共查询到20条相似文献,搜索用时 15 毫秒
1.
Effect of HRT on the biological pre-denitrification process for the simultaneous removal of toxic pollutants from cokes wastewater 总被引:6,自引:0,他引:6
A lab-scale serial anoxic-aerobic reactor for the pre-denitrification process was continuously operated to efficiently and economically treat actual cokes wastewater containing various pollutants, such as phenol, ammonia, thiocyanate and cyanide compounds. The biodegradation efficiencies of the pollutants were examined by changing hydraulic retention time (HRT) as a main operating variable. The long-term operation of the pre-denitrification process reactor showed that approximately 100% phenol, approximately 100% free cyanide, approximately 100% SCN(-), 97% ammonia, 85% COD, 84% TOC (total organic carbon) and 83% TN (total nitrogen) were removed at HRT above 11.9h. Removal efficiency of total cyanides significantly decreased with a decrease in the HRT. Free cyanide and some of total cyanides were removed in anoxic reactor, whereas thiocyanate was removed in aerobic reactor. Phenol was completely removed under successive anoxic and aerobic conditions. Although actual cokes wastewater contained high concentrations of various toxic pollutants, the pre-denitrification process showed stable and successful performances in both nitrification and denitrification reactions. 相似文献
2.
《Journal of biotechnology》1987,5(4):279-292
The biological removal of phenol was studied in a multi-stage fixed-film reactor at phenol concentrations in the range of 190–900 mg l−1, hydraulic loadings of 0.02–0.22 m3 m−2 day−1 and temperatures of 20–35°C. Phenol removals up to 99.9% were obtained at 20°C but the efficiency decreased as the loading rate or phenol concentration was increased. The reactor coped with organic overloads better than with hydraulic overloads. Removal efficiencies increased as temperature was increased. Reactor performance was stable under extreme loadings and the reactor was capable of handling a ten-fold increase in loading with less than 20% loss in phenol removal efficiency. A large amount of attached biomass was retained in the reactor and was mostly present in the first stage where the majority of organic removal occurred. 相似文献
3.
Biological treatment of nitrogen deficient wastewaters are usually accomplished by external addition of nitrogen sources to the wastewater which is an extra cost item. As an alternative for effective biological treatment of nitrogen deficient wastewaters, the nitrogen fixing bacterium, Azotobacter vinelandii, was used in activated sludge and also in pure culture. Total organic carbon (TOC) removal performances of Azotobacter-added and free activated sludge cultures were compared at different initial TN/TOC ratios. The rate and extent of TOC removal were comparable for all cultures when initial TN/TOC ratio was larger than 0.12; however, both the rate and extent of TOC removal from nitrogen deficient (TN/TOC<12%) synthetic wastewater were improved by using Azotobacter-added activated sludge as compared to the Azotobacter-free activated sludge culture. More than 90% TOC removal was obtained with pure Azotobacter or Azotobacter-added activated sludge culture from a nitrogen deficient synthetic wastewater. 相似文献
4.
Young Mo Kim Donghee Park Dae Sung Lee Kyung A Jung Jong Moon Park 《Bioresource technology》2009,100(19):4340-4347
A full-scale pre-denitrification process treating cokes wastewater containing toxic compounds such as phenols, cyanides and thiocyanate has shown good performance in carbon and nitrogen removal. However, field operators have been having trouble with its instability without being able to identify the causes. To clarify the main cause of these sudden failures of the process, comprehensive studies were conducted on the pre-denitrification process using a lab-scale reactor system with real cokes wastewater. First, the shock loading effects of three major pollutants were investigated individually. As the loading amount of phenol increased to 600 mg/L, more COD, TOC and phenol itself were flowed into the aerobic reactor, but phenol itself did not inhibit nitrification and denitrification, owing to the effect of dilution and its rapid biodegradation. Higher loading of ammonia or thiocyanate slightly enhanced the removal efficiency of organic matter, but caused the final discharge concentration of total nitrogen to be above its legal limit of 60 mg-N/L. Meanwhile, continuous inflow of abnormal wastewater collected during unstable operation of the full-scale pre-denitrification process, caused a sudden failure of nitrogen removal in the lab-scale process, like the removal pattern of the full-scale one. This was discovered to be due to the lack of inorganic carbon in the aerobic reactor where autotrophic nitrification occurs. 相似文献
5.
Prieto MB Hidalgo A Rodríguez-Fernández C Serra JL Llama MJ 《Applied microbiology and biotechnology》2002,58(6):853-859
Phenol biodegradation by suspended and immobilized cells of Rhodococcus erythropolis UPV-1 was studied in discontinuous and continuous mode under optimum culture conditions. Phenol-acclimