Removal of nitrate-nitrogen from drinking water using bamboo powder charcoal

The adsorption effectiveness of bamboo powder charcoal (BPC); made from the residual of Moso bamboo manufacturing; in removing nitrate-nitrogen from water has been investigated. Commercial activated carbon (CAC) was also used to compare the effectiveness of adsorption in removal of nitrate-nitrogen. The adsorption effectiveness of BPC was higher than that of CAC; regardless of the concentration of nitrate-nitrogen; in the range of 0-10 mg/l. The effect of temperature on adsorption by BPC and CAC in the range of 10-20 degrees C was also investigated. From the results, it was found that the temperature dependency of the adsorption effectiveness of BPC was weaker than that of CAC. This fact indicates that BPC can be an attractive option for the in situ treatment by adsorption of nitrate-nitrogen-contaminated underground and surface water.     

Achieving the nitrite pathway using aeration phase length control and step-feed in an SBR removing nutrients from abattoir wastewater

Aeration phase length control and step-feed of wastewater are used to achieve nitrogen removal from wastewater via nitrite in sequencing batch reactors (SBR). Aeration is switched off as soon as ammonia oxidation is completed, which is followed by the addition of a fraction of the wastewater that the SBR receives over a cycle to facilitate denitrification. The end-point of ammonia oxidation is detected from the on-line measured pH and oxygen uptake rate (OUR). The method was implemented in an SBR achieving biological nitrogen and phosphorus removal from anaerobically pre-treated abattoir wastewater. The degree of nitrite accumulation during the aeration period was monitored along with the variation in the nitrite oxidizing bacteria (NOB) population using fluorescence in situ hybridization (FISH) techniques. It is demonstrated that the nitrite pathway could be repeatedly and reliably achieved, which significantly reduced the carbon requirement for nutrient removal. Model-based studies show that the establishment of the nitrite pathway was primarily the result of a gradual reduction of the amount of nitrite that is available to provide energy for the growth of NOB, eventually leading to the elimination of NOB from the system.     

以纸为碳源去除地下水硝酸盐的研究

研究了以纸为碳源和反应介质的生物反应器对水中硝酸盐的去除。结果表明,以纸为碳源的反应器启动快．反硝化反应受温度及水力停留时间影响大。25℃的反硝化速率是14℃的1．7倍。在室温25±1℃,进水硝酸盐氮浓度为45．2mg·L^-1、水力停留时间8．6h时,反应器对硝酸盐氮的去除率在99．6％以上,当水力停留时间为7．2h,氮去除率只有50％。反硝化反应受pH值和溶解氧的影响小,反应进行过程中,纸表面形成了生物膜,纸也被消耗了．采用反应器出水再经活性炭吸附的工艺流程处理高硝酸盐氮地下水,<33．9mg·L^-1的硝酸盐氮完全去除,没有出现NC2-N,最终出水水质DOC<11mg·L^-1。     

Determination of nitrate and nitrite by high-performance liquid chromatography in human plasma

A new, accurate, fast and simple method has been implemented by which nitrite and nitrate ions, as stable forms of nitric oxide production were studied. A study of these two ions was carried out by a sensitive and accurate HPLC method with two detectors. The most important advantages of the reported method are: short time of analysis, minimal sample pre-treatment, long life of the analytical column and stable eluent solution. The photodiode array UV-Vis detector detected nitrite and nitrate ions at an absorbance of 212 nm. Much more sensitive electrochemical detection with a WE (glassy carbon) electrode was used for the detection of nitrite ions. An analytical chromatographic column was formed by a sorbent, containing strong base anion-exchange groups bound in Cl(-) form in the hydrophilic hydroxyethyl methacrylate matrix. The anions were analysed in human plasma without deproteinization using 0.02 M sodium perchlorate monohydrate as eluent solution at pH 3.9. At this pH organic substances do not affect the analysis. The retention times for nitrite and nitrate were 3.62 and 3.72 min (by electrochemical detection) and 4.44 min, respectively. The method was linear (r=0.9992, 0.9998, 0.996) within a 1-100 (nitrate), 1-20 micro mol/l (nitrite) concentration range.     

Control of microbial souring by nitrate,nitrite or glutaraldehyde injection in a sandstone column

Microbial souring (production of hydrogen sulfide by sulfate-reducing bacteria, SRB) in crushed Berea sandstone columns with oil field-produced water consortia incubated at 60°C was inhibited by the addition of nitrate (NO₃) or nitrite (NO ₂ ^– ). Added nitrate (as nitrogen) at a concentration of 0.71 mM resulted in the production of 0.57–0.71 mM nitrite by the native microbial population present during souring and suppressed sulfate reduction to below detection limits. Nitrate added at 0.36 mM did not inhibit active souring but was enough to maintain inhibition if the column had been previously treated with 0.71 mM or greater. Continuous addition of 0.71–0.86 mM nitrite also completely inhibited souring in the column. Pulses of nitrite were more effective than the same amount of nitrite added continuously. Nitrite was more effective at inhibiting souring than was glutaraldehyde, and SRB recovery was delayed longer with nitrite than with glutaraldehyde. It was hypothesized that glutaraldehyde killed SRB while nitrite provided a long-term inhibition without cell death. Removal of nitrate after as long as 3 months of continuous addition allowed SRB in a biofilm to return to their previous level of activity. Inhibition was achieved with much lower levels of nitrate and nitrite, and at higher temperatures, than noted by other researchers.     

Effect of soil permeability on virus removal through soil columns

Laboratory experiments were performed on four different soils, using 100 cm long columns, to determine the extent of virus movement when wastewater percolated through the soils at various hydraulic flow rates. Unchlorinated secondary sewage effluent seeded with either poliovirus type 1 (strain LSc) or echovirus type 1 (isolate V239) was continuously applied to soil columns for 3 to 4 days at constant flow rates. Water samples were extracted daily from ceramic samplers at various depths of the column for the virus assay. The effectiveness of virus removal from wastewater varied greatly among the different soil types but appeared to be largely related to hydraulic flow rates. At a flow rate of 33 cm/day, Anthony sandy loam removed 99% of seeded poliovirus within the first 7 cm of the column. At flow rates of 300 cm/day and above, Rubicon sand gave the poorest removal of viruses; less than 90% of the seeded viruses were removed by passage of effluent through the entire length of the soil column. By linear regression analyses, the rate of virus removal in soil columns was found to be negatively correlated with the flow of the percolating sewage effluent. There was no significant difference in rate of removal between poliovirus and echovirus in soil columns 87 cm long. The rate of virus removal in the upper 17 cm of the soil column was found to be significantly greater than in the lower depths of the soil column. This study suggests that the flow rate of water through the soil may be the most important factor in predicting the potential of virus movement into the groundwater. Furthermore, the length of the soil column is critical in obtaining useful data to predict virus movement into groundwater.     

Effect of soil permeability on virus removal through soil columns.

Laboratory experiments were performed on four different soils, using 100 cm long columns, to determine the extent of virus movement when wastewater percolated through the soils at various hydraulic flow rates. Unchlorinated secondary sewage effluent seeded with either poliovirus type 1 (strain LSc) or echovirus type 1 (isolate V239) was continuously applied to soil columns for 3 to 4 days at constant flow rates. Water samples were extracted daily from ceramic samplers at various depths of the column for the virus assay. The effectiveness of virus removal from wastewater varied greatly among the different soil types but appeared to be largely related to hydraulic flow rates. At a flow rate of 33 cm/day, Anthony sandy loam removed 99% of seeded poliovirus within the first 7 cm of the column. At flow rates of 300 cm/day and above, Rubicon sand gave the poorest removal of viruses; less than 90% of the seeded viruses were removed by passage of effluent through the entire length of the soil column. By linear regression analyses, the rate of virus removal in soil columns was found to be negatively correlated with the flow of the percolating sewage effluent. There was no significant difference in rate of removal between poliovirus and echovirus in soil columns 87 cm long. The rate of virus removal in the upper 17 cm of the soil column was found to be significantly greater than in the lower depths of the soil column. This study suggests that the flow rate of water through the soil may be the most important factor in predicting the potential of virus movement into the groundwater. Furthermore, the length of the soil column is critical in obtaining useful data to predict virus movement into groundwater.     

Use of an immunoaffinity column for tetrachlorodibenzo-p-dioxin serum sample cleanup

Covalently linking 1-amino-3,7,8-trichlorodibenzo-p-dioxin with either keyhole limpet hemocyanin (KLH) or bovine serum albumin (BSA) provided antigens that generated antibodies in chickens. Competitive ELISA analysis demonstrated that the antibodies isolated from egg yolk (IgY) bound with 1,3,7,8-tetrachlorodibenzo-p-dioxin (1,3,7,8-TCDD). The antibodies were linked to CNBr-Sepharose to generate an immunoaffinity column. Radiolabeled 1,3,7,8-TCDD in a 0.05% Tween 20 solution was retained by the column and could be eluted by increasing the Tween 20 concentration. The binding efficiency for 10.7 ng per ml gel matrix ranged from 85 to 97%. Immunoaffinity columns generated by this method did not effectively bind ¹⁴C-1,3,7,8-TCDD from serum samples. Diluting the serum 1:20 with 0.05% Tween 20 increased the binding efficiency. Alternately, ethanol–hexane extraction followed by solid phase extraction on a carbon column using a fat removal protocol also provided an appropriate preaffinity column cleanup for serum samples. After this preaffinity column cleanup, spiked serum samples applied to the immunoaffinity column showed binding efficiencies of over 90%.     

Monitoring the denitrification of wastewater containing high concentrations of nitrate with methanol in a sulfur-packed reactor

Biological denitrification of high nitrate-containing wastewater was examined in a sulfur-packed column using a smaller amount of methanol than required stoichiometrically for heterotrophic denitrification. In the absence of methanol, the observed nitrate removal efficiency was only about 40%, and remained at 400 mg NO(3)(-)-N/l, which was due to an alkalinity deficiency of the pH buffer and of CO(2) as a carbon source. Complete denitrification was achieved by adding approximately 1.4 g methanol/g nitrate-nitrogen (NO(3)(-)-N) to a sulfur-packed reactor. As the methanol concentration increased, the overall nitrate removal efficiency increased. As influent methanol concentrations increased from 285 to 570, 855, and 1,140 mg/l, the value of Delta mg alkalinity as CaCO(3) consumed/Delta mg NO(3)(-)-N removed increased from -1.94 to -0.84, 0.24, and 0.96, and Delta mg SO(4)(2-) produced/Delta mg NO(3)(-)-N removed decreased from 4.42 to 3.57, 2.58, and 1.26, respectively. These results imply the co-occurrence of simultaneous autotrophic and heterotrophic denitrification. Sulfur-utilizing autotrophic denitrification in the presence of a small amount of methanol is very effective at decreasing both sulfate production and alkalinity consumption. Most of methanol added was removed completely in the effluent. A small amount of nitrite accumulated in the mixotrophic column, which was less than 20 mg NO(2)(-) -N/l, while under heterotrophic denitrification conditions, nitrite accumulated steadily and increased to 60 mg NO(2)(-) -N/l with increasing column height.     

Removal of highly elevated nitrate from drinking water by pH-heterogenized heterotrophic denitrification facilitated with ferrous sulfide-based autotrophic denitrification

The performance of acetic acid-supported pH-heterogenized heterotrophic denitrification (HD) facilitated with ferrous sulfide-based autotrophic denitrification (AD) was investigated in upflow activated carbon-packed column reactors for reliable removal of highly elevated nitrate (42 mg NO₃-N l⁻¹) in drinking water. The use of acetic acid as substrate provided sufficient internal carbon dioxide to completely eliminate the need of external pH adjustment for HD, but simultaneously created vertically heterogenized pH varying from 4.8 to 7.8 in the HD reactor. After 5-week acclimation, the HD reactor developed a moderate nitrate removal capacity with about one third of nitrate removal occurring in the acidic zone (pH 4.8–6.2). To increase the treatment reliability, acetic acid-supported HD was operated under 10% carbon limitation to remove >85% of nitrate, and ferrous sulfide-based AD was supplementally operated to remove residual nitrate and formed nitrite without excess of soluble organic carbon, nitrite or sulfate in the final effluent.     

Inhibition of microbial H<Subscript>2</Subscript>S production in an oil reservoir model column by nitrate injection

The effect of nitrate addition on microbial H2S production in a seawater-flooded oil reservoir model column with crude oil as carbon and energy source was investigated. Injection of 0.5 mM nitrate for 2.5-3.5 months led to complete elimination of H2S (initially 0.45-0.67 mM). The major decline in H2S level coincided with the first complete nitrate consumption and production of nitrite. When nitrate was excluded, H2S production resumed after approximately 2.5 months and reached previous levels after approximately 5 months. Using a fluorescent antibody technique, three populations each of sulfate-reducing bacteria (SRB) and nitrate-reducing bacteria (NRB) were monitored. SRB dominated the anoxic zone prior to nitrate addition, comprising 64-93% of the total bacterial population. The monitored NRB constituted less than 6% and no increase was observed during nitrate addition (indicating that other, unidentified, NRB populations were present). After 1-3 months without significant H2S production (3.5-5.5 months with nitrate), the SRB population collapsed, the fraction being reduced to 9-25%. The dominant SRB strain in the column, which constituted on average 94% of the monitored SRB population, was partly/completely inhibited by 50/75 microM nitrite in batch culture tests. Similar nitrite concentrations (50-150 microM) were detected in the column when the H2S level declined, indicating that nitrite inhibition was the main cause of H2S elimination. The results from this study indicate that nitrate/nitrite can be used to prevent detrimental SRB activity in oil reservoirs.     

沼泽红假单胞菌(Rhodopseudomonas palustris)CQV97对无机三态氮共存水体中氮素的去除效率及其影响因素

研究水体环境因素(温度、光照和pH)、小分子有机碳和有机氮化合物对一株具有高效脱氮潜力的沼泽红假单胞菌(Rhodopseudomonas palustris)CQV97在无机三态氮共存体系中脱除无机三态氮的影响规律。结果显示,该菌株在20~40℃,500~5 000lux,pH 6.0~9.0环境条件下,能够脱除高浓度无机三态氮(其中亚硝氮不低于40mg·L-1),表明该菌株具有较强的适应复杂环境的能力;以乙酸钠/乙醇为唯一碳源时,该菌株能有效地去除无机三态氮,而以葡萄糖为唯一碳源时,能有效去除硝氮,但不能去除氨氮,亚硝氮明显积累,表明环境中小分子有机碳源影响菌体对无机三态氮的去除能力;体系中添加高浓度(120mg·L-1)蛋白胨或尿素时,由于有机氮降解的释氨作用,菌体对氨氮的去除能力受到明显抑制,氨氮积累明显,13d时氨氮去除率仅分别为16%(蛋白胨)和6%(尿素),但硝氮和亚硝氮的去除能力并没有受到明显影响。异位处理实际水体结果表明,菌株可使水体中氨氮含量明显降低、硝氮和亚硝氮被完全去除。综上,沼泽红假单胞菌CQV97菌株环境适应能力强,具有高效脱除水体无机三态氮的应用潜力,这为进一步开发高效脱氮微生物制剂及其合理使用奠定了基础。     

Microbially enhanced oil recovery from miniature model columns through stimulation of indigenous microflora with nitrate

Sandpack columns filled with heavy oil and water, with or without a nitrate-reducing inoculum, were used to determine if nitrate injections could lead to enhanced oil recovery. Production of oil and water into vials filled with helium or argon was monitored during repeated anaerobic incubations at 30 °C. Regardless of the presence of inoculum, columns containing nitrate consistently produced more oil than those without nitrate during incubations. Microbial reduction of nitrate to nitrogen with production of carbon dioxide might contribute to the establishment of gas drive. The presence of nitrate could also lead to increased production of biomass and/or biosurfactants, reducing oil-water interfacial tension. Counter-diffusion of nitrogen and carbon dioxide dissolved in column liquids and of helium or argon present in the vial gas phase likely contributed to the establishment of gas drive in all columns. Heptane was present in consistently lower concentrations in columns with nitrate than in those without nitrate at the end of incubations, suggesting that it was an important source of carbon and energy for microbial growth. Azoarcus spp. dominated the consortium when the inoculum was grown with heptane as the sole source of carbon and energy, indicating that this bacterium might contribute to the observed oil production.     

一株养殖水体中亚硝酸盐去除菌的鉴定及其去除条件

【目的】从养殖污泥中分离筛选优良亚硝酸盐去除菌,并对其去除条件进行研究。【方法】从养殖污泥中分离亚硝酸盐去除菌,进一步通过测定比较分离菌株对亚硝酸盐的去除率,筛选优良的亚硝酸盐去除菌,通过API ID32GN细菌鉴定系统以及16S rDNA序列分析法对其进行鉴定,并采用单因子法研究其去除亚硝酸盐的条件。【结果】从养殖污泥中分离筛选了一株优良的亚硝酸盐去除菌AQ-3,其对50 mg/L亚硝酸盐的去除率高达99.47%。菌株AQ-3被鉴定为鲍曼氏不动杆菌(Acinetobacter baumannii)(GenBank登录号:JF751054.1),其16S rDNA序列与基因库中不动杆菌属菌株的16S rDNA序列有99%?100%的同源性,而且与鲍曼氏不动杆菌KF714株(GenBank登录号:AB109775)的亲缘关系最近。菌株AQ-3去除亚硝酸盐的最适初始pH范围为7?9,最佳碳源为乙酸钠和丁二酸钠,而且随着初始菌浓度的不断增大,菌株AQ-3对亚硝酸盐的去除率显著升高;随着亚硝酸盐浓度的不断增大,菌株AQ-3对亚硝酸盐的去除率逐渐降低。【结论】在丰富亚硝酸盐去除菌种质资源的同时,为该菌在养殖水体中的实际应用提供了理论基础。     

Dynamics of corrosion rates associated with nitrite or nitrate mediated control of souring under biological conditions simulating an oil reservoir

Representative microbial cultures from an oil reservoir and electrochemical techniques including potentiodynamic scan and linear polarization were used to investigate the time dependent corrosion rate associated with control of biogenic sulphide production through addition of nitrite, nitrate and a combination of nitrate-reducing, sulphide-oxidizing bacteria (NR-SOB) and nitrate. The addition of nitrate alone did not prevent the biogenic production of sulphide but the produced sulphide was eventually oxidized and removed from the system. The addition of nitrate and NR-SOB had a similar effect on oxidation and removal of sulphide present in the system. However, as the addition of nitrate and NR-SOB was performed towards the end of sulphide production phase, the assessment of immediate impact was not possible. The addition of nitrite inhibited the biogenic production of sulphide immediately and led to removal of sulphide through nitrite mediated chemical oxidation of sulphide. The real time corrosion rate measurement revealed that in all three cases an acceleration in the corrosion rate occurred during the oxidation and removal of sulphide. Amendments of nitrate and NR-SOB or nitrate alone both gave rise to localized corrosion in the form of pits, with the maximum observed corrosion rates of 0.72 and 1.4 mm year⁻¹, respectively. The addition of nitrite also accelerated the corrosion rate but the maximum corrosion rate observed following nitrite addition was 0.3 mm year⁻¹. Furthermore, in the presence of nitrite the extent of pitting was not as high as those observed with other control methods.     

Autotrophic nitrite removal in the cathode of microbial fuel cells

Nitrification to nitrite (nitritation process) followed by reduction to dinitrogen gas decreases the energy demand and the carbon requirements of the overall process of nitrogen removal. This work studies autotrophic nitrite removal in the cathode of microbial fuel cells (MFCs). Special attention was paid to determining whether nitrite is used as the electron acceptor by exoelectrogenic bacteria (biologic reaction) or by graphite electrodes (abiotic reaction). The results demonstrated that, after a nitrate pulse at the cathode, nitrite was initially accumulated; subsequently, nitrite was removed. Nitrite and nitrate can be used interchangeably as an electron acceptor by exoelectrogenic bacteria for nitrogen reduction from wastewater while producing bioelectricity. However, if oxygen is present in the cathode chamber, nitrite is oxidised via biological or electrochemical processes. The identification of a dominant bacterial member similar to Oligotropha carboxidovorans confirms that autotrophic denitrification is the main metabolism mechanism in the cathode of an MFC.     

Nitratreduktion durch pilze und die verwertbarkeit des merkmals für die systematik

Nearly 200 species of fungi of various orders has been assayed for presence of nitrate reductase by examining the presence of nitrite in the culture medium. This property seems to be useful for identification purposes in the same way as the widely used Bavendamm-test for extracellular oxidases. A literature survey has also been made of fungi assimilating nitrate-nitrogen and those unable to grow with nitrate as sole source of nitrogen. The data in this paper show that there is a good correlation between the ability to reduce nitrate and the assimilation of nitrate-nitrogen. Most of the Deuteromycetes (14 out of 17 investigated) reduce nitrate, whereas the Basidiomycetes (135 species investigated) generally lack this property, except for few taxa like Lepista (Tricholomataceae; Agaricales). A correlation between nitrate reduction and ecological requirements was shown only for Deuteromycetes, where the pathogenic Dermatophytes do not use nitrate-nitrogen and the nematode trapping Arthrobotrys dactyloides is unable to reduce nitrate.     

Free nitrous acid (FNA) inhibition on denitrifying poly-phosphate accumulating organisms (DPAOs)

Free nitrous acid (FNA) has been identified to be a ubiquitous inhibitor of a wide range of microorganisms, including bacteria involved in wastewater treatment. The FNA-induced inhibition on the anoxic (nitrite as electron acceptor) metabolism of denitrifying poly-phosphate accumulating organisms (DPAOs) was investigated using sludge from a sequencing batch reactor performing carbon, nitrogen, and phosphorus removal from synthetic wastewater. We found that FNA had a much stronger inhibitory effect on phosphorus (P) uptake and glycogen production than on poly-β-hydroxyalkanoate degradation and nitrite reduction. The intracellular adenosine triphosphate levels decreased sharply during the FNA incubation, and the decreasing rates were positively correlated with increasing FNA concentrations. The electron transport activity of DPAOs when exposed to FNA displayed a similar trend. Further, at FNA concentrations above 0.044 mg HNO₂-N/L, the anaerobic metabolism of DPAOs was initiated despite of the presence of nitrite, as evidenced by the release of phosphorus and the consumption of glycogen. DPAO metabolism did not recover completely from FNA inhibition in the subsequent FNA-free environment. The recovery rate depended on the concentration of FNA applied in the previous anoxic period. These results suggest that the inhibitory effects are diverse and may be attributable to different mechanisms operating simultaneously.     

Selenite reduction by a denitrifying culture: batch- and packed-bed reactor studies

Selenite reduction by a bacterial consortium enriched from an oil refinery waste sludge was studied under denitrifying conditions using acetate as the electron donor. Fed-batch studies with nitrate as the primary electron acceptor showed that accumulation of nitrite led to a decrease in the extent of selenite reduction. Also, when nitrite was added as the primary electron acceptor, rapid selenite reduction was observed only after nitrite was significantly depleted from the medium. These results indicate that selenite reduction was inhibited at high nitrite concentrations. In addition to batch experiments, continuous-flow selenite reduction experiments were performed in packed-bed columns using immobilized enrichment cultures. These experiments were carried out in three phases: in phase I, a continuous nitrate feed with different inlet selenite concentration was applied; in phase II, nitrate was fed in a pulsed fashion; and in phase III, nitrate was fed in a continuous mode but at much lower concentrations than the other two phases. During the phase I experiments, little selenite was removed from the influent. However, when the column was operated in the pulse feed strategy (phase II) or in the continuous mode with low nitrate levels (phase III), significant quantities of selenium were removed from solution and retained in the immobilization matrix in the column. Thus, immobilized denitrifying cultures can be effective in removing selenium from waste streams, but nitrate-limited operating conditions might be required.     

Construction of a bacterial consortium for the biofiltration of benzene,toluene and xylene emissions

On equal parts of benzene, toluene and p-xylene (BTX), a stable bacterial consortium was enriched for removal of BTX vapours from air. As demonstrated by gas chromatographic monitoring, this consortium removed all three BTX components but was able to grow only on benzene and/or toluene. A Pseudomonas putida strain, PPO1, isolated from this consortium behaved in an identical manner. When immobilized on a porous peat/perlite column, both the consortium and the PPO1 isolated removed all three BTX components from metered air streams. However, due to the accumulation of products from the incompletely metabolized p-xylene, the removal rates were unsatisfactory and declined further with time. P. putida ATCC 33015 bearing the TOL plasmid was capable of growing on toluene, on para- and on meta- xylene isomers, but not on benzene. When the PPO1 and ATCC 33015 strains were immobilized, in equal parts, on peat/perlite columns a much improved and sustainable removal of all three BTX components was observed at the rate of 40–50 g/h. m3 filter bed. Due to the dominance of the ring-hydroxylating pathways over the TOL pathway, the classical enrichment approach did not result in a consortium capable of the sustained removal of all BTX components. However, a rationally formulated consortium consisting of members with complementary metabolic abilities was capable of this task and should be of use both in industrial emission control and in soil venting operations.