCPs and micropollutants from treated wastewater

    DEFF Research Database (Denmark)

    Lee, Carson; Howe, Kerry J.; Thomson, Bruce M.


    This pilot-scale research project investigated and compared the removal of pharmaceuticals and personal care products (PPCPs) and other micropollutants from treated wastewater by ozone/biofiltration and reverse osmosis (RO). The reduction in UV254 absorbance as a function of ozone dose correlated...... well with the reduction in nonbiodegradable dissolved organic carbon and simultaneous production of biodegradable dissolved organic carbon (BDOC). BDOC analyses demonstrated that ozone does not mineralize organics in treated wastewater and that biofiltration can remove the organic oxidation products...... of ozonation. Biofiltration is recommended for treatment of ozone contactor effluent to minimize the presence of unknown micropollutant oxidation products in the treated water. Ozone/biofiltration and RO were compared on the basis of micropollutant removal efficiency, energy consumption, and waste production...

  20. Modeling the improvement of ultrafiltration membrane mass transfer when using biofiltration pretreatment in surface water applications. (United States)

    Netcher, Andrea C; Duranceau, Steven J


    In surface water treatment, ultrafiltration (UF) membranes are widely used because of their ability to supply safe drinking water. Although UF membranes produce high-quality water, their efficiency is limited by fouling. Improving UF filtrate productivity is economically desirable and has been attempted by incorporating sustainable biofiltration processes as pretreatment to UF with varying success. The availability of models that can be applied to describe the effectiveness of biofiltration on membrane mass transfer are lacking. In this work, UF water productivity was empirically modeled as a function of biofilter feed water quality using either a quadratic or Gaussian relationship. UF membrane mass transfer variability was found to be governed by the dimensionless mass ratio between the alkalinity (ALK) and dissolved organic carbon (DOC). UF membrane productivity was optimized when the biofilter feed water ALK to DOC ratio fell between 10 and 14.

  1. Treatment of a colored groundwater by ozone-biofiltration: pilot studies and modeling interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Rittmann, B.E.; Stilwell, D.; Garside, J.C.; Amy, G.L.; Spangenberg, C.; Kalinsky, A.; Akiyoshi, E. [Northwestern University, Evanston, IL (USA). Dept. of Civil & Environmental Engineers


    Pilot studies investigated the fates of color, dissolved organic carbon (DOC), and biodegradable organic matter (BOM) by the tandem of ozone plus biofiltration for treating a source water having significant color (50 cu) and DOC (3.2 mg/l). Transferred ozone doses were from 1.0 to 1.8 g O{sub 3}/g C. Rapid biofilters used sand, anthracite, or granular activated carbon as media with empty-bed contact time (EBCT) up to 9 min. The pilot studies demonstrated that ozonation plus biofiltration removed most color and substantial DOC, and increasing the transferred ozone dose enhanced the removals. Compared to sand and anthracite biofilters, the GAC biofilter gave the best performance for color and DOC removal, but some of this enhanced performance was caused by adsorption, since the GAC was virgin at the beginning of the pilot studies.

  2. Estimates of evapotranspiration and CO2 fluxes in a biofiltration system (United States)

    Daly, E.; Niculescu, A.; Beringer, J.; Deletic, A.


    Biofiltration systems (or biofilters, bioretention systems or rain gardens) have been adopted to improve the quality of urban aquatic ecosystems and to reduce volumes and peaks of stormwater runoff. Given their good performances, it is likely that the implementation of such systems in urban areas will greatly increase in the future. As an example, the city of Melbourne (Australia) is planning to install 10,000 biofiltration systems within its area by 2013. Because biofiltration systems are commonly installed in urban areas, along roads and highways, their vegetation is often under atmospheric CO2 concentrations higher than average ambient conditions (i.e., above 380 ppm). Additionally, since these systems are designed to receive runoff from large catchment areas (typically around 50-100 times the area of the biofilter), their vegetation rarely experiences water and nitrogen limitations. These surrounding environmental conditions suggest that biofilters might experience high evapotranspiration (ET) rates and CO2 assimilation via photosynthesis, which could potentially provide benefits to the local microclimate in terms of temperature reduction (cooling due to enhanced ET) and CO2 uptake from the atmosphere, in addition to the benefit related to stormwater treatment. These hypotheses have been strengthen by preliminary tests based on laboratory experiments with soil columns vegetated with C.appressa, in which ET has been estimated to be as high as 0.7-0.8 cm per day. To further study these processes, several measurements are being performed in a biofiltration system installed at Monash University, Clayton Campus (Melbourne, VIC). This biofilter receives runoff diverted from a 100% impervious car park and discharges the treated stormwater to an adjacent pond. A chamber that encloses part of the vegetation in the biofilter has been constructed to monitor water and greenhouse gas fluxes. Preliminary results on daily patterns of water and CO2 fluxes within the system in

  3. Biofiltration as a Viable Alternative for Air Pollution Control at Department of Defense Surface Coating Facilities (United States)


    Management” and EO 13134, “Developing and Promoting Biobased Products and Bioenergy” (OFEE, 2006). 1.6 Problem Statement Air pollution...and bark to synthetic materials such as plastic rings or Styrofoam cubes. Though the concept behind biofiltration remains relatively simple—a filter... plastic rings, open pore foam, or lava 20 rock (Cox and Deshusses, 2002). Microbes attached to the stationary and synthetic material along with

  4. Biofiltration of high formaldehyde loads with ozone additions in long-term operation. (United States)

    Maldonado-Diaz, G; Arriaga, S


    Formaldehyde (FA) biofiltration was evaluated over 310 days with and without ozone addition. Without ozone, the biofilter was able to treat formaldehyde at inlet loads (ILs) lower than 40 g m(-3) h(-1), maintaining, under this condition, an average removal efficiency (RE) of 88 % for a few days before collapsing to zero. The continuous addition of ozone (90 ppbv) helped to recover the RE from zero to 98 ± 2 % and made it possible to operate at an IL of 40 g m(-3) h(-1) for long periods of operation (107 days). Furthermore, the ozone addition aided in operating the biofilter at a formaldehyde IL of up to 120 g m(-3) h(-1) values that have never before been reached. GC-mass spectrometry (MS) analysis showed that dimethoxymethane was the common compound in leachate during the performance decay. Also, the addition of ozone aided in maintaining an optimal pH in the biofilter with values between 7.5 and 8.2, due to the carbonate species formed during the ozone reactions with formaldehyde and its by-products. Thus, the pH control was confirmed and the alkalinity of the biofilter increased from 334.1 ± 100.3 to 1450 ± 127 mg CaCO3 L(-1) when ozone was added. Ozone addition diminished the exopolymeric substances (EPS) content of biofilm and biofilm thickness without affecting cell viability. Kinetic parameters suggested that the best conditions for carrying out FA biofiltration were reached under ozone addition. The addition of ozone during formaldehyde biofiltration could be a good strategy to maintain the pH and the steady state of the system under high ILs and for long periods of operation.

  5. Geochemistry and Microbial Communities in Iron- and Manganese-Enriched Cold Groundwater Biofiltration Units (United States)

    Chang, W.; Dangeti, S.; Roshani, B.; McBeth, J. M.


    Exploring how to enhance the microbially mediated oxidization of iron (Fe) and manganese (Mn) in natural and engineered environments in cold climates requires an understanding of the interactive relationships between the geochemistry of cold groundwater and Fe- and Mn-oxidizing bacteria. This study precisely measured geochemical and microbial communities in a scaled-up biofiltration system using synchrotron-based X-ray Absorption Near-Edge Spectroscopy (XANES) analyses coupled with next-generation sequencing (Illumina Miseq). Two pilot-scale biofiltration columns for Fe (Filter 1) and Mn (Filter 2) were connected in series and installed at the Langham Water Treatment Plant in Saskatoon, Canada. The groundwater temperature ranged from 4 to 8 °C. The pilot-scale study showed that successful treatment (99% removal) of both Fe and Mn was achieved in the biofilters. However, the Mn removal was significantly retarded for four months, likely due to the slow growth of Mn-oxidizing bacteria (MnOB) in Filter 2. The removal of Mn was accelerated once the redox potential in Filter 2 exceeded +300 mV. At that point, the XANES analyses showed that the oxidization states of Mn in Filter 2 were mainly +3 and +4, confirming that Mn oxidization had occurred. Geochemical analyses (PHREEQCi) also indicated changed geochemical conditions that favoured the formation of Mn-oxides during biofiltration. Next-generation sequencing analyses indicated the enrichment of iron-oxidizing bacteria (FeOB), including Gallionella sp. and Sideroxydans sp., in Filter 1. There were high read numbers for MnOB relatives, including Pseudomonas sp., Hydrogenophaga sp., Bdellovibrio sp., and Leptothrix sp., in Filter 2. Furthermore, the addition of anthracite (coal-based filter media) positively affected the growth MnOB and enhanced Mn oxidization. The evidence obtained in this study provides insight into how Mn oxidization can be accelerated in cold groundwater treatment systems.

  6. Reusing H2S-exhausted carbon as packing material for odor biofiltration. (United States)

    Jiang, Xia; Yan, Rong; Jay, Joo Hwa


    Exhausted carbon coming from the H2S adsorption process is a big environmental problem in Wastewater Treatment Plants. In this study, reusing exhausted carbon as a carrier of sulfide-oxidizing bacteria in lab-scale biofilters was evaluated. The exhausted carbons from different heights of the adsorption bed have different exhaustion extents, i.e. characteristics in terms of sulfur content, pH and porosity. Therefore, four biofilters were packed separately with exhausted carbon from top, middle, bottom of H2S adsorption bed, and a mixture of the three, to investigate the suitability for further H2S biofiltration. The results showed a quick startup in these biofilters (approximately 80 h). The numbers of sulfide-oxidizing bacteria immobilized on activated carbon were approximately 4.8, 9.2 and 14 x 108 CFU g-1 top, middle and bottom carbon after the 240-h operation, respectively. In addition, the biofilters demonstrated a rapid recovery to the original removal efficiency (RE) within 2 h after the H2S spike loadings. After a 110-h shutdown, the RE was rapidly recovered for all the biofilters within 5 h, with a shorter time (1 h) observed for the bottom carbon biofilter. The H2S removal mechanism of these biofilters was studied through a full analysis of sulfur products in both liquid (recycling medium) and activated carbon, and variable characterization of activated carbon before and after biofiltration. This study shows that the exhausted carbon-based biofilter is a feasible and economical alternative to conventional odor biofiltration.

  7. A comparative study of fungal and bacterial biofiltration treating a VOC mixture

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, José M. [Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Artificios 40, Col. Miguel Hidalgo, Delegación Álvaro Obregón (Mexico); Departamento de Ingeniería Química y Tecnología del Medio Ambiente – Universidad de Valladolid, Valladolid (Spain); Hernández, Sergio [Departmento de Procesos e Hidráulica – Universidad Autónoma Metropolitana – Iztapalapa Mexico D.F. Mexico (Mexico); Muñoz, Raúl [Departamento de Ingeniería Química y Tecnología del Medio Ambiente – Universidad de Valladolid, Valladolid (Spain); Revah, Sergio, E-mail: [Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Artificios 40, Col. Miguel Hidalgo, Delegación Álvaro Obregón (Mexico)


    Highlights: ► Bacterial biofilter showed better EC and ΔP than fungal biofilter. ► The preferential biodegradation order was: propanal > hexanol > MIBK > toluene. ► Propanal partially inhibited the biodegradation of the rest of VOCs. ► The two-stage biofilter showed a higher stability than the individual units. -- Abstract: Bacterial biofilters usually exhibit a high microbial diversity and robustness, while fungal biofilters have been claimed to better withstand low moisture contents and pH values, and to be more efficient coping with hydrophobic volatile organic compounds (VOCs). However, there are only few systematic evaluations of both biofiltration technologies. The present study compared fungal and bacterial biofiltration for the treatment of a VOC mixture (propanal, methyl isobutyl ketone-MIBK, toluene and hexanol) under the same operating conditions. Overall, fungal biofiltration supported lower elimination capacities than its bacterial counterpart (27.7 ± 8.9 vs 40.2 ± 5.4 g C m{sup −3} reactor h{sup −1}), which exhibited a final pressure drop 60% higher than that of the bacterial biofilter due to mycelial growth. The VOC mineralization ratio was also higher in the bacterial bed (≈63% vs ≈43%). However, the substrate biodegradation preference order was similar for both biofilters (propanal > hexanol > MIBK > toluene) with propanal partially inhibiting the consumption of the rest of the VOCs. Both systems supported an excellent robustness versus 24 h VOC starvation episodes. The implementation of a fungal/bacterial coupled system did not significantly improve the VOC removal performance compared to the individual biofilter performances.

  8. Total ammoniacal nitrogen biofiltration of wastewaters from aquaculture systems using Macrocystis spp. (United States)

    Bravo, R; Segovia, E; Guerrero, L; Montalvo, S; Barahona, A; Borja, R


    The results of total ammoniacal nitrogen (NH(3) + NH(4) (+)) removal in aquaculture systems using two experimental sets, aquatic seedlings produced in laboratory controlled conditions and wild seaweed (Macrocystis spp.) in reproductive state, are shown in this work. Biofiltration assays were carried out using a load of total ammoniacal nitrogen (TAN) of 1 mg/L. Absorption rates were measured taking into account a previous surface characterization, which gave values of 44 ± 14 cm(2)/g and 18 ± 6 cm(2)/g for aquatic seedlings and wild algae, respectively. The following parameters were measured during the experimental runs: temperature, pH, O(2), illuminance or light intensity, salinity and total solids. TAN removals of 61% and 70% were achieved for the seedlings and Macrocystis spp., respectively, after 17 h of treatment. The TAN absorption results were expressed as a function of surface and mass achieving the following values: 3.0 nmol N cm(-2) h(-1) and 111 nmol N g(-1) h(-1) for the seedlings, and 6.9 nmol N cm(-2) h(-1) and 122.4 nmol N g(-1) h(-1) for the macroalgae. In the light of these biofiltration processes, the initial TAN concentration decreased by 90% for the seedlings and wild algae over approximately 110 and 41 h, respectively. In addition, TAN removals achieved with Macrocystis spp. were always higher than those obtained with aquatic seedlings for the same operating periods.

  9. Hydrologic and pollutant removal performance of stormwater biofiltration systems at the field scale (United States)

    Hatt, Belinda E.; Fletcher, Tim D.; Deletic, Ana


    SummaryBiofiltration systems are a recommended and increasingly popular technology for stormwater management; however there is a general lack of performance data for these systems, particularly at the field scale. The objective of this study was to investigate the hydrologic and pollutant removal performance of three field-scale biofiltration systems in two different climates. Biofilters were shown to effectively attenuate peak runoff flow rates by at least 80%. Performance assessment of a lined biofilter demonstrated that retention of inflow volumes by the filter media, for subsequent loss via evapotranspiration, reduced runoff volumes by 33% on average. Retention of water was found to be most influenced by inflow volumes, although only small to medium storms could be assessed. Vegetation was shown to be important for maintaining hydraulic capacity, because root growth and senescence countered compaction and clogging. Suspended solids and heavy metals were effectively removed, irrespective of the design configuration, with load reductions generally in excess of 90%. In contrast, nutrient retention was variable, and ranged from consistent leaching to effective and reliable removal, depending on the design. To ensure effective removal of phosphorus, a filter medium with a low phosphorus content should be selected. Nitrogen is more difficult to remove because it is highly soluble and strongly influenced by the variable wetting and drying regime that is inherent in biofilter operation. The results of this research suggest that reconfiguration of biofilter design to manage the deleterious effects of drying on biological activity is necessary to ensure long term nitrogen removal.

  10. Bio-filtering of a VOC mixture; Biofiltration d'un melange de COV

    Energy Technology Data Exchange (ETDEWEB)

    Aizpuru, A.


    The study is focused on the bio-filtration of a mixture of Volatile Organic Compounds (VOC). Its primary interest is the complexity of the mixture treated which includes eleven components with different chemical structures (esters, ketones, alcohol, aromatic rings and chlorinated compounds). The first experiment, carried out with a natural material (peat), allowed the verification of the applicability of the process for treating such complex gas effluents. Even if global removal performance (120 g/m{sup 3} filter/h) is comparable to those attempted for less complex effluents, phenomena of competitions between substrates are observed. Therefore, the presence of many compounds reduces the elimination capacity for each pollutant, increases the microbial acclimatization time and Leads to a stratification of the degradation inside the reactor. On the other hand, a theoretical approach of the bio-filtration process based on Quantitative Structure Activity Relationships (QSAR) exhibits three preponderant factors that determine pollutant treatability in a bio-filter:the Henry's law coefficient, octanol-water partition constant, and the first order connectivity index. These parameters can be correlated to the gas-liquid transfer, the solubility and the biodegradability of a molecule, respectively. Finally, the examination of a strong adsorption capacity material (active carbon) as a filter bed indicates the material used has a significant effect on system's removal. Therefore, in the present study, by modifying the respective retention times of pollutants, such a material increases the competition phenomena and thus reduces elimination capacities. (author)

  11. Removal of geosmin and MIB by biofiltration--an investigation discriminating between adsorption and biodegradation. (United States)

    Persson, F; Heinicke, G; Hedberg, T; Hermansson, M; Uhl, W


    Geosmin and 2-methylisoborneol (MIB) are two substances causing earthy/musty odours that are difficult to remove by conventional chemical drinking water treatment. In this study removal of geosmin and MIB by biofiltration of untreated surface water was investigated using granular activated carbon (GAC) and crushed expanded clay (EC) as filter media. Biofiltration through both GAC and EC removed geosmin and MIB present at low (20 ng l(-1)) concentrations by at least 97% at an empty bed contact time of 30 minutes and a temperature of 15 degrees C. At lower temperature (6-12 degrees C) and simultaneously lower biomass concentrations, removal efficiency was similar in the GAC but considerably lower in the EC biofilter, pointing to a second mechanism different from biodegradation. Consequently, microbial activity was suppressed with azide to enable discrimination between biodegradation and adsorption. During azide dosage, the GAC biofilters still removed geosmin and MIB nearly unaffectedly. In the EC biofilter, however, removal of both odorants ceased completely. Methylene blue adsorption confirmed that the GAC, even after almost four years of operation receiving surface water, had capacity to remove geosmin and MIB by adsorption. Since odour episodes commonly occur during the warm season when microbiological activity is high, EC constitutes a viable option as carrier medium for direct biological filtration of surface water. The additional GAC adsorption capacity however adds robustness to the removal process.

  12. Coupled Physical/Chemical and Biofiltration Technologies to Reduce Air Emissions from Forest Products Industries

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. McGinnis


    The research is a laboratory and bench-scale investigation of a system to concentrate and destroy volatile organic compounds (VOCs), including hazardous air pollutants, formed from the drying of wood and the manufacture of wood board products (e.g., particle board and oriented strandboard). The approach that was investigated involved concentrating the dilute VOCs (<500 ppmv) with a physical/chemical adsorption unit, followed by the treatment of the concentrated voc stream (2,000 to 2,500 ppmv) with a biofiltration unit. The research program lasted three years, and involved three research organizations. Michigan Technological University was the primary recipient of the financial assistance, the USDA Forest Products Laboratory (FPL) and Mississippi State University (MSU) were subcontractors to MTU. The ultimate objective of this research was to develop a pilot-scale demonstration of the technology with sufficient data to provide for the design of an industrial system. No commercialization activities were included in this project.

  13. Deterioration of organic packing materials commonly used in air biofiltration: effect of VOC-packing interactions. (United States)

    Lebrero, Raquel; Estrada, José M; Muñoz, Raúl; Quijano, Guillermo


    The abiotic deterioration of three conventional organic packing materials used in biofiltration (compost, wood bark and Macadamia nutshells) caused by their interaction with toluene (used as a model volatile organic compound) was here studied. The deterioration of the materials was evaluated in terms of structural damage, release of co-substrates and increase of the packing biodegradability. After 21 days of exposure to toluene, all packing materials released co-substrates able to support microbial growth, which were not released by the control materials not exposed to toluene. Likewise, the exposure to toluene increased the packing material biodegradability by 26% in wood bark, 20% in compost and 17% in Macadamia nutshells. Finally, scanning electron microscopy analysis confirmed the deterioration in the structure of the packing materials evaluated due to the exposure to toluene, Macadamia nutshells being the material with the highest resistance to volatile organic compound attack.

  14. Modeling the formation of soluble microbial products (SMP in drinking water biofiltration

    Directory of Open Access Journals (Sweden)

    Xin YU


    Full Text Available Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium were fed with different acetate loadings for the determination of SMP formation. Using numerically simulated and measured parameters, the theoretical model was developed according to the substrate and biomass balance. The results of this model matched the measured data better for higher SMP formation but did not fit well when SMP formation was lower. In order to better simulate the reality and overcome the difficulties of measuring the kinetic parameters, a simpler empirical model was also developed. In this model, SMP formation was expressed as a function of fed organic loadings and the depth of the medium, and a much better fit was obtained.

  15. Desorption and biofiltration for the treatment of residual organic gases evolved in soil decontamination processes

    Energy Technology Data Exchange (ETDEWEB)

    Barona, A.; Elias, A.; Arias, R.; Acha, E.; Cano, I. [Department of Chemical and Environmental Engineering, University of the Basque Country, Bilbao (Spain)


    In order to analyze the combination of a rotary kiln and a biofilter in soil decontamination processes, a previously characterized soil was artificially contaminated with toluene, ethylbenzene or p-xylene. The desorption peak of the three compounds occurred very quickly at 20 C, and consequently, the outlet gas flow from the rotary kiln was initially divided into two different flows. One of them was reduced to a 1/9{sup th} fraction of the total flow to be treated in an independent biofiltration system specially acclimated to each contaminant. The sharp desorption peak observed for the three compounds at the outlet of the kiln involved a very high inlet concentration fed into the biofilters in a very short period of time (shorter than 3 h). Consequently, the removal efficiency for toluene was lower than 70 %. However, the removal efficiencies for ethylbenzene and xylene were always higher than 65 %. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  16. Modeling the formation of soluble microbial products (SMP) in drinking water biofiltration

    Institute of Scientific and Technical Information of China (English)

    Yu Xin; Ye Lin; Wei Gu


    Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP) during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium were fed with different acetate loadings for the determination of SMP formation. Using numerically simulated and measured parameters, the theoretical model was developed according to the substrate and biomass balance. The results of this model matched the measured data better for higher SMP formation but did not fit well when SMP formation was lower. In order to better simulate the reality and overcome the difficulties of measuring the kinetic parameters, a simpler empirical model was also developed. In this model, SMP formation was expressed as a function of fed organic loadings and the depth of the medium, and a much better fit was obtained.

  17. Advantages of combined UV photodegradation and biofiltration processes to treat gaseous chlorobenzene

    Energy Technology Data Exchange (ETDEWEB)

    Wang Can; Xi Jinying [Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Hu Hongying, E-mail: [Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Yao Yuan [Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)


    A combined ultraviolet photodegradation and biofiltration (UV-BF) process was developed to treat gaseous chlorobenzene. The performance of this process was evaluated under various operating conditions, including different inlet concentrations, residence times, and transient loadings, and compared with a control biofiltration (BF) process. Furthermore, the acute biotoxicities of the photodegradation products, the bioaerosol emissions from biofilters, the biomass accumulation and pressure drop in biofilters were investigated. The experimental results showed that the UV-BF process provided higher removal efficiencies than those of the control BF process over an inlet concentration range of 250-1500 mg m{sup -3} for residence times of 41-122 s inside the biofilters and 24-81 s inside the UV reactor. After UV pretreatment, removal rates of the subsequent biofilter increased linearly with biofilter inlet loading, even beyond 50 g m{sup -3} h{sup -1}. Similar inlet loading resulted in a gradual decline of removal rates for the control process due to a substrate inhibition effect. These results suggested that UV pretreatment reduced the inhibitory effects of chlorobenzene on microorganisms inside biofilters. Transient loading conditions were tested by increasing the inlet concentration from 1000 to 2500 mg m{sup -3} or shifting the gas flow rate from 0.1 to 0.3 m{sup 3} h{sup -1}, which led to reduced outlet concentrations in the UV-BF process compared with those of the control BF process. The standalone UV photodegradation of chlorobenzene can produce products with significant acute biotoxicity. Acute biotoxicities as high as 12 mg-Zn{sup 2+} L{sup -1} were measured. Biotoxicity levels were reduced to less than 5 mg-Zn{sup 2+} L{sup -1} after the biofilter. Ozone, a by-product produced during the UV photodegradation process, contributed to a reduction in bioaerosol emission from the biofilters and helped to control the biomass, thus slowing down the pressure drop increase

  18. The effects of methanol on the biofiltration of dimethyl sulfide in inorganic biofilters. (United States)

    Zhang, Yuefeng; Liss, Steven N; Allen, D Grant


    Air emissions from the pulp and paper industry frequently contain reduced sulfur compounds (RSC), such as dimethyl sulfide (DMS) mixed with volatile organic compounds (VOC) (e.g., methanol, MeOH) and it is desirable to treat either one or both of these groups of compounds. The objective of this study was to assess the effects of VOC (MeOH) on the biofiltration of DMS. Results obtained from continuous experiments using three bench-scale biofilters packed with inorganic material clearly show that MeOH has a positive effect (11-fold increase) on the biofiltration of DMS. Further experiments indicate that MeOH addition enhances biomass concentration and viability (threefold) in the biofilters. However, a suspension of MeOH addition causes a rapid significant increase (twofold) in the removal rate of DMS, suggesting that the presence of MeOH also has a competitive effect on DMS biodegradation. This negative effect was also confirmed in batch experiments. The decrease of biofilter performance with time for a long-term suspension of MeOH addition indicates that MeOH addition is necessary to sustain a high removal rate of DMS in inorganic biofilters. Results on metabolic products of DMS biodegradation demonstrate that DMS is almost completely converted to sulfate in the absence of MeOH, while it is partially oxidized to elemental sulfur in the presence of MeOH. This study suggests that there exists an optimum mix of DMS and MeOH for the treatment of DMS emissions in inorganic biofilters.

  19. VOC and air toxics control using biofiltration: 2 full-scale system case studies

    Energy Technology Data Exchange (ETDEWEB)

    Fucich, W.J.; Togna, A.P.; Loudon, R.E. [Envirogen, Inc., Lawrenceville, NJ (United States)] [and others


    Industry continuous to search for innovative air treatment technologies to cost effectively meet the stringent requirements of the CAAA. High volume process exhaust streams contaminated with dilute concentrations of VOCs and HAPs are an especially challenging problem. Biological treatment is an option that must be evaluated with the traditional control technologies (chemical scrubbing, condensation, adsorption, thermal oxidation, etc.) because of the low operating costs and the system is environmentally friendly. In the United States, biofiltration is considered an emerging technology, however, full-scale biofiltration systems are now successfully operating in two rigorous services. At Nylonge Corporation, a biofilter is safely and efficiently degrading CS{sub 2} and H{sub 2}S vapor emissions. The ABTco system is successfully treating the target compounds, methanol and formaldehyde, in a press exhaust containing inert particulate and semi-volatiles. These systems are both based on a unique, patented modular design. The modular concept allows the system to be easily installed resulting in construction cost minimization and maintaining critical project schedules. The modular system offers flexibility because the biofilter is easily expanded to accommodate future plant growth. The modular design benefits the end user because individual modules or biofilter sections can be isolated for service and inspection while the biofilter system stays on-line. An up-flow configuration and the patented irrigation system allow biofilters to be used on the most difficult services. In the case of Nylonge, the biofilter is handling the sulfuric acid generated during the degradation of CS{sub 2} and H{sub 2}S vapors. At ABTco, stable operation is achieved in a stream containing particulates and semi-volatiles.

  20. Biological Removal of Ammonia from Contaminated Air Streams Using Biofiltration System

    Directory of Open Access Journals (Sweden)

    MR Shahmansouri, H Taghipour, B Bina, H Movahdian


    Full Text Available Ammonia is a colorless, toxic, reactive and corrosive gas with a sharp odor. It is irritating to the skin, eyes, nose, throat, and lungs. Ammonia gas occurs in the environment naturally and is emitted by many industries and, therefore, its control is essential. Biofiltration is a new emerging technology that is being used as a control procedure. This study evaluates the use of a mixture of compost, sludge, and pieces of PVC as biofilter media to remove ammonia gas. The study investigates the effects of parameters such as inlet concentration, accumulation time, and depth of filter media to evaluate the removal efficiency. A laboratory scale biofilter column was built and operated to investigate the removal of ammonia from a waste gas stream. The findings indicate that for inlet concentrations of 236 ppm, and ammonia loading of less than 9.86 g-NH3/m3.h at empty bed residence time of 1 min, an ammonia removal efficiency of more than 99.9% was obtained. The acclimation period of the bacteria was 10 days. The average pressure drop during measurement was 4.44 mm H2O. The study also revealed that for concentration levels of 99, 211, and 236 ppmv, biofilter media depths of 40, 80, and 120 cm will be required, respectively. The results obtained in this study indicate that the biofiltration system composed of compost in the mixture of sludge and smashed polyvinyl chloride as biofilter media is an efficient method for the removal of ammonia from waste gas streams. It is also found that the optimum depth of biofilter media depends on the inlet concentration of ammonia.

  1. Emission control system for nitrogen oxides using enhanced oxidation, scrubbing, and biofiltration

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, A.; Cabezas, J. [Texas A& amp; M University Kingsville, Kingsville, TX (United States). Dept. of Environmental Engineering


    Nitric oxide (NO) constitutes about 90% of the nitrogen oxide (NOx) species in the flue gases emitted from combustion processes, but NO is difficult to remove in existing scrubbers due to its low solubility. NO may be oxidized with hydrogen peroxide (H{sub 2}O{sub 2}) into soluble species that can be partially removed in wet scrubbers simultaneously with sulfur dioxide (SO{sub 2}) and biofilters located downstream of the scrubber can increase the removal efficiency. This article presents the results of a bench-scale evaluation of such an integrated system combining enhanced oxidation, scrubbing, and biofiltration. Main components of the bench-scale system consisted of a quartz tube in a furnace to simulate the NO oxidation stage and two vertical packed bed cylinders constituting the scrubber and the biofilter. Inlet synthetic gas had a concentration of 50 mu L/L of NO. Overall removal efficiency by the integrated system was in the range of 53% to 93% with an average of 79%, absorption accounted for 43% and biofiltration for 36% of the total removal. Key parameters in the operation of the system are the H{sub 2}O{sub 2}:NO mole ratio, the reaction temperature, the liquid to gas flow ratio, and the biofilter residence time. Experimental results suggest a path for optimization of the technology focusing simultaneously in minimizing H{sub 2}O{sub 2} use in the enhanced oxidation stage, reducing water consumption in the scrubber stage and balancing the residence times in the three stages of the integrated system.

  2. Temporary storage or permanent removal? The division of nitrogen between biotic assimilation and denitrification in stormwater biofiltration systems.

    Directory of Open Access Journals (Sweden)

    Emily G I Payne

    Full Text Available The long-term efficacy of stormwater treatment systems requires continuous pollutant removal without substantial re-release. Hence, the division of incoming pollutants between temporary and permanent removal pathways is fundamental. This is pertinent to nitrogen, a critical water body pollutant, which on a broad level may be assimilated by plants or microbes and temporarily stored, or transformed by bacteria to gaseous forms and permanently lost via denitrification. Biofiltration systems have demonstrated effective removal of nitrogen from urban stormwater runoff, but to date studies have been limited to a 'black-box' approach. The lack of understanding on internal nitrogen processes constrains future design and threatens the reliability of long-term system performance. While nitrogen processes have been thoroughly studied in other environments, including wastewater treatment wetlands, biofiltration systems differ fundamentally in design and the composition and hydrology of stormwater inflows, with intermittent inundation and prolonged dry periods. Two mesocosm experiments were conducted to investigate biofilter nitrogen processes using the stable isotope tracer 15NO3(- (nitrate over the course of one inflow event. The immediate partitioning of 15NO3(- between biotic assimilation and denitrification were investigated for a range of different inflow concentrations and plant species. Assimilation was the primary fate for NO3(- under typical stormwater concentrations (∼1-2 mg N/L, contributing an average 89-99% of 15NO3(- processing in biofilter columns containing the most effective plant species, while only 0-3% was denitrified and 0-8% remained in the pore water. Denitrification played a greater role for columns containing less effective species, processing up to 8% of 15NO3(-, and increased further with nitrate loading. This study uniquely applied isotope tracing to biofiltration systems and revealed the dominance of assimilation in stormwater

  3. Biofouling reduction in recirculating cooling systems through biofiltration of process water. (United States)

    Meesters, K P H; Van Groenestijn, J W; Gerritse, J


    Biofouling is a serious problem in industrial recirculating cooling systems. It damages equipment, through biocorrosion, and causes clogging and increased energy consumption, through decreased heat transfer. In this research a fixed-bed biofilter was developed which removed assimilable organic carbon (AOC) from process water, thus limiting the major substrate for the growth of biofouling. The biofilter was tested in a laboratory model recirculating cooling water system, including a heat exchanger and a cooling tower. A second identical model system without a biofilter served as a reference. Both installations were challenged with organic carbon (sucrose and yeast extract) to provoke biofouling. The biofilter improved the quality of the recirculating cooling water by reducing the AOC content, the ATP concentration, bacterial numbers (30-40 fold) and the turbidity (OD660). The process of biofouling in the heat exchangers, the process water pipelines and the cooling towers, was monitored by protein increase, heat transfer resistance, and chlorine demanded for maintenance. This revealed that biofouling was lower in the system with the biofilter compared to the reference installation. It was concluded that AOC removal through biofiltration provides an attractive, environmental-friendly means to reduce biofouling in industrial cooling systems.

  4. Coupling biofiltration process and electrocoagulation using magnesium-based anode for the treatment of landfill leachate. (United States)

    Oumar, Dia; Patrick, Drogui; Gerardo, Buelna; Rino, Dubé; Ihsen, Ben Salah


    In this research paper, a combination of biofiltration (BF) and electrocoagulation (EC) processes was used for the treatment of sanitary landfill leachate. Landfill leachate is often characterized by the presence of refractory organic compounds (BOD/COD < 0.13). BF process was used as secondary treatment to remove effectively ammonia nitrogen (N-NH4 removal of 94%), BOD (94% removed), turbidity (95% removed) and phosphorus (more than 98% removed). Subsequently, EC process using magnesium-based anode was used as tertiary treatment. The best performances of COD and color removal from landfill leachate were obtained by applying a current density of 10 mA/cm(2) through 30 min of treatment. The COD removal reached 53%, whereas 85% of color removal was recorded. It has been proved that the alkalinity had a negative effect on COD removal during EC treatment. COD removal efficiencies of 52%, 41% and 27% were recorded in the presence of 1.0, 2.0 and 3.0 g/L of sodium bicarbonate (NaHCO3), respectively. Hydroxide ions produced at the cathode electrode reacted with the bicarbonate ions to form carbonates. The presence of bicarbonates in solution hampered the increase in pH, so that the precipitation of magnesium hydroxides could not take place to effectively remove organic pollutants.

  5. Influence of mixing on the removal rate of toluene vapors by biofiltration

    Energy Technology Data Exchange (ETDEWEB)

    Morales, M.; Acuna, M.E.; Perez, F.; Revah, S. [UAM-Iztapalapa, Mexico City (Mexico). Dept. of Chemical Engineering; Frere, G. [ENSCP, Paris (France); Auria, R. [ORSTOM, Los Morales, Mexico City (Mexico)


    Biofilter performance can be influenced by different factors. Among these, packing material heterogeneity generated during the biofiltration process has an important effect both micro and macro scale. In this paper, the influence of the packing material mixing on the performance of a biofilter adapted for toluene removal will be presented. The biofilter was packed with peat previously sterilized by g irradiation and inoculated with a specific microbial consortium. After three months of biofilter operation a steady state elimination capacity (EC) of 18 g/m{sup 3}/h was attained with observable heterogeneity. At this point, the packing material was thoroughly mixed. A new start up was observed with a maximum EC of 127 g/m{sup 3}/h, outlet CO{sub 2} concentration of 4.0 g/m{sup 3} and a temperature difference between the inlet and the packed bed of {minus}5.5 C were measured showing that an increased metabolic activity was triggered by mixing. This operation was repeated on a period of four months and a similar behavior was observed but with decreased intensities. These global measurements were correlated with simultaneous microcosm experiments performed with biofilter samples. Successive mixing yielded average global EC above 50 g/m{sup 3}/h during the experiment, which is higher than the values normally obtained with biofilters. This paper discusses possible causes for this response and perspectives.

  6. Enhancing the biofiltration of geosmin by seeding sand filter columns with a consortium of geosmin-degrading bacteria. (United States)

    McDowall, Bridget; Hoefel, Daniel; Newcombe, Gayle; Saint, Christopher P; Ho, Lionel


    Geosmin is a secondary metabolite that can be produced by many species of cyanobacteria and Actinomycetes. It imparts a musty/earthy taste and odour to drinking water which can result in consumer complaints and a general perception that there is a problem with the water quality. As geosmin is recalcitrant to conventional water treatment, processes are sought to ensure effective removal of this compound from potable water. Biological filtration (biofiltration) is an attractive option for geosmin removal as this compound has been shown to be biodegradable. However, effective biofiltration of geosmin can be site specific as it is highly dependent upon the types of organism present and there is often an extended acclimation period before efficient removals are achieved. We report here, a novel approach to enhance the biofiltration of geosmin by seeding sand filter columns with a bacterial consortium previously shown to be capable of effectively degrading geosmin. Geosmin removals of up to 75% were evident through sand columns which had been inoculated with the geosmin-degrading bacteria, when compared with non-inoculated sand columns where geosmin removals were as low as 25%. These low geosmin removals through the non-inoculated sand columns are consistent with previous studies and were attributed to physical/abiotic losses. The presence of an existing biofilm was shown to influence geosmin removal, as the biofilm allowed for greater attachment of the geosmin-degrading consortium (as determined by an ATP assay), and enhanced removals of geosmin. Minimal difference in geosmin removal was observed when the geosmin-degrading bacteria were inoculated into the sand columns containing either an active or inactive biofilm.

  7. Removal of Disinfection By-Products from Contaminated Water Using a Synthetic Goethite Catalyst via Catalytic Ozonation and a Biofiltration System

    Directory of Open Access Journals (Sweden)

    Yu-Hsiang Wang


    Full Text Available The effects of synthetic goethite (α-FeOOH used as the catalyst in catalytic ozonation for the degradation of disinfection by-product (DBP precursors are investigated. A biofiltration column applied following the catalytic ozonation process is used to evaluate the efficiency of removing DBP precursors via biotreatment. Ozone can rapidly react with aromatic compounds and oxidize organic compounds, resulting in a decrease in the fluorescence intensity of dissolved organic matter (DOM. In addition, catalytic ozonation can break down large organic molecules, which causes a blue shift in the emission-excitation matrix spectra. Water treated with catalytic ozonation is composed of low-molecular structures, including soluble microbial products (SMPs and other aromatic proteins (APs. The DOM in SMPs and APs is removed by subsequent biofiltration. Catalytic ozonation has a higher removal efficiency for dissolved organic carbon and higher ultraviolet absorbance at 254 nm compared to those of ozonation without a catalyst. The use of catalytic ozonation and subsequent biofiltration leads to a lower DBP formation potential during chlorination compared to that obtained using ozonation and catalytic ozonation alone. Regarding DBP species during chlorination, the bromine incorporation factor (BIF of trihalomethanes and haloacetic acids increases with increasing catalyst dosage in catalytic ozonation. Moreover, the highest BIF is obtained for catalytic ozonation and subsequent biofiltration.

  8. Removal of micropollutants during tertiary wastewater treatment by biofiltration: Role of nitrifiers and removal mechanisms. (United States)

    Rattier, M; Reungoat, J; Keller, J; Gernjak, W


    The objective of this study was to determine the extent to which a suite of organic micropollutants (MPs) can be removed by biological filtration and the role of bioavailability and ammonia oxidizing microorganisms (AOMs) in the biodegradation process. During approximately one year, laboratory-scale columns with 8 min empty bed contact time (EBCT) and packed with anthracite as filter media were used for treating a tertiary effluent spiked with a broad range of MPs at a target concentration of 2 μg L(-1). In parallel columns, aerobic biomass growth was inhibited by using either the biocide sodium azide (500 mg L(-1) NaN3) or allylthiourea (5 mg L(-1) ATU), specifically inhibiting nitrifying bacteria. Once the biomass had colonized the media, around 15% of the dissolved organic carbon (DOC) contained in the untreated tertiary effluent was removed by non-inhibited columns. The removal of several MPs increased over time indicating the relevance of biological activity for the removal of MPs, while the negative control, the NaN3 inhibited column, showed no significant removal. Out of 33 MPs, 19 were recalcitrant (nitrification inhibitor. A relationship between the qualitative assessment of sorption of MPs on granular activated carbon (GAC) and their removal efficiency by biodegradation on anthracite was observed. This result suggested that the affinity of the MPs for GAC media could be a useful indicator of the bioavailability of compounds during biofiltration on anthracite.

  9. Comparison of filter media materials for heavy metal removal from urban stormwater runoff using biofiltration systems. (United States)

    Lim, H S; Lim, W; Hu, J Y; Ziegler, A; Ong, S L


    The filter media in biofiltration systems play an important role in removing potentially harmful pollutants from urban stormwater runoff. This study compares the heavy metal removal potential (Cu, Zn, Cd, Pb) of five materials (potting soil, compost, coconut coir, sludge and a commercial mix) using laboratory columns. Total/dissolved organic carbon (TOC/DOC) was also analysed because some of the test materials had high carbon content which affects heavy metal uptake/release. Potting soil and the commercial mix offered the best metal uptake when dosed with low (Cu: 44.78 μg/L, Zn: 436.4 μg/L, Cd, 1.82 μg/L, Pb: 51.32 μg/L) and high concentrations of heavy metals (Cu: 241 μg/L, Zn: 1127 μg/L, Cd: 4.57 μg/L, Pb: 90.25 μg/L). Compost and sludge also had high removal efficiencies (>90%). Heavy metal leaching from these materials was negligible. A one-month dry period between dosing experiments did not affect metal removal efficiencies. TOC concentrations from all materials increased after the dry period. Heavy metal removal was not affected by filter media depth (600 mm vs. 300 mm). Heavy metals tended to accumulate at the upper 5 cm of the filter media although potting soil showed bottom-enriched concentrations. We recommend using potting soil as the principal media mixed with compost or sludge since these materials perform well and are readily available. The use of renewable materials commonly found in Singapore supports a sustainable approach to urban water management.

  10. Conventional drinking water treatment and direct biofiltration for the removal of pharmaceuticals and artificial sweeteners: A pilot-scale approach. (United States)

    McKie, Michael J; Andrews, Susan A; Andrews, Robert C


    The presence of endocrine disrupting compounds (EDCs), pharmaceutically active compounds (PhACs) and artificial sweeteners are of concern to water providers because they may be incompletely removed by wastewater treatment processes and they pose an unknown risk to consumers due to long-term consumption of low concentrations of these compounds. This study utilized pilot-scale conventional and biological drinking water treatment processes to assess the removal of nine PhACs and EDCs, and two artificial sweeteners. Conventional treatment (coagulation, flocculation, settling, non-biological dual-media filtration) was compared to biofilters with or without the addition of in-line coagulant (0.2-0.8 mg Al(3+)/L; alum or PACl). A combination of biofiltration, with or without in-line alum, and conventional filtration was able to reduce 7 of the 9 PhACs and EDCs by more than 50% from river water while artificial sweeteners were inconsistently removed by conventional treatment or biofiltration. Increasing doses of PACl from 0 to 0.8 mg/L resulted in average removals of PhACs, EDCs increasing from 39 to 70% and artificial sweeteners removal increasing from ~15% to ~35% in lake water. These results suggest that a combination of biological, chemical and physical treatment can be applied to effectively reduce the concentration of EDCs, PhACs, and artificial sweeteners.

  11. Impact of extraction methods on bio-flocculants recovered from backwashed sludge of bio-filtration unit. (United States)

    Nguyen, Viet Hoang; Klai, Nouha; Nguyen, Thanh Dong; Tyagi, Rajeshwar Dayal


    Effect of ten extraction methods on flocculation activity and chemical composition of bio-flocculants recovered from backwashed sludge of bio-filtration unit was studied. The results showed that the chemical method was better than physical method with respect to the extracted BFs weight and its flocculation activity. Cell lysis did not affect to the flocculation activity of BFs. Among ten extraction methods, EDTA (20 g/L) was the best one with extracted BFs dry weight of 6242 mg/L and flocculation activity of 83%. Optimization of EDTA concentration showed that 5 g EDTA/L (or 0.2 g EDTA/g SS) was suitable for recovery of BFs from backwashed sludge. The flocculation activity of BFs was 94% when using 2.4 mg of BFs/g of kaolin. The outcome of this study suggested that backwashed sludge of the bio-filtration unit was a potential source for exploiting bio-flocculants.

  12. Biofiltration of waste gases with the fungi Exophiala oligosperma and Paecilomyces variotti

    Energy Technology Data Exchange (ETDEWEB)

    Estevez, E.; Veiga, M.C.; Kennes, C. [University of La Coruna (Spain). Chemical Engineering Lab.


    Two biofilters fed toluene-polluted air were inoculated with new fungal isolates of either Exophiala oligosperma or Paecilomyces variotii, while a third bioreactor was inoculated with a defined consortium composed of both fungi and a co-culture of a Pseudomonas strain and a Bacillus strain. Elimination capacities of 77 g m{sup -3} h{sup -1} and 55 g m{sup -3} h{sup -1} were reached in the fungal biofilters (with removal efficiencies exceeding 99%) in the case of, respectively, E. oligosperma and Paecilomyces variotii when feeding air with a relative humidity (RH) of 85%. The inoculated fungal strains remained the single dominant populations throughout the experiment. Conversely, in the biofilter inoculated with the bacterial-fungal consortium, the bacteria were gradually overgrown by the fungi, reaching a maximum elimination capacity around 77 g m{sup -3} h{sup -1}. Determination of carbon dioxide concentrations both in batch assays and in biofiltration studies suggested the near complete mineralization of toluene. The non-linear toluene removal along the height of the biofilters resulted in local elimination capacities of up to 170 g m{sup -3} h{sup -1} and 94 g m{sup -3} h{sup -1} in the reactors inoculated, respectively, with E. oligosperma and P. variotii. Further studies with the most efficient strain, E. oligosperma, showed that the performance was highly dependent on the RH of the air and the pH of the nutrient solution. At a constant 85% RH, the maximum elimination capacity either dropped to 48.7 g m{sup -3} h{sup -1} or increased to 95.6 g m{sup -3} h{sup -1}, respectively, when modifying the pH of the nutrient solution from 5.9 to either 4.5 or 7.5. The optimal conditions were 100% RH and pH 7.5, which allowed a maximum elimination capacity of 164.4 g m{sup -3} h{sup -1} under steady-state conditions, with near-complete toluene degradation. (orig.)

  13. Variability of Acid-Base Status in Acetate-Free Biofiltration 84% versus Bicarbonate Dialysis

    Directory of Open Access Journals (Sweden)

    Harzallah Kais


    Full Text Available The ultimate goal of hemodialysis (HD treatment is to achieve the highest level of efficacy in the presence of maximal clinical tolerance. With an aim to offer good hemodynamic stability, as observed during the acetate-free biofiltration 14% (AFB 14% to patients who are intolerant to bicarbonate dialysis (BD and with less cost, we have developed since June 1994, a new HD technique, namely AFB 84%. This study was carried out to analyze acid-base variations during the AFB 84% in comparison to BD in hemodynamically stable patients on regular HD. This was a prospective randomized crossover study carried out on 12 patients (6 males and 6 females for a total of 144 HD sessions (72 BD and 72 AFB 84%. Patients with decompensated cardiomyopathy, respiratory diseases or uncontrolled hypertension were not included in the trial. All the patients were treated with BD or AFB 84%; the latter is characterized by the absence of acetate in the dialysate and a complete correction of buffer balance by post-dilutional infusion of bicarbonate-based replacement solution. The comparison of pre-dialysis arterial acid-base and blood-gas parameters revealed no significant differences of pH, HCO 3 - and paCO 2 levels between the two techniques. Analysis of post-dialysis parameters showed that, among patients dialyzed with BD, there was over correction of metabolic acidosis with a tendency towards metabolic alkalosis. In contrast, in patients dialyzed with AFB 84%, we observed a significant improvement in pH and HCO 3 - levels but the increase in paCO2 level was not significant. A comparison of these parameters between the two techniques showed statistically significant difference in pH, HCO3 - and paCO2 levels, but not for paO2 level. AFB 84% can offer some important advantages with the complete absence of acetate from the substitution fluids, and permits a better correction of metabolic acidosis than BD, without causing alkalosis.

  14. Integration of biofiltration and advanced oxidation processes for tertiary treatment of an oil refinery wastewater aiming at water reuse. (United States)

    Nogueira, A A; Bassin, J P; Cerqueira, A C; Dezotti, M


    The combination of biological and chemical oxidation processes is an interesting approach to remove ready, poor, and non-biodegradable compounds from complex industrial wastewaters. In this study, biofiltration followed by H2O2/UV oxidation (or microfiltration) and final reverse osmosis (RO) step was employed for tertiary treatment of an oil refinery wastewater. Biofiltration alone allowed obtaining total organic carbon (TOC), chemical oxygen demand (COD), UV absorbance at 254 nm (UV254), ammonium, and turbidity removal of around 46, 46, 23, 50, and 61 %, respectively. After the combined biological-chemical oxidation treatment, TOC and UV254 removal amounted to 88 and 79 %, respectively. Whereas, the treatment performance achieved with different UV lamp powers (55 and 95 W) and therefore distinct irradiance levels (26.8 and 46.3 mW/cm(2), respectively) were very similar and TOC and UV254 removal rates were highly affected by the applied C/H2O2 ratio. Silt density index (SDI) was effectively reduced by H2O2/UV oxidation, favoring further RO application. C/H2O2 ratio of 1:4, 55 W UV lamp, and 20-min oxidation reaction corresponded to the experimental condition which provided the best cost/benefit ratio for TOC, UV254, and SDI reduction from the biofilter effluent. The array of treatment processes proposed in this study has shown to be adequate for tertiary treatment of the oil refinery wastewater, ensuring the mitigation of membrane fouling problems and producing a final effluent which is suitable for reuse applications.

  15. Ammonia biofiltration and nitrous oxide generation during the start-up of gas-phase compost biofilters (United States)

    Maia, Guilherme D. N.; Day V, George B.; Gates, Richard S.; Taraba, Joseph L.


    Gas-Phase Biofiltration technology is widely utilized for treating ammonia gas (NH 3) with one of its potential detrimental by-products being nitrous oxide (N 2O), a potent greenhouse gas (100-y radiative forcing 298 times greater than carbon dioxide). The present work was conducted to investigate the relation between NH 3 removal during biofiltration and N 2O generation as a product of incomplete denitrification during the start-up of gas-phase compost biofilters. Four laboratory scale tubular biofilters in up flow mode (20 s residence-time) were studied for 21 days: 3 replicates were subjected to 16 ppm v (0.78 g m -2 h -1) of NH 3 and a statistical control not subjected to NH 3. Ammonia concentration differences between biofilter inlet (Bottom = 16 ppm v) and outlet (Top) and N 2O concentration differences between biofilter outlet (Top) and biofilter inlet (background concentrations at the bottom) were used to determine the extent of the correlation between NH 3 removal and N 2O generation. Correlations with CH 4 and CO 2 were also reported. The high Spearman correlation coefficients for the three replicates ( ρ = -0.845, -0.820, and -0.841, with P ≤ 0.0001 for replications A, B and C, respectively) suggested that availability of nitrate/nitrite owing to NH 3 nitrification favored conditions for N 2O generation as a sub-product of denitrification. The statistical control received no NH 3 inputs and did not generate N 2O. Therefore, the results indicated that the process of NH 3 removal was a trigger for N 2O production. Carbon dioxide and N 2O were moderately correlated. Methane and N 2O were weakly correlated and only for replicate C. No significant correlation was found for the Statistical Control between N 2O and CH 4.

  16. Occasional large emissions of nitrous oxide and methane observed in stormwater biofiltration systems

    Energy Technology Data Exchange (ETDEWEB)

    Grover, Samantha P.P., E-mail: [Department of Civil Engineering, Monash University, Clayton, Victoria, 3800 (Australia); Cohan, Amanda, E-mail: [Department of Civil Engineering, Monash University, Clayton, Victoria, 3800 (Australia); Chan, Hon Sen, E-mail: [Department of Civil Engineering, Monash University, Clayton, Victoria, 3800 (Australia); Livesley, Stephen J., E-mail: [Department of Resource Management and Geography, The University of Melbourne, Richmond, Victoria, 3121 (Australia); Beringer, Jason, E-mail: [School of Geography and Environmental Science, Monash University, Clayton, Victoria, 3800 (Australia); Monash Water for Liveability, Monash University, Clayton, Victoria, 3800 (Australia); Daly, Edoardo, E-mail: [Department of Civil Engineering, Monash University, Clayton, Victoria, 3800 (Australia); Monash Water for Liveability, Monash University, Clayton, Victoria, 3800 (Australia)


    Designed, green infrastructures are becoming a customary feature of the urban landscape. Sustainable technologies for stormwater management, and biofilters in particular, are increasingly used to reduce stormwater runoff volumes and peaks as well as improve the water quality of runoff discharged into urban water bodies. Although a lot of research has been devoted to these technologies, their effect in terms of greenhouse gas fluxes in urban areas has not been yet investigated. We present the first study aimed at quantifying greenhouse gas fluxes between the soil of stormwater biofilters and the atmosphere. N{sub 2}O, CH{sub 4}, and CO{sub 2} were measured periodically over a year in two operational vegetated biofiltration cells at Monash University in Melbourne, Australia. One cell had a saturated zone at the bottom, and compost and hardwood mulch added to the sandy loam filter media. The other cell had no saturated zone and was composed of sandy loam. Similar sedges were planted in both cells. The biofilter soil was a small N{sub 2}O source and a sink for CH{sub 4} for most measurement events, with occasional large emissions of both N{sub 2}O and CH{sub 4} under very wet conditions. Average N{sub 2}O fluxes from the cell with the saturated zone were almost five-fold greater (65.6 μg N{sub 2}O–N m{sup −2} h{sup −1}) than from the other cell (13.7 μg N{sub 2}O–N m{sup −2} h{sup −1}), with peaks up to 1100 μg N{sub 2}O–N m{sup −2} h{sup −1}. These N{sub 2}O fluxes are of similar magnitude to those measured in other urban soils, but with larger peak emissions. The CH{sub 4} sink strength of the cell with the saturated zone (− 3.8 μg CH{sub 4}–C m{sup −2} h{sup −1}) was lower than the other cell (− 18.3 μg CH{sub 4}–C m{sup −2} h{sup −1}). Both cells of the biofilter appeared to take up CH{sub 4} at similar rates to other urban lawn systems; however, the biofilter cells displayed occasional large CH{sub 4} emissions following

  17. 雨水生物过滤处理技术在澳大利亚的研究与应用%Research and Application on Stormwater Biofiltration Treatment Technology in Australia

    Institute of Scientific and Technical Information of China (English)

    张翔凌; Ana Deletic


    介绍了一种澳大利亚采用的雨水生物过滤处理技术.阐述了FAWB研究人员在系统构型、填料选择、植物选择种植及其净化效果等方面所取得的主要研究成果.针对雨水生物过滤处理技术在悬浮物、重金属离子和营养性污染物去除方面的优势,以及在系统构型方面有效储存雨水以回用的特色,提出可对该技术改进为我国的雨水处理系统研究和雨水处理构筑物设计所借鉴的建议.%A new kind of stormwater biofiltration treatment technology in Australia was introduced. The major research and progress on the stormwater biofiltration system's configuration, filler media selection, plant selection and other aspects of the purifying effect which were researched by Facility for Advancing Water Bio-Filtration (abbr FAWB) were summarized. Aimed at the stormwater biofiltration system's advantages in suspended solids, heavy metals and nutrient pollutants removal, and system configuration's characteristics for effectively store reuse-rainwater, the technical improvements were suggested for the stormwater biofiltration treatment system's research and reference design in China.

  18. Abundance and composition of indigenous bacterial communities in a multi-step biofiltration-based drinking water treatment plant. (United States)

    Lautenschlager, Karin; Hwang, Chiachi; Ling, Fangqiong; Liu, Wen-Tso; Boon, Nico; Köster, Oliver; Egli, Thomas; Hammes, Frederik


    Indigenous bacterial communities are essential for biofiltration processes in drinking water treatment systems. In this study, we examined the microbial community composition and abundance of three different biofilter types (rapid sand, granular activated carbon, and slow sand filters) and their respective effluents in a full-scale, multi-step treatment plant (Zürich, CH). Detailed analysis of organic carbon degradation underpinned biodegradation as the primary function of the biofilter biomass. The biomass was present in concentrations ranging between 2-5 × 10(15) cells/m(3) in all filters but was phylogenetically, enzymatically and metabolically diverse. Based on 16S rRNA gene-based 454 pyrosequencing analysis for microbial community composition, similar microbial taxa (predominantly Proteobacteria, Planctomycetes, Acidobacteria, Bacteriodetes, Nitrospira and Chloroflexi) were present in all biofilters and in their respective effluents, but the ratio of microbial taxa was different in each filter type. This change was also reflected in the cluster analysis, which revealed a change of 50-60% in microbial community composition between the different filter types. This study documents the direct influence of the filter biomass on the microbial community composition of the final drinking water, particularly when the water is distributed without post-disinfection. The results provide new insights on the complexity of indigenous bacteria colonizing drinking water systems, especially in different biofilters of a multi-step treatment plant.

  19. Developing sulfide-oxidizing biofilm on H2S-exhausted carbon for sustainable bio-regeneration and biofiltration. (United States)

    Jiang, Xia; Yan, Rong; Tay, Joo Hwa


    The feasibility of developing biofilm on exhausted carbon using pre-deposited sulfur compounds as the sole energy source was studied, aiming to re-use them in odor biofiltration. The exhausted carbon with different properties, including surface pH, sulfur content and porosity, was used. A series of off-line trials were conducted to investigate the release of sulfur compounds from the exhausted carbon and the attachment of sulfide-oxidizing bacteria on the exhausted carbon. Without any pre-treatment, a few bacteria attachment on exhausted carbon was observed by SEM, due to possibly the limitation of reduced sulfur compounds release for bacterial growth. The biofilm development was much improved by adding NaOH solution to partially pre-desorb the deposited sulfur into liquid phase, which provided initial energy for bacterial growth. With the attached bacteria, the further significant release of the deposited sulfur was achieved through an additional driving force: biodegradation. The key issues for developing biofilm on exhausted carbon were concluded, which mainly concerned of desorption of pre-deposited reduced sulfur compounds and porosity of carbon. The sulfur-associated reactions occurring in developing biofilm on exhausted carbon was proposed. Bio-regeneration of exhausted carbon in the course of biofilm development was also preliminarily assessed.

  20. Fungal biofilters for toluene biofiltration: evaluation of the performance with four packing materials under different operating conditions. (United States)

    Maestre, Juan P; Gamisans, Xavier; Gabriel, David; Lafuente, Javier


    Packing materials play a key role in the performance of bioreactors for waste gas treatment and particularly in biofilter applications. In this work, the performance of four differently packed biofilters operated in parallel for the treatment of relatively high inlet concentration of toluene was studied. The reactors were compared for determining the suitability of coconut fiber, digested sludge compost from a waste water treatment plant, peat and pine leaves as packing materials for biofiltration of toluene. A deep characterisation of materials was carried out. Biological activity and packing capabilities related to toluene removal were determined throughout 240 days of operation under different conditions of nutrients addition and watering regime. Also, biofilters recovering after a short shutdown was investigated. Nutrient addition resulted in improved removal efficiencies (RE) and elimination capacities (EC) of biofilters reaching maximum ECs between 75 and 95 g m(-3)h(-1) of toluene. In the first 80 days, the pH decreased progressively within the reactors, causing a population change from bacteria to fungi, which were the predominant decontaminant microorganisms thereafter. All reactors were found to recover the RE rapidly after a 5 days shutdown and, in a maximum of 7 days, all reactors had been completely recuperated. These results point out that fungal biofilters are a suitable choice to treat high loads of toluene. In general, coconut fiber and compost biofilters exhibited a better performance in terms of elimination capacity and long-term stability.

  1. Modeling the biofiltration of dimethyl sulfide in the presence of methanol in inorganic biofilters at steady state. (United States)

    Zhang, Yuefeng; Allen, D Grant; Liss, Steven N


    The presence of methanol (MeOH) improves DMS removal (up to 11-fold) by enhancing biomass growth in inorganic biofilters. Although the overall effect is positive, prolonged growth on methanol also negatively affects DMS degradation as a result of competition with DMS. The objectives of this study were to explore the potential to optimize DMS removal with methanol addition and to develop and experimentally validate a mathematical model describing the biofiltration of DMS in the presence of MeOH. Continuous experiments using three bench-scale biofilters packed with inorganic material were performed to examine the removal of DMS under different MeOH addition rates ranging from 0 to 140 g/m3/h. For a constant DMS loading of 3.5 g/m3/h, a maximum DMS removal rate of 1.8 g/m3/h was achieved at a MeOH addition rate of 20 g/m3/h in the inorganic biofilters. A steady-state model incorporating the competitive and activation effects of MeOH on DMS biodegradation was developed, and the modeled results on DMS and MeOH removal were in close agreement with experimental data. Both the experimental data and model simulation suggest that there is an optimum MeOH addition rate for a given DMS loading. A step-feeding strategy for MeOH addition was proposed and tested by the model to optimize DMS removal. The model-predicted results demonstrate that six-step feeding of MeOH enhances DMS treatment by 46% in the biofilters when compared to conventional feeding (one-step) of MeOH at the same total mass loading.

  2. By-passing acidification limitations during the biofiltration of high formaldehyde loads via the application of ozone pulses

    Energy Technology Data Exchange (ETDEWEB)

    García-Pérez, Teresa [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), Camino a la Presa San José 2055, Col. Lomas 4a Sección, San Luis Potosí, SLP 78216 (Mexico); Aizpuru, Aitor [Universidad del Mar, Puerto Ángel, Distrito de San Pedro Pochutla, Oaxaca, México C.P. 70902 (Mexico); Arriaga, Sonia, E-mail: [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), Camino a la Presa San José 2055, Col. Lomas 4a Sección, San Luis Potosí, SLP 78216 (Mexico)


    Highlights: • Ozone addition permits to treat higher formaldehyde loads than ever reported. • Ozone addition acts as an indirect in situ pH regulator, minimizing the accumulation of acid byproducts. • Mineralization of formaldehyde occurs, which has never been reported. • Low ozone levels have no negative effects on biological degradation activity. • The use of hybrid processes allows overcoming biofiltration limitations. -- Abstract: A formaldehyde airstream was treated in a biofilter for an extended period of time. During the first 133 days, the reactor was operated without ozone, whereas over the following 82 days ozone was intermittently implemented. The maximum stable elimination capacity obtained without ozone was around 57 g m{sup −3} h{sup −1}. A greater load could not be treated under these conditions, and no significant formaldehyde removal was maintained for inlet loads greater than 65 g m{sup −3} h{sup −1}; the activity of microorganisms was then inhibited by the presence of acidic byproducts, and the media acidified (pH < 4). The implementation of ozone pulses allowed a stable elimination capacity to be obtained, even at greater loads (74 g m{sup −3} h{sup −1}). The effect of ozone on the extra cellular polymeric substances detachment from the biofilm could not be confirmed due to the too low biofilter biomass content. Thus, the results suggest that ozone acted as an in situ pH regulator, preventing acidic byproducts accumulation, and allowing the treatment of high loads of formaldehyde.

  3. Experimental study of the performance of bio-filtration systems for the treatment of a mixture of volatile organic compounds; Etude experimentale sur la performance de systemes de biofiltration pour le traitement d'un melange de composes organiques volatils

    Energy Technology Data Exchange (ETDEWEB)

    Gidas, M.B.


    The objective of this essentially experimental work was to study the treatment of a gaseous tributary containing a mixture of three VOCs (acetone, toluene and trichloroethylene) by bio-filtration with four bio-filters (B1, B2, B3 and B4), and to compare their performance in degrading pollutants. The filtering material for bio-filters B1 and B2 was an organic support (pig manure) and, for bio-filter B3, a mineral support (pozzolana). Bio-filter B4 consisted of a mixture of two supports, one organic and the other mineral, in correct proportions (pozzolana and pig manure). The feature of this study is the combination of the three VOCs with the two entirely different filtering materials used. A study on the state of knowledge allowed us to define the nature and sources of VOCs, the existing rules, the physico-chemical proprieties and the impact of the three VOCs used, the existing treatment procedures and in particularly bio-filtration: details on the principal operational parameters of the bio-filtration system and those influencing the performance of the bio-filter are detailed in the study. The methodology used, the complete installation set up in the laboratory and the characteristics of the material supports used are described, as well as the operational conditions for all the bio-filters studied. The experimental results for bio-filters B1, B2, B3 and B4 allowed us to follow the evolution of the parameters revealing the effectiveness (effectiveness and elimination capacity, mass load) and that of the operational parameters (pH, load losses, temperature, humidity, TOC, TEE, biomass, the flow rate of polluted gas and the bio-filter inlet VOS concentration).The elimination effectiveness attained by bio-filters B1 and B2 was 100% for acetone and 90% for toluene. For bio-filter B3, the maximum values were 100% for acetone and 50% for toluene, respectively after the third inoculation. Bio-filter B4 rapidly attained an elimination effectiveness of 100% for acetone and

  4. 土壤生物过滤去除畜禽养殖臭气%Odor removal from livestock and poultry by soil bio-filtration

    Institute of Scientific and Technical Information of China (English)

    陈敏; 杨有泉; 邓素芳; 詹杰; 刘晖


    To supply basis for primary structure parameters, operating parameter and their optimizing configuration, efficacy of soil bio-filtration on odor removal from livestock and poultry was studied. A bio-filtration deodorization tester, which can carry through multi-treating simultaneously, was set up for analyzing environmental factors of deodorization effect of soil bio-filtration process. The results show that when filter material is 75% of humus, 20% of pearlite and 5% of black wood charcoal, filtering layer height is 1 000 mm, load factor of filter material is 18 m3/(m2 · h) , filter material humidity is 55% , the removal rate of NH3, CH4, H2S and CO2 is more than 95% , that of CO and NO2 is more than 85% . The total volatility organic substance (TVOC) , inhal-able particulate matter(PM10) and total suspended matter (TSP) diffused with odor can be removed more than 95% . Odor concentration is 7. 5 ~ 8. 0. The odor discharged by system reach the discharge standard. Control filter material humidity in (52 ±3)% , airway "short circuit" phenomenon won' t come out, deodorization effect will be stable.%研究土壤生物过滤去除畜禽养殖臭气,旨在为土壤生物滤体除臭装置主要结构参数和运行参数及其优化配置提供依据.建立能同时进行多个处理的生物过滤除臭实验装置,分析影响土壤生物过滤法除臭效果的环境因子.结果表明,活性滤料组合草腐土75%,珍珠岩20%,黑炭5%,滤层高度1 000 mm,滤料表面负荷18 m3/(m2h),滤料湿度55%的条件下,主要恶臭气体和温室气体释放物NH3、CH4、H2S和CO2去除率>95%,CO和NO2去除率>85%,与畜禽臭气共同扩散的总挥发性有机物(TVOC)、可吸入颗粒物(PM10)和总悬浮物(TSP)去除率>95%,系统排出气体的臭气浓度7.5~8.0,均符合达标排放要求.系统加湿策略应控制滤料湿度(52±3)%,不会出现气道“短路”现象,除臭效果稳定.

  5. Performance of innovative PU-foam and natural fiber-based composites for the biofiltration of a mixture of volatile organic compounds by a fungal biofilm. (United States)

    Gutiérrez-Acosta, O B; Arriaga, S; Escobar-Barrios, V A; Casas-Flores, S; Almendarez-Camarillo, A


    The performance of perlite and two innovative carriers that consist of polyurethane (PU) chemically modified with starch; and polypropylene reinforced with agave fibers was evaluated in the biofiltration of a mixture of VOCs composed of hexane, toluene and methyl-ethyl-ketone. At a total organic loading rate of 145 gCm(-3)h(-1) the elimination capacities (ECs) obtained were 145, 24 and 96 gCm(-3)h(-1) for the biofilters packed with the PU, the reinforced polypropylene, and perlite, respectively. Specific maximum biodegradation rates of the mixture, in the biofilters, were 416 mgCg(protein)(-1)  h(-1) for the PU and 63 mgCg(protein)(-1) h(-1) for perlite, which confirms the highest performance of the PU-composite. 18S rDNA analysis from the PU-biofilter revealed the presence of Fusarium solani in its sexual and asexual states, respectively. The modified PU carrier significantly reduced the start-up period of the biofilter and enhanced the EC of the VOCs. Thus, this study gives new alternatives in the field of packing materials synthesis, promoting the addition of easily biodegradable sources to enhance the performance of biofilters.

  6. Biofiltration of fishpond effluents and accumulation of N-compounds (phycobiliproteins and mycosporine-like amino acids) versus C-compounds (polysaccharides) in Hydropuntia cornea (Rhodophyta). (United States)

    Figueroa, Félix L; Korbee, Nathalie; Abdala, Roberto; Jerez, Celia G; López-de la Torre, Mayra; Güenaga, Leire; Larrubia, María A; Gómez-Pinchetti, Juan L


    The biofiltration capacity, biomass-yield and accumulation of N- and C-compounds of Hydropuntia cornea were analyzed. Algae were grown in different conditions for 28 d: outdoor and indoor, with or without fishpond effluents. N-uptake efficiency of these effluents was higher than 95% after 7 d both outdoors and indoors. N-enriched conditions reduced the extent of photoinhibition and increased the maximal quantum yield in H. cornea. The biomass-yield was higher in outdoor grown-algae after 7 d and decreased independently of the treatment after 28 d. N, acid polysaccharide (AP) and mycosporine-like amino acid (MAA)-yields decreased throughout the experiment in all conditions. The highest MAA-yield was observed in fishpond effluent outdoor-grown algae, indicating a positive effect of increased radiation on MAA accumulation. However, APs were higher under N-depleted conditions. The use of MAAs as UV-screening and antioxidants, and the use of AP as immunostimulants are discussed.

  7. A randomized controlled study on the effects of acetate-free biofiltration on organic anions and acid-base balance in hemodialysis patients. (United States)

    Sánchez-Canel, Juan J; Hernández-Jaras, Julio; Pons-Prades, Ramón


    Metabolic acidosis correction is achieved by the transfer of bicarbonate and other buffer anions in dialysis. The aim of this study was to evaluate changes in the main anions of intermediary metabolism on standard hemodiafiltration (HDF) and on acetate-free biofiltration (AFB). A prospective, in-center, crossover study was carried out with 22 patients on maintenance dialysis. Patients were randomly assigned to start with 12 successive sessions of standard HDF with bicarbonate (34 mmol/L) and acetate dialysate (3 mmol/L) or 12 successive sessions of AFB without base in the dialysate. Acetate increased significantly during the standard HDF session from 0.078 ± 0.062 mmol/L to 0.156 ± 0.128 mmol/L (P anions (OA) were higher in HDF compared to AFB (P < 0.05). AFB achieves an optimal control of acid-base equilibrium through a bicarbonate substitution fluid. It also prevents hyperacetatemia and restores internal homeostasis with less production of intermediary metabolites.

  8. Enhancing ethylbenzene vapors degradation in a hybrid system based on photocatalytic oxidation UV/TiO{sub 2}-In and a biofiltration process

    Energy Technology Data Exchange (ETDEWEB)

    Hinojosa-Reyes, M. [Instituto Potosino de Investigacion Cientifica y Tecnologica A.C., Division de Ciencias Ambientales, Camino a la Presa San Jose 2055, Lomas 4a seccion, CP. 78216, San Luis Potosi, S.L.P. (Mexico); Rodriguez-Gonzalez, V. [Instituto Potosino de Investigacion Cientifica y Tecnologica A.C., Division de Materiales Avanzados, Camino a la Presa San Jose 2055, Lomas 4a seccion, CP. 78216, San Luis Potosi, S.L.P. (Mexico); Arriaga, S., E-mail: [Instituto Potosino de Investigacion Cientifica y Tecnologica A.C., Division de Ciencias Ambientales, Camino a la Presa San Jose 2055, Lomas 4a seccion, CP. 78216, San Luis Potosi, S.L.P. (Mexico)


    Highlights: Black-Right-Pointing-Pointer The best photocatalytic system for EB degradation was based on TiO{sub 2}-In 1%/365 nm. Black-Right-Pointing-Pointer A maximum EC of 290 g m{sup -3} h{sup -1} for the hybrid system was obtained. Black-Right-Pointing-Pointer The hybrid process enhanced 40% the overall EC of ethylbenzene. Black-Right-Pointing-Pointer An overall mineralization of 67% for EB degradation was reached in the hybrid system. - Abstract: The use of hybrid processes for the continuous degradation of ethylbenzene (EB) vapors has been evaluated. The hybrid system consists of an UV/TiO{sub 2}-In photooxidation coupled with a biofiltration process. Both the photocatalytic system using P25-Degussa or indium-doped TiO{sub 2} catalysts and the photolytic process were performed at UV-wavelengths of 254 nm and 365 nm. The experiments were carried out in an annular plug flow photoreactor packed with granular perlite previously impregnated with the catalysts, and in a glass biofilter packed with perlite and inoculated with a microbial consortium. Both reactors were operated at an inlet loading rate of 127 g m{sup -3} h{sup -1}. The greatest degradation rate of EB (0.414 ng m{sup -2} min{sup -1}) was obtained with the TiO{sub 2}-In 1%/365 nm photocatalytic system. The elimination capacity (EC) obtained in the control biofilter had values {approx}60 g m{sup -3} h{sup -1}. Consequently, the coupled system was operated for 15 days, and a maximal EC of 275 g m{sup -3} h{sup -1}. Thus, the results indicate that the use of hybrid processes enhanced the EB vapor degradation and that this could be a promising technology for the abatement of recalcitrant volatile organic compounds.

  9. 臭氧-接种生物滤池组合工艺去除饮用水中典型致嗅物质%Ozonation-Inoculated Biofiltration for Removal of the Typical Taste and Odor Compounds in Drinking Water

    Institute of Scientific and Technical Information of China (English)

    袁蓉芳; 周北海; 施春红; 顾军农; 李玉仙


    通过在生物滤池表面接种MIB(2-甲基异茨醇)及geosmin(土臭素)降解菌,增强生物滤池的作用,并探讨臭氧-生物滤池组合工艺对MIB和geosmin的处理效果.结果表明:单独接种生物滤池可使ρ(MIB)和ρ(geosmin)从初始的500 ng/L分别降至125和112 ng/L,MIB和geosmin的去除效果先随EBCT(空床停留时间)的延长而显著增加,但当EBCT大于20 min后无明显变化;随着滤料深度的增加,滤池生物量逐渐降低,对污染物的去除率增加缓慢.在接种生物滤池前增加臭氧单元,当EBCT为20min、臭氧投加量为2 mg/L时,臭氧-接种生物滤池组合工艺可去除84%的MIB和94%的geosmin,其中接种生物滤池单元中生物量随滤池深度的增加呈先增后减的趋势,滤料深度为100~200 mm时,单位高度滤料的去除率最高.采用臭氧-接种生物滤池组合工艺可有效去除水中的MIB和geosmin.%2-methylisoborneol (MIB) and geosmin are two of the most common taste and odor compounds which can not be readily removed by conventional drinking water treatment processes.The objective of this study was to enhance the biofiltration of MIB and geosmin by inoculating the sand filter with MIB and geosmin degraders,and to examine the removal efficiencies of MIB and geosmin using inoculated filter and non-inoculated filter in the presence and absence of ozonation.The degraders were Micrococcus sp.,Flavobacterium sp.,Brevibacterium sp.and Pseudomonas MIB degraders,and Chryseobacterium sp.,Sinorhizobium sp.,and Stenotrophomonas geosmin degraders.These bacteria were isolated from granular activated carbon in a commercial water plant.For the filter inoculated with a consortium of MIB and geosmin biodegraders,MIB and geosmin contents were decreased to 125 and 112 ng/L from 500 ng/L,respectively.Initially,removal efficiencies of MIB and geosmin rapidly increased with the extension of empty bed contact time (EBCT),and resulted in no obvious change when EBCT

  10. Nitrogenated compounds' biofiltration under alternative bacterium fixation substrates Biofiltración de compuestos nitrogenados bajo medios de fijación bacteriana alternativos

    Directory of Open Access Journals (Sweden)

    Carlos Carroza


    Full Text Available This study compares the behavior of nitrification (NH4+, NO2- and NO3-, and performance, in terms of the surface TAN conversion rate (STR, volumetric TAN conversion rate (VTR and removal percentage of TAN (PTR among three fixation media of nitrifying bacteria (two alternatives (S1, S2 and one commercial (Co. The experiment was performed in two tests of 42 days each. Three isolated biofiltration systems were built for the experience, to which were added media colonized by bacteria as a "seed" to start the process of nitrification. Ammonium chloride (NH4Cl was attached as source of ammonium in reconditioned freshwater, also gradually adding inorganic carbon (HCO3- to maintain moderate water hardness. The average results for both tests indicate that the substrates S1 and S2 show a statistically similar behavior to the substrate Co (P > 0.05 during the first 33 days (until steady state. For the second test in terms of performance, STR values were 0.40, 0.39, 0.39 g TAN m-2 d-1 recorded for S2 and Co respectively; in terms of PRN, values were 92(3 9־/ and 93% for S1, S2 and Co, respectively. Regarding VTR, values of 72.31, 114.94, and 39.02 g TAN m-3 d-1 were recorded for S2 and Co respectively. Statistical analysis provided that for STR and PRN, no significant differences, were found. But for VTR, statistically significant differences between means were evaluated, registering for the S2 media the highest value of VTR.Se compara el comportamiento del proceso de nitrificación (NH4+, NO2- y NO3-, y el rendimiento, en términos de la tasa superficial de conversión de NAT, tasa volumétrica de conversión de NAT y porcentaje de remoción de NAT (PRN entre tres medios de fijación de bacterias nitrificantes, dos alternativos (S1, S2 y uno comercial (Co. La experiencia se realizó en dos pruebas de 42 días cada una. Se construyeron tres sistemas aislados para la experiencia, a los cuales se adicionaron medios colonizados por bacterias a modo de

  11. Upgrading of an activated sludge wastewater treatment plant by adding a moving bed biofilm reactor as pre-treatment and ozonation followed by biofiltration for enhanced COD reduction: design and operation experience. (United States)

    Kaindl, Nikolaus


    A paper mill producing 500,000 ton of graphic paper annually has an on-site wastewater treatment plant that treats 7,240,000 m³ of wastewater per year, mechanically first, then biologically and at last by ozonation. Increased paper production capacity led to higher COD load in the mill effluent while production of higher proportions of brighter products gave worse biodegradability. Therefore the biological capacity of the WWTP needed to be increased and extra measures were necessary to enhance the efficiency of COD reduction. The full scale implementation of one MBBR with a volume of 1,230 m³ was accomplished in 2000 followed by another MBBR of 2,475 m³ in 2002. An ozonation step with a capacity of 75 kg O₃/h was added in 2004 to meet higher COD reduction demands during the production of brighter products and thus keeping the given outflow limits. Adding a moving bed biofilm reactor prior to the existing activated sludge step gives: (i) cost advantages when increasing biological capacity as higher COD volume loads of MBBRs allow smaller reactors than usual for activated sludge plants; (ii) a relief of strain from the activated sludge step by biological degradation in the MBBR; (iii) equalizing of peaks in the COD load and toxic effects before affecting the activated sludge step; (iv) a stable volume sludge index below 100 ml/g in combination with an optimization of the activated sludge step allows good sludge separation--an important condition for further treatment with ozone. Ozonation and subsequent bio-filtration pre-treated waste water provide: (i) reduction of hard COD unobtainable by conventional treatment; (ii) controllable COD reduction in a very wide range and therefore elimination of COD-peaks; (iii) reduction of treatment costs by combination of ozonation and subsequent bio-filtration; (iv) decrease of the color in the ozonated wastewater. The MBBR step proved very simple to operate as part of the biological treatment. Excellent control of the COD

  12. Trimethylamine (TMA) biofiltration and transformation in biofilters. (United States)

    Ding, Ying; Shi, Ji-Yan; Wu, Wei-Xiang; Yin, Jun; Chen, Ying-Xu


    Bioremoval of trimethylamine (TMA) in two three-stage biofilters packed with compost (A) and sludge (B), respectively, was investigated. Both biofilters were operated with an influent TMA concentration of 19.2-57.2mgm(-3) for 67 days. Results showed that all of the inlet TMA could be removed by both biofilters. However, removal efficiency and transformation of TMA in each section of both biofilters was different. In the Introduction section, TMA removal efficiency and maximum elimination capacity of the compost medium were greater than those of sludge medium under higher inlet TMA concentration. In comparison with biofilter A, considerably higher NH(3) concentrations in effluent of all three sections in biofilter B were observed after day 19. Although, NO(2)(-)-N concentration in each section of biofilter A was relatively lower, NO(3)(-)-N content in each section of biofilter A increased after day 26, especially in the Materials and method section which increased remarkably due to a lesser amount of TMA and higher ammonia oxidation and nitrification in compost medium. In contrast, neither NO(2)(-)-N nor NO(3)(-)-N were detected in either section of biofilter B at any time throughout the course of the experiment. The cumulative results indicated that compost is more favorable for the growth of TMA-degrading and nitrifying bacteria as compared to the sludge and could be a highly suitable packing material for biodegradation and transformation of TMA.

  13. Removal of volatile organic compounds (VOCs) present in a synthetic waste gas stream by a bio-filter packed with wood bark; Elimination de composes organiques volatils (COV) presents dans l'air par un biofiltre a garnissage naturel structure

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Lopez, E.M.


    The Environmental Council of the European Union requires the reduction of 54 % of volatile organic compounds (VOCs) emitted in waste gas streams to the ambient air. Nowadays, bio-filtration is a bio-process used to treat large waste air streams with low concentration of pollutants. Bio-filters have the advantage of low cost operation and maintenance. Bio-filters are generally packed with organic material as a support to fix microorganisms. These microorganisms degrade pollutants in waste gas streams to carbon dioxide, water and mineral salts. The performance of a bio-filter depends on the biological, physical and chemical properties of the support. Parameters studied in this research include water holding capacity of the support, specific surface area, void fraction, uniform pore size distribution, bulk density of the support, pressure drop, and buffer capacity. The support must provide enough nutrients. These parameters were measured for wood bark. A hydrodynamic study was carried out in the experimental bio-filter using wood bark as a support. The Comiti and Renaud model was used in order to determine the tortuosity and the dynamic specific surface area of the packing material. This model takes into consideration the wall effect corrections. The bio-filter performance was evaluated for ethanol biodegradation by varying either the superficial gas velocity (99 to 1288 m.h{sup -1}) or the ethanol concentration (35 to 480 g.m{sup -3}.h{sup -1}) of the simulated gas stream. The experimental values were validated by using the Ottengraf's model. In this model, zero-order kinetics with diffusion limitation was assumed. Microorganisms fixed in the support include yeast, fungi and bacteria. Biodegradation of a mixture of ethanol, dichloromethane, methyl ethyl ketone and toluene in the simulated waste stream was also evaluated. The influence of parameters such as pH, pressure drop, temperature and humidity were measured in this system. (author)

  14. Desarrollo de un inóculo microbiano empleando lodos activados para la remoción de ácido sulfhídrico (H2S mediante biofiltración* Inoculum development by using activated sludge to remove hydrogen sulphide (H2S through biofiltration*

    Directory of Open Access Journals (Sweden)

    Carmona Salgado Yezid


    Full Text Available Se utilizaron lodos activados de diferentes orígenes para el desarrollo de un inóculo apto para la degradación de ácido sulfhídrico en un sistema piloto de biofiltración con dos unidades de diferentes materiales de soporte: bagazo de caña en un caso y una mezcla de este y piedra pómez en el otro. Mediante la adición a los lodos activados, de medio nutritivo con un sustrato específico, se favoreció el proceso de adaptación y selección de las especies microbianas que degradan el ácido sulfhídrico (H2S. Durante la operación de la planta piloto se realizó el seguimiento de la variación poblacional de los diferentes grupos tróficos presentes en los soportes, observándose una tendencia al crecimiento de las bacterias sulfooxidantes (BSO y la disminución de heterótrofos, mohos y levaduras. Para la estandarización del proceso de preparación del inóculo se seleccionó el lodo activado que presentó mayor velocidad de degradación del sustrato, proceso en el cual se evaluaron diferentes medios nutritivos. La medición de algunas variables de control permitió escoger el pH como la variable que determinaba el punto óptimo de adaptación de un inóculo para este sustrato. La inoculación y las características de los soportes para el establecimiento y desarrollo de las especies microbianas condujeron a que los biofiltros presentaran eficiencias de remoción mayores de 99% desde su arranque. Palabras clave: biofiltro, lodos activados, microorganismos adaptados, bacterias sulfooxidantes, respirometría.Different activated sludges were used for developing an inoculum able to degrade hydrogen sulphide in a pilot scale biofiltration plant using two different support materials: sugarcane bagasse and this bagasse mixed with pumice stone. Adapting and selecting microbial species which degrade hydrogen sulphide (H2S was aided by adding nutrients plus a specific substrate to the activated sludge. Population variation was monitored within

  15. Styrene biofiltration in a trickle-bed reactor

    Directory of Open Access Journals (Sweden)

    V. Novak


    Full Text Available The biological treatment of styrene waste gas in a trickle-bed filter (TBF was investigated. The bioreactor consisted of a two-part glass cylinder (ID 150 mm filled with 25 mm polypropylene Pall rings serving as packing material. The bed height was 1m. Although the laboratory temperature was maintained at 22 ºC, the water temperature in the trickle-bed filter was slightly lower (about 18 ºC.The main aim of our study was to observe the effect of empty-bed residence time (EBRT on bioreactor performance at a constant pollutant concentration over an extended time period. The bioreactor was inoculated with a mixed microbial consortium isolated from a styrene-degrading biofilter that had been running for the previous two years. After three weeks of acclimation period, the bioreactor was loaded with styrene (100 mg.m-3. EBRT was in the range of 53 s to 13 s. A maximum elimination capacity (EC of 11.3 gC.m-3.h-1 was reached at an organic loading (OL rate of 18.6 gC.m-3.h-1.

  16. Energy reduction using biofiltration in a highly efficient residential home (United States)

    Rodgers, Kevin L.

    The objective of this research was to design, demonstrate, and monitor the Biowall; a novel system for improving indoor air quality in a residential building, which has the potential to save energy compared to traditional air quality control. The Biowall was integrated into the heating, ventilation, and air-condition system of a high performance home and utilized plants as a passive filter system to remove volatile organic compounds from the interior space of the home. The testing environment in this study was a 984 square foot efficient residential home constructed for the U.S. Department of Energy Solar Decathlon 2011 competition. A number of sensors were installed in the home to monitor the operation of the wall including temperature, relative humidity, carbon dioxide, and total volatile organic compound (TVOC) sensors. The main outcomes of the project included the design and construction of a test platform for the current study and future research, energy results that showed as high as 160% energy savings over a 1 week test period and $170 per year in cost savings versus a traditional ventilation strategy, and lessons learned and suggestions for future research.

  17. Biofiltration of odorous fume emitted from recycled nylon melting operations. (United States)

    Chen, Kuan-Po; Chang, Hsiao-Yu; Chou, Ming-Shean


    This study aimed to develop a biofilter packed only with fern chips for the removal of odorous compounds from recycled nylon melting operations. The fern chip biofilters could avoid the shortcomings of traditional media, such as compaction, drying, and breakdown, which lead to the performance failure of the biofilters. A pilot-scale biofilter consisting of an acrylic column (14 cm2 x 120 cm height) packed with fern chips to a volume of around 19.6 L was used for the test. Experimental results indicate that oxygen- and nitrogen-containing hydrocarbons as well as paraffins were major volatile organic compounds (VOCs) emitted from thermal smelting of recycled nylon at 250 degrees C. With operation conditions of medium pH of 5.5-7.0, empty bed retention time (EBRT) of 6-12 sec, influent total hydrocarbon (THC) concentrations of 0.65-2.61 mg m(-3), and volumetric organic loading of 0.05-0.85 g m(-3) hr(-1), the fern-chip-packed biofilter with nutrients of milk, potassium dihydrogen phosphate, and glucose could achieve an overall THC removal efficiency of around 80%. Burnt odor emitted from the smelting of the recycled nylon could be eliminated by the biofilter.

  18. Effect of methanol on the biofiltration of n-hexane. (United States)

    Zehraoui, Abderrahman; Hassan, Ashraf Aly; Sorial, George A


    This study investigated the removal of recalcitrant compounds in the presence of a hydrophilic compound. n-Hexane is used as a model compound to represent hydrophobic compounds. Methanol has been introduced in mixture with n-hexane in order to increase the bioavailability of n-hexane in trickle-bed-air-biofilters (TBABs). The mixing ratios investigated were: 70% methanol:30% n-hexane, and 80% methanol:20% n-hexane by volume. n-Hexane loading rates (LRs) ranged from 0.9 to 13.2 g m(-3) h(-1). Methanol LRs varied from 4.6 to 64.5 g m(-3) h(-1) and from 2.3 to 45.2 g m(-3) h(-1) depending upon the mixing ratio used. Biofilter performance, effect of mixing ratios of methanol to n-hexane, removal profile along biofilter depth, COD/nitrogen consumption and CO(2) production were studied under continuous loading operation conditions. Results have shown that the degradation of n-hexane is significantly enhanced by the presence of methanol for n-hexane LRs less than 13.2 g m(-3) h(-1). For n-hexane LR greater than 13.2 g m(-3) h(-1), even though methanol had impacted n-hexane biodegradation, its removal efficiency was higher than our previous study for biodegradation of n-hexane alone, in presence of surfactant, or in presence of benzene. On the other hand, the degradation of methanol was not impacted by the presence of n-hexane.

  19. Indoor air treatment by coupling biofiltration and adsortion


    Luengas Muñoz, Angela Tatiana


    225 p. La calidad del aire interior juega un papel importante en la salud de las personas y su bienestar puesto que la población pasa una parte importante de su vida dentro de lugares cerrados. Los Compuestos Orgánicos Volátiles (COVs) representan un grupo prioritario dentro de la lista de contaminantes de aires interiores. Si bien la concentración individual de cada uno de los contaminantes es generalmente baja, cientos de ellos pueden encontrarse simultáneamente, lo que ha llevado a que ...

  20. Biofiltration for Mitigation of Methane Emission from Animal Husbandry

    NARCIS (Netherlands)

    Melse, R.W.; Werf, van der A.W.


    Removal of methane from exhaust air of animal houses and manure storage has a large potential for the reduction of greenhouse gas emissions from animal husbandry. The aim of this study was to design a biofilter for methane removal at a full-scale livestock production facility. Air from the headspace

  1. Biofiltration and electrochemical treatment for the production of service water from outflows of small-scaled sewage treatment plants; Biofiltration und elektrochemische Behandlung zur Brauchwassererzeugung aus Kleinklaeranlagenablaeufen

    Energy Technology Data Exchange (ETDEWEB)

    Ilian, Jens


    Up to the 1990s a mechanical partly biological wastewater treatment was performed at remote locations or collected in reservoirs without outflow. The currently valid legal regulations require a biological treatment of wastewater. Thus, biological small-scale sewage treatment plants experience a broad dissemination recently. Under this aspect, the author of the contribution under consideration reports on the bio filtration and electrochemical treatment in order to produce service water from outflows of small-scale sewage treatment plants. The author investigates the legal regulations, and supplements these regulations by own definitions and requirements on the consideration of a hygienic potential for damage. Additionally, investigations on the cleaning performance of properly operated small-scaled sewage treatment plants are performed. The hygienic risk potential as an inflow condition of a disinfection is determined.

  2. Biofiltration of Methane from Ruminants Gas Effluent Using Autoclaved Aerated Concrete as the Carrier Material

    NARCIS (Netherlands)

    Ganendra, Giovanni; Mercado-Garcia, Daniel; Hernandez-Sanabria, Emma; Peiren, Nico; De Campeneere, Sam; Ho, Adrian; Boon, Nico


    Abstract The performance of Methane-Oxidizing Bacteria (MOB) immobilized on Autoclaved Aerated Concrete (AAC) in a biofilter setup to remove methane from ruminants gas effluent was investigated. Two dairy cows were housed in respiration chambers for two days where the exhaust gas from the chambers w

  3. Improving Removal Efficiency of Organic Matters by Adding Phosphorus in Drinking Water Biofiltration Treatment

    Institute of Scientific and Technical Information of China (English)


    Objective To investigate phosphorus limitation and its effect on the removal efficiency of organic matters in drinking water biological treatment. Methods Bacterial growth potential (BGP) method and a pair of parallel pilot-scale biofilters were used for the two objectives, respectively. Results The addition of phosphorus could substantially increase the BGPs of the water samples and the effect was stronger than that of the addition of carbon. When nothing was added into the influents, both CODMn removals of the parallel biofilters (BF1 and BF2) were about 15%. When phosphate was added into its influent, BF1 performed a CODMn removal, 6.02 percentage points higher than the control filter (BF2) and its effluent had a higher biological stability. When the addition dose was <20 ìg@L-1, no phosphorus pollution would occur and there was a good linear relationship between the microbial utilization of phosphorus and the removal efficiency of organic matters. Conclusions Phosphorus was a limiting nutrient and its limitation was stronger than that of carbon. The addition of phosphate was a practical way to improve the removal efficiency of organic matters in drinking water biological treatment.

  4. Bio-filtration of helminth eggs and coliforms from municipal sewage for agricultural reuse in Peru

    NARCIS (Netherlands)

    Yaya Beas, R.E.


    Where fresh water resources are scarce, treated wastewater becomes an attractive alternative for agricultural irrigation. However, the presence of large amounts of pathogens, even in treated wastewater, constraints its productive use, which is aggravated when sanitation and public health are poor. A

  5. Overview of sustainable marine aquaculture systems engineering projects with emphasis on biofiltration (United States)

    The rate of ammonia removal for moving bed and static bed biofilters with plastic media was determined for various feed loading rates, flow rates, and salinity. Ammonia removal rates in the eight propeller-wash floating plastic bead filters (0.71 m3) utilized in the 45 m3 recirculating aquaculture ...

  6. Impact of biocatalyst and moisture content on toluene/xylene mixture biofiltration

    Directory of Open Access Journals (Sweden)

    Eva Klapková


    Full Text Available The objective of this work was to determine the influence of microbial inoculation on degradation efficiency. Three biofilters were used for the treatment of waste gas. A mixture of compost and perlite (8:2 served as the packing material. One biofilter was inoculated with a constructed microbial population. The second remained uninoculated, having the natural population present in the compost. The third biofilter was uninoculated and the packing material was sterilized. The degradation ability of the uninoculated biofilter started to drop after 18 days, while the removal efficiency of inoculated biofilter was stable. The sterile biofilter proved to have no removal efficiency. Moisture content of the packing and ability of the packing to keep moisture was tested. The results showed a significant dependence of the degradation efficiency on the packing moisture content, with highest removal efficiency observed at 70 % moisture content.

  7. Impact of biocatalyst and moisture content on toluene/xylene mixture biofiltration

    Directory of Open Access Journals (Sweden)

    Klapková Eva


    Full Text Available The objective of this work was to determine the influence of microbial inoculation on degradation efficiency. Three biofilters were used for the treatment of waste gas. A mixture of compost and perlite (8:2 served as the packing material. One biofilter was inoculated with a constructed microbial population. The second remained uninoculated, having the natural population present in the compost. The third biofilter was uninoculated and the packing material was sterilized. The degradation ability of the uninoculated biofilter started to drop after 18 days, while the removal efficiency of inoculated biofilter was stable. The sterile biofilter proved to have no removal efficiency. Moisture content of the packing and ability of the packing to keep moisture was tested. The results showed a significant dependence of the degradation efficiency on the packing moisture content, with highest removal efficiency observed at 70 % moisture content.

  8. Biofiltration of waste gases containing a mixture of formaldehyde and methanol

    Energy Technology Data Exchange (ETDEWEB)

    Prado, O.J.; Veiga, M.C.; Kennes, C. [Chemical Engineering Lab., Faculty of Sciences, Univ. of La Coruna, La Coruna (Spain)


    Several biofilters and biotrickling filters were used for the treatment of a mixture of formaldehyde and methanol; and their efficiencies were compared. Results obtained with three different inert filter bed materials (lava rock, perlite, activated carbon) suggested that the packing material had only little influence on the performance. The best results were obtained in a biotrickling filter packed with lava rock and fed a nutrient solution that was renewed weekly. A maximum formaldehyde elimination capacity of 180 g m{sup -3} h{sup -1} was reached, while the methanol elimination capacity rose occasionally to more than 600 g m{sup -3} h{sup -1}. Formaldehyde degradation was affected by the inlet methanol concentration. Several combinations of load vs empty bed residence time (EBRTs of 71.9, 46.5, 30.0, 20.7 s) were studied, reaching a formaldehyde elimination capacity of 112 g m{sup -3} h{sup -1} with about 80% removal efficiency at the lowest EBRT (20.7 s). (orig.)

  9. Ammonia biofiltration and community analysis of ammonia-oxidizing bacteria in biofilters. (United States)

    Jun, Yin; Wenfeng, Xu


    Biological removal of ammonia was investigated using compost and sludge as packing materials in laboratory-scale biofilters. The aim of this study is to characterize the composition of ammonia-oxidizing bacteria (AOB) in two biofilters designed to remove ammonia. Experimental tests and measurements included analysis of removal efficiency and metabolic products. The inlet concentration of ammonia applied was 20-100 mg m(-3). Removal efficiencies of BFC and BFS were in the range of 97-99% and 95-99%, respectively. Periodic analysis of the biofilter packing materials showed ammonia was removed from air stream by nitrification and by the improved absorption of NH(3) in the resultant acidity. Nitrate was the dominant product of NH(3) transformation. Changes in the composition of AOB were examined by using nested PCR, denaturing gradient gel electrophoresis (DGGE) and sequencing of DGGE bands. DGGE analysis of biofilter samples revealed that shifts in the community structure of AOB were observed in the experiment; however, the idle phase did not cause the structural shift of AOB. Phylogenetic analysis revealed the population of AOB showed Nitrosospira sp. remains the predominant population in BFC, while Nitrosomonas sp. is the predominant population in BFS.

  10. Identifying the limitations of conventional biofiltration of diffuse methane emissions at long-term operation. (United States)

    Gómez-Cuervo, S; Hernández, J; Omil, F


    There is growing international concern about the increasing levels of greenhouse gases in the atmosphere, particularly CO2 and methane. The emissions of methane derived from human activities are associated with large flows and very low concentrations, such as those emitted from landfills and wastewater treatment plants, among others. The present work was focused on the biological methane degradation at diffuse concentrations (0.2% vv(-1)) in a conventional biofilter using a mixture of compost, perlite and bark chips as carrier. An extensive characterization of the process was carried out at long-term operation (250 days) in a fully monitored pilot plant, achieving stable conditions during the entire period. Operational parameters such as waterings, nitrogen addition and inlet loads and contact time influences were evaluated. Obtained results indicate that empty bed residence times within 4-8 min are crucial to maximize elimination rates. Waterings and the type of nitrogen supplied in the nutrient solution (ammonia or nitrate) have a strong impact on the biofilter performance. The better results compatible with a stable operation were achieved using nitrate, with elimination capacities up to 7.6 ± 1.1 g CH4 m(-3 )h(-1). The operation at low inlet concentrations (IC) implied that removal rates obtained were quite limited (ranging 3-8 g CH4 m(-3 )h(-1)); however, these results could be significantly increased (up to 20.6 g CH4 m(-3) h(-1)) at higher IC, which indicates that the mass transfer from the gas to the liquid layer surrounding the biofilm is a key limitation of the process.

  11. Biofiltration, growth and body composition of oyster Crassostrea rhizophorae in effluents from shrimp Litopenaeus vannamei1

    Directory of Open Access Journals (Sweden)

    Rafael Vieira de Azevedo

    Full Text Available The objective of this study was to use oyster as biofilter to improve the quality of effluent from shrimp farming and to assess its growth performance and body composition. It was distributed 1,080 oysters into lanterns in fiberglass tanks (170 L in a completely randomized design with three treatments (0, 60 and 120 oysters and six replicates. It was used the effluent from the sedimentation tank. It was measured weekly: temperature, salinity, dissolved oxygen and pH, and it was analyzed ammonia-N, nitrite-N, nitrate-N, orthophosphate-P, suspended solids and chlorophyll-α of the input effluent. The control tanks (without oysters were more efficient at removing ammonia-N, nitrite-N, nitrate-N and orthophosphate-P. The tanks containing oysters were more efficient at removing suspended solids and chlorophyll-α. Stocking density influenced the height growth of oysters, but not width. Wet and daily weight, condition and yield index were not affected by stocking density, and a significant increase in comparison to the initials values was observed. Body composition was not affected by stocking density, and a significant difference (p0.05. Under the conditions evaluated, the oyster Crassostrea rhizophorae improves water quality and presents growth rates and body composition similar to those obtained in traditional crops.

  12. Biofiltration of mixtures of gas-phase styrene and acetone with the fungus Sporothrix variecibatus

    Energy Technology Data Exchange (ETDEWEB)

    Rene, Eldon R.; Spackova, Radka; Veiga, Maria C. [University of La Coruna, Dpt. of Chemical Engineering, Campus da Zapateira, Rua da Fraga, 10, 15008 La Coruna (Spain); Kennes, Christian, E-mail: [University of La Coruna, Dpt. of Chemical Engineering, Campus da Zapateira, Rua da Fraga, 10, 15008 La Coruna (Spain)


    The biodegradation performance of a biofilter, inoculated with the fungus Sporothrix variecibatus, to treat gas-phase styrene and acetone mixtures under steady-state and transient conditions was evaluated. Experiments were carried out by varying the gas-flow rates (0.05-0.4 m{sup 3} h{sup -1}), leading to empty bed residence times as low as 17.1 s, and by changing the concentrations of gas-phase styrene (0.01-6.3 g m{sup -3}) and acetone (0.01-8.9 g m{sup -3}). The total elimination capacities were as high as 360 g m{sup -3} h{sup -1}, with nearly 97.5% removal of styrene and 75.6% for acetone. The biodegradation of acetone was inhibited by the presence of styrene, while styrene removal was affected only slightly by the presence of acetone. During transient-state experiments, increasing the overall pollutant load by almost 3-fold, i.e., from 220 to 600 g m{sup -3} h{sup -1}, resulted in a sudden drop of removal efficiency (>90-70%), but still high elimination capacities were maintained. Periodic microscopic observations revealed that the originally inoculated Sporothrix sp. remained present in the reactor and actively dominant in the biofilm.

  13. Optimization of an Innovative Biofiltration System as a VOC Control Technology for Aircraft Painting Facilities (United States)


    Cladosporium resinae (ATCC 34066), Cladosporium sphaerospermum (ATCC 200384), Exophiala lecanii-corni (CBS 102400), Mucor rouxii (ATCC 44260), and...degrade all VOCs tested except for styrene under the conditions imposed. Cladosporium resinae was able to degrade both organic acids, all of the ketones...2002). Cladosporium Cladosporium Exophiala Mucor Phanerochaete resinae sphaerospermum lecanii-corni rouxii chrysosporium No carbon source Glucose

  14. Understanding the fate of organic micropollutants in sand and granular activated carbon biofiltration systems

    Energy Technology Data Exchange (ETDEWEB)

    Paredes, L., E-mail:; Fernandez-Fontaina, E., E-mail:; Lema, J.M., E-mail:; Omil, F., E-mail:; Carballa, M., E-mail:


    In this study, sand and granular activated carbon (GAC) biofilters were comparatively assessed as post-treatment technologies of secondary effluents, including the fate of 18 organic micropollutants (OMPs). To determine the contribution of adsorption and biotransformation in OMP removal, four reactors were operated (two biofilters (with biological activity) and two filters (without biological activity)). In addition, the influence of empty bed contact time (EBCT), ranging from 0.012 to 3.2 d, and type of secondary effluent (anaerobic and aerobic) were evaluated. Organic matter, ammonium and nitrate were removed in both biofilters, being their adsorption higher on GAC than on sand. According to the behaviour exhibited, OMPs were classified in three different categories: I) biotransformation and high adsorption on GAC and sand (galaxolide, tonalide, celestolide and triclosan), II) biotransformation, high adsorption on GAC but low or null adsorption on sand (ibuprofen, naproxen, fluoxetine, erythromycin, roxythromycim, sulfamethoxazole, trimethoprim, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol), and, III) only adsorption on GAC (carbamazepine, diazepam and diclofenac). No influence of EBCT (in the range tested) and type of secondary effluent was observed in GAC reactors, whereas saturation and kinetic limitation of biotransformation were observed in sand reactors. Taking into account that most of the organic micropollutants studied (around 60%) fell into category II, biotransformation is crucial for the elimination of OMPs in sand biofilters. - Highlights: • OMP removal was comparatively assessed in sand and GAC biofilters. • The contribution of adsorption and biotransformation in OMP removal was identified. • The filtering material did not affect the biological activities in biofilters. • There is no direct correlation between EBCT and OMP removal in biofilters. • The type of secondary effluent determines the lifespan of filtering material.

  15. Hydrogen sulfide removal by compost biofiltration: effect of mixing the filter media on operational factors. (United States)

    Morgan-Sagastume, J M; Noyola, A


    The overall goal of this work was to determine the effect of mixing the filter media of a compost biofilter on H(2)S removal efficiency. The behavior of important operational factors such as moisture of filter media, pressure drop and sulfate accumulation were evaluated, considering mixing the media. Additionally, tracer studies were performed in order to determine the effect of mixing the media on gas distribution. H(2)S removal capacity decreased over time, from 100% to 90%. When bed mixing was carried out, the removal capacity remained constant, close to 100%, and moisture content and sulfates accumulation were better controlled at 50% and at 12 mg S-SO(4)/g dry media respectively. In addition, under this operational pattern, an improvement in gas and particle size distribution was observed inside the filter media, fitting the axial dispersion model and the Ergun equation.

  16. The Use of Biofiltration Technology and 3-dimensional Cubical Bamboo Shelter for Nursery Phase Productivity Improvement of Giant Freshwater Prawn

    Directory of Open Access Journals (Sweden)

    Gede Suantika


    Full Text Available This experiment aimed to know the effect of nitrifying bacteria and Chlorellasp. addition and different number of 3-dimensional cubical bamboo shelter in enhancing growth performance of Giant Freshwater Prawn (Macrobrachium rosenbergii de Man during nursery phase in indoor system. During28 days of culture, treatment II (4 shelters addition~40% culture volume occupation resulted in better prawn growth and culture performance compared to control (no shelter addition (p<0,05. At the end of experiment, treatment II shown the highest biomass, SGR, mean body weight and length of the prawn with (1.96+0.05 g.cage-1,, (2.18 +0,89 g and (6.50 +0.91 cm, respectively. However, the results were not significantly different compared to treatment I (2 shelters addition~20%culture volume occupation. Survival rate the two treatments (treatment I="90"%, and treatment II="92"% was significantly higher compared to control (78%. During the experiments, increase of ammonium concentration and nitrate can be controlled and maintained by addition of nitrifying bacteria and microalgae which can keep the microbial loop between ammonium reduction by bacteria and nitrate uptake by microalgae in balance. Addition of nitrifying bacteria and microalgae and also availability of 40% bamboo shelter occupation in the culture can enhance prawn culture productivity.

  17. Study on biofiltration capacity and kinetics of nutrient uptake by Gracilaria cervicornis (Turner J. Agardh (Rhodophyta, Gracilariaceae

    Directory of Open Access Journals (Sweden)

    Marcella A. A. Carneiro


    Full Text Available The absorption efficiency and kinetic parameters (Vmax, Ks and Vmax:Ks of the seaweed Gracilaria cervicornis for the nutrients NH4+, NO3- and PO4(3- were evaluated. Absorption efficiency was measured by monitoring nutrient concentrations for 5 h in culture media with initial concentrations of 5, 10, 20 and 30µM. Kinetic parameters were determined by using the Michaelis-Menten formula. Absorption efficiencies for this algae were greater in treatments with lower concentrations, as evidenced by a reduction of 85.3, 97.5 and 81.2% for NH4+, NO3- and PO4(3-, respectively. Kinetic parameters show that G. cervicornis exhibits greater ability to take up high concentrations of NH4+ (Vmax=158.5µM g dw-1 h-1 and low concentrations of PO4(3- (Ks=5µM and Vmax:Ks=10.3. These results suggest that this algal species has good absorption capacity for the nutrients tested and may be a promising candidate as a bioremediator of eutrophized environments.

  18. By-passing acidification limitations during the biofiltration of high formaldehyde loads via the application of ozone pulses. (United States)

    García-Pérez, Teresa; Aizpuru, Aitor; Arriaga, Sonia


    A formaldehyde airstream was treated in a biofilter for an extended period of time. During the first 133 days, the reactor was operated without ozone, whereas over the following 82 days ozone was intermittently implemented. The maximum stable elimination capacity obtained without ozone was around 57 g m(-3) h(-1). A greater load could not be treated under these conditions, and no significant formaldehyde removal was maintained for inlet loads greater than 65 g m(-3) h(-1); the activity of microorganisms was then inhibited by the presence of acidic byproducts, and the media acidified (pHformaldehyde.

  19. Development and application of a hybrid inert/organic packing material for the biofiltration of composting off-gases mimics

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Jeronimo; Prado, Oscar J. [Chemical Engineering Department, Escola d' Enginyeria, Universitat Autonoma de Barcelona, Edifici Q, 08193 Bellaterra, Barcelona (Spain); Almarcha, Manuel [Sistemas y Tecnologias Ambientales S.A., c/Mao 22, 1o 2a, 08022 Barcelona (Spain); Lafuente, Javier [Chemical Engineering Department, Escola d' Enginyeria, Universitat Autonoma de Barcelona, Edifici Q, 08193 Bellaterra, Barcelona (Spain); Gabriel, David, E-mail: [Chemical Engineering Department, Escola d' Enginyeria, Universitat Autonoma de Barcelona, Edifici Q, 08193 Bellaterra, Barcelona (Spain)


    The performance of three biofilters (BF1-BF3) packed with a new hybrid (inert/organic) packing material that consists of spherical argyle pellets covered with compost was examined in different operational scenarios and compared with a biofilter packed with pine bark (BF4). BF1, BF2 and BF4 were inoculated with an enriched microbial population, while BF3 was inoculated with sludge from a wastewater treatment plant. A gas mixture containing ammonia and six VOCs was fed to the reactors with N-NH{sub 3} loads ranging from 0 to 10 g N/m{sup 3} h and a VOCs load of around 10 g C/m{sup 3} h. A profound analysis of the fate of nitrogen was performed in all four reactors. Results show that the biofilters packed with the hybrid packing material and inoculated with the microbial pre-adapted population (BF1 and BF2) achieved the highest nitrification rates and VOCs removal efficiencies. In BF3, nitratation was inhibited during most of the study, while only slight evidence of nitrification could be observed in BF4. All four reactors were able to treat the VOCs mixture with efficiencies greater than 80% during the entire experimental period, regardless of the inlet ammonia load.

  20. Biofiltration for stormwater harvesting: Comparison of Campylobacter spp. and Escherichia coli removal under normal and challenging operational conditions (United States)

    Chandrasena, G. I.; Deletic, A.; McCarthy, D. T.


    Knowledge of pathogen removal in stormwater biofilters (also known as stormwater bioretention systems or rain gardens) has predominately been determined using bacterial indicators, and the removal of reference pathogens in these systems has rarely been investigated. Furthermore, current understanding of indicator bacteria removal in these systems is largely built upon laboratory-scale work. This paper examines whether indicator organism removal from urban stormwater using biofilters in laboratory settings are representative of the removal of pathogens in field conditions, by studying the removal of Escherichia coli (a typical indicator microorganism) and Campylobacter spp. (a typical reference pathogen) from urban stormwater by two established field-scale biofilters. It was found that E. coli log reduction was higher than that of Campylobacter spp. in both biofilters, and that there was no correlation between E. coli and Campylobacter spp. log removal performance. This confirms that E. coli behaves significantly differently to this reference pathogen, reinforcing that single organisms should not be employed to understand faecal microorganism removal in urban stormwater treatment systems. The average reduction in E. coli from only one of the tested biofilters was able to meet the log reduction targets suggested in the current Australian stormwater harvesting guidelines for irrigating sports fields and golf courses. The difference in the performance of the two biofilters is likely a result of a number of design and operational factors; the most important being that the biofilter that did not meet the guidelines was tested using extremely high influent volumes and microbial concentrations, and long antecedent dry weather periods. As such, the E. coli removal performances identified in this study confirmed laboratory findings that inflow concentration and antecedent dry period impact overall microbial removal. In general, this paper emphasizes the need for the validation of stormwater harvesting systems, namely, the testing of treatment systems under challenging operational conditions using multiple indicators and reference pathogens.

  1. Biofiltration of trimethylamine, dimethylamine, and methylamine by immobilized Paracoccus sp. CP2 and Arthrobacter sp. CP1. (United States)

    Ho, Kuo-Ling; Chung, Ying-Chien; Lin, Yueh-Hsien; Tseng, Ching-Ping


    A biofilter using granular activated carbon with immobilized Paracoccus sp. CP2 was applied to the elimination of 10-250 ppm of trimethylamine (TMA), dimethylamine (DMA), and methylamine (MA). The results indicated that the system effectively treated MA (>93%), DMA (>90%), and TMA (>85%) under high loading conditions, and the maximum degradation rates were 1.4, 1.2, and 0.9g-Nkg(-1) GAC d(-1). Among the three different amines treated, TMA was the most difficult to degrade and resulted in ammonia accumulation. Further study on TMA removal showed that the optimal pH was near neutral (6.0-8.0). The supply of high glucose (>0.1%) inhibited TMA removal, maybe due to substrate competition. However, complete TMA degradation was achieved under the co-immobilization of Paracoccus sp. CP2 and Arthrobacter sp. CP1 ( approximately 96%). Metabolite analysis results demonstrated that the metabolite NH(4)(+) concentrations decreased by a relatively small 27% while the metabolite NO(2)(-) apparently increased by heterotrophic nitrification of Arthrobacter sp. CP1 in the co-immobilization biofilter.

  2. Biofiltration of composting gases using different municipal solid waste-pruning residue composts: monitoring by using an electronic nose. (United States)

    López, R; Cabeza, I O; Giráldez, I; Díaz, M J


    The concentration of volatile organic compounds (VOCs) during the composting of kitchen waste and pruning residues, and the abatement of VOCs by different compost biofilters was studied. VOCs removal efficiencies greater than 90% were obtained using composts of municipal solid waste (MSW) or MSW-pruning residue as biofilter material. An electronic nose identified qualitative differences among the biofilter output gases at very low concentrations of VOCs. These differences were related to compost constituents, compost particle size (2-7 or 7-20mm), and a combination of both factors. The total concentration of VOCs determined by a photoionization analyser and inferred from electronic nose data sets were correlated over an ample range of concentrations of VOCs, showing that these techniques could be specially adapted for the monitoring of these processes.

  3. Bed mixing and leachate recycling strategies to overcome pressure drop buildup in the biofiltration of hydrogen sulfide. (United States)

    Roshani, Babak; Torkian, Ayoob; Aslani, Hasan; Dehghanzadeh, Reza


    The effects of leachate recycling and bed mixing on the removal rate of H(2)S from waste gas stream were investigated. The experimental setup consisted of an epoxy-coated three-section biofilter with an ID of 8 cm and effective bed height of 120 cm. Bed material consisted of municipal solid waste compost and PVC bits with an overall porosity of 54% and dry bulk density of 0.456 g cm(-3). Leachate recycling had a positive effect of increasing elimination capacity (EC) up to 21 g S m(-3) bed h(-1) at recycling rates of 75 ml d(-1), but in the bed mixing period EC declined to 8 g S m(-3) bed h(-1). Pressure drop had a range of zero to 18 mm H(2)O m(-1) in the course of leachate recycling. Accumulation of sulfur reduced removal efficiency and increased pressure drop up to 110 mm H(2)O m(-1) filter during the bed mixing stage.

  4. Biofiltration of wastewater lift station emissions: evaluation of VOC removal in the presence of H{sub 2}S

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Alvaro; Rathibandla, Snehasheela; Jones, Kim; Cabezas, Jose [Texas A and M University-Kingsville, Department of Environmental Engineering, Kingsville, TX (United States)


    The capacity of biofilter systems to remove volatile organic compounds in the presence of high concentrations of hydrogen sulfide was investigated for applications in wastewater lift stations. The treatment system was an enclosed unit composed of a biotrickling filter coupled with a biofilter. The biofilter media were plastic hollow spherical balls filled with a compost mixture; and the biotrickling filter media was a structured plastic packing. The gases from the pumping station wet well were a mixture of H{sub 2}S and low concentration aliphatic and aromatic VOCs, toluene being the most significant in concentrations of 41 ppb. The H{sub 2}S concentration was 314 ppm with fluctuations of 100 ppm resulting from pumping cycles at the station. No inhibition effect was detected from the simultaneous biological removal of VOCs and H{sub 2}S: toluene removal efficiency was 91% with the two sections contributing approximately equally to the pollutant removal; and the average removal of H{sub 2}S was 74%. A traditional open-in-ground biofilter filled with wood chips and compost, existing in the site, attained similar removal efficiencies for toluene, but the elimination capacity of the biotrickling/biofilter system was 3.3-times higher than the open biofilter. (orig.)

  5. 生物过滤法处理城市污水处理厂臭气%Removal on odor of municipal sewage by biofiltration

    Institute of Scientific and Technical Information of China (English)

    屈艳芬; 叶锦韶; 尹华


    对某城市污水处理厂沉砂池的臭气进行了生物过滤处理.生物过滤池滤料层高1.5 m,滤料体积55 m3,臭气处理量为12 000 m3·h-1.对除臭效果120 d的监测和研究结果表明,进气中H2S浓度在1.96~4.63 mg·m-3之间,NH3的浓度为2.21~5.68 mg·m-3.处理后,出气中H2S的浓度在0.03~0.97 mg·m-3间,去除率均达80%以上,NH3浓度最高值仅为0.46 mg·m-3,低于1.0 mg·m-3的一级排放标准.生物除臭复合微生物主要包括细菌、酵母和霉菌,其中细菌含量最高,每克干滤料细菌含量达1.8~3.1×108 CFU.菌种鉴定结果表明,除臭菌主要有芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)、动胶菌属(Zoogloea)、不动杆菌属(Acinetobacter)、硫杆菌属(Thiobacillus)、酵母属(Saceharomyces)、假丝酵母属(Candida)、曲霉属(Aspergillus)、青霉属(Penicillium)、根霉属(Rhizopus)等种属的微生物.


    Institute of Scientific and Technical Information of China (English)

    刘永慧; 孙玉梅; 全燮; 陈景文; 薛大明; 张晓飞


    Two biofilters,RA which had been exposed to varying concentration of ethyl acetate for 20 days and RB which had been exposed to varying concentration of toluene for 20 days, were used to remove mixed gas of ethyl acetate and toluene. The two biofilters used a mixture of compost and lava, with the initial medium moisture content of 50%. The experimental results demonstrated several characteristics of the two biofilters:The maximum elimination capacities were about 400g·m-3·h-1 for ethyl acetate and 50 gm-3·h-1 for toluene;Under the condition that the empty bed residence time was 1.0 minute, for ethyl acetate concentration in the inlet air ranging from 2000 mg·m-3 to 4500mg·m-3 and toluene concentration ranging from 200mgm-3 to 400mg·m-3,the removal efficiency for binary VOCs of both biofilter RA was above 90%;Biofilter RA was better than biofilter RB in elimination capacity, stability and adaptability.


    Directory of Open Access Journals (Sweden)

    Monika Wierzbińska


    Full Text Available One of the methods of deodorization of noxious gases is biofiltration. This method consists of pollutants biodegradation by using micro-organisms, what leads to the formation of nontoxic and innoxious compounds. In comparison with conventional techniques, bio-filtration requires lower investments and exploitation costs, moreover it is nature friendly. This technique is still developing. Scientists have carried out research on the optimization of biofiltration process, biofilters and selecting parameters of purified gases or improving the method of efficiency. However, industrial application of biofilters is still difficult for many reasons. In this paper we present the mechanism of biofiltration process, the parameters and conditions which have to be fulfilled by purified gases, installation structure for gases biofiltration, application field of this method and specific example of exploited biofilters, including practical operational guidelines.

  8. The solid/gas catalyst against the volatile pollutants; La catalyse solide/gaz contre les polluants volatils

    Energy Technology Data Exchange (ETDEWEB)

    Erable, B.; Goubet, I.; Lamare, S.; Legoy, M.D.; Maugard, Th. [Laboratoire de Biotechnologie et Chimie Bio-Organique, CNRS FRE 2766, 17 - La Rochelle (France)


    In order to improve the classical bio-filtration systems, the LBCB (Laboratoire de biotechnologies et de chimie bioorganique) uses a new generation of bio-filter for the transformation of volatile pollutants directly in gas phase. (O.M.)

  9. Multiscale Modelling Approach for a Fungal Biofilter Unit for the Hydrophobic Abatement of Volatile Organic Compounds

    DEFF Research Database (Denmark)

    Vergara-Fernández, A.; Rebolledo-Castro, J.; Morales Rodriguez, Ricardo


    Currently, biofiltration has become a viable and potential alternative for the treatment of airstreams with low concentrations of hydrophobic volatile organic compounds (VOCs), which can employ to this end, diverse microorganisms (such as, bacteria, fungal or microbial consortia, etc.) growing...

  10. Reduction of toxic products and bioaerosol emission of a combined ultraviolet-biofilter process for chlorobenzene treatment. (United States)

    Wang, Can; Xi, Jin-Ying; Hu, Hong-Ying


    A combined process involving ultraviolet (UV) photodegradation and biofiltration was developed to treat gaseous chlorobenzene. The toxicity of the photodegradation products and the bioaerosol emissions from the biofilter were investigated. The experimental results showed that a standalone UV photodegradation of chlorobenzene can result in products having significant acute toxicity and genotoxicity, whereas a biofiltration process can produce a high concentration of bioaerosols, which are a potential health risk. In the combined process, the toxic products produced by the UV photodegradation were removed by the subsequent biofilter. The acute toxicity of the products was reduced from 0.042 to 0.005 mg zinc/mg total organic carbon (TOC). Also the genotoxicity was reduced from 0.76 to 0.16 microg 4-nitroquinoline-N-oxide per milligram TOC. On the other hand, the bioaerosol concentration emitted from the biofilter decreased from 1.38 x 10(3) colony-forming units (CFU) x m(-3) (without UV pretreatment) to 60 CFU x m(-3) (with UV pretreatment), nearly the same as the background level of 40 CFU x m(-3). The significant decrease in bioaerosol emission might be due to a high concentration of ozone (50 mg x m(-3) or 25 parts per million by volume produced by the UV pretreatment. Hence, the UV photodegradation and biofiltration process exhibited synergistic effects. Also, the combined UV-biofiltration process was ecologically safer and exhibited a lower degree of infectivity as compared with standalone UV or biofiltration processes.


    Directory of Open Access Journals (Sweden)

    K. Yogi Purnamawati


    Full Text Available The textile industry is growing rapidly and as the result it’s producing waste that can harm the environment. One of which is rhodamine B. Rhodamine B is a synthetics dyes that have a form crystalline which an organic base containing amino groups, so it is difficult to degrade naturally by microorganism. Biofiltration system method is one of many ways in handling wastewater. Layered filtration unit of sand and rocks combine with the adsorption of plant and decomposition by microorganisms in rhizosphere so that wastewater can be reused. The aim of this study determined effectiveness and capacity of biofiltration system vegetation in reducing concentrate of rhodamine-B, total dissolved solid (TDS, total suspended solid (TSS and the pH in wastewater. The result showed that biofiltration effectiveness in reducing rhodamine B, TDS and TSS concetrate were 51,70%; 47,60%; 50,44% while decreasing and stabilization of pH obtained at 30 hours treatment time with pH value is 7,5. Capacity of biofiltration system vegetation with volume 0,06 m3 can reduced rhodamine B, TDS and TSS by 0,2256 ppm; 278,0237 ppm and 9,4978 ppm respectively, while the optimum detention time of wastewater in the biosystem for reducing rhodamine B was 30 hours and for TSS and TDS was 36 hours. It can be concluded that biofiltration system vegetation was able to reduce rhodamine B, TDS, TSS and pH of wastewater

  12. Function and limits of biofilters for the removal of methane in exhaust gases from the pig industry. (United States)

    Veillette, Marc; Girard, Matthieu; Viens, Pascal; Brzezinski, Ryszard; Heitz, Michèle


    The agricultural sector is responsible for an important part of Canadian greenhouse gas (GHG) emissions, 8 % of the 747 Mt eq. CO(2) emitted each year. The pork industry, a key sector of the agrifood industry, has had a rapid growth in Canada since the middle 1980s. For this industry, slurry storage accounts for the major part of methane (CH(4)) emissions, a GHG 25 times higher than carbon dioxide (CO(2)) on a 100-year time horizon. Intending to reduce these emissions, biofiltration, a process effective to treat CH(4) from landfills and coal mines, could be effective to treat CH(4) from the pig industry. Biofiltration is a complex process that requires the understanding of the biological process of CH(4) oxidation and a control of the engineering parameters (filter bed, temperature, etc.). Some biofiltration studies show that this technology could be used to treat CH(4) at a relatively low cost and with a relatively high purification performance.

  13. Removal of nitrogen by Algal Turf Scrubber Technology in recirculating aquaculture system

    NARCIS (Netherlands)

    Valeta, J.; Verdegem, M.C.J.


    Ongoing research in recirculation aquaculture focuses on evaluating and improving the purification potential of different types of filters. Algal Turf Scrubber (ATS) are special as they combine sedimentation and biofiltration. An ATS was subjected to high nutrient loads of catfish effluent to examin

  14. Livestock air treatment using PVA-coated powdered activated carbon biofilter (United States)

    The efficacy of polyvinyl alcohol (PVA) biofilters was studied using bench-scale biofilters and air from aerobically-treated swine manure. The PVA-coated powdered activated carbon particles showed excellent properties as a biofiltration medium: water holding capacity of 1.39 g H2O/g-dry PVA; wet por...


    Biofiltration technology is widely utilized for treating ammonia gas (NH3), with one of its potential detrimental by-products being nitrous oxide (N2O), a greenhouse gas approximately 300 times more reactive to infrared than CO2. The present work intends to provide the relation between NH3 removal d...

  16. Pumps vs. airlifts: Theoretical and practical energy implications (United States)

    In the design of a recirculating aquaculture system five life-supporting issues should be considered which include aeration, degasification, circulation, biofiltration, and clarification. The implications associated with choosing a pumped system versus an airlift system to address these issues was e...

  17. Biodegradation of organic contaminants from the dairy industry

    Directory of Open Access Journals (Sweden)

    Diego Prócel


    Full Text Available One of the environmental aspects of high impact in dairy industries is the discharge of wastewaters, because of contaminating organic matter as well as the substantial generation of effluents. In the present study, a biofiltration of effluents from a dairy industry in San Miguel de Nono (Ecuador with a pollution load of 10.000 mg/L in terms of chemical oxygen demand and turbidity of 799 NTU was implemented. The system with a capacity of 55 L per batch consisted of three biofilters in series and activated zeolite assisted clarification. Organic degradation reached 98,9%; turbidity removal was 95,2%, 94,4% of nitrogen and 89,1% of phosphorus. The presence of milk fat did not decrease the efficiency of the biofiltration but increased the removal of suspended matter and pH neutralisation in the clarification. The optimal operating time was 6 hours under aerobic conditions.

  18. Biodegradation of methanol vapor in a biofilter

    Institute of Scientific and Technical Information of China (English)

    Durai Arulneyam; T. Swaminathan


    Volatile organic compounds (VOCs) are a new class of air pollutants posing threat to the environment. Newer technologies are being developed for their control among which biofiltration seem to be most attractive. Biofiltration of methanol vapor from air stream was evaluated in this study. Experimental investigations were conducted on a laboratory scale biofilter, containing mixture of compost and polystyrene inert particles as the filter materials. Mixed consortium of activated sludge was used as an inoculum. The continuous performance of biofilter for methanol removal was monitored for different concentrations and flow rates. The removal efficiencies decreased at higher concentrations and higher gas flow rates. A maximum elimination capacity of 85 g/(m3.h) was achieved. The response of biofilter to upset loading operation showed that the biofilm in the biofilters was quite stable and quickly adapted to adverse operational conditions.

  19. Biological Treatment of Solvent-Based Paint (United States)


    GAC granular activated carbon H2O water HP horsepower IWG inches of water gauge IWTC Industrial Wastewater Treatment Complex JGDM Joint...biofiltration system) were procured, installed, and tested over a 1-yr period in cooperation with the Industrial Wastewater Treatment Complex (IWTC) in...were steam reforming, incineration, ultrafiltration , activated carbon, and photochemical oxidation. Because the paint is not suspended in water, its

  20. Soil-based filtration technology for air purification: potentials for environmental and space life support application (United States)

    Nelson, Mark; Bohn, Hinrich

    Soil biofiltration, also known as Soil bed reactor (SBR), technology was originally developed in Germany to take advantage of the diversity in microbial mechanisms to control gases producing malodor in industrial processes. The approach has since gained wider international acceptance and seen numerous improvements, for example, by the use of high-organic compost beds to maximize microbial processes. This paper reviews the basic mechanisms which underlay soil processes involved in air purification, advantages and limitations of the technology and the cur-rent research status of the approach. Soil biofiltration has lower capital and operating/energetic costs than conventional technologies and is well adapted to handle contaminants in moderate concentrations. The systems can be engineered to optimize efficiency though manipulation of temperature, pH, moisture content, soil organic matter and airflow rates. SBR technology was modified for application in the Biosphere 2 project, which demonstrated in preparatory research with a number of closed system testbeds that soil could also support crop plants while also serving as soil filters with air pumps to push air through the soil. This Biosphere 2 research demonstrated in several closed system testbeds that a number of important trace gases could be kept under control and led to the engineering of the entire agricultural soil of Biosphere 2 to serve as a soil filtration unit for the facility. Soil biofiltration, coupled with food crop produc-tion, as a component of bioregenerative space life support systems has the advantages of lower energy use and avoidance of the consumables required for other air purification approaches. Expanding use of soil biofiltration can aid a number of environmental applications, from the mitigation of indoor air pollution, improvement of industrial air emissions and prevention of accidental release of toxic gases.

  1. Removal characteristics and kinetic analysis of an aerobic vapor-phase bioreactor for hydrophobic alpha-pinene

    Institute of Scientific and Technical Information of China (English)

    Yifeng Jiang; Shanshan Li; Zhuowei Cheng; Runye Zhu; Jianmeng Chen


    Biofiltration is considered an effective method to control volatile organic compounds(VOCs)pollution.This study was conducted to evaluate the potential use of a bacterial biofilter packed with wood chips and peat for the removal of hydrophobic α-pinene.When inoculated with two pure degraders and adapted activated sludge,a removal efficiency(RE)of more than 95% was achieved after a start-up period of 11 days.The maximum elimination capacity(EC)of 50 g/(m3?hr)with RE of 94% was obtained at empty bed retention time (EBRT) of 102 sec.When higher α-pinene concentrations and shorter EBRTs were applied,the REs and ECs decreased significantly due to mass-transfer and biological reaction limitations.As deduced from the experimental results,approximately 74% of α-pinene were completely mineralized by the consortiums and the biomass yield was 0.60 g biomass/g α-pinene.Sequence analysis of the selected bands excised from denaturing gradient gel electrophoresis revealed that the inoculated pure cultures could be present during the whole operation,and others were closely related to bacteria being able to degrade hydrocarbons.The kinetic results demonstrated that the whole biofiltration for α-pinene was diffusion-limit controlled owing to its hydrophobic characteristics.These findings indicated that this bacterial biofiltration is a promising technology for the remediation of hydrophobic industrial waste gases containing α-pinene.

  2. The Potential Role of Urban Forests in Removing Nutrients from Stormwater. (United States)

    Denman, E C; May, P B; Moore, G M


    Biofiltration systems can be used to improve the quality of stormwater by treating runoff using plants grown in a moderately permeable soil. Most biofilters use herbaceous species, but in highly urbanized locations, such as streets, trees may be a more suitable vegetation. Biofilters that use urban woody vegetation are less studied. This experiment investigated the use of four street tree species [ Schauer, (R. Br.) Peter G. Wilson & J.T. Waterh., (Sm.) Colvill ex Sweet, and L.] and an unplanted control in model biofilters. All four tree species are used in urban landscapes in southern Australia and were chosen to investigate potential species differences in biofiltration systems. The trees were grown in mesocosms as a randomized block factorial design in soils with three saturated hydraulic conductivity rates (4, 95, and 170 mm h). The trees were regularly flooded with mains water (tap water) or artificial stormwater. Tree growth and nutrient removal performance of the systems were investigated over 13 mo. All four species grew well in all three soils, including one chosen for its low, and potentially growth-limiting, drainage rate. Tree growth increased significantly, except for , when flooded with stormwater. Unplanted controls were a source of nutrients; however, the presence of trees reduced oxidized nitrogen and filterable reactive phosphorus concentrations in leachate. There was little effect of species on the removal of nutrients from stormwater. Trees have the potential to be effective elements in urban biofiltration systems, but further field-level evaluation of these systems is required to fully assess this potential.

  3. Low-dose hydrogen peroxide application in closed recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Good, C.; Pedersen, Per Bovbjerg


    The aim of the present work was to simulate water treatment practices with hydrogen peroxide (HP) in recirculating aquaculture systems (RAS). Six identical 1,700-L pilot-scale RAS were divided into two experimental groups based on daily feed allocation and operated under constant conditions...... and contradict prevailing notions that HP cannot be used safely in RAS that employ biofiltration. The development of effective new HP treatment protocols for recirculating aquaculture could reduce the current dependence on formalin to improve water quality and control parasitic loads...

  4. Effectiveness of Floating Micro-Bead Bio-Filter for Ornamental Fish in a Re-Circulating Aquaculture System


    R Fadhil


    Bio-filtration has been widely used in re-circulating aquaculture system to remove waste and to convert toxic ammonia andnitrite into safe end products ornamental fish and other aquatic organisms. However, the study of micro-bead usage as the filter medium has not yet been broadened and thoroughly developed. Therefore, the aim of this study is to construct a biological filter made from polyethylene micro-bead as the filter medium and to analyze its effectiveness in removingwaste as well as in...

  5. Increasing the Economical Efficiency and Sustainability of Indoor Fish Farming by Means of Aquaponics - Review

    Directory of Open Access Journals (Sweden)

    Flavius Blidariu


    Full Text Available This review focuses on increasing economical efficiency and sustainability of indoor fish farming. Aspects like sustainability and economical efficiency were reviewed. In order to improve man`s health we must reconsider the agricultural sciences, by this we understand that we must develop technologies friendly for the environment. Sustainable indoor fish farming is the farming of the new millennium. Combining aquaculture with hydroponics we obtain a new innovation named aquaponics which respects principles of sustainable agriculture (wastewater biofiltration by plants and gives us the possibility to increase economical efficiency with an additional production (organic vegetables.

  6. NOM removal technologies – Norwegian experiences

    Directory of Open Access Journals (Sweden)

    H. Ødegaard


    Full Text Available The paper gives an overview of the methods for removal of natural organic matter (NOM, particularly humic substances (HS, in water with focus on the Norwegian experiences. It is demonstrated that humic substances may be removed by a variety of methods, such as; molecular sieving through nanofiltration membranes, coagulation with subsequent floc separation (including granular media or membrane filtration, oxidation followed by biofiltration and sorption processes including chemisorption (ion exchange and physical adsorption (activated carbon. All these processes are in use in Norway and the paper gives an overview of the operational experiences.

  7. NOM removal technologies – Norwegian experiences

    Directory of Open Access Journals (Sweden)

    H. Ødegaard


    Full Text Available The paper gives an overview of the methods for removal of natural organic matter (NOM in water, particularly humic substances (HS, with focus on the Norwegian experiences. It is demonstrated that humic substances may be removed by a variety of methods, such as; molecular sieving through nanofiltration membranes, coagulation with subsequent floc separation (including granular media or membrane filtration, oxidation followed by biofiltration and sorption processes including chemisorption (ion exchange and physical adsorption (activated carbon. All these processes are in use in Norway and the paper gives an overview of the operational experiences.


    Directory of Open Access Journals (Sweden)

    Ivo Šarić


    Full Text Available Recirculating aquaculture is one of the solutions to an environmentally sustainable and economically feasible aquaculture production, and can be established in either urban or rural communities. Controlled conditions enable optimal growth conditions suitable for the species in question during the whole growth process, as well as the shortening of the process itself, when compared to open uncontrolled systems. Recirculating systems are now one of the most researched fields of aquaculture, and biofiltration as the reduction of the poisonous ammonia compounds generated by digestion of proteins, is one of its most important parts. The aim of this study was to stress the importance of biofiltration, and to describe different designs of biofilters. Many biofilters are being used in commercial and research aquaculture facilities with differences in choice of working organism, design, material, price and etc. For the proper choice of biofilter it is necessary to know characteristics of each recirculating aquaculture system, because there are still no strict criteria for categorizing and applying different biofilter designs.

  9. Assessment of Biosorption Activated Media Under Roadside Swales for the Removal of Phosphorus from Stormwater

    Directory of Open Access Journals (Sweden)

    Andrew Hood


    Full Text Available Stormwater runoff from highways is a source of pollution to surface water bodies and groundwater. Excess loadings of phosphorus in stormwater discharged to surface water bodies can result in eutrophication. Treatment of stormwater for phosphorus is necessary in order to sustain ecological and economical benefits related to aquatic resources. If phosphorus is removed, the water can be sustained for other uses, such as irrigation and industrial applications. The data presented in this paper is used to evaluate the treatment performance of a roadside biosorption activated media system with regards to the removal of total phosphorus and soluble reactive phosphorus from highway runoff. The evaluation also compares removal efficiencies and effluent concentrations using biosorption activated media (BAM to that with sandy soil commonly found in the Florida area. The results presented in this paper indicate that BAM bio-filtration systems are a feasible treatment method for removing phosphorus from highway runoff. A discussion concerning the additional treatment and reuse of water by harvesting, as part of a Bio-filtration & Harvesting Swale System, is also presented in the paper.

  10. Molecular characterization of low molecular weight dissolved organic matter in water reclamation processes using Orbitrap mass spectrometry. (United States)

    Phungsai, Phanwatt; Kurisu, Futoshi; Kasuga, Ikuro; Furumai, Hiroaki


    Reclaimed water has recently become an important water source for urban use, but the composition of dissolved organic matter (DOM) in reclaimed water has rarely been characterized at the compound level because of its complexity. In this study, the transformation and changes in composition of low molecular weight DOM in water reclamation processes, where secondary effluent of the municipal wastewater treatment plant was further treated by biofiltration, ozonation and chlorination, were investigated by "unknown" screening analysis using Orbitrap mass spectrometry (Orbitrap MS). The intense ions were detected over an m/z range from 100 to 450. In total, 2412 formulae with various heteroatoms were assigned, and formulae with carbon (C), hydrogen (H) and oxygen (O) only and C, H, O and sulfur (S) were the most abundant species. During biofiltration, CHO-only compounds with relatively high hydrogen to carbon (H/C) ratio or with saturated structure were preferentially removed, while CHOS compounds were mostly removed. Ozonation induced the greatest changes in DOM composition. CHOS compounds were mostly decreased after ozonation while ozone selectively removed CHO compounds with relatively unsaturated structure and produced compounds that were more saturated and with a higher degree of oxidation. After chlorination, 168 chlorine-containing formulae, chlorinated disinfection by-products (DBPs), were additionally detected. Candidate DBP precursors were determined by tracking chlorinated DBPs formed via electrophilic substitution, half of which were generated during the ozonation.

  11. Treatment of gaseous toluene in three biofilters inoculated with fungi/bacteria: Microbial analysis, performance and starvation response. (United States)

    Cheng, Zhuowei; Lu, Lichao; Kennes, Christian; Yu, Jianming; Chen, Jianmeng


    Bacteria and fungi are often utilized for the biodegradation of organic pollutants. This study compared fungal and/or bacterial biofiltration in treating toluene under both steady and unsteady states. Fungal biofilter (F-BF) removed less toluene than both bacterial biofilters (B-BF) and fungal & bacterial biofilters (F&B-BF) (60% vs >90%). The mineralization ratio was also lower in F-BF-levels were 2/3 and 1/2 of those values obtained by the other biofilters. Microbial analysis showed that richer communities were present in B-BF and F&B-BF, and that the Hypocreales genus which Trichoderma viride belongs to was much better represented in F&B-BF. The F&B-BF also supported enhanced robustness after 15-day starvation episodes; 1 day later the performance recovered to 80% of the original removal level. The combination of bacteria and fungi makes biofiltration a good option for VOC treatment including better removal and performance stability versus individual biofilters (bacteria or fungi dominated).

  12. Influence of intermittent wetting and drying conditions on heavy metal removal by stormwater biofilters. (United States)

    Blecken, Godecke-Tobias; Zinger, Yaron; Deletić, Ana; Fletcher, Tim D; Viklander, Maria


    Biofiltration is a technology to treat urban stormwater runoff, which conveys pollutants, including heavy metals. However, the variability of metals removal performance in biofiltration systems is as yet unknown. A laboratory study has been conducted with vegetated biofilter mesocosms, partly fitted with a submerged zone at the bottom of the filter combined with a carbon source. The biofilters were dosed with stormwater according to three different dry/wet schemes, to investigate the effect of intermittent wetting and drying conditions on metal removal. Provided that the biofilters received regular stormwater input, metal removal exceeded 95%. The highest metal accumulation occurs in the top layer of the filter media. However, after antecedent drying before a storm event exceeding 3-4 weeks the filters performed significantly worse, although metal removal still remained relatively high. Introducing a submerged zone into the filter improved the performance significantly after extended dry periods. In particular, copper removal in filters equipped with a submerged zone was increased by around 12% (alpha=0.05) both during wet and dry periods and for lead the negative effect of drying could completely be eliminated, with consistently low outflow concentrations even after long drying periods.

  13. Performance of a biofilter system with agave fiber filter media for municipal wastewater treatment. (United States)

    Vigueras-Cortés, Juan Manuel; Villanueva-Fierro, Ignacio; Garzón-Zúñiga, Marco Antonio; de Jesús Návar-Cháidez, José; Chaires-Hernández, Isaías; Hernández-Rodríguez, César


    Agave plants grow in semi-arid regions and are used for mescal production. However, agave fiber by-products are considered waste materials. Thus, we tested agave fiber as a filter media and biofilm material carrier for removing pollutants from municipal wastewater. Three laboratory-scale biofiltration reactors were used in two trials with five hydraulic loading rates (HLRs = 0.27, 0.54, 0.80, 1.07 and 1.34 m(3) m(-2) d(-1)). One series was conducted using mechanical aeration (0.62 m(3) m(-2) h(-1)). To prevent compaction, decreasing pressure and clogging of the filter media, 4, 8 and 12 internal divisions were evaluated in the biofilter column. After 17 months of continuous operation at an HLR of 0.80 m(3) m(-2) d(-1), the removal efficiencies of the aerated biofilters were 92.0% biochemical oxygen demand, 79.7% chemical oxygen demand, 98.0% helminth eggs, 99.9% fecal coliforms and 91.9% total suspended solids. Statistical analysis showed that the chosen operational parameters significantly influenced the removal efficiencies of the biofilters. The effluent quality obtained under these conditions complied with the Mexican and US EPA standards for agricultural irrigation and green spaces, except for coliforms, which is why the effluents must be disinfected. Thus, agave fiber is a favorable choice for use as a packing material in biofiltration processes.

  14. Control of disinfection by-product formation using ozone-based advanced oxidation processes. (United States)

    Chen, Kuan-Chung; Wang, Yu-Hsiang


    The effects of ozone dosage, water temperature and catalyst addition in an ozonation-fluidized bed reactor (O3/FBR) on treated water quality and on the control of chlorinated and ozonated disinfection by-products (DBPs) were investigated. A biofiltration column was used to evaluate its removal efficiency on biodegradable organic matter and to reduce DBP formation. The Dong-Gang River, polluted by agricultural and domestic wastewater in Pingtung, Taiwan, was used as the water source. The treated water quality in terms of dissolved organic carbon (DOC), biodegradable DOC, ultraviolet absorbance at 254 nm (UV254) and specific UV absorbance (SUVA) improved with increasing ozone and catalyst dosages. Catalytic ozonation was more effective than ozonation alone at reducing the formation of DBPs at a given dosage. Experimental results show that water temperature had little effect on the treated water quality with the O3/FBR system used in this study (p > 0.05). The combination of O3/FBR and the biofiltration process effectively decreased the amount ofDBP precursors. The concentration of total trihalomethanes (TTHMs) was less than the maximum contaminant level (MCL) requirement, which is 80 microg/L, for all treated waters and the concentration of five haloacetic acids (HAA5) fell below 60 microg/L with an ozone dosage higher than 2.5 mg/L.

  15. The removal of hydrogen sulfide from biogas in a microaerobic biotrickling filter using polypropylene carrier as packing material. (United States)

    Zhou, Qiying; Liang, Hong; Yang, Senlin; Jiang, Xia


    Biological removal of hydrogen sulfide in biogas is an increasingly adopted alternative to the conventional physicochemical processes, because of its economic and environmental benefits. In this study, a microaerobic biofiltration system packed with polypropylene carrier was used to investigate the removal of high concentrations of H2S contained in biogas from an anaerobic digester. The results show that H2S in biogas was removed completely under different inlet concentrations of H2S from 2065 ± 234 to 7818 ± 131 ppmv, and the elimination capacity of H2S in the filter achieved about 122 g H2S/m(3)/h. It was observed that the content of CH4 in biogas increased after the biogas biodesulfurization process, which was beneficial for the further utilization of biogas. The elemental sulfur and sulfate were the main sulfur species of H2S degradation, and elemental sulfur was dominant (about 80 %) under high inlet H2S concentration. The results of terminal restriction fragment length polymorphism (T-RFLP) and fluorescence in situ hybridization (FISH) show that the population of sulfide-oxidizing bacteria (SOB) species in the filter changed with different concentrations of H2S. The microaerobic biofiltration system allows the potential use of biogas and the recovery of elemental sulfur resource simultaneously.

  16. Effect of advanced oxidation on N-nitrosodimethylamine (NDMA) formation and microbial ecology during pilot-scale biological activated carbon filtration. (United States)

    Li, Dong; Stanford, Ben; Dickenson, Eric; Khunjar, Wendell O; Homme, Carissa L; Rosenfeldt, Erik J; Sharp, Jonathan O


    Water treatment combining advanced oxidative processes with subsequent exposure to biological activated carbon (BAC) holds promise for the attenuation of recalcitrant pollutants. Here we contrast oxidation and subsequent biofiltration of treated wastewater effluent employing either ozone or UV/H2O2 followed by BAC during pilot-scale implementation. Both treatment trains largely met target water quality goals by facilitating the removal of a suite of trace organics and bulk water parameters. N-nitrosodimethylamine (NDMA) formation was observed in ozone fed BAC columns during biofiltration and to a lesser extent in UV/H2O2 fed columns and was most pronounced at 20 min of empty bed contact time (EBCT) when compared to shorter EBCTs evaluated. While microbial populations were highly similar in the upper reaches, deeper samples revealed a divergence within and between BAC filtration systems where EBCT was identified to be a significant environmental predictor for shifts in microbial populations. The abundance of Nitrospira in the top samples of both columns provides an explanation for the oxidation of nitrite and corresponding increases in nitrate concentrations during BAC transit and support interplay between nitrogen cycling with nitrosamine formation. The results of this study demonstrate that pretreatments using ozone versus UV/H2O2 impart modest differences to the overall BAC microbial population structural and functional attributes, and further highlight the need to evaluate NDMA formation prior to full-scale implementation of BAC in potable reuse applications.

  17. A hybridized membrane-botanical biofilter for improving air quality in occupied spaces (United States)

    Llewellyn, David; Darlington, Alan; van Ras, Niels; Kraakman, Bart; Dixon, Mike

    Botanical biofilters have been shown to be effective in improving indoor air quality through the removal of complex mixtures of gaseous contaminants typically found in human-occupied environments. Traditional, botanical biofilters have been comprised of plants rooted into a thin and highly porous synthetic medium that is hung on vertical surfaces. Water flows from the top of the biofilter and air is drawn horizontally through the rooting medium. These botanical biofilters have been successfully marketed in office and institutional settings. They operate efficiently, with adequate contaminant removal and little maintenance for many years. Depending on climate and outdoor air quality, botanical biofiltration can substantially reduce costs associated with ventilation of stale indoor air. However, there are several limitations that continue to inhibit widespread acceptance: 1. Current designs are architecturally limiting and inefficient at capturing ambient light 2. These biofilters can add significant amounts of humidity to an indoor space. This water loss also leads to a rapid accumulation of dissolved salts; reducing biofilter health and performance 3. There is the perception of potentially actively introducing harmful bioaerosols into the air stream 4. Design and practical limitations inhibit the entrance of this technology into the lucrative residential marketplace This paper describes the hybridization of membrane and botanical biofiltration technologies by incorporating a membrane array into the rootzone of a conventional interior planting. This technology has the potential for addressing all of the above limitations, expanding the range of indoor settings where botanical biofiltration can be applied. This technology was developed as the CSA-funded Canadian component an ESA-MAP project entitled: "Biological airfilter for air quality control of life support systems in manned space craft and other closed environments", A0-99-LSS-019. While the project addressed a

  18. Pilot scale land-based cultivation of Saccharina latissima Linnaeus at southern European climate conditions: Growth and nutrient uptake at high temperatures

    DEFF Research Database (Denmark)

    Azevedo, Isabel C.; Silva Marinho, Goncalo; Silva, Diogo M.


    of integrated multi-trophic aquaculture (IMTA) systems, presenting good results considering both growth and biofiltration performance. In the present work, the cultivation of S. latissima in a pilot land-based system was performed in order to assess the efficiency of two different methods: tumbling in the water...... during high temperature periods. Densities around 8 kg m− 3 were effective in keeping epiphytes development low. This system may be used for seaweed monoculture or as a biofilter component of IMTA systems.......Saccharina latissima is a cold water seaweed species with commercial potential. The northern Portuguese coast is the southern distribution limit of the species, where some dispersed populations can be found. S. latissima has been identified as being a potential candidate for monoculture or as part...

  19. Basis for a valuation of the Polish Exclusive Economic Zone of the Baltic Sea: Rationale and quest for tools

    Directory of Open Access Journals (Sweden)

    Jan Marcin Węsławski


    Full Text Available This paper summarises current knowledge of goods and servicesin the Polish Exclusive Economic Zone of the Baltic Sea ecosystem.It reviews specific properties of the Baltic that could be usedfor economic valuation. Goods and services range from the familiarresources of fish and minerals, which were valued with the ProductivityMethod, to less obvious services provided by the ecosystem suchas biofiltration in coastal sands, valued with either the ReplacementCost or Damage Cost Avoided methods. Disservices to the marineecosystem are also considered, e.g. erosion and coastal flooding,including the costs of planned mitigating measures. This paperemphasises the importance of using valuation methods to helpmake better-educated decisions for the sustainability of theBaltic Sea.

  20. Effect of biostimulation on biodegradation of dissolved organic carbon in biological granular activated carbon filters

    Directory of Open Access Journals (Sweden)

    K. Tihomirova


    Full Text Available The addition of labile organic carbon (LOC to enhance the biodegradation rate of dissolved organic carbon (DOC in biological columns was studied. Acetate standard solution (NaAc and LB (Luria Bertrani medium were used as LOC as biostimulants in glass column system used for measurements of biodegradable dissolved organic carbon (BDOC. The addition of LOC related with the increase of total DOC in sample. The concentration of BDOC increased up to 7 and 5 times and was utilized after 24 min. contact time. The biodegradation rate constant was increased at least 8 times during adaptation-biostimulation period. There was a strong positive correlation between the biodegradation rate constant and the concentration of BDOC. Biostimulation period ranged from 24 to 53 h for NaAc biostimulant and from 20 to 168 h for LB. The study has shown that LOC could be used as stimulator to enhance the biodegradation rate of DOC during biofiltration.

  1. Effect of biostimulation on biodegradation of dissolved organic carbon in biological filters

    Directory of Open Access Journals (Sweden)

    K. Tihomirova


    Full Text Available The addition of labile organic carbon (LOC to enhance the biodegradation rate of dissolved organic carbon (DOC in biological columns was studied. Acetate standard solution (NaAc and Luria Bertrani (LB medium were used as LOC as biostimulants in glass column system used for measurements of biodegradable dissolved organic carbon (BDOC. The addition of LOC related with the increase of total DOC in sample. The concentration of BDOC increased up to 7 and 5 times and was utilized after 24 min. contact time. The biodegradation rate constant was increased at least 26 times during adaptation-biostimulation period. There was a strong positive correlation between the biodegradation rate constant and the concentration of BDOC. Biostimulation period ranged from 24 to 53 h for NaAc biostimulant and from 20 to 168 h for LB. The study has shown that LOC could be used as stimulator to enhance the biodegradation rate of DOC during biofiltration.

  2. 1994 - 1995 annual report of the NRC Biotechnology Research Institute

    Energy Technology Data Exchange (ETDEWEB)



    One of the roles of the Biotechnology Research Institute is to promote leading edge research and development in biotechnology and molecular biology as they relate to industries in the natural resource sectors. To this end, researchers work with industry to develop less polluting, more efficient and economic processes and to solve environmental problems. Scientific studies undertaken in 1994 and 1995 included new analytical techniques and biosensors, bioprocesses for waste and ground water treatment, biopesticides, biodegradation of toxic compounds, biodesulfurization of bitumen, solvent- less sample preparation techniques to analyze environmental pollutants in soils and waste water, protocol for the analysis of petroleum hydrocarbons, gene probes and their applications, biodegradation of energetic compounds, and biofiltration of air emissions. These, and other noteworthy projects undertaken by the Institute, were reviewed and presented ,combined with institutional data. 2 tabs.

  3. Quality and Indoor Air treatment

    Directory of Open Access Journals (Sweden)

    Cécile HORT


    Full Text Available In developed countries, between 70% and 90% of the life time are spent in confined spaces (housing, transport, etc.. Air quality in these closed spaces is generally inferior than outside. Our lifestylesand the growing use of new products and materials create cocktails of chemicals compounds (COV, CIV... that can cause an increase of worrying diseases such as asthma, allergies or even cancer. These pollutants are particularly present in indoor air. These increasing public health problems gives rise to the development of devices for the treatment of indoor air. However, indoor air contains a lot of chemical substances showing very different physicochemical properties. The “Laboratoire de Thermique, Energétique et Procédés” (LaTEP studies the coupling of treatment processes, such as biofiltration coupled to adsorption.

  4. Potential applications of bioprocess technology in petroleum industry. (United States)

    Singh, Ajay; Singh, Brajesh; Ward, Owen


    Petroleum refining is traditionally based on the use of physicochemical processes such as distillation and chemical catalysis that operate under high temperatures and pressures conditions, which are energy intensive and costly. Biotechnology has become an important tool for providing new approaches in petroleum industry during oil production, refining and processing as well as managing environmentally safe pollutant remediation and disposal practices. Earlier biotechnology applications in the petroleum industry were limited to microbial enhanced oil recovery, applications of bioremediation to contaminated marine shorelines, soils and sludges. The potential role of bioprocess technology in this industry has now expanded further into the areas of biorefining and upgrading of fuels, production of fine chemicals, control of souring during production and air VOC biofiltration. In this paper we provide an overview of the major applications of bioprocesses and technology development in the petroleum industry both in upstream and downstream areas and highlight future challenges and opportunities.

  5. Indoor-biofilter growth and exposure to airborne chemicals drive similar changes in plant root bacterial communities. (United States)

    Russell, Jacob A; Hu, Yi; Chau, Linh; Pauliushchyk, Margarita; Anastopoulos, Ioannis; Anandan, Shivanthi; Waring, Michael S


    Due to the long durations spent inside by many humans, indoor air quality has become a growing concern. Biofiltration has emerged as a potential mechanism to clean indoor air of harmful volatile organic compounds (VOCs), which are typically found at concentrations higher indoors than outdoors. Root-associated microbes are thought to drive the functioning of plant-based biofilters, or biowalls, converting VOCs into biomass, energy, and carbon dioxide, but little is known about the root microbial communities of such artificially grown plants, how or whether they differ from those of plants grown in soil, and whether any changes in composition are driven by VOCs. In this study, we investigated how bacterial communities on biofilter plant roots change over time and in response to VOC exposure. Through 16S rRNA amplicon sequencing, we compared root bacterial communities from soil-grown plants with those from two biowalls, while also comparing communities from roots exposed to clean versus VOC-laden air in a laboratory biofiltration system. The results showed differences in bacterial communities between soil-grown and biowall-grown plants and between bacterial communities from plant roots exposed to clean air and those from VOC-exposed plant roots. Both biowall-grown and VOC-exposed roots harbored enriched levels of bacteria from the genus Hyphomicrobium. Given their known capacities to break down aromatic and halogenated compounds, we hypothesize that these bacteria are important VOC degraders. While different strains of Hyphomicrobium proliferated in the two studied biowalls and our lab experiment, strains were shared across plant species, suggesting that a wide range of ornamental houseplants harbor similar microbes of potential use in living biofilters.

  6. Evaluation of bacterial communities by bacteriome analysis targeting 16S rRNA genes and quantitative analysis of ammonia monooxygenase gene in different types of compost. (United States)

    Kitamura, Rika; Ishii, Kazuo; Maeda, Isamu; Kozaki, Toshinori; Iwabuchi, Kazunori; Saito, Takahiro


    Biofiltration technology based on microbial degradation and assimilation is used for the removal of malodorous compounds, such as ammonia. Microbes that degrade malodorous and/or organic substances are involved in composting and are retained after composting; therefore, mature composts can serve as an ideal candidate for a biofilter medium. In this study, we focused on different types of raw compost materials, as these are important factors determining the bacterial community profile and the chemical component of the compost. Therefore, bacterial community profiles, the abundance of the bacterial ammonia monooxygenase gene (amoA), and the quantities of chemical components were analyzed in composts produced from either food waste or cattle manure. The community profiles with the lowest beta diversity were obtained from single type of cattle manure compost. However, cattle manure composts showed greater alpha diversity, contained higher amounts of various rRNA gene fragments than those of food waste composts and contained the amoA gene by relative quantification, and Proteobacteria were abundantly found and nitrifying bacteria were detected in it. Nitrifying bacteria are responsible for ammonia oxidation and mainly belong to the Proteobacteria or Nitrospira phyla. The quantities of chemical components, such as salt, phosphorus, and nitrogen, differed between the cattle manure and food waste composts, indicating that the raw materials provided different fermentation environments that were crucial for the formation of different community profiles. The results also suggest that cattle manure might be a more suitable raw material for the production of composts to be used in the biofiltration of ammonia.

  7. Indoor-Biofilter Growth and Exposure to Airborne Chemicals Drive Similar Changes in Plant Root Bacterial Communities (United States)

    Hu, Yi; Chau, Linh; Pauliushchyk, Margarita; Anastopoulos, Ioannis; Anandan, Shivanthi; Waring, Michael S.


    Due to the long durations spent inside by many humans, indoor air quality has become a growing concern. Biofiltration has emerged as a potential mechanism to clean indoor air of harmful volatile organic compounds (VOCs), which are typically found at concentrations higher indoors than outdoors. Root-associated microbes are thought to drive the functioning of plant-based biofilters, or biowalls, converting VOCs into biomass, energy, and carbon dioxide, but little is known about the root microbial communities of such artificially grown plants, how or whether they differ from those of plants grown in soil, and whether any changes in composition are driven by VOCs. In this study, we investigated how bacterial communities on biofilter plant roots change over time and in response to VOC exposure. Through 16S rRNA amplicon sequencing, we compared root bacterial communities from soil-grown plants with those from two biowalls, while also comparing communities from roots exposed to clean versus VOC-laden air in a laboratory biofiltration system. The results showed differences in bacterial communities between soil-grown and biowall-grown plants and between bacterial communities from plant roots exposed to clean air and those from VOC-exposed plant roots. Both biowall-grown and VOC-exposed roots harbored enriched levels of bacteria from the genus Hyphomicrobium. Given their known capacities to break down aromatic and halogenated compounds, we hypothesize that these bacteria are important VOC degraders. While different strains of Hyphomicrobium proliferated in the two studied biowalls and our lab experiment, strains were shared across plant species, suggesting that a wide range of ornamental houseplants harbor similar microbes of potential use in living biofilters. PMID:24878602

  8. Dynamic analysis of a bio filter treating autothermal thermophilic aerobic digestion offgas

    Energy Technology Data Exchange (ETDEWEB)

    Shanchayan, B. [Carleton Univ., Ottawa, ON (Canada). Dept. of Civil and Environmental Engineering; Parker, W. [Waterloo Univ., ON (Canada). Dept. of Civil Engineering; Pride, C. [Ambio Biofiltration, Rockland, ON (Canada)


    Biofiltration has become the preferred technology to treat offgases from wastewater treatment facilities because of its low operating cost. However, the underlying principles of biofiltration have only recently begun to be understood. In this study, the dynamic variation in the composition of offgases from a full-scale autothermal thermophilic aerobic digestion (ATAD) was characterized, and the performance of a biofilter treating the offgases was examined. Gas and liquid phase streams in the biofilter were measured to identify the mechanisms responsible for the removal of odorants. ATAD is a sludge process that has been found to emit relatively high quantities of ammonia (NH{sub 3}) and reduced sulfur compounds (RSCs). An existing ATAD and biofilter system at a site in Oregon was used in the study. Gas flows were calculated from air velocities that were measured with a hotwire thermo-anemometer at the biofilter inlet. Sampling was performed on an hourly basis over a 24 hour period. Liquid flows were measured hourly at the biofilter leachate sump inlet. It was observed that the ATAD reactors released NH{sub 3} and RSCs in a cyclic pattern. Gas phase concentrations of NH{sub 3} increased with time and location along the digester sequence. A wet scrubber removed nearly 85 per cent of NH{sub 3} and 60 per cent of H{sub 2}S. The removal efficiencies in the biofilter were more than 99 per cent for hydrogen sulfide and methyl mercaptan, and more than 94 per cent for dimethyl sulfide and dimethyl disulfide. The removal efficiency of each compound demonstrated the effectiveness of the biofilter and wet scrubber combination for the ATAD offgas removal. 24 refs., 5 tabs., 9 figs.

  9. Removal of geosmin and 2-methylisoborneol by biological filtration. (United States)

    Elhadi, S L N; Huck, P M; Slawson, R M


    The quality of drinking water is sometimes diminished by the presence of certain compounds that can impart particular tastes or odours. One of the most common and problematic types of taste and odour is the earthy/musty odour produced by geosmin (trans-1, 10-dimethyl-trans-9-decalol) and MIB (2-methylisoborneol). Taste and odour treatment processes including powdered activated carbon, and oxidation using chlorine, chloramines, potassium permanganate, and sometimes even ozone are largely ineffective for reducing these compounds to below their odour threshold concentration levels. Ozonation followed by biological filtration, however, has the potential to provide effective treatment. Ozone provides partial removal of geosmin and MIB but also creates other compounds more amenable to biodegradation and potentially undesirable biological instability. Subsequent biofiltration can remove residual geosmin and MIB in addition to removing these other biodegradable compounds. Bench scale experiments were conducted using two parallel filter columns containing fresh and exhausted granular activated carbon (GAC) media and sand. Source water consisted of dechlorinated tap water to which geosmin and MIB were added, as well as, a cocktail of easily biodegradable organic matter (i.e. typical ozonation by-products) in order to simulate water that had been subjected to ozonation prior to filtration. Using fresh GAC, total removals of geosmin ranged from 76 to 100% and total MIB removals ranged from 47% to 100%. The exhausted GAC initially removed less geosmin and MIB but removals increased over time. Overall the results of these experiments are encouraging for the use of biofiltration following ozonation as a means of geosmin and MIB removal. These results provide important information with respect to the role biofilters play during their startup phase in the reduction of these particular compounds. In addition, the results demonstrate the potential biofilters have in responding to

  10. Macrokinetic determination of isopropanol removal using a downward flow biofilter

    Directory of Open Access Journals (Sweden)

    Vissanu Meeyoo


    Full Text Available Biofiltration is a process for eliminating contaminants in air using microorganisms immobilized on a surface of solid support media. This technique has been used successfully to control a number of air contaminants such as odors, Volatile Organic Compounds (VOCs, and Hazardous Air Pollutants (HAPs due to its economic attraction.Microorganisms obtained from local activated sludge (Huay-Kwang wastewater treatment plant (Bangkok, Thailand were selectively enriched and inoculated to the biofilter. The downward flow biofilterwas chosen, due to the ease of water compensation at the dry zone, to operate continuously for more than 3 months under various concentrations of isopropanol alcohol (IPA input at a constant filtered air flow rate of 3 L/min. The maximum IPA elimination capacity of 276 g/m3-h was achieved at the IPA inlet of 342 g/m3-h with acetone production rate of 56 g/m3-h as the intermediate. It was also found that the acetone vapour was partly degraded by the acetone-utilizing microorganisms before leaving the bed. In order to understand the transport phenomena of biofiltration, it is necessary to consider the kinetic behavior of the bioreaction. Therefore, this paper introduces Wani’s method of macrokinetic determination based on the simple Monod kinetic (Wani, Lau and Branion, 1999. In this study, the maximum reaction rate per unit volume (Rm and the Monod constant (KM were found to be 0.12 g/m3 -s and 2.72 g/m3 respectively.

  11. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture

    Directory of Open Access Journals (Sweden)

    S. Sumoharjo


    Full Text Available Integrated multi-trophic aquaculture pays more attention as a bio-integrated food production system that serves as a model of sustainable aquaculture, minimizes waste discharge, increases diversity and yields multiple products. The objectives of this research were to analyze the efficiency of total ammonia nitrogen biofiltration and its effect on carrying capacity of fish rearing units. Pilot-scale bioreactor was designed with eight run-raceways (two meters of each that assembled in series. Race 1-3 were used to stock silky worm (Tubifex sp as detrivorous converter, then race 4-8 were used to plant three species of leaf-vegetable as photoautotrophic converters, i.e; spinach (Ipomoea reptana, green mustard (Brassica juncea and basil (Ocimum basilicum. The three plants were placed in randomized block design based on water flow direction. Mass balance of nutrient analysis, was applied to figure out the efficiency of bio-filtration and its effect on carrying capacity of rearing units. The result of the experiment showed that 86.5 % of total ammonia nitrogen removal was achieved in 32 days of culturing period. This efficiency able to support the carrying capacity of the fish tank up to 25.95 kg/lpm with maximum density was 62.69 kg/m3 of fish biomass productionDoi: [How to cite this article: Sumoharjo, S.  and Maidie, A. (2013. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture.  International Journal of  Science and Engineering, 4(2,80-85. Doi:

  12. Biological anoxic treatment of O{sub 2}-free VOC emissions from the petrochemical industry: A proof of concept study

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz, Raúl; Souza, Theo S.O. [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr Mergelina s/n, 47011 Valladolid (Spain); Glittmann, Lina [Ostfalia University of Applied Sciences, Department of Supply Engineering, Wolfenbüttel (Germany); Pérez, Rebeca [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr Mergelina s/n, 47011 Valladolid (Spain); Quijano, Guillermo, E-mail: [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr Mergelina s/n, 47011 Valladolid (Spain)


    Highlights: • The treatment of O{sub 2}-free VOC emissions can be done by means of denitrifying processes. •Toluene vapors were successfully removed under anoxic denitrifying conditions. • A high bacterial diversity was observed. • Actinobacteria and Proteobacteria were the predominant phyla. • The nature and number of metabolites accumulated varied with the toluene load -- Abstract: An innovative biofiltration technology based on anoxic biodegradation was proposed in this work for the treatment of inert VOC-laden emissions from the petrochemical industry. Anoxic biofiltration does not require conventional O{sub 2} supply to mineralize VOCs, which increases process safety and allows for the reuse of the residual gas for inertization purposes in plant. The potential of this technology was evaluated in a biotrickling filter using toluene as a model VOC at loads of 3, 5, 12 and 34 g m{sup −3} h{sup −1} (corresponding to empty bed residence times of 16, 8, 4 and 1.3 min) with a maximum elimination capacity of ∼3 g m{sup −3} h{sup −1}. However, significant differences in the nature and number of metabolites accumulated at each toluene load tested were observed, o- and p-cresol being detected only at 34 g m{sup −3} h{sup −1}, while benzyl alcohol, benzaldehyde and phenol were detected at lower loads. A complete toluene removal was maintained after increasing the inlet toluene concentration from 0.5 to 1 g m{sup −3} (which entailed a loading rate increase from 3 to 6 g m{sup −3} h{sup −1}), indicating that the system was limited by mass transfer rather than by biological activity. A high bacterial diversity was observed, the predominant phyla being Actinobacteria and Proteobacteria.

  13. Ability of the aquatic fern Azolla to remove chemical oxygen demand and polyphenols from olive mill wastewater

    Directory of Open Access Journals (Sweden)

    Sacchi, Angelo


    Full Text Available We investigated the biofiltration ability of the aquatic fern Azolla to remove polyphenols and chemical oxygen demand (COD from olive mill wastewater (OMWw collected from the traditional (TS and continuous (CS extraction systems. Azolla biomass was packed into five sequential Imhoff cones and five sequential columns. In both experiments, the filtrates collected from the 5th biofilter showed a decrease in polyphenol contents: from 7650 mg l–1 to 3610 mg l–1 in TS OMWw and from 3852 mg l–1 to 1351 mg l–1 in CS OMWw. The COD contents decreased from 110200 mg L–1 to 52400 mg L–1 in TS OMWw and from 41600 mg L–1 to 2300 mg L–1 in CS OMWw. A 5:1 OMWw to Azolla-fresh-weight ratio was optimal for both polyphenol and COD removal. The biofiltration ability of alfalfa was compared with that of Azolla, but the treatment with alfalfa did not result in the reduction of COD or polyphenols.La eficacia del helecho de agua azolla para eliminar polifenoles y reducir la demanda química de oxígeno (DQO de los alpechines obtenidos en el proceso de obtención tradicional y continuo del aceite de oliva, fue investigado mediante ensayos de filtración. Cinco conos secuenciales de Imhoff y cinco columnas secuenciales se rellenaron de biomasa de Azolla. En ambos experimentos, el filtrado procedente de la quinta extracción mostró una disminución en el contenido de polifenoles de 7650 mg L–1 a 3610 mg L–1en el alpechín obtenido mediante el sistema tradicional y de 3852 mg L–1 a 1351 mg L–1en el alpechín del sistema continuo. La demanda química de oxígeno del alpechín del sistema tradicional disminuyó de 110200 mg L–1 a 52400 mg L–1 en y de 41600 mg L–1a 2300 mg L–1en el procedente del sistema continuo. Una proporción en peso 5:1 de alpechín: Azolla fue la óptima tanto para la reducción de los polifenoles como para la de la DQO. La eficiencia del tratamiento biológico con alfalfa se comparó con la obtenida con Azolla. Los

  14. Removal of hydrogen sulfide by sulfate-resistant Acidithiobacillus thiooxidans AZ11. (United States)

    Lee, Eun Young; Lee, Nae Yoon; Cho, Kyung-Suk; Ryu, Hee Wook


    Toxic H2S gas is an important industrial pollutant that is applied to biofiltration. Here, we examined the effects of factors such as inlet concentration and space velocity on the removal efficiency of a bacterial strain capable of tolerating high sulfate concentrations and low pH conditions. We examined three strains of Acidithiobacillus thiooxidans known to have sulfur-oxidizing activity, and identified strain AZ11 as having the highest tolerance for sulfate. A. thiooxidans AZ11 could grow at pH 0.2 in the presence of 74 g l(-1) sulfate, the final oxidation product of elemental sulfur, in the culture broth. Under these conditions, the specific sulfur oxidation rate was 2.9 g-S g-DCW (dry cell weight)(-1) d(-1). The maximum specific sulfur oxidation rate of A. thiooxidans AZ11 was 21.2 g-S g-DCW(-1) d(-1), which was observed in the presence of 4.2 g-SO4(2-) l(-1) and pH 1.5, in the culture medium. To test the effects of various factors on biofiltration by this strain, A. thiooxidans AZ11 was inoculated into a porous ceramic biofilter. First, a maximum inlet loading of 670 g-S m(-3) h(-1) was applied with a constant space velocity (SV) of 200 h(-1) (residence time, 18 s) and the inlet concentration of H2S was experimentally increased from 200 ppmv to 2200 ppmv. Under these conditions, less than 0.1 ppmv H2S was detected at the biofilter outlet. When the inlet H2S was maintained at a constant concentration of 200 ppmv and the SV was increased from 200 h(-1) to 400 h(-1) (residence time, 9 s), an H2S removal of 99.9% was obtained. However, H2S removal efficiencies decreased to 98% and 94% when the SV was set to 500 h(-1) (residence time, 7.2 s) and 600 h(-1) (residence time, 6 s), respectively. The critical elimination capacity guaranteeing 96% removal of the inlet H2S was determined to be 160 g-S m(-3) h(-1) at a space velocity of 600 h(-1). Collectively, these findings show for the first time that a sulfur oxidizing bacterium has a high sulfate tolerance and a high

  15. Evaluating odour control technologies using reliability and sustainability criteria--a case study for water treatment plants. (United States)

    Kraakman, N J R; Estrada, J M; Lebrero, R; Cesca, J; Muñoz, R


    Technologies for odour control have been widely reviewed and their optimal range of application and performance has been clearly established. Selection criteria, mainly driven by process economics, are usually based on the air flow volume, the inlet concentrations and the required removal efficiency. However, these criteria are shifting with social and environmental issues becoming as important as process economics. A methodology is illustrated to quantify sustainability and robustness of odour control technology in the context of odour control at wastewater treatment or water recycling plants. The most commonly used odour abatement techniques (biofiltration, biotrickling filtration, activated carbon adsorption, chemical scrubbing, activated sludge diffusion and biotrickling filtration coupled with activated carbon adsorption) are evaluated in terms of: (1) sustainability, with quantification of process economics, environmental performance and social impact using the sustainability metrics of the Institution of Chemical Engineers; (2) sensitivity towards design and operating parameters like utility prices (energy and labour), inlet odour concentration (H2S) and design safety (gas contact time); (3) robustness, quantifications of operating reliability, with recommendations to improve reliability during their lifespan of operations. The results show that the odour treatment technologies with the highest investments presented the lowest operating costs, which means that the net present value (NPV) should be used as a selection criterion rather than investment costs. Economies of scale are more important in biotechniques (biofiltration and biotrickling filtration) as, at increased airflows, their reduction in overall costs over 20 years (NPV20) is more extreme when compared to the physical/chemical technologies (chemical scrubbing and activated carbon filtration). Due to their low NPV and their low environmental impact, activated sludge diffusion and biotrickling


    Directory of Open Access Journals (Sweden)

    Tania Surya Utami


    Full Text Available  LANGMUIR ADSORPTION MODEL FOR DINITROGEN MONOXIDE IN BIOFILTER SYSTEM USING COMPOST FERTILIZER MEDIUM. Nitrous oxide (N2O is mostly emitted from various industrial processes and agricultural activities. This gas causes serious environmental problems and is considered as a dangerous pollutant. In the past, traditional control technologies, such as Selective Catalytic Reduction (SCR and Selective Non-Catalytic Reduction (SNCR, were applied to control N2O emissions in some industries. However, these two processes required high temperatures and the use of catalysts. Economic and technical constraints in SCR and SNCR methods motivated researchers to develop new, cost-effective processes to remove N2O. Biofiltration is an emerging technology that offers a number of advantages over traditional methods of air pollution control. The purpose of this research is to modelise the biofiltration experimental results into the Langmuir adsorption model. This research is conducted in laboratory scale biofilter column, with parameters studied are effect of biofilter length and N2O gas flowrate. The result of the model is simulated into sensitivity analysis. The average Langmuir constant obtained in the model of the research is 16.006 liter/mol. Dinitrogen Monoksida (N2O merupakan emisi dari proses industri dan kegiatan pertanian. Gas tersebut merupakan gas polutan berbahaya dan menyebabkan masalah lingkungan yang serius. Sebelumnya, teknologi kontrol tradisional seperti Selective Catalytic Reduction (SCR dan Selective Non-Catalytic Reduction (SNCR digunakan untuk mengontrol emisi N2O pada kegiatan-kegiatan industri. Akan tetapi, kedua proses ini membutuhkan suhu yang tinggi dan penggunaan katalis. Adanya masalah dari segi ekonomi dan teknis memotivasi peneliti untuk mengembangkan teknologi baru yang lebih murah dan efisien untuk menghilangkan N2O dari gas buangan. Pengolahan N2O secara biologis dalam proses biofiltrasi adalah salah satu alternatif ramah

  17. Evaluation of the Efficiency of a Biofilter System’s Phenol Removal From Wastewater

    Directory of Open Access Journals (Sweden)

    Reza Shokoohi


    Full Text Available Phenol is a toxic hydrocarbon that has been found in the wastewater of several industries, including the petroleum and petrochemical industries. The discharge of untreated wastewater from these industries causes environmental pollution, especially in water. The aim of this study was to evaluate the efficiency of phenol removal from wastewater using a biofiltration system. In this experimental study, a cylindrical plexiglass biofilter reactor with an effective volume of 12 liters was used. A total of 30 pcs of plastic grid discs were placed inside the reactor by plastic pipes to maintain the biofilm media in the reactor. The microorganisms used in this study were obtained from the biological sludge of a municipal wastewater treatment plant. The reproduction and adaptation of the microorganisms to 500 mg/L of phenol lasted three months. The effects of pH, phenol, nitrogen, phosphorus, glucose concentration, and hydraulic retention time on the biofilter system’s performance was evaluated. The results of this study showed that in optimal conditions, this system can reduce the phenol concentration from 500 mg/L to zero within about 4 hr. Maximum efficiency occurred in pH = 7, and the proper COD/N/P ratio was 100/10/2, respectively. In general, this biofilter system is capable of removing 500 mg/L of phenol concentrations and an organic load of 4 - 4.5 kg COD/m3.d within 4 - 5 hr. with high efficiency.

  18. Behaviour and fate of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in drinking water treatment: a review. (United States)

    Rahman, Mohammad Feisal; Peldszus, Sigrid; Anderson, William B


    This article reviews perfluoroalkyl and polyfluoroalkyl substance (PFAS) characteristics, their occurrence in surface water, and their fate in drinking water treatment processes. PFASs have been detected globally in the aquatic environment including drinking water at trace concentrations and due, in part, to their persistence in human tissue some are being investigated for regulation. They are aliphatic compounds containing saturated carbon-fluorine bonds and are resistant to chemical, physical, and biological degradation. Functional groups, carbon chain length, and hydrophilicity/hydrophobicity are some of the important structural properties of PFASs that affect their fate during drinking water treatment. Full-scale drinking water treatment plant occurrence data indicate that PFASs, if present in raw water, are not substantially removed by most drinking water treatment processes including coagulation, flocculation, sedimentation, filtration, biofiltration, oxidation (chlorination, ozonation, AOPs), UV irradiation, and low pressure membranes. Early observations suggest that activated carbon adsorption, ion exchange, and high pressure membrane filtration may be effective in controlling these contaminants. However, branched isomers and the increasingly used shorter chain PFAS replacement products may be problematic as it pertains to the accurate assessment of PFAS behaviour through drinking water treatment processes since only limited information is available for these PFASs.

  19. Removal of the cyanotoxin anatoxin-a by drinking water treatment processes: a review. (United States)

    Vlad, Silvia; Anderson, William B; Peldszus, Sigrid; Huck, Peter M


    Anatoxin-a (ANTX-a) is a potent alkaloid neurotoxin, produced by several species of cyanobacteria and detected throughout the world. The presence of cyanotoxins, including ANTX-a, in drinking water sources is a potential risk to public health. This article presents a thorough examination of the cumulative body of research on the use of drinking water treatment technologies for extracellular ANTX-a removal, focusing on providing an analysis of the specific operating parameters required for effective treatment and on compiling a series of best-practice recommendations for owners and operators of systems impacted by this cyanotoxin. Of the oxidants used in drinking water treatment, chlorine-based processes (chlorine, chloramines and chlorine dioxide) have been shown to be ineffective for ANTX-a treatment, while ozone, advanced oxidation processes and permanganate can be successful. High-pressure membrane filtration (nanofiltration and reverse osmosis) is likely effective, while adsorption and biofiltration may be effective but further investigation into the implementation of these processes is necessary. Given the lack of full-scale verification, a multiple-barrier approach is recommended, employing a combination of chemical and non-chemical processes.

  20. Advanced organic and biological analysis of dual media filtration used as a pretreatment in a full-scale seawater desalination plant

    KAUST Repository

    Jeong, Sanghyun


    Dual media filter (DMF) is being used as a primary pretreatment to remove particulate foulants at seawater desalination plants. However, many plants experience organic and biological fouling. The first part of this paper focuses on the monitoring of organic and biological foulants using advanced analytical techniques to optimize functioning of DMF at Perth Seawater Desalination Plant (PSDP) in Western Australia. In addition, microbial community analysis in DMF filtered seawater, and on DMF media (DMF-M) and cartridge filter (CF) was conducted using terminal restriction fragment length polymorphism (T-RFLP) and 454-pyrosequencing. In the full-scale DMF system, the bacterial community structure was clustered along with the filtration time and sampling positions. For the DMF effluent samples, the bacterial community structure significantly shifted after 4 h of filtration time, which corresponded with the permeability reduction trend. The dominant bacterial communities in the DMF effluent were OTU 13 (Phaeobacter) and OTU 19 (Oceaniserpentilla). The different biofilm-forming bacteria communities were found in the biofilm samples on DMF-M and CF. In the second part of the study, semi-pilot scale DMF columns were operated on-site under same operating conditions used in PSDP. It demonstrated the advantage of operating DMF at the biofiltration mode for improving the reduction of biofoulants. © 2016 Elsevier B.V.

  1. Development and laboratory-scale testing of a fully automated online flow cytometer for drinking water analysis. (United States)

    Hammes, Frederik; Broger, Tobias; Weilenmann, Hans-Ulrich; Vital, Marius; Helbing, Jakob; Bosshart, Ulrich; Huber, Pascal; Odermatt, Res Peter; Sonnleitner, Bernhard


    Accurate and sensitive online detection tools would benefit both fundamental research and practical applications in aquatic microbiology. Here, we describe the development and testing of an online flow cytometer (FCM), with a specific use foreseen in the field of drinking water microbiology. The system incorporated fully automated sampling and fluorescent labeling of bacterial nucleic acids with analysis at 5-min intervals for periods in excess of 24 h. The laboratory scale testing showed sensitive detection (< 5% error) of bacteria over a broad concentration range (1 × 10(3) -1 × 10(6) cells mL(-1) ) and particularly the ability to track both gradual changes and dramatic events in water samples. The system was tested with bacterial pure cultures as well as indigenous microbial communities from natural water samples. Moreover, we demonstrated the possibility of using either a single fluorescent dye (e.g., SYBR Green I) or a combination of two dyes (SYBR Green I and Propidium Iodide), thus broadening the application possibilities of the system. The online FCM approach described herein has considerable potential for routine and continuous monitoring of drinking water, optimization of specific drinking water processes such as biofiltration or disinfection, as well as aquatic microbiology research in general.

  2. Treatment of taste and odor causing compounds 2-methyl isoborneol and geosmin in drinking water: A critical review

    Institute of Scientific and Technical Information of China (English)

    Rangesh Srinivasan; George A. Sorial


    Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinking water and are mainly caused by the presence of two semi-volatile compounds - 2-methyl isoborneol (MIB) and geosmin. A review of these two taste and odor causing compounds in drinking water is presented. The sources for the formation of these compounds in water are discussed alongwith the health and regulatory implications. The recent developments in the analysis of MIB/geosmin in water which have allowed for rapid measurements in the nanogram per liter concentrations are also discussed. This review focuses on the relevant treatment alternatives,that are described in detail with emphasis on their respective advantages and problems associated with their implementation in a fullscale facility. Conventional treatment processes in water treatment plants, such as coagulation, sedimentation and chlorination have been found to be ineffective for removal of MIB/geosmin. Studies have shown powdered activated carbon, ozonation and biofiltration to be effective in treatment of these two compounds. Although some of these technologies are more effective and show more promise than the others, much work remains to be done to optimize these technologies so that they can be retrofitted or installed with minimal impact on the overall operation and effectiveness of the treatment system.

  3. A novel integrated UV-biofilter system to treat high concentration of gaseous chlorobenzene

    Institute of Scientific and Technical Information of China (English)

    WANG Can; XI JinYing; HU HongYing


    A novel integrated UV-biofilter system using UV reactor as the pretreatment process was setup to treat high concentration of gaseous volatile organic compounds (VOCs). Another control biofilter without the UV pretreatment was also established to compare the performance of the two systems. Chloro-benzene was selected as a model compound. The two systems were operated in parallel under different the integrated system could eliminate chlorobenzene completely (100% removal efficiency) at the inlet ter. Also the elimination capacity for the organic carbon of the integrated system was much higher than that of the control biofilter. On the basis of intermediates analysis by lon Chromatography and Gas Chromatography-Mass Spectrometry, the UV pretreatment has been proven to be able to enhance the performance of the following biofilter by transferring the recalcitrant target to some more biodegrad-able and soluble organic products (such as formic acid and chlorophenol). Furthermore, the produced ozone, a harmful by-product from UV photo-degradation, could be easily eliminated by the following biofiltration process.

  4. Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils

    Energy Technology Data Exchange (ETDEWEB)

    Jeremy Semrau; Sung-Woo Lee; Jeongdae Im; Sukhwan Yoon; Michael Barcelona


    The overall objective of this project, 'Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils' was to develop effective, efficient, and economic methodologies by which microbial production of nitrous oxide can be minimized while also maximizing microbial consumption of methane in landfill cover soils. A combination of laboratory and field site experiments found that the addition of nitrogen and phenylacetylene stimulated in situ methane oxidation while minimizing nitrous oxide production. Molecular analyses also indicated that methane-oxidizing bacteria may play a significant role in not only removing methane, but in nitrous oxide production as well, although the contribution of ammonia-oxidizing archaea to nitrous oxide production can not be excluded at this time. Future efforts to control both methane and nitrous oxide emissions from landfills as well as from other environments (e.g., agricultural soils) should consider these issues. Finally, a methanotrophic biofiltration system was designed and modeled for the promotion of methanotrophic activity in local methane 'hotspots' such as landfills. Model results as well as economic analyses of these biofilters indicate that the use of methanotrophic biofilters for controlling methane emissions is technically feasible, and provided either the costs of biofilter construction and operation are reduced or the value of CO{sub 2} credits is increased, can also be economically attractive.

  5. Effects of anionic surfactant on n-hexane removal in biofilters. (United States)

    Cheng, Yan; He, Huijun; Yang, Chunping; Yan, Zhou; Zeng, Guangming; Qian, Hui


    The biodegradability of three anion surfactants by biofilm microorganisms and the toxicity of the most readily biodegradable surfactant to biofilm microorganisms were examined using batch experiments, and the optimal concentration of SDS for enhanced removal of hexane was investigated using two biotrickling filters (BTFs) for comparison. Results showed that SDS could be biodegraded by microorganisms, and its toxicity to microorganisms within the experimental range was negligible. The best concentration of SDS in biofiltration of n-hexane was 0.1 CMC and the elimination capacity (EC) of 50.4 g m(-3) h(-1) was achieved at a fixed loading rate (LR) of 72 g m(-3) h(-1). When an inlet concentration of n-hexane increased from 600 to 850 mg m(-3), the removal efficiency (RE) decreased from 67% to 41% by BTF2 (with SDS) and from 52% to 42% by BTF1 (without SDS). SDS could enhance hexane removal from 43% (BTF1) to 60% (BTF2) at gas empty-bed residence time (EBRT) of 7.5 s and an inlet concentration of 200 mg m(-3).

  6. Microbiological and kinetic aspects of a biofilter for the removal of toluene from waste gases

    Energy Technology Data Exchange (ETDEWEB)

    Acuna, M.E.; Perez, F.; Revah, S. [Univ. Autonoma Metropolitana-Iztapalapa, Mexico City (Mexico). Dept. de Ingenieria de Procesos e Hidraulica; Auria, R. [ORSTOM, Mexico City (Mexico). Inst. Francais of Recherche Scientifique pour Developpement en Cooperation


    Microbiological and kinetic aspects of a biofilter inoculated with a consortium of five bacteria and two yeast adapted to remove toluene vapors were investigated. Initially the toluene sorption isotherm on peat and the effect of different environmental conditions on the toluene consumption rates of this consortium were measured. The fast start-up of the biofilter and the decay in the elimination capacity (EC) were reproduced using microcosm assays with toluene successive additions. Nutrient limitation and a large degree of heterogeneity were also detected. EC values, extrapolated from microcosms, were higher than biofilter EC when it was operating close to 100% efficiency but tended to relate better as the biofilter EC diminished. In studies on the microbial evolution in the biofilter, an increase in the cell count and variation in the ecology of the consortium were noted. Bacterial counts up to 10 {times} 10{sup 11} cfu/g{sub dry peat} were found in 88 days, which corresponds to about a 10{sup 4} increase from inoculum. Observations with SEM showed a nonuniform biofilm development on the support and the presence of an extracellular material. The results obtained in this work demonstrated that activity measurement in microcosms concomitant to the biofilter operation could be an important tool for understanding, predicting and improving the biofiltration performance.

  7. Oxygen Effects on Thermophilic Microbial Populations in Biofilters Treating Nitric Oxide Containing Off-Gas Streams

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Brady Douglas; Apel, William Arnold; Smith, William Aaron


    Electricity generation from coal has increased by an average of 51 billion kWh per year over the past 3 years. For this reason cost-effective strategies to control nitrogen oxides (NOx) from coal-fired power plant combustion gases must be developed. Compost biofilters operated at 55°C at an empty bed contact time (EBCT) of 13 seconds were shown to be feasible for removal of nitric oxide (NO) from synthetic flue gas. Denitrifying microbial populations in these biofilters were shown to reduce influent NO feeds by 90 to 95% at inlet NO concentrations of 500 ppmv. Oxygen was shown to have a significant effect on the NO removal efficiency demonstrated by these biofilters. Two biofilters were set up under identical conditions for the purpose of monitoring NO removal as well as changes in the microbial population in the bed medium under anaerobic and aerobic conditions. Changes in the microbial population were monitored to determine the maximum oxygen tolerance of a denitrifying biofilter as well as methods of optimizing microbial populations capable of denitrification in the presence of low oxygen concentrations. Nitric oxide removal dropped to between 10 and 20% when oxygen was present in the influent stream. The inactive compost used to pack the biofilters may have also caused the decreased NO removal efficiency compared to previous biofiltration experiments. Analysis of the bed medium microbial population using environmental scanning electron microscopy indicated significant increases in biomass populating the surface of the compost when compared to unacclimated compost.

  8. Bacterial dynamics in steady-state biofilters: beyond functional stability. (United States)

    Cabrol, Léa; Malhautier, Luc; Poly, Franck; Lepeuple, Anne-Sophie; Fanlo, Jean-Louis


    The spatial and temporal dynamics of microbial community structure and function were surveyed in duplicated woodchip-biofilters operated under constant conditions for 231 days. The contaminated gaseous stream for treatment was representative of composting emissions, included ammonia, dimethyl disulfide and a mixture of five oxygenated volatile organic compounds. The community structure and diversity were investigated by denaturing gradient gel electrophoresis on 16S rRNA gene fragments. During the first 42 days, microbial acclimatization revealed the influence of operating conditions and contaminant loading on the biofiltration community structure and diversity, as well as the limited impact of inoculum compared to the greater persistence of the endogenous woodchip community. During long-term operation, a high and stable removal efficiency was maintained despite a highly dynamic microbial community, suggesting the probable functional redundancy of the community. Most of the contaminant removal occurred in the first compartment, near the gas inlet, where the microbial diversity was the highest. The stratification of the microbial structures along the filter bed was statistically correlated to the longitudinal distribution of environmental conditions (selective pressure imposed by contaminant concentrations) and function (contaminant elimination capacity), highlighting the central role of the bacterial community. The reproducibility of microbial succession in replicates suggests that the community changes were presumably driven by a deterministic process.

  9. Soluble microbial products in pilot-scale drinking water biofilters with acetate as sole carbon source. (United States)

    Zhang, Ying; Ye, Chengsong; Gong, Song; Wei, Gu; Yu, Xin; Feng, Lin


    A comprehensive study on formation and characteristics of soluble microbial products (SMP) during drinking water biofiltration was made in four parallel pilot-scale ceramic biofilters with acetate as the substrate. Excellent treatment performance was achieved while microbial biomass and acetate carbon both declined with the depth of filter. The SMP concentration was determined by calculating the difference between the concentration of dissolved organic carbon (DOC), biodegradable dissolved organic carbon (BDOC) and acetate carbon. The results revealed that SMP showed an obvious increase from 0 to 100 cm depth of the filter. A rising specific ultraviolet absorbance (SUVA) was also found, indicating that benzene or carbonyl might exist in these compounds. SMP produced during this drinking water biological process were proved to have weak mutagenicity and were not precursors of by-products of chlorination disinfection. The volatile parts of SMP were half-quantity analyzed and most of them were dicarboxyl acids, others were hydrocarbons or benzene with 16-17 carbon atoms.

  10. Stabilization of Stormwater Biofilters: Impacts of Wetting and Drying Phases and the Addition of Organic Matter to Filter Media (United States)

    Subramaniam, D. N.; Egodawatta, P.; Mather, P.; Rajapakse, J. P.


    Ripening period refers to a phase of stabilization in sand filters in water treatment systems that follow a new installation or cleaning of the filter. Intermittent wetting and drying, a unique property of stormwater biofilters, would similarly be subjected to a phase of stabilization. Suspended solids are an important parameter that is often used to monitor the stabilization of sand filters in water treatment systems. Stormwater biofilters, however, contain organic material that is added to the filter layer to enhance nitrate removal, the dynamics of which is seldom analyzed in stabilization of stormwater biofilters. Therefore, in this study of stormwater biofiltration in addition to suspended solids (turbidity), organic matter (TOC, DOC, TN, and TKN) was also monitored as a parameter for stabilization of the stormwater biofilter. One Perspex bioretention column (94 mm internal diameter) was fabricated with filter layer that contained 8 % organic material and fed with tapwater with different antecedent dry days (0-40 day) at 100 mL/min. Samples were collected from the outflow at different time intervals between 2 and 150 min and were tested for total organic carbon, dissolved organic carbon, total nitrogen, total Kjeldhal nitrogen, and turbidity. The column was observed to experience two phases of stabilization, one at the beginning of each event that lasted for 30 min, while the other phase was observed across subsequent events that are related to the age of filter.

  11. Comparison between conventional biofilters and biotrickling filters applied to waste bio-drying in terms of atmospheric dispersion and air quality. (United States)

    Schiavon, Marco; Ragazzi, Marco; Torretta, Vincenzo; Rada, Elena Cristina


    Biofiltration has been widely applied to remove odours and volatile organic compounds (VOCs) from industrial off-gas and mechanical-biological waste treatments. However, conventional open biofilters cannot guarantee an efficient dispersion of air pollutants emitted into the atmosphere. The aim of this paper is to compare conventional open biofilters with biotrickling filters (BTFs) in terms of VOC dispersion in the atmosphere and air quality in the vicinity of a hypothetical municipal solid waste bio-drying plant. Simulations of dispersion were carried out regarding two VOCs of interest due to their impact in terms of odours and cancer risk: dimethyl disulphide and benzene, respectively. The use of BTFs, instead of conventional biofilters, led to significant improvements in the odour impact and the cancer risk: when adopting BTFs instead of an open biofilter, the area with an odour concentration > 1 OU m(-3) and a cancer risk > 10(-6) was reduced by 91.6% and 95.2%, respectively. When replacing the biofilter with BTFs, the annual mean concentrations of odorants and benzene decreased by more than 90% in the vicinity of the plant. These improvements are achieved above all because of the higher release height of BTFs and the higher velocity of the outgoing air flow.

  12. High salinity effect on bioremediation of pretreated pesticide lixiviates from greenhouses. (United States)

    Micó, María M; González, Óscar; Bacardit, Jordi; Malfeito, Jorge; Sans, Carme


    Hydroponics culture greenhouses usually work in closed and semi-closed irrigation systems for nutrients and water-saving purposes. Photo-Fenton reaction has been revealed as an efficient way to depollute that kind of recycled effluents containing pesticides, even for high salinity concentrations. However, the inefficacy of organic matter chemical depletion imposes the use of a subsequent treatment. This work proposes the suitability of an integration of advanced oxidation process with a subsequent bioreactor to treat greenhouse lixiviates effluents at high or extremely high conductivity (salts concentration: up to 42 g L⁻¹). As a first step in this study, the performance of a series of sequencing batch reactors was monitored in order to check the biocompatibility of photo-Fenton pretreated effluents depending on their salinity content. In the second step, those same pretreated effluents were loaded to a biofiltration column filled with expanded clay. Finally, bacterial 16S rRNA gene sequencing was carried out to analyse microbial diversity of the biomass developed in the column. Results stated that the chemical-biological coupled system is effective for the treatment of water effluents containing pesticides. The integrated system is able to deplete more than 80% of the organic load, even under extremely high salinity.

  13. Treatment of taste and odor causing compounds 2-methyl isoborneol and geosmin in drinking water: a critical review. (United States)

    Srinivasan, Rangesh; Sorial, George A


    Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinking water and are mainly caused by the presence of two semi-volatile compounds--2-methyl isoborneol (MIB) and geosmin. A review of these two taste and odor causing compounds in drinking water is presented. The sources for the formation of these compounds in water are discussed along with the health and regulatory implications. The recent developments in the analysis of MIB/geosmin in water which have allowed for rapid measurements in the nanogram per liter concentrations are also discussed. This review focuses on the relevant treatment alternatives, that are described in detail with emphasis on their respective advantages and problems associated with their implementation in a full-scale facility. Conventional treatment processes in water treatment plants, such as coagulation, sedimentation and chlorination have been found to be ineffective for removal of MIB/geosmin. Studies have shown powdered activated carbon, ozonation and biofiltration to be effective in treatment of these two compounds. Although some of these technologies are more effective and show more promise than the others, much work remains to be done to optimize these technologies so that they can be retrofitted or installed with minimal impact on the overall operation and effectiveness of the treatment system.

  14. Biofilms in drinking water and their role as reservoir for pathogens. (United States)

    Wingender, Jost; Flemming, Hans-Curt


    Most microorganisms on Earth live in various aggregates which are generally termed "biofilms". They are ubiquitous and represent the most successful form of life. They are the active agent in biofiltration and the carriers of the self-cleaning potential in soils, sediments and water. They are also common on surfaces in technical systems where they sometimes cause biofouling. In recent years it has become evident that biofilms in drinking water distribution networks can become transient or long-term habitats for hygienically relevant microorganisms. Important categories of these organisms include faecal indicator bacteria (e.g., Escherichia coli), obligate bacterial pathogens of faecal origin (e.g., Campylobacter spp.) opportunistic bacteria of environmental origin (e.g., Legionella spp., Pseudomonas aeruginosa), enteric viruses (e.g., adenoviruses, rotaviruses, noroviruses) and parasitic protozoa (e.g., Cryptosporidium parvum). These organisms can attach to preexisting biofilms, where they become integrated and survive for days to weeks or even longer, depending on the biology and ecology of the organism and the environmental conditions. There are indications that at least a part of the biofilm populations of pathogenic bacteria persists in a viable but non-culturable (VBNC) state and remains unnoticed by the methods appointed to their detection. Thus, biofilms in drinking water systems can serve as an environmental reservoir for pathogenic microorganisms and represent a potential source of water contamination, resulting in a potential health risk for humans if left unnoticed.

  15. Natural microbial populations in a water-based biowaste management system for space life support (United States)

    Bornemann, Gerhild; Waßer, Kai; Tonat, Tim; Moeller, Ralf; Bohmeier, Maria; Hauslage, Jens


    The reutilization of wastewater is a key issue with regard to long-term space missions and planetary habitation. This study reports the design, test runs and microbiological analyses of a fixed bed biofiltration system which applies pumice grain (16-25 mm grain size, 90 m2 /m3 active surface) as matrix and calcium carbonate as buffer. For activation, the pumice was inoculated with garden soil known to contain a diverse community of microorganisms, thus enabling the filtration system to potentially degrade all kinds of organic matter. Current experiments over 194 days with diluted synthetic urine (7% and 20%) showed that the 7% filter units produced nitrate slowly but steadily (max. 2191 mg NO3-N/day). In the 20% units nitrate production was slower and less stable (max. 1411 mg NO3-N/day). 84% and 76% of the contained nitrogen was converted into nitrate. The low conversion rate is assumed to be due to the high flow rate, which keeps the biofilm on the pumice thin. At the same time the thin biofilm seems to prevent the activity of denitrifiers implicating the existence of a trade off between rate and the amount of nitrogen loss. Microbiological analyses identified a comparatively low number of species (26 in the filter material, 12 in the filtrate) indicating that urine serves as a strongly selective medium and filter units for the degradation of mixed feedstock have to be pre-conditioned on the intended substrates from the beginning.

  16. Electrothermal adsorption and desorption of volatile organic compounds on activated carbon fiber cloth. (United States)

    Son, H K; Sivakumar, S; Rood, M J; Kim, B J


    Adsorption is an effective means to selectively remove volatile organic compounds (VOCs) from industrial gas streams and is particularly of use for gas streams that exhibit highly variable daily concentrations of VOCs. Adsorption of such gas streams by activated carbon fiber cloths (ACFCs) and subsequent controlled desorption can provide gas streams of well-defined concentration that can then be more efficiently treated by biofiltration than streams exhibiting large variability in concentration. In this study, we passed VOC-containing gas through an ACFC vessel for adsorption and then desorption in a concentration-controlled manner via electrothermal heating. Set-point concentrations (40-900 ppm(v)) and superficial gas velocity (6.3-9.9 m/s) were controlled by a data acquisition and control system. The results of the average VOC desorption, desorption factor and VOC in-and-out ratio were calculated and compared for various gas set-point concentrations and superficial gas velocities. Our results reveal that desorption is strongly dependent on the set-point concentration and that the VOC desorption rate can be successfully equalized and controlled via an electrothermal adsorption system.

  17. Biological elimination of volatile, organic compounds from waste gases in a biofilter

    Energy Technology Data Exchange (ETDEWEB)

    Wu, G.; Chabot, J.C.; Caron, J.J.; Heitz, M. [Universite de Sherbrooke, Sherbrooke, PQ (Canada). Dept. de Genie Chimique


    A great deal of research has been directed towards the problem of reduction and control of volatile organic compounds (VOCs). The aim of this research is to find a process that is both efficient and inexpensive in comparison with traditional air treatment technologies. The biofilter used, a one stage system, 2 m in height, is an aerobic system for waste gases containing VOC`s using the degradation properties of microbial flora (assorted cultures of Bacillus, Micrococcus, Acinetobacter and yeast). In this process, polluted gas diffuses across a filter bed into which a microbial culture has previously been introduced. Peat is the medium of choice for inoculation with microorganisms because of its adsorption and absorption properties, ability to retain moisture, and buffering capacity. Furthermore, the peat utilized is spherical in shape; thus, it is possible to avoid problems related to compacting. The objective of this study was to eliminate VOCs emitted from a rotogravure process. The team was able to achieve promising results from biofiltration of two types of VOCs (a mixed solvent containing isopropyl acetate and 1-nitropropane, and the solvent: 1-nitropropane). The results obtained indicate that the elimination of nitropropane and the mixed solvent in the biofilter are considered to follow zero-order kinetics with reaction rate limitation and diffusion rate limitation, respectively. 8 refs., 5 figs.

  18. Utilisation of Food and Woodworking Production By-products by Composting

    Directory of Open Access Journals (Sweden)

    Uldis Viesturs


    Full Text Available The purpose of the study was to develop laboratory-scale technologies for composting milk/cheese whey, spent liquor, brewery yeast, fish processing by-products, etc., adding these by-products and special microorganism associations to the basic material - sawdust, bark, etc., also arranging different experimental composting sites. Two Trichoderma strains (Tr. lignorum, Tr. viride and a nitrification association for regulating the circulation of nitrogen-ammonification and nitrification processes were applied. Monitoring of the composting quality was realised by microbiological and chemical analyses, and biotests for compost quality (toxicity assessment. For purifying the polluted air from the composting facilities, the biofiltration technique was realised in a modified SSF system. Biodegradation of ammonia was investigated in a two-stage system with the inert packing material - dolomite broken bricks, and hemoautotrophic microorganisms: DN-1 (Pseudomonas sp., DN-2 (Nitrosomonas sp., DN-3 (Nitrobacter sp. and DN-13 (Sarcina sp.. For hydrogen sulphide biodegradation, Thiobacillus thioparus-3 was immobilised on glass bricks as the carrier material. Biodegradation efficiency of hydrogen sulphide was 87%. Biodegradation of ammonia in the first step in the two-stage system reached 77%, degradation of the gas remaining in the second step was 75%. Compost's quality was similar to black soil - brown-coloured, with good soil odour and without toxic compounds.

  19. Surface modification of nanoporous alumina surfaces with poly(ethylene glycol). (United States)

    Popat, Ketul C; Mor, Gopal; Grimes, Craig A; Desai, Tejal A


    Nanoporous alumina surfaces have a variety of applications in biosensors, biofiltration, and targeted drug delivery. However, the fabrication route to create these nanopores in alumina results in surface defects in the crystal lattice. This results in inherent charge on the porous surface causing biofouling, that is, nonspecific adsorption of biomolecules. Poly(ethylene glycol) (PEG) is known to form biocompatible nonfouling films on silicon surfaces. However, its application to alumina surfaces is very limited and has not been well investigated. In this study, we have covalently attached PEG to nanoporous alumina surfaces to improve their nonfouling properties. A PEG-silane coupling technique was used to modify the surface. Different concentrations of PEG for different immobilization times were used to form PEG films of various grafting densities. X-ray photoelectron spectroscopy (XPS) was used to verify the presence of PEG moieties on the alumina surface. High-resolution C1s spectra show that with an increase in concentration and immobilization time, the grafting density of PEG also increases. Further, a standard overlayer model was used to calculate the thickness of PEG films formed using the XPS intensities of the Al2p peaks. The films formed by this technique are less than 2.5 nm thick, suggesting that such films will not clog the pores which are in the range of 70-80 nm.

  20. Performance of a small - scale modular aquaponic system

    Directory of Open Access Journals (Sweden)

    Costas Perdikaris


    Full Text Available Aquaponic systems aim to exploit the advantages of aquaculture and hydroponic systems. Areasonable fish production can be sustained and at the same time a wide range of green plants andvegetableswill bebeneffited from the nutrient-rich outflowofthe fish tanks, providing nitrificationservices to reduce the ammonia and nitrite loads. In this paper, the performance of a small-scalemodular aquaponic system wasassessed for thecriticalinitial running period of 14 daysduringSeptember 2011,using lettuce,basiland Nile tilapia.It was evidentfrom the resultsthat mid-range fishstocking densities and accordingly nutrient loads are able to support a plant harvest at a ratio of1:4 to1:5 (amount of fish feed provided:harvestablebiomass inboth species, depending on theinitialsize ofthe plants. Very small plants with sensitive root system should be avoided,as well as increased ammonialoads. Furtherimprovements could be achieved by fine-tunning of theflow characteristics of the system,thestandardization of water quality profile, the appropriate selectionof substrateand the addition ofextra biofiltration compartment.


    Directory of Open Access Journals (Sweden)

    Marlon Brancher


    Full Text Available Odour annoyances are considered a major cause of public complaints to regulatory agencies regarding air quality and represent a growing social problem, especially in industrialized countries. In view of the need to diagnose odour sources for control and mitigation of possible impacts on communities, was assessed, through a case study, the odorous emissions from an open biofilter. The equipment was responsible for gas treatment generated in the wastewater plant treatment of a textile industry. Sampling was conducted in the inlet duct of the biofilter using direct sampling and on the emission surface (output using a hood (VDI 3477:2004. Samples were stored in plastic bags manufactured in polyvinyl fluoride (Tedlar® and transported to the laboratory, where the odour concentration (in UO m-3 was determined based on the dynamic olfactometry dilution procedure (EN 13725:2003. To calculate the odour emission rate (OER (in UO h-1, the volumetric flow rate (in m3 h-1 was measured in the inlet duct of the biofilter. The values obtained for the efficiency and the OER were 98.7 % and 0.34 x 106 UO h-1, respectively. Comparing the efficiency value with the criterion established by Article 12 of Resolution SEMA No 054:2006 (State of Paraná, Brazil, adopted as reference, the biofiltration system meets the minimum efficiency rating of 85 % required in removing odour.

  2. Biodegradation of toluene vapor in coir based upflow packed bed reactor by Trichoderma asperellum isolate. (United States)

    Gopinath, M; Mohanapriya, C; Sivakumar, K; Baskar, G; Muthukumaran, C; Dhanasekar, R


    In the present study, a new biofiltration system involving a selective microbial strain isolated from aerated municipal sewage water attached with coir as packing material was developed for toluene degradation. The selected fungal isolate was identified as Trichoderma asperellum by 16S ribosomal RNA (16S rRNA) sequencing method, and pylogenetic tree was constructed using BLASTn search. Effect of various factors on growth and toluene degradation by newly isolated T. asperellum was studied in batch studies, and the optimum conditions were found to be pH 7.0, temperature 30 °C, and initial toluene concentration 1.5 (v/v)%. Continuous removal of gaseous toluene was monitored in upflow packed bed reactor (UFPBR) using T. asperellum. Effect of various parameters like column height, flow rate, and the inlet toluene concentration were studied to evaluate the performance of the biofilter. The maximum elimination capacity (257 g m(-3) h(-1)) was obtained with the packing height of 100 cm with the empty bed residence time of 5 min. Under these optimum conditions, the T. asperellum showed better toluene removal efficiency. Kinetic models have been developed for toluene degradation by T. asperellum using macrokinetic approach of the plug flow model incorporated with Monod model.

  3. Effectiveness of Floating Micro-Bead Bio-Filter for Ornamental Fish in a Re-Circulating Aquaculture System

    Directory of Open Access Journals (Sweden)

    R Fadhil


    Full Text Available Bio-filtration has been widely used in re-circulating aquaculture system to remove waste and to convert toxic ammonia andnitrite into safe end products ornamental fish and other aquatic organisms. However, the study of micro-bead usage as the filter medium has not yet been broadened and thoroughly developed. Therefore, the aim of this study is to construct a biological filter made from polyethylene micro-bead as the filter medium and to analyze its effectiveness in removingwaste as well as in converting the toxic organic matter into stable substances. The bio-filter was constructed under a rotational molding process. The tubes, hoses, and piping were made from polyvinyl chloride (PVC while the fasteners were made from stainless steel and other non-corrosive materials. The effectiveness of this bio-filter was measured by using biochemical oxygen demand (BOD and total suspended solids (TSS analysis. Results indicated that this bio-filter is efficient enough to remove suspended solids and BOD. Therefore, this floating micro-bead bio-filter can be used in aquaculture systems.

  4. Effect of Soil Filtration and Ozonation in the Change of Baseline Toxicity in Wastewater Spiked with Organic Micro-pollutants

    KAUST Repository

    Gan, Alexander


    Bioassays for baseline toxicity, which measure toxicants’ non-specific effects, have been shown in previous studies to effectively correlate with the increased presence of pharmaceuticals, personal care products, endocrine-disrupting compounds, and other synthetic organics in treated sewage effluent. This study investigated how the baseline toxicity of anthropogenic compounds-spiked wastewater changed during the treatment of biofiltration and ozone oxidation, as measured by the bioluminescence inhibition of the Vibrio fischeri bacterium. The water quality parameters of dissolved organic carbon, seven common anions, and fluorescence spectroscopy were used to corroborate and collate with the toxicity results. Water quality was evaluated on two bench-scale soil filtration columns, which were configured for pre-ozonation and post-ozonation. Both systems’ soil aerobically removed similar amounts of dissolved organic carbon, and the reduction ranged between 57.7% and 62.1% for the post-ozonation and pre-ozonation systems, respectively. Biological removal of DOC, protein-like, humic-like, and soluble microbial product-like material was highest in the first 28.5 cm of each 114 cm-long system. While bioluminescence inhibition showed that ozonation was effective at lowering baseline toxicity, this study’s bioassay procedure was a very poor indicator of soil filtration treatment; both system’s effluents were significantly more toxic than their non-ozonated influents.

  5. Ethylene removal evaluation and bacterial community analysis of vermicompost as biofilter material. (United States)

    Fu, Yuming; Shao, Lingzhi; Liu, Hui; Tong, Ling; Liu, Hong


    Biofiltration of ethylene provides an environmentally friendly and economically beneficial option relative to physical/chemical removal, where selection of appropriate bed material is crucial. Here the vermicompost with indigenous microorganisms as bed material was evaluated for ethylene removal through batch test and biofilter experiment. Temporal and spatial dynamics of bacterial community in the vermicompost-biofilter under different ethylene loads were characterized by culture and denaturing gradient gel electrophoresis (DGGE) methods. The results showed that ethylene was effectively degraded by the vermicompost under conditions of 25-50% moisture content and 25-35°C temperature. The vermicompost-biofilter achieved nearly 100% ethylene removal up to an inlet load of 11mg m(-3)h(-1). Local nitrogen lack of the vermicompost in the biofilter was observed over operation time, but the change of pH was slight. DGGE analysis demonstrated that the bacterial abundance and community structure of vermicompost-biofilter varied with the height of biofilter under different ethylene loads. Pseudomonads and Actinobacteria were predominant in the biofilter throughout the whole experiment.

  6. Retrofitting impervious urban infrastructure with green technology for rainfall-runoff restoration, indirect reuse and pollution load reduction. (United States)

    Sansalone, John; Raje, Saurabh; Kertesz, Ruben; Maccarone, Kerrilynn; Seltzer, Karl; Siminari, Michele; Simms, Peter; Wood, Brandon


    The built environs alter hydrology and water resource chemistry. Florida is subject to nutrient criteria and is promulgating "no-net-load-increase" criteria for runoff and constituents (nutrients and particulate matter, PM). With such criteria, green infrastructure, hydrologic restoration, indirect reuse and source control are potential design solutions. The study simulates runoff and constituent load control through urban source area re-design to provide long-term "no-net-load-increases". A long-term continuous simulation of pre- and post-development response for an existing surface parking facility is quantified. Retrofits include a biofiltration area reactor (BAR) for hydrologic and denitrification control. A linear infiltration reactor (LIR) of cementitious permeable pavement (CPP) provides infiltration, adsorption and filtration. Pavement cleaning provided source control. Simulation of climate and source area data indicates re-design achieves "no-net-load-increases" at lower costs compared to standard construction. The retrofit system yields lower cost per nutrient load treated compared to Best Management Practices (BMPs).

  7. Impact of UV and peracetic acid disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenic Escherichia coli in wastewater effluents. (United States)

    Biswal, Basanta Kumar; Khairallah, Ramzi; Bibi, Kareem; Mazza, Alberto; Gehr, Ronald; Masson, Luke; Frigon, Dominic


    Wastewater discharges may increase the populations of pathogens, including Escherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenic Escherichia coli (UPEC), the most abundant E. coli pathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766 E. coli isolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm(2) and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters.

  8. Mesquite wood chips (Prosopis) as filter media in a biofilter system for municipal wastewater treatment. (United States)

    Sosa-Hernández, D B; Vigueras-Cortés, J M; Garzón-Zúñiga, M A


    The biofiltration system over organic bed (BFOB) uses organic filter material (OFM) to treat municipal wastewater (MWW). This study evaluated the performance of a BFOB system employing mesquite wood chips (Prosopis) as OFM. It also evaluated the effect of hydraulic loading rates (HLRs) in order to achieve the operational parameters required to remove organic matter, suspended material, and pathogens, thus meeting Mexican and US regulations for reuse in irrigation. Two biofilters (BFs) connected in series were installed; the first one aerated (0.62 m(3)air m(-2)h(-1)) and the second one unaerated. The source of MWW was a treatment plant located in Durango, Mexico. For 200 days, three HLRs (0.54, 1.07, and 1.34 m(3)m(-2)d(-1)) were tested. The maximum HLR at which the system showed a high removal efficiency of pollutants and met regulatory standards for reuse in irrigation was 1.07 m(3)m(-2)d(-1), achieving removal efficiencies of biochemical oxygen demand (BOD5) 92%, chemical oxygen demand (COD) 78%, total suspended solids (TSS) 95%, and four log units of fecal coliforms. Electrical conductivity in the effluent ensures that it would not cause soil salinity. Therefore, mesquite wood chips can be considered an innovative material suitable as OFM for BFs treating wastewaters.

  9. Integrated natural treatment systems for developing communities: low-tech N-removal through the fluctuating microbial pathways. (United States)

    Shipin, O; Koottatep, T; Khanh, N T T; Polprasert, C


    Integration of natural treatment systems (NTS) (WSP, wetlands etc.) with each other as well as with advanced unit processes (biofiltration) offers a second lease of life to NTS. Long-term full and pilot cale experience in South Africa and Thailand have shown that contrary to a common view, a low tech N-removal from municipal and light industrial wastewater is a reality for a developing community The high treatment efficiency is ascribed to interplay of N-related processes complementing each other. The present FISH-based (Fluorescence In Situ Hybridization) approach to microbial community structure is a pioneering effort in the field of NTS. It establishes interrelationships between major N-removing groups (aerobic and anaerobic ammonia oxidizers (ANAMMOX), denitrifiers) within integrated systems and links them to the high treatment performance. Seasonally fluctuating presence of the ANAMMOX bacteria (0-2.5% of total bacterial numbers) in the NTS (free surface flow wetland) is reported for the first time. Their numbers correlate with metabolically dependent ammonia-oxidizers (2.0-3.0%) but not with stable overall Planctomycetes population (4.5-5.1%). As a result of the flexible microbial structure the robust low cost removal down to TN < 10 mg/L is routinely feasible at the loading rates ranging from 0.005 to 0.08 TN kg/m3/day.

  10. Diverse manganese(II)-oxidizing bacteria are prevalent in drinking water systems. (United States)

    Marcus, Daniel N; Pinto, Ameet; Anantharaman, Karthik; Ruberg, Steven A; Kramer, Eva L; Raskin, Lutgarde; Dick, Gregory J


    Manganese (Mn) oxides are highly reactive minerals that influence the speciation, mobility, bioavailability and toxicity of a wide variety of organic and inorganic compounds. Although Mn(II)-oxidizing bacteria are known to catalyze the formation of Mn oxides, little is known about the organisms responsible for Mn oxidation in situ, especially in engineered environments. Mn(II)-oxidizing bacteria are important in drinking water systems, including in biofiltration and water distribution systems. Here, we used cultivation dependent and independent approaches to investigate Mn(II)-oxidizing bacteria in drinking water sources, a treatment plant and associated distribution system. We isolated 29 strains of Mn(II)-oxidizing bacteria and found that highly similar 16S rRNA gene sequences were present in all culture-independent datasets and dominant in the studied drinking water treatment plant. These results highlight a potentially important role for Mn(II)-oxidizing bacteria in drinking water systems, where biogenic Mn oxides may affect water quality in terms of aesthetic appearance, speciation of metals and oxidation of organic and inorganic compounds. Deciphering the ecology of these organisms and the factors that regulate their Mn(II)-oxidizing activity could yield important insights into how microbial communities influence the quality of drinking water.

  11. Applications of Fluorescence Spectroscopy for dissolved organic matter characterization in wastewater treatment plants (United States)

    Goffin, Angélique; Guérin, Sabrina; Rocher, Vincent; Varrault, Gilles


    Dissolved organic matter (DOM) influences wastewater treatment plants efficiency (WTTP): variations in its quality and quantity can induce a foaming phenomenon and a fouling event inside biofiltration processes. Moreover, in order to manage denitrification step (control and optimization of the nitrate recirculation), it is important to be able to estimate biodegradable organic matter quantity before biological treatment. But the current methods used to characterize organic matter quality, like biological oxygen demand are laborious, time consuming and sometimes not applicable to directly monitor organic matter in situ. In the context of MOCOPEE research program (, this study aims to assess the use of optical techniques, such as UV-Visible absorbance and more specifically fluorescence spectroscopy in order to monitor and to optimize process efficiency in WWTP. Fluorescence excitation-emission matrix (EEM) spectroscopy was employed to prospect the possibility of using this technology online and in real time to characterize dissolved organic matter in different effluents of the WWTP Seine Centre (240,000 m3/day) in Paris, France. 35 sewage water influent samples were collected on 10 days at different hours. Data treatment were performed by two methods: peak picking and parallel factor analysis (PARAFAC). An evolution of DOM quality (position of excitation - emission peaks) and quantity (intensity of fluorescence) was observed between the different treatment steps (influent, primary treatment, biological treatment, effluent). Correlations were found between fluorescence indicators and different water quality key parameters in the sewage influents. We developed different multivariate linear regression models in order to predict a variety of water quality parameters by fluorescence intensity at specific excitation-emission wavelengths. For example dissolved biological oxygen demand (r2=0,900; p<0,0001) and ammonium concentration (r2=0,898; p<0

  12. Aspects microbiologiques de la production par fermentation solide des endo-beta-1,4-xylanases de moisissures : le cas de Penicillium canescens

    Directory of Open Access Journals (Sweden)

    Assamoi AA.


    Full Text Available Microbial aspects of endo-β-1,4-xylanase production in solid-state fermentation by Penicillia: the case of Penicillium canescens. Production of xylanases by Penicillium canescens 10-10c is the research object in Walloon Center of Industrial Biology. Previous works used submerged or liquid fermentation. The actual works are oriented more and more towards solid fermentation from agricultural or agro-alimentary residues. In addition to the valorization of these residues, solid-state fermentation reaches an increasingly significant interest in various other fields like the biological breakdown of the solid residues, the bioremediation of the organic pollutants in the grounds and the reduction of the air pollution by the biofiltration. Xylanase is an industrial enzyme used in general in extraction and clarification processes. P. canescens can produce an activity of it, particularly in its balanced forms of xylanases, beta-xylosidase and arabinosidase, and not contaminated by cellulolytic and amylolytic activities. It is a hyper producing strain of xylanase. The production rate is one of the highest in literature (535 and 9,632 U.g-1 in Erlenmeyer flasks, in submerged and solid state fermentation, respectively. The biobleaching activity of the cellulose pulp by the purified enzyme is higher than a commercial preparation of xylanases from Trichoderma longibrachiatum used industrially. It has a complete hydrolysis degree of 40% (on glucuronoxylan and 35% (on arabinoxylan at 55°C and at pH of 5.9. These characteristics lead to many industrial applications of this enzyme. That is why the optimization of its production by the solid-state fermentation at the laboratory scale in order to define a policy for the industrial transposition later is carried out. This article presents a summary of the scientific literature on this subject.

  13. Investigating the Efficiency of Biological Filters for Ammonia Removal

    Directory of Open Access Journals (Sweden)

    S Motesaddi Zarandi, MR Massoudinejad, A Mazaheri Tehrani, H Pouri


    Full Text Available Backgrounds and Aims: Ammonia removal from air to prevent severe damage to the environment and living organisms is very important. Biofiltration is an efficient, easy, cost-effective, and environmentally friendly process for degradation of ammonia from waste air. The aim of this study is to investigate the efficiency of biological filtration using a compost and scallop bed for ammonia removal. Materials and Methods: According to the ammonia removal method a column with 14cm inner diameter and 45cm height made from transparent Plexiglas was used. The column was filled up to 25 cm with compost and scallop (with a scallop: compost ratio of 1:4. In this study, performance of the biofilter was studied under 10 different flow rates (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 lit/min and 5 different concentrations (0-20, 20-40, 40-60, 60-80 and 80-100 ppm at a temperature of 25 degrees Celsius. Results: The results of this study showed that efficiency is decreased when the flow rate or concentration is increased because the microbial population is reduced. The efficiency was reduced by 84.6-98.2 percent. Maximum efficiency occurred at a 0.19g/(m3.h loading rate. Efficiency was in 0-20 concentration intervals at a flow rate of 1 lit/min and at an Empty Bed Residence Time (EBRT of 240 seconds. Conclusion: The results show that a biofilter with a compost and scallop bed is efficient for ammonia removal from air. Results can be optimized in the design and operation of biological systems to be used in the industrial control of ammonia gas.

  14. Nutrient uptake efficiency of Gracilaria chilensis and Ulva lactuca in an IMTA system with the red abalone Haliotis rufescens

    Directory of Open Access Journals (Sweden)

    Juan Macchiavello


    Full Text Available The current study examined the nutrient uptake efficiency of Ulva lactuca and Gracilaria chilensis cultivated in tanks associated with the wastewater of a land-based abalone culture. The experiments evaluated different seaweed stocking densities (1200, 1900, 2600, and 3200 g m-2 and water exchange rates (60, 80, 125, and 250 L h-1. The results show that both U. lactuca and G. chilensis were efficient in capturing and removing all of the inorganic nutrients originating from the abalone cultivation for all of the tested conditions. Furthermore, an annual experiment was performed with U. lactuca, cultivated at a stocking density of 1900 g m-2 and at a water exchanged rate of 125 L h-1, in order to evaluate seasonal changes in the nutrient uptake efficiency, productivity, and growth rate associated with the wastewater of a land-based abalone culture. The results confirmed high uptake efficiency during the entire year, equivalent to a 100% removal of the NH4, NO3, and PO4 produced by the land-based abalone culture. The growth rate and productivity of U. lactuca presented a marked seasonality, increasing from fall until summer and varying from 0.5 ± 0.2% to 2.6 ± 0.2% d-1 and 10 ± 6.1% to 73.6 ± 8.4% g m-2 d-1 for sustainable growth rate and productivity, respectively. We conclude that there is sufficient evidence that demonstrates the high possibility of changing the traditional monoculture system of abalone in Chile, to a sustainable integrated multi-trophic aquaculture system, generating positive environmental externalities, including the use of U. lactuca as a biofiltration unit.

  15. Green walls in Vancouver

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R. [Sharp and Diamond Landscape Architecture Inc., Vancouver, BC (Canada)


    With the renewed interest in design for microclimate control and energy conservation, many cities are implementing clean air initiatives and sustainable planning policies to mitigate the effects of urban climate and the urban heat island effect. Green roofs, sky courts and green walls must be thoughtfully designed to withstand severe conditions such as moisture stress, extremes in temperature, tropical storms and strong desiccating winds. This paper focused on the installation of green wall systems. There are 2 general types of green walls systems, namely facade greening and living walls. Green facades are trellis systems where climbing plants can grow vertically without attaching to the surface of the building. Living walls are part of a building envelope system where plants are actually planted and grown in a wall system. A modular G-SKY Green Wall Panel was installed at the Aquaquest Learning Centre at the Vancouver Aquarium in Stanley Park in September 2006. This green wall panel, which was originally developed in Japan, incorporates many innovative features in the building envelope. It provides an exterior wall covered with 8 species of plants native to the Coastal Temperate Rain Forest. The living wall is irrigated by rainwater collected from the roof, stored in an underground cistern and fed through a drip irrigation system. From a habitat perspective, the building imitates an escarpment. Installation, support systems, irrigation, replacement of modules and maintenance are included in the complete wall system. Living walls reduce the surface temperature of buildings by as much as 10 degrees C when covered with vegetation and a growing medium. The project team is anticipating LEED gold certification under the United States-Canada Green Building Council. It was concluded that this technology of vegetated building envelopes is applicable for acoustical control at airports, biofiltration of indoor air, greywater treatment, and urban agriculture and vertical

  16. Performance of rotating drum biofilter for volatile organic compound removal at high organic loading rates

    Institute of Scientific and Technical Information of China (English)

    YANG Chunping; CHEN Hong; ZENG Guangming; ZHU Xueqing; SUIDAN Makram T


    Uneven distribution of volatile organic compounds (VOCs) and biomass,and excess biomass accumulation in some biofilters hinder the application of biofiltration technology.An innovative multilayer rotating drum biofilter (RDB) was developed to correct these problems.The RDB was operated at an empty bed contact time (EBCT) of 30 s and a rotational rate of 1.0 r/rain.Diethyl ether was chosen as the model VOC.Performance of the RDB was evaluated at organic loading rates of 32.1,64.2,128,and 256 g ether/(m3·h) (16.06 g ether/(m3·h) ≈1.0 kg chemical oxygen demand (COD)/(m3·d)).The EBCT and organic loading rates were recorded on the basis of the medium volume.Results show that the ether removal efficiency decreased with an increased VOC loading rate.Ether removal efficiencies exceeding 99% were achieved without biomass control even at a high VOC loading rate of 128 g ether/(m3·h). However,when the VOC loading rate was increased to 256 g ether/(m3·h),the average removal efficiency dropped to 43%.Nutrient limitation possibly contributed to the drop in ether removal efficiency.High biomass accumulation rate was also observed in the medium at the two higher ether loading rates,and removal of the excess biomass in the media was necessary to maintain stable performance. This work showed that the RDB is effective in the removal of diethyl ether from waste gas streams even at high organic loading rates. The results might help establish criteria for designing and operating RDBs.

  17. Green house gas emissions from composting and mechanical biological treatment. (United States)

    Amlinger, Florian; Peyr, Stefan; Cuhls, Carsten


    In order to carry out life-cycle assessments as a basis for far-reaching decisions about environmentally sustainable waste treatment, it is important that the input data be reliable and sound. A comparison of the potential greenhouse gas (GHG) emissions associated with each solid waste treatment option is essential. This paper addresses GHG emissions from controlled composting processes. Some important methodological prerequisites for proper measurement and data interpretation are described, and a common scale and dimension of emission data are proposed so that data from different studies can be compared. A range of emission factors associated with home composting, open windrow composting, encapsulated composting systems with waste air treatment and mechanical biological waste treatment (MBT) are presented from our own investigations as well as from the literature. The composition of source materials along with process management issues such as aeration, mechanical agitation, moisture control and temperature regime are the most important factors controlling methane (CH4), nitrous oxide (N2O) and ammoniac (NH3) emissions. If ammoniac is not stripped during the initial rotting phase or eliminated by acid scrubber systems, biofiltration of waste air provides only limited GHG mitigation, since additional N2O may be synthesized during the oxidation of NH3, and only a small amount of CH4 degradation occurs in the biofilter. It is estimated that composting contributes very little to national GHG inventories generating only 0.01-0.06% of global emissions. This analysis does not include emissions from preceding or post-treatment activities (such as collection, transport, energy consumption during processing and land spreading), so that for a full emissions account, emissions from these activities would need to be added to an analysis.

  18. Microbial community analysis in biotrickling filters treating isopropanol air emissions. (United States)

    Pérez, M Carmen; Alvarez-Hornos, F Javier; San-Valero, Pau; Marzal, Paula; Gabaldón, Carmen


    The evolution of the microbial community was analysed over one year in two biotrickling filters operating under intermittent feeding conditions and treating isopropanol emissions, a pollutant typically found in the flexography sector. Each reactor was packed with one media: plastic cross-flow-structured material or polypropylene rings. The communities were monitored by fluorescence in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rRNA region. After inoculation with activated sludge, the biotrickling filters were operated using inlet loads (ILs) from 20 to 65 g C m(-3) h(-1) and empty-bed residence times (EBRTs) from 14 to 160 s. Removal efficiencies higher than 80% were obtained with ILs up to 35 g C m(-3) h(-1) working at EBRTs as low as 24 s. There was an increase in the total percentage of the target domains of up to around 80% at the end of the experiment. Specifically, the Gammaproteobacteria domain group, which includes the well-known volatile organic compound (VOC)-degrading species such as Pseudomonas putida, showed a noticeable rise in the two biotrickling filters of 26% and 27%, respectively. DGGE pattern band analysis revealed a stable band of Pseudomonas putida in all the samples monitored, even in the lower diversity communities. In addition, at similar operational conditions, the biotrickling filter with a greater relative abundance of Pseudomonas sp. (19.2% vs. 8%) showed higher removal efficiency (90% vs. 79%). Results indicate the importance of undertaking a further in-depth study of the involved species in the biofiltration process and their specific function.

  19. Economical assessment of the design, construction and operation of open-bed biofilters for waste gas treatment. (United States)

    Prado, O J; Gabriel, D; Lafuente, J


    A protocol was developed with the purpose of assessing the main costs implied in the set-up, operation and maintenance of a waste gas-treating conventional biofilter. The main operating parameters considered in the protocol were the empty bed residence time and the gas flow rate. A wide variety of investment and operating costs were considered. In order to check its reliability, the protocol was applied to a number of scenarios, with biofilter volumes ranging from 8.3 to 4000 m(3). Results show that total annualized costs were between 20,000 and 220,000 euro/year and directly dependent, among other factors, on the size of the system. Total investment and operating costs for average-size compost biofilters were around 60,000 euro and 20,000 euro/year, respectively, which are concordant with actual costs. Also, a sensitivity analysis was performed in order to assess the relative influence of a series of selected costs. Results prove that operating costs are those that influence the total annual costs to a higher extent. Also, packing material replacement costs contribute significantly to the total yearly costs in biofilters with a volume higher than 800 m(3). Among operating costs, the electricity consumption is the main influencing factor in biofilters with a gas flow rate above 50,000 m(3)/h, while labor costs are critical at lower gas flow rates. In addition, the use of a variety of packing materials commonly employed in biofiltration was assessed. According to the results obtained, special attention should be paid to the packing material selected, as it is the main parameter influencing the medium replacement costs, and one of the main factors affecting investment costs.

  20. Removal of alpha-pinene from gases using biofilters containing fungi (United States)

    van Groenestijn, J. W.; Liu, J. X.

    Biofiltration is cost-effective for the treatment of gases containing low concentrations of volatile organic compounds (biofilters, based on compost and bacterial activity, face problems with the elimination of hydrophobic compounds. Besides that, biofilter operational stability is often hampered by acidification and drying out of the filter bed. To overcome these problems, biofilters with fungi on inert packing material have been developed. Fungi are more resistant to acid and dry conditions than bacteria, and it is hypothesised that the aerial mycelia of fungi, which are in direct contact with the gas, can take up hydrophobic compounds faster than flat aqueous bacterial biofilm surfaces. Alpha-pinene was chosen as a model compound. It is an odorous compound emitted by the wood processing industry. In 2 l biofilter columns four different packing materials were tested: perlite, expanded clay granules, polyurethane foam cubes and compost. The filters were inoculated with forest soil and ventilated with gas containing alpha-pinene. Start up took 1-2 months and removal efficiencies of more than 90% were observed, but mostly ranged from 50% to 90% due to overloading. In the filters containing perlite, clay, polyurethane and compost volumetric removal capacities of, respectively, 24, 33, 38 and 24 g alpha- pinene m -3 filter bed h -1 were attained and the gas pressure drops in the 60 cm high filter beds measured at a superficial gas velocity of 35 m h -1 were 70, 550, 180 and 250 Pa. The results indicate that it is possible to develop biofilters based on the action of fungi with higher elimination capacities for alpha-pinene as reported in literature for bacterial biofilters. The use of polyurethane foam cubes is preferred because of the low gas pressure drop in combination with a high volumetric elimination capacity.

  1. Biofilter Treating Ammonia Gas Using Agricultural Residues Media

    Directory of Open Access Journals (Sweden)

    Thaniya Kaosol


    Full Text Available Problem statement: Agricultural residues such as manure and sugarcane bagasse are wastes from agro-industry which has low value and requires some sustainable waste management method. In this research, a mixture of manure fertilizer and sugarcane bagasse is used as a biofilter media for an ammonia gas removal application. The aim of this research is to study the ammonia gas removal efficiency of such media. Approach: The experiments were conducted in laboratory-scale biofilters. Two inlet ammonia gas concentrations were used which are 500 and 1,000 ppm. Three ratios of manure fertilizer and sugarcane bagasse were studied including 1:3, 1:5 and 1:7 by volume. All experiments were conducted for a period of 40 days. Two Empty Bed Retention Time (EBRT of these experiments were used which is 39s and 78s. The moisture content of the biofilter media was maintained at 45-60% by adding water. Results: The maximum ammonia gas removal efficiency at 89.93% is observed from the following conditions: 500 ppm of the inlet ammonia gas concentration, the manure fertilizer and sugarcane bagasse mixture ratio of 1:5 and the EBRT of 78s. The important factors of the ammonia gas removal in biofiltration process are the inlet ammonia gas concentration and the EBRT. Conclusion: The experimental results showed that the mixture of manure fertilizer and sugarcane bagasse is an effective biofilter media for ammonia gas removal applications. However, the biofilter is more effective at low inlet ammonia gas concentration, while the ratio of manure fertilizer and sugarcane bagasse has no significant effect on the ammonia gas removal efficiency. Therefore, using both residues as biofilter media for ammonia gas removal application is an alternative sustainable way to such manage argo-industry waste.

  2. The use of novel packing material for improving methane oxidation in biofilters. (United States)

    Brandt, Emanuel Manfred F; Duarte, Felipe V; Vieira, João Paulo R; Melo, Vinícius M; Souza, Cláudio L; Araújo, Juliana C; Chernicharo, Carlos Augusto L


    The use of biofilters (working bed volume of 7.85 L) for the oxidation of CH4 at low concentrations (from 0.17%v/v to 3.63%v/v, typically in waste gas from anaerobic sewage treatment) was investigated and four empty bed residence times were tested (in min): 42.8, 29.5, 19.6, and 7.4. Mixtures of organic (composted leaves) and three non-organic materials (sponge-based material - SBM, blast furnace slag - BFS, and expanded vermiculite - ExpV) were used as packing media. Along 188 operational days after the steady state was reached (95 days for start-up), the CH4 mineralization decreased while the inlet loads gradually increased from 3.0 ± 0.8 gCH4 m(-3) h(-1) to 148.8 ± 4.4 gCH4 m(-3) h(-1). The biofilter packed with ExpV showed the best results, since the CH4 conversions decreased from 95.0 ± 5.0% to 12.7 ± 3.7% as a function of inlet concentration, compared to the other two biofilters (SBM and BFS) which showed CH4 conversions decreasing from 56.0 ± 5.4% to 3.5 ± 1.2% as a function of inlet concentration. The methanotrophic activity of biomass taken from ExpV biofilter was three times higher than the activity of biomass from the other two biofilters. Taken together, these results suggested that ExpV provides an attractive environment for microbial growth, besides the mechanical resistance provided to the whole packing media, showing the potential to its use in biofiltration of diffuse CH4 emissions.

  3. Dynamics of bacterial communities before and after distribution in a full-scale drinking water network

    KAUST Repository

    El Chakhtoura, Joline


    Understanding the biological stability of drinking water distribution systems is imperative in the framework of process control and risk management. The objective of this research was to examine the dynamics of the bacterial community during drinking water distribution at high temporal resolution. Water samples (156 in total) were collected over short time-scales (minutes/hours/days) from the outlet of a treatment plant and a location in its corresponding distribution network. The drinking water is treated by biofiltration and disinfectant residuals are absent during distribution. The community was analyzed by 16S rRNA gene pyrosequencing and flow cytometry as well as conventional, culture-based methods. Despite a random dramatic event (detected with pyrosequencing and flow cytometry but not with plate counts), the bacterial community profile at the two locations did not vary significantly over time. A diverse core microbiome was shared between the two locations (58-65% of the taxa and 86-91% of the sequences) and found to be dependent on the treatment strategy. The bacterial community structure changed during distribution, with greater richness detected in the network and phyla such as Acidobacteria and Gemmatimonadetes becoming abundant. The rare taxa displayed the highest dynamicity, causing the major change during water distribution. This change did not have hygienic implications and is contingent on the sensitivity of the applied methods. The concept of biological stability therefore needs to be revised. Biostability is generally desired in drinking water guidelines but may be difficult to achieve in large-scale complex distribution systems that are inherently dynamic.

  4. Nutrients' removal from aquaculture wastewater using the macroalgae Gracilaria birdiae

    Energy Technology Data Exchange (ETDEWEB)

    Marinho-Soriano, E.; Nunes, S.O.; Carneiro, M.A.A.; Pereira, D.C. [Universidade Federal do Rio Grande do Norte, Depto. de Oceanografia e Limnologia, Via Costeira, Praia de Mae Luiza, s/n, Natal, RN 59014-100 (Brazil)


    Intensive aquaculture releases large amount of nutrients into aquatic ecosystems and can lead to eutrophication of coastal waters. Studies conducted in aquaculture systems have demonstrated that the seaweeds are efficient in reducing nutrients and at the same time provides extra income, when species of economic importance are used. This study was conducted to evaluate whether Gracilaria birdiae could be cultivated efficiently for the production of useful algal biomass and removal of nutrients from shrimp pond effluents. The results obtained showed a gradual increase in biomass and relative growth rate (RGR) over the experimental period. Mean RGR between the weeks varied significantly (p < 0.01), reaching a maximum of 3.6 {+-} 0.35% d{sup -1} and a minimum of 1.6 {+-} 0.52% d{sup -1}. The mean for the whole period was 2.6% d{sup -1}. The biofiltration capacity of G. birdiae was confirmed by the significantly reduced concentration of the three nutrients analyzed (PO{sub 4}{sup 3-}, NH{sub 4}{sup +} and NO{sub 3}{sup -}) over the study period. The concentration of PO{sub 4}{sup 3-} decreased by 93.5%, NH{sub 4}{sup +} by 34% and NO{sub 3}{sup -} by 100% after the 4-week experimental period. The results obtained in this study indicated that G. birdiae can be used in aquaculture systems as a biofilter. In addition, the macroalgae biomass produced offers alternative source of raw material for the extraction of the phycocolloid agar, human food and animal feed. (author)

  5. Fabrication, Characterization, and Functionalization of Porous Nanocrystalline Silicon Membranes (United States)

    Fang, David Z.

    Porous nanocrystalline silicon (pnc-Si) membranes are promising for a wide range of applications from biofiltration to use as a platform for cell culture. It is an order of magnitude thinner than any commercially available or experimentally fabricated membrane. Because the thickness of a pnc-Si membrane is between 15 nm and 30 nm, comparable to the size of molecules to be separated, mass transport through the membrane is greatly enhanced. The first part of this work focuses on the fabrication of pnc-Si. For applications involving separation and concentration of molecular species, it is crucial that a membrane passes certain species while rejecting others. One manner in which this can be achieved is by tuning the size and density of the pores by changing key fabrication conditions. These parameters are identified and a systematic study was performed to determine their effect on pore morphology. In the second part of this work, a phenomenological model for pore formation is presented based on empirical observations and prior studies on polycrystalline materials. Next, the structural, optical, and mechanical properties of pnc-Si are examined using an array of characterization tools. In the final part of this thesis, post-production methods for pore size control and functionalization are discussed. It is demonstrated that the hydraulic permeability of pnc-Si, in both the unmodified and modified forms, follows theoretical predications for transport through an ultrathin porous material. Additonally, nanoparticle and protein separations are presented as a demonstration of the potential use of pnc-Si membranes in biomedical research and industry.

  6. How much is enough? Minimal responses of water quality and stream biota to partial retrofit stormwater management in a suburban neighborhood.

    Directory of Open Access Journals (Sweden)

    Allison H Roy

    Full Text Available Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems. However, there is little research on the effectiveness of retrofit, parcel-scale stormwater management practices for improving downstream aquatic ecosystem health. A reverse auction was used to encourage homeowners to mitigate stormwater on their property within the suburban, 1.8 km(2 Shepherd Creek catchment in Cincinnati, Ohio (USA. In 2007-2008, 165 rain barrels and 81 rain gardens were installed on 30% of the properties in four experimental (treatment subcatchments, and two additional subcatchments were maintained as controls. At the base of the subcatchments, we sampled monthly baseflow water quality, and seasonal (5×/year physical habitat, periphyton assemblages, and macroinvertebrate assemblages in the streams for the three years before and after treatment implementation. Given the minor reductions in directly connected impervious area from the rain barrel installations (11.6% to 10.4% in the most impaired subcatchment and high total impervious levels (13.1% to 19.9% in experimental subcatchments, we expected minor or no responses of water quality and biota to stormwater management. There were trends of increased conductivity, iron, and sulfate for control sites, but no such contemporaneous trends for experimental sites. The minor effects of treatment on streamflow volume and water quality did not translate into changes in biotic health, and the few periphyton and macroinvertebrate responses could be explained by factors not associated with the treatment (e.g., vegetation clearing, drought conditions. Improvement of overall stream health is unlikely without additional treatment of major impervious surfaces (including roads, apartment buildings, and

  7. Removal of p-xylene from an air stream in a hybrid biofilter

    Energy Technology Data Exchange (ETDEWEB)

    Wu Dan [School of Environmental and Biological Science and Technology, Dalian University of Technology No. 2, Linggong Road, Dalian, Liaoning Province 116023 (China); Quan Xie [School of Environmental and Biological Science and Technology, Dalian University of Technology No. 2, Linggong Road, Dalian, Liaoning Province 116023 (China)]. E-mail:; Zhao Yazhi [School of Environmental and Biological Science and Technology, Dalian University of Technology No. 2, Linggong Road, Dalian, Liaoning Province 116023 (China); Chen Shuo [School of Environmental and Biological Science and Technology, Dalian University of Technology No. 2, Linggong Road, Dalian, Liaoning Province 116023 (China)


    Biofiltration of an air stream containing p-xylene has been studied in a laboratory hybrid biofilter packed with a mixture of mature pig compost, forest soil and the packing material which was made of polyethylene (PE) and used in the moving bed biological reactor (MBBR) in wastewater treatment. Three flow rates, 9.17, 19.87 and 40.66m{sup 3}m{sup -2}h{sup -1}, were investigated for p-xylene inlet concentration ranging from 0.1 to 3.3gm{sup -3}. A high elimination capacity of 80gm{sup -3}h{sup -1} corresponding to removal efficiency of 96% was obtained at a flow rate of 9.17m{sup 3}m{sup -2}h{sup -1} (empty bed residence time of 132s). At a flow rate of 40.66m{sup 3}m{sup -2}h{sup -1} (empty bed residence time of 30s), the maximum elimination capacity for p-xylene was 40gm{sup -3}h{sup -1} and removal efficiencies were in the range of 47-100%. The production of carbon dioxide (P{sub CO{sub 2}}) is proportional to elimination capacity (EC) and the linear relation was formulated as P{sub CO{sub 2}}=1.65EC+15.58. Stable pH values ranging from 6.3 to 7.6 and low pressure drop values less than 0.2cm H{sub 2}O (19.6Pa) of packing media in compost-based biofilter of hybrid biofilter were observed, which avoided acidification and compaction of packing media and sustained the activity of microorganism populations.

  8. Removal of gaseous toluene by the combination of photocatalytic oxidation under complex light irradiation of UV and visible light and biological process. (United States)

    Wei, Zaishan; Sun, Jianliang; Xie, Zhirong; Liang, Mingyan; Chen, Shangzhi


    Photocatalysis is a promising technology for treatment of gaseous waste; its disadvantages, however, include causing secondary pollution. Biofiltration has been known as an efficient technology for treatment volatile organic compounds (VOCs) at low cost of maintenance, and produces harmless by-products; its disadvantages, include large volume of bioreactor and slow adaptation to fluctuating concentrations in waste gas. A bench scale system integrated with a photocatalytic oxidation and a biofilter unit for the treatment of gases containing toluene was investigated. The integrated system can effectively oxidize toluene with high removal efficiency. The photocatalytic activity of N-TiO(2)/zeolite was evaluated by the decomposition of toluene in air under UV and visible light (VL) illumination. The N-TiO(2)/zeolite has more photocatalytic activity under complex light irradiation of UV and visible light for toluene removal than that of pure TiO(2)/zeolite under UV or visible light irradiation. N-TiO(2)/zeolite was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectrum analysis (XPS), Fourier transform infrared spectroscopy (FT-IR), and as-obtained products were identified by means of gas chromatography/mass spectrometry (GC/MS). Results revealed that the photocatalyst was porous and was high photoactive for mineralizing toluene. The high activity can be attributed to the results of the synergetic effects of strong UV and visible light absorption, surface hydroxyl groups. The photocatalytic degradation reaction of toluene with the N-TiO(2)/zeolite follows Langmuir-Hinshelwood kinetics. Toluene biodegradation rate matches enzymatic oxidation kinetics model.

  9. Bacterial CS2 hydrolases from Acidithiobacillus thiooxidans strains are homologous to the archaeal catenane CS2 hydrolase. (United States)

    Smeulders, Marjan J; Pol, Arjan; Venselaar, Hanka; Barends, Thomas R M; Hermans, John; Jetten, Mike S M; Op den Camp, Huub J M


    Carbon disulfide (CS(2)) and carbonyl sulfide (COS) are important in the global sulfur cycle, and CS(2) is used as a solvent in the viscose industry. These compounds can be converted by sulfur-oxidizing bacteria, such as Acidithiobacillus thiooxidans species, to carbon dioxide (CO(2)) and hydrogen sulfide (H2S), a property used in industrial biofiltration of CS(2)-polluted airstreams. We report on the mechanism of bacterial CS(2) conversion in the extremely acidophilic A. thiooxidans strains S1p and G8. The bacterial CS(2) hydrolases were highly abundant. They were purified and found to be homologous to the only other described (archaeal) CS(2) hydrolase from Acidianus strain A1-3, which forms a catenane of two interlocked rings. The enzymes cluster in a group of β-carbonic anhydrase (β-CA) homologues that may comprise a subclass of CS(2) hydrolases within the β-CA family. Unlike CAs, the CS(2) hydrolases did not hydrate CO(2) but converted CS(2) and COS with H(2)O to H(2)S and CO(2). The CS(2) hydrolases of A. thiooxidans strains G8, 2Bp, Sts 4-3, and BBW1, like the CS(2) hydrolase of Acidianus strain A1-3, exist as both octamers and hexadecamers in solution. The CS(2) hydrolase of A. thiooxidans strain S1p forms only octamers. Structure models of the A. thiooxidans CS(2) hydrolases based on the structure of Acidianus strain A1-3 CS(2) hydrolase suggest that the A. thiooxidans strain G8 CS(2) hydrolase may also form a catenane. In the A. thiooxidans strain S1p enzyme, two insertions (positions 26 and 27 [PD] and positions 56 to 61 [TPAGGG]) and a nine-amino-acid-longer C-terminal tail may prevent catenane formation.

  10. Diversity and Ecophysiology of New Isolates of Extremely Acidophilic CS2-Converting Acidithiobacillus Strains (United States)

    Smeulders, Marjan J.; Pol, Arjan; Zandvoort, Marcel H.; Jetten, Mike S. M.


    Biofiltration of industrial carbon disulfide (CS2)-contaminated waste air streams results in the acidification of biofilters and therefore reduced performance, high water use, and increased costs. To address these issues, we isolated 16 extremely acidophilic CS2-converting Acidithiobacillus thiooxidans strains that tolerated up to 6% (vol/vol) sulfuric acid. The ecophysiological properties of five selected strains (2Bp, Sts 4-3, S1p, G8, and BBW1) were compared. These five strains had pH optima between 1 (2Bp) and 2 (S1p). Their affinities for CS2 ranged between 80 (G8) and 130 (2Bp) μM. Strains S1p, G8, and BBW1 had more hydrophobic cell surfaces and produced less extracellular polymeric substance than did strains 2Bp and Sts 4-3. All five strains converted about 80% of the S added as CS2 to S0 when CS2 was supplied in excess. The rate of S0 consumption varied between 7 (Sts 4-3) and 63 (S1p) nmol O2 min−1 ml culture−1. Low S0 consumption rates correlated partly with low levels of cell attachment to externally produced S0 globules. During chemostat growth, the relative amount of CS2 hydrolase in the cell increased with decreasing growth rates. This resulted in more S0 accumulation during CS2 overloads at low growth rates. Intermittent interruptions of the CS2 supply affected all five strains. Strains S1p, G8, and BBW1 recovered from 24 h of starvation within 4 h, and strains 2Bp and Sts 4-3 recovered within 24 h after CS2 was resupplied. We recommend the use of mixtures of Acidithiobacillus strains in industrial biofilters. PMID:23995926

  11. Biological deodorization of hydrogen sulfide using porous lava as a carrier of Thiobacillus thiooxidans. (United States)

    Cho, K S; Ryu, H W; Lee, N Y


    Biological deodorization of hydrogen sulfide (H2S) was studied using porous lava as a carrier of Thiobacillus thiooxidans in a laboratory-scale biofilter. Three different samples of porous lava, A, B, and C, which were obtained from Cheju Island in Korea, were used. The water-holding capacities of samples A, B and C were 0.38, 0.25, and 0.47 g-H2O/g-lava, respectively. The pHs and densities of the lava samples ranged from 8.25-9.24 and 920-1190 kg/m3, respectively. The buffering capacities, expressed as the amount of sulfate added to lower the pH to 4, were 60 g-SO4(2-)/kg-lava for sample A, 50 g-SO4(2-)/kg-lava for B, and 90 g-SO4(2-)/kg-lava for C. To investigate the removal characteristics of H2S by the lava biofilters, T. thiooxidans was immobilized on the lava samples. Biofilters A and C showed a removal capacity of 428 g-S.m(-3).h(-1) when H2S was supplied with 428 g-S.m(-3).h(-1) of inlet load at a space velocity (SV) of 300 h(-1). At the same inlet load and SV, the removal capacity of biofilter B was 396 g-S.m(-3).h(-1). The H2S critical loads of biofilters A, B and C at a SV of 400 h(-1) were 396, 157 and 342 g-S.m(-3).h(-1), respectively. It is suggested that natural, porous lava is a promising candidate as a carrier of microorganisms in biofiltration.

  12. Numerical study on the heterogeneous flow in p orous biofilters%生物过滤器中非均匀性流动的数值研究

    Institute of Scientific and Technical Information of China (English)

    项蓉; 严微微; 苏中地; 吴杰; 张凯; 包福兵


    生物过滤技术因其具有有效性、低成本和环境友好等优点引起了人们的广泛关注。该技术主要通过生物过滤器去除含有H2 S等废气的有毒有害气体。运用格子Boltzmann方法对三种生物过滤器模型中多孔介质的非均匀性流动进行了数值模拟。数值模拟结果表明,多孔介质的性质和进口流动条件对临界Rayleigh数有显著影响,临界Rayleigh数随着多孔介质的孔隙度和Darcy数的增大而逐渐变小,并随着进口Reynolds数的增大而逐渐变大。所得结果可望为生物过滤器的优化设计提供一个合理的理论依据。%Biofiltration technology has received much attention because of its effectiveness, economy and environmentally friendly property, which can filter the odors caused chiefly by H2S via the biological treatments. In this study, the lattice Boltzmann method is adopted to numerically investigate the heterogeneous flow in three porous biofilter models. The numerical results indicate that the property of porous media and the inlet flow condition have significant influence on the value of critical Rayleigh number. With the increase of Darcy number and porosity, the critical Rayleigh number will gradually decrease;however, it will steadily increase with the augment of inlet Reynolds number. The present study is helpful to provide a rational theoretical guidance for the optimized design of biofilters.

  13. Bioremediation potential, growth and biomass yield of the green seaweed, Ulva lactuca in an integrated marine aquaculture system at the Red Sea coast of Saudi Arabia at different stocking densities and effluent flow rates

    KAUST Repository

    Al-Hafedh, Yousef S.


    Growth, production and biofiltration rates of seaweed, Ulva lactuca were investigated at two stocking densities (3 kg and 6 kg m-2) and two effluent flow rates (5.4 and 10.8 m3 day-1) to optimize an integrated mariculture system at Saudi Red Sea coast. effluents from fish-rearing tank, stocked with 200 kg fish (Oreochromis spilurus), fed to six seaweed tanks via sedimentation tank. Fish growth (weight gain 1.75 g fish day-1), net production (NP, 10.16 kg m-3) and survival (94.24%) were within acceptable limits. Ulva showed significantly higher (F = 62.62, d.f. 3, 35; P < 0.0001) specific growth rates at lower density compared with higher density and under high flow versus low flow (SGR = 5.78% vs. 2.55% at lower flow and 10.60% vs. 6.26% at higher flow). Biomass yield of Ulva at low- and high-stocking densities (111.11 and 83.2 g wet wt m-2 day-1, respectively) at low flow and (267.44 and 244.19 g wet wt m-2 day-1, respectively) at high flow show that high flow rate and lower density favoured growth. Removal rates of total ammonia nitrogen (TAN) (0.26-0.31 g m-2 day-1) and phosphate phosphorus (0.32-0.41 g m-2 day-1) by U. lactuca were not significantly different (F = 1.9, d.f. 3, 59; P = 0.1394 for TAN and F = 0.29, d.f. 3, 59; P = 0.8324 for phosphates) at both the flow rates and stocking densities. Results show that the effluent flow rate has significant impact over the performance of the seaweed than stocking density.

  14. Biological removal of air loaded with a hydrogen sulfide and ammonia mixture

    Institute of Scientific and Technical Information of China (English)

    CHEN Ying-xu; YIN Jun; FANG Shi


    The nuisance impact of air pollutant emissions from wastewater pumping stations is a major issue of concern to China. Hydrogen sulfide and ammonia are commonly the primary odor and are important targets for removal. An alternative control technology, biofiltration, was studied. The aim of this study is to investigate the potential of unit systems packed with compost in terms of ammonia and hydrogen sulfide emissions treatment, and to establish optimal operating conditions for a full-scale conceptual design. The laboratory scale biofilter packed with compost was continuously supplied with hydrogen sulfide and ammonia gas mixtures. A volumetric load of less than 150 gH2S/(m3· d) and 230 gNH3/(m3· d) was applied for about fifteen weeks. Hydrogen sulfide and ammonia elimination occurred in the biofilter simultaneously. The removal efficiency, removal capacity and removal kinetics in the biofilter were studied. The hydrogen sulfide removal efficiency reached was very high above 99%, and ammonia removal efficiency was about 80%. Hydrogen sulfide was oxidized into sulphate. The ammonia oxidation products were nitrite and nitrate. Ammonia in the biofilter was mainly removed by adsorption onto the carrier material and by absorption into the water fraction of the carrier material. High percentages of hydrogen sulfide or ammonia were oxidized in the first section of the column. Through kinetics analysis, the presence of amrronia did not hinder the hydrogen sulfide removal. According to the relationship between pressure drop and gas velocity for the biofilter and Reynolds number, non-Darcy flow can be assumed to represent the flow in the medium.

  15. The treatment of gaseous benzene by two-phase partitioning bioreactors: a high performance alternative to the use of biofilters

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, C.T.; Daugulis, A.J. [Dept. of Chemical Engineering, Queen' s Univ., Kingston, ON (Canada)


    A 2-1 (1-1 working volume) two-phase partitioning bioreactor (TPPB) was used as an integrated scrubber/bioreactor in which the removal and destruction of benzene from a gas stream was achieved by the reactor's organic/aqueous liquid contents. The organic solvent used to trap benzene was n-hexadecane, and degradation of benzene was achieved in the aqueous phase using the bacterium Alcaligenes xylosoxidans Y234. A gas stream with a benzene concentration of 340 mg l{sup -1} at a flow rate of 0.414 l h{sup -1} was delivered to the system at a loading capacity of 140 g m{sup -3} h{sup -1}, and an elimination capacity of 133 g m{sup -3} h{sup -1} was achieved (the volume in this term is the total liquid volume of the TPPB). This elimination capacity is between 3 and 13 times greater than any benzene elimination achieved by biofiltration, a competing biological air treatment strategy. It was also determined that the evaluation of TPPB performance in terms of elimination capacity should include the cell mass present in the system, as this is a readily controllable quantity. A specific benzene utilization rate of 0.57 g benzene (g cells){sup -1} h{sup -1} was experimentally determined in a bioreactor with a cell concentration that varied dynamically between 0.2 and 1 g l{sup -1}. If it assumed that this specific benzene utilization rate (0.57 g g{sup -1} h{sup -1}) is independent of cell concentration, then a TPPB operated at high cell concentrations could potentially achieve elimination capacities several hundred times greater than those obtained with biofilters. (orig.)

  16. Sustainable urban development in Brisbane City--the Holy Grail? (United States)

    Rahman, K; Weber, T


    Impacts from urban stormwater runoff on receiving environments have been well documented, particularly through specific regional scientific studies. Using various local government planning and management elements, urban developments in Brisbane City are now able to address stormwater management in an increasingly holistic context. One key initiative includes facilitating Water Sensitive Urban Design (WSUD) components within an Integrated Water Management Strategy that looks at policy formation, planning strategies, design option, community marketing and acceptance, maintenance programs and finally evaluation of various WSUD approaches. These can include the use of Natural Channel Designs, grassed swales, bio-filtration systems, porous pavements and roofwater tanks in several economic combinations. By linking with the Cooperative Research Centre for Catchment Hydrology, Brisbane City Council has influenced the design of WSUD planning tools and benefited the city with academic inputs into extensive evaluation programs. As well, it has also contributed to the Cooperative Research Centre's research outcomes. These evaluation programs are increasingly providing better understanding of various stormwater quality best management practices throughout Australia. As part of the overall implementation process, active involvement by a range of stakeholders has been crucial. These stakeholders have included internal planning, development assessment and design staff, external consultants, developers, and other local and state government agencies. The latter two groups are assisting in the important task of "regionalisation" of Brisbane City Council's policies and guidelines. Implementation of WSUD initiatives and stormwater re-use strategies under Council's new "Integrated Water Management" agenda are showing some excellent results, suggesting that sustainable urban development is no longer like the search for the Holy Grail.

  17. Assessment of biogas production in Argentina from co-digestion of sludge and municipal solid waste. (United States)

    Morero, Betzabet; Vicentin, Rocio; Campanella, Enrique A


    In Argentina, there is an important potential to utilize organic waste to generate bioenergy. This work analyzes the environmental impacts and the energetic and economic requirements of the biogas produced by digesting the sewage sludge (SS) produced in a wastewater treatment plant in a medium city in Argentina. The SS is co-digested with the organic fraction of municipal solid waste (OFMSW), and the basis of this study is the life cycle assessment (LCA). The LCA is performed according to ISO 14040-44 using the SimaPro simulator. First, the transport of the raw materials to the biogas plant was defined. Then, the co-digestion and the biogas treatment for final use were evaluated. The co-digestion was improved with glycerol, and the generation of biogas was estimated using the GPS-X software. Two alternatives for the end use of biogas were considered: combined heat and power (CHP) and biomethane generation. For the first, H2S and water vapor were removed from the raw biogas stream, and for the second, also CO2 was removed. The H2S removal process was simulated in the SuperPro software by anaerobic biofiltration. The same software was used to simulate the removal of CO2 absorption-desorption with water as solvent. Finally, the environmental impacts related to the end use of biogas (CHP and biomethane) were evaluated. The environmental, energetic and economic analyses showed that the co-digestion of SS and OFMSW has great potential for reducing the environmental impacts and increasing the economic and energetic value of the substances via the production of biomethane, electricity and, potentially, fertilizer.

  18. Dynamic olfactometry and GC–TOFMS to monitor the efficiency of an industrial biofilter

    Energy Technology Data Exchange (ETDEWEB)

    Gutiérrez, M.C.; Martín, M.A. [University of Cordoba, Department of Inorganic Chemical and Chemical Engineering, Campus Universitario de Rabanales, Carretera N-IV, km 396, Edificio Marie Curie, 14071 Córdoba (Spain); Pagans, E.; Vera, L. [Odournet SL, Parc de Recerca UAB, Edificio Eureka, Espacio P2M2, 08193, Bellaterra, Cerdanyola del Vallès, Barcelona (Spain); García-Olmo, J. [NIR/MIR Spectroscopy Unit, Central Service for Research Support (SCAI), University of Cordoba, Campus de Rabanales, 14071 Cordoba (Spain); Chica, A.F., E-mail: [University of Cordoba, Department of Inorganic Chemical and Chemical Engineering, Campus Universitario de Rabanales, Carretera N-IV, km 396, Edificio Marie Curie, 14071 Córdoba (Spain)


    Biofiltration is the most widely used technique for eliminating odours in waste treatment plants. Volatile organic compounds (VOCs) are among the odorous compounds emitted by waste management plants, and serve as variables to measure odour emissions depending on the type of aeration process used. In this work, we assess the performance of an industrial-scale biofilter where composting is the main source of VOCs and odour emissions. Dynamic olfactometry is the sensorial technique used to determine odour concentration, while gas chromatography–time of flight-mass spectrometry (GC–TOFMS) is used to perform the chemical characterization. This work examines a total of 82 compounds belonging to 15 odorous families of VOCs, particularly mercaptans, sulphur-containing compounds, alcohols and terpenes, among others. Principal component analysis (PCA) is used to assess the influence of each of these families of VOCs on the total variance of the measure with regard to both the input and output flow of the biofilter. Finally, partial least-squares (PLS) regression is used to estimate the odour concentration in each of the samples taken at the inlet and outlet of the biofilter in each of the samples based on the chemical information provided by chromatographic analysis. The study shows that there is an adequate correlation (r = 0.9751) between real and estimated odour concentrations, both of which are expressed in European odour units per cubic metre (ou{sub E}·m{sup −3}). - Highlights: • Odour and VOC removal by industrial biofilter was evaluated. • Dynamic olfactometry and GC-TOF MS were the techniques used. • The compost aeration mode was considered in this study. • The influence of 15 VOC families on sample variance was demonstrated by PCA. • Odour concentration was predicted from selected chromatographic information by PLS.

  19. Research on treatment of odor gas containing hydrogen sulfide by multilayer biofilter%多层生物滤塔净化硫化氢废气研究

    Institute of Scientific and Technical Information of China (English)

    张华新; 李顺义; 杨松波; 马红妍; 王岩


    以木屑为填料,采用多层生物滤塔净化H2S气体,研究其适宜的工艺条件及生物降解宏观动力学.结果表明,填料分层可提高H2S去除率,当进气容积负荷<153.2 g H2S/(m3·d)时,H2S的去除率保持在90%以上;进气浓度低于70 mg/m3,下层200mm填料对H2S总去除率的贡献在50%以上;填料含水率为50%~60%,生物滤塔的微生物活性较高,净化效率高;实验条件下,采用Micbaelis-Menten模型进行生物降解宏观动力学研究,其中Ks(半饱和常数)为22.5 mg/m3,Vm(污染物最大去除速率)为1 000 g H2S/(m3·d).%Using sawdust as filler, biofiltration technique for treating H2S-contaminated gas streams was investigated. The suitable technological conditions and removal kinetics were studied. The results showed that the multilayer biofilter had a higher removal rate of H2S than that of the single layer biofilter. The removal rate of H2S was higher than 90% when the inlet volumetric loading rate of H2S was below 153.2 g H2S/(m3 · d).When the inlet hydrogen sulfide was lower than 70 mg/m3, the bottom layer which was 200 mm thick removed more than 50% of the total HaS removal. The biofilter worked well as the moisture content ranged from 50% to 60%. The removal kinetics were researched based on the Michaelis-Menten model, two kinetic parameters were K8 with a value of 22.5 mg/m3 and Vm with a value of 1 000 g H2S/(m3 · d).

  20. Methane flux in potential hydrate-bearing sediments offshore southwestern Taiwan (United States)

    Chen, Nai-Chen; Yang, Tsanyao Frank; Chuang, Pei-Chuan; Hong, Wei-Li; Chen, Hsuan-Wen; Lin, Saulwood; Lin, Li-Hung; Mastumoto, Ryo; Hiruta, Akihiro; Sun, Chih-Hsien; Wang, Pei-Ling; Yang, Tau; Jiang, Shao-yong; Wang, Yun-shuen; Chung, San-Hsiung; Chen, Cheng-Hong


    infiltrating from seawater was consumed by AOM. Gas compositions and methane carbon isotopes show microbial gas dominated at passive margin and lower slope of active margin; by contrast, thermogenic gas source was prevalent at upper slope of active margin. In summary, transport of deeply sourced methane in potential hydrate-bearing sediments is strongly controlled by geological structures and microbial processes. For most of sites, anaerobic and aerobic methanotrophy in sediments act as efficient biofiltration for the removal of methane. For sites with strong fluid advection, a great fraction of deeply-sourced methane could escape from anaerobic and aerobic methanotrophy and be discharged into seawater column. The changing mechanisms for gas generation from passive to active margin highlights the interplay between in situ methanogenesis, sediment loading, and connectivity of fluid conduits.

  1. On-line monitoring of gas-phase bioreactors for biogas treatment: hydrogen sulfide and sulfide analysis by automated flow systems

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Rosa; Cunha Machado, Vinicius; Lafuente, Javier; Gabriel, David [Universitat Autonoma de Barcelona, Departament d' Enginyeria Quimica, Escola Tecnica Superior d' Enginyeria (ETSE), Bellaterra (Spain); Baeza, Mireia [Edifici C-Nord, Universitat Autonoma de Barcelona, Grup de Sensors i Biosensors, Departament de Quimica, Facultat de Ciencies, Bellaterra (Spain)


    Biogas is produced by biological processes under anaerobic conditions and may contain up to 20,000 ppm{sub v} hydrogen sulfide (H{sub 2}S), a corrosive substance that attacks power engines and can affect the health of the industrial staff. H{sub 2}S must be removed from the biogas, especially in co-generation facilities where the biogas is burnt for energy production. Nowadays, biofiltration is being studied and considered as an interesting alternative for removing H{sub 2}S from the biogas besides classical chemical processes. The novelty of this work is the design and construction of an automated H{sub 2}S on-line analyser to assess the composition of the liquid and gas phases of gas-phase bioreactors. The analyser is made of two parallel flow configurations which share the same detection device. The first configuration is a single-channel flow injection analyser (FIA) to detect S{sup 2-} in the liquid phase. The second configuration is a continuous flow analyser (CFA) with a gaseous diffusion step (GD-CFA) for detecting H{sub 2}S in the gas phase. The diffusion step enables separation of the H{sub 2}S{sub (g)} from the sample and its conversion into a detectable chemical species (S{sup 2-}). S{sup 2-} detection was performed with an Ag{sub 2}S ion-selective electrode (ISE) selective to S{sup 2-}{sub (aq)}. The main response parameters of the FIA system are a linear range between 3 x 10{sup -5} and 1 x 10{sup -1} mol L{sup -1} S{sup 2-} (0.61-3,200 mg L{sup -1}), with a sensitivity of 27.9 mV decade{sup -1} and a detection limit of 1.93 x 10{sup -5} mol L{sup -1} S{sup 2-}. The GD-CFA configuration presents a linear range between 400 and 10,000 ppm{sub v} H{sub 2}S{sub (g)} with a sensitivity of 26.1 mV decade{sup -1} and a detection limit of 245 ppm{sub v} H{sub 2}S. The proposed analyser was used by analysing real gas and liquid samples with optimal results at a full-scale biotrickling filter for biogas treatment at a municipal wastewater treatment plant. (orig.)

  2. Water treatment processes in marine recirculating aquaculture systems: A review%海水循环养殖系统水处理工艺综述

    Institute of Scientific and Technical Information of China (English)

    姜妍君; 强志民; 董慧峪; 贲伟伟; 王磊


    This paper reviews the key water quality parameters and the related unit treatment processes in marine recirculating aquaculture systems ( RAS). Besides routinely monitoring and controlling salinity, pH, temperature, and dissolved oxygen, RAS usually adopts physical, chemical and biological combinational treatment processes to reduce the concentrations of solid particles, ammonia nitrogen, nitrite, nitrate, organic matter and pathogens. Solid particles can be removed by sedimentation, filtration, foam fractionation or biofiltration according to different particle sizes and settlabilities. Ammonia nitrogen, nitrite and nitrate are mainly removed by biological nitrification and denitrification. Organic matter can be decomposed by microorganisms. Chemical oxidants and ultraviolet radiation are commonly-used disinfection methods in RAS. Disinfectant residue and disinfection byproducts, two critical factors impacting water quality and animal health, should be primarily concerned when selecting appropriate disinfection method. Finally, several commonly-adopted combinational treatment processes for RAS are exemplified with suggestions for future improvement provided.%论述了海水循环养殖系统(RAS)需要控制的水质参数及相关单元水处理工艺.RAS需要对盐度、pH、温度、溶解氧等水质参数进行监测控制,并常采用物理、生物、化学处理的组合工艺,使固体物质、氨氮、亚硝酸盐、硝酸盐、有机物以及致病微生物等的浓度维持在安全范围内.固体物质根据粒径和可沉降性的不同,可采用沉降、过滤、泡沫分离或生物过滤法去除;氨氮、亚硝酸盐以及硝酸盐主要通过生物的硝化和反硝化作用去除;有机物主要通过生物降解去除;化学药剂消毒以及紫外辐照是RAS常用的消毒方法,消毒剂残余及消毒副产物对水质和动物健康的影响是选择合适消毒方法需要考虑的两个关键因素.最后,列举了几种海

  3. Comparison of NOx Removal Efficiencies in Compost Based Biofilters Using Four Different Compost Sources

    Energy Technology Data Exchange (ETDEWEB)

    Lacey, Jeffrey Alan; Lee, Brady Douglas; Apel, William Arnold


    In 1998, 3.6 trillion kilowatt-hours of electricity were generated in the United States. Over half of this was from coal-fired power plants, resulting in more than 8.3 million tons of nitrogen oxide (NOx) compounds being released into the environment. Over 95% of the NOx compounds produced during coal combustion are in the form of nitric oxide (NO). NOx emission regulations are becoming increasingly stringent, leading to the need for new, cost effective NOx treatment technologies. Biofiltration is such a technology. NO removal efficiencies were compared in compost based biofilters using four different composts. In previous experiments, removal efficiencies were typically highest at the beginning of the experiment, and decreased as the experiments proceeded. This work tested different types of compost in an effort to find a compost that could maintain NO removal efficiencies comparable to those seen early in the previous experiments. One of the composts was wood based with manure, two were wood based with high nitrogen content sludge, and one was dairy compost. The wood based with manure and one of the wood based with sludge composts were taken directly from an active compost pile while the other two composts were received in retail packaging which had been out of active piles for an indeterminate amount of time. A high temperature (55-60°C) off-gas stream was treated in biofilters operated under denitrifying conditions. Biofilters were operated at an empty bed residence time of 13 seconds with target inlet NO concentrations of 500 ppmv. Lactate was the carbon and energy source. Compost was sampled at 10-day intervals to determine aerobic and anaerobic microbial densities. Compost was mixed at a 1:1 ratio with lava rock and calcite was added at 100g/kg of compost. In each compost tested, the highest removal efficiencies occurred within the first 10 days of the experiment. The wood based with manure peaked at day 3 (77.14%), the dairy compost at day 1 (80.74%), the

  4. Martian base agriculture: The effect of low gravity on water flow, nutrient cycles, and microbial biomass dynamics (United States)

    Maggi, Federico; Pallud, Céline


    The latest advances in bioregenerative strategies for long-term life support in extraterrestrial outposts such as on Mars have indicated soil-based cropping as an effective approach for waste decomposition, carbon sequestration, oxygen production, and water biofiltration as compared to hydroponics and aeroponics cropping. However, it is still unknown if cropping using soil systems could be sustainable in a Martian greenhouse under a gravity of 0.38 g. The most challenging aspects are linked to the gravity-induced soil water flow; because water is crucial in driving nutrient and oxygen transport in both liquid and gaseous phases, a gravitational acceleration lower than g = 9.806 m s -2 could lead to suffocation of microorganisms and roots, with concomitant emissions of toxic gases. The effect of Martian gravity on soil processes was investigated using a highly mechanistic model previously tested for terrestrial crops that couples soil hydraulics and nutrient biogeochemistry. Net leaching of NO3- solute, gaseous fluxes of NH 3, CO 2, N 2O, NO and N 2, depth concentrations of O 2, CO 2 and dissolved organic carbon (DOC), and pH in the root zone were calculated for a bioregenerative cropping unit under gravitational acceleration of Earth and for its homologous on Mars, but under 0.38 g. The two cropping units were treated with the same fertilizer type and rate, and with the same irrigation regime, but under different initial soil moisture content. Martian gravity reduced water and solute leaching by about 90% compared to Earth. This higher water holding capacity in soil under Martian gravity led to moisture content and nutrient concentrations that favoured the metabolism of various microbial functional groups, whose density increased by 5-10% on Mars as compared to Earth. Denitrification rates became substantially more important than on Earth and ultimately resulted in 60%, 200% and 1200% higher emissions of NO, N 2O and N 2 gases, respectively. Similarly, O 2 and DOC

  5. A Pilot Study of the Effectiveness of Indoor Plants for Removal of Volatile Organic Compounds in Indoor Air in a Seven-Story Office Building

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael G.; Apte, Joshua S.


    The Paharpur Business Centre and Software Technology Incubator Park (PBC) is a 7 story, 50,400 ft{sup 2} office building located near Nehru Place in New Delhi India. The occupancy of the building at full normal operations is about 500 people. The building management philosophy embodies innovation in energy efficiency while providing full service and a comfortable, safe, healthy environment to the occupants. Provision of excellent Indoor Air Quality (IAQ) is an expressed goal of the facility, and the management has gone to great lengths to achieve it. This is particularly challenging in New Delhi, where ambient urban pollution levels rank among the worst on the planet. The approach to provide good IAQ in the building includes a range of technical elements: air washing and filtration of ventilation intake air from rooftop air handler, the use of an enclosed rooftop greenhouse with a high density of potted plants as a bio-filtration system, dedicated secondary HVAC/air handling units on each floor with re-circulating high efficiency filtration and UVC treatment of the heat exchanger coils, additional potted plants for bio-filtration on each floor, and a final exhaust via the restrooms located at each floor. The conditioned building exhaust air is passed through an energy recovery wheel and chemisorbent cartridge, transferring some heat to the incoming air to increase the HVAC energy efficiency. The management uses 'green' cleaning products exclusively in the building. Flooring is a combination of stone, tile and 'zero VOC' carpeting. Wood trim and finish appears to be primarily of solid sawn materials, with very little evidence of composite wood products. Furniture is likewise in large proportion constructed from solid wood materials. The overall impression is that of a very clean and well-kept facility. Surfaces are polished to a high sheen, probably with wax products. There was an odor of urinal cake in the restrooms. Smoking is not allowed in

  6. A Pilot Study of the Effectiveness of Indoor Plants for Removal of Volatile Organic Compounds in Indoor Air in a Seven-Story Office Building

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael G.; Apte, Joshua S.


    The Paharpur Business Centre and Software Technology Incubator Park (PBC) is a 7 story, 50,400 ft{sup 2} office building located near Nehru Place in New Delhi India. The occupancy of the building at full normal operations is about 500 people. The building management philosophy embodies innovation in energy efficiency while providing full service and a comfortable, safe, healthy environment to the occupants. Provision of excellent Indoor Air Quality (IAQ) is an expressed goal of the facility, and the management has gone to great lengths to achieve it. This is particularly challenging in New Delhi, where ambient urban pollution levels rank among the worst on the planet. The approach to provide good IAQ in the building includes a range of technical elements: air washing and filtration of ventilation intake air from rooftop air handler, the use of an enclosed rooftop greenhouse with a high density of potted plants as a bio-filtration system, dedicated secondary HVAC/air handling units on each floor with re-circulating high efficiency filtration and UVC treatment of the heat exchanger coils, additional potted plants for bio-filtration on each floor, and a final exhaust via the restrooms located at each floor. The conditioned building exhaust air is passed through an energy recovery wheel and chemisorbent cartridge, transferring some heat to the incoming air to increase the HVAC energy efficiency. The management uses 'green' cleaning products exclusively in the building. Flooring is a combination of stone, tile and 'zero VOC' carpeting. Wood trim and finish appears to be primarily of solid sawn materials, with very little evidence of composite wood products. Furniture is likewise in large proportion constructed from solid wood materials. The overall impression is that of a very clean and well-kept facility. Surfaces are polished to a high sheen, probably with wax products. There was an odor of urinal cake in the restrooms. Smoking is not allowed in

  7. 农业工程类学科教育与课程整合--庆祝中国农业大学百年校庆%Reshaping curriculum and education for engineering in agriculture--For the Centennial Anniversary of China Agricultural University

    Institute of Scientific and Technical Information of China (English)



    reducing water contamination through biofiltration and runoff control. The result is an increasing biological science and application emphasis. Rapid advances in technology allow us to take advantage of developments in global positioning systems by, distributed power supply, nanotechnology, biosensors and robotics to develop precision agriculture, where each plant or animal can be treated as an entity to maximize profitability and to minimize environmental impact. Other constant challenges, such as biomass and bioenergy, are revitalized in our research and economic domains. To meet these challenges, we must educate our students, and the profession, to be able to adapt changes, that is, to be able to learn.

  8. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    David W. Mazyck; Angela Lindner; CY Wu, Rick Sheahan, Ashok Jain


    Forest products provide essential resources for human civilization, including energy and materials. In processing forest products, however, unwanted byproducts, such as volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) are generated. The goal of this study was to develop a cost effective and reliable air pollution control system to reduce VOC and HAP emissions from pulp, paper and paperboard mills and solid wood product facilities. Specifically, this work focused on the removal of VOCs and HAPs from high volume low concentration (HVLC) gases, particularly methanol since it is the largest HAP constituent in these gases. Three technologies were developed and tested at the bench-scale: (1) A novel composite material of activated carbon coated with a photocatalyst titanium dioxide (TiO{sub 2}) (referred to as TiO{sub 2}-coated activated carbon or TiO{sub 2}/AC), (2) a novel silica gel impregnated with nanosized TiO{sub 2} (referred to as silica-titania composites or STC), and (3) biofiltration. A pilot-scale reactor was also fabricated and tested for methanol removal using the TiO{sub 2}/AC and STC. The technical feasibility of removing methanol with TiO{sub 2}/AC was studied using a composite synthesized via a spay desiccation method. The removal of methanol consists of two consecutive operation steps: removal of methanol using fixed-bed activated carbon adsorption and regeneration of spent activated carbon using in-situ photocatalytic oxidation. Regeneration using photocatalytic oxidation employed irradiation of the TiO{sub 2} catalyst with low-energy ultraviolet (UV) light. Results of this technical feasibility study showed that photocatalytic oxidation can be used to regenerate a spent TiO{sub 2}/AC adsorbent. A TiO{sub 2}/AC adsorbent was then developed using a dry impregnation method, which performed better than the TiO{sub 2}/AC synthesized using the spray desiccation method. The enhanced performance was likely a result of the better

  9. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    David W. Mazyck; Angela Lindner; CY Wu, Rick Sheahan, Ashok Jain


    Forest products provide essential resources for human civilization, including energy and materials. In processing forest products, however, unwanted byproducts, such as volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) are generated. The goal of this study was to develop a cost effective and reliable air pollution control system to reduce VOC and HAP emissions from pulp, paper and paperboard mills and solid wood product facilities. Specifically, this work focused on the removal of VOCs and HAPs from high volume low concentration (HVLC) gases, particularly methanol since it is the largest HAP constituent in these gases. Three technologies were developed and tested at the bench-scale: (1) A novel composite material of activated carbon coated with a photocatalyst titanium dioxide (TiO{sub 2}) (referred to as TiO{sub 2}-coated activated carbon or TiO{sub 2}/AC), (2) a novel silica gel impregnated with nanosized TiO{sub 2} (referred to as silica-titania composites or STC), and (3) biofiltration. A pilot-scale reactor was also fabricated and tested for methanol removal using the TiO{sub 2}/AC and STC. The technical feasibility of removing methanol with TiO{sub 2}/AC was studied using a composite synthesized via a spay desiccation method. The removal of methanol consists of two consecutive operation steps: removal of methanol using fixed-bed activated carbon adsorption and regeneration of spent activated carbon using in-situ photocatalytic oxidation. Regeneration using photocatalytic oxidation employed irradiation of the TiO{sub 2} catalyst with low-energy ultraviolet (UV) light. Results of this technical feasibility study showed that photocatalytic oxidation can be used to regenerate a spent TiO{sub 2}/AC adsorbent. A TiO{sub 2}/AC adsorbent was then developed using a dry impregnation method, which performed better than the TiO{sub 2}/AC synthesized using the spray desiccation method. The enhanced performance was likely a result of the better

  10. The possibility of applying the single-sludge denitri-nitrification system in reconstruction of wastewater treatment plants in the russian federation Исследование принципиальной возможности применения одноиловой схемы денитри-нитрификации при реконструкции очистных сооружений Российской Федерации

    Directory of Open Access Journals (Sweden)

    Gogina Igor Alekseevich


    Full Text Available In Russia the standards for wastewater discharge have increased in the nineties of the twentieth century, and the main question was the removal of nutrients. In recent years there have been many studies in order to develop new methods of wastewater treatment, and to adopt Western technologies in Russian treatment plants. But the main problem now is that most of the plants in Russia were built more than thirty years ago. And now they need reconstruction. It requires great financial investments, but the possibilities are limited. Therefore it is necessary to reconstruct with minimal expenses, maximum usage of existing tanks and equipment, and the quality of wastewater treatment satisfying the standards. In Moscow State University of Civil Engineering (MGSU extensive researches are carried out in the field of biological wastewater treatment, including the removal of nutrients. The results of the researches were used for constructions and reconstructions of treatment plants in Russia.Technological Scheme «Deep biological wastewater treatment system with ammonium-nitrogen removal», which was developed and patented in MGSU, treats wastewater biologically in the aeration tank, which is divided into a sequence of alternating anoxic and aerobic zones. The reconstruction of biological treatment plants under this Scheme is possible at minimal cost, and the quality of treatment satisfies the modern standards.Nowadays, in the Russian Federation there are about sixty two percent of plants with aeration tanks, thirty three percent of biofiltration plants, and five percent of the plants with only mechanical treatment. The main task of the present research was to investigate the possibility of applying single-sludge denitri-nitrification system in the reconstruction of wastewater treatment plants in the Russian Federation. Only plants with aeration tanks were studied, because only they can be reconstructed with the use of the Scheme.The research includes fifty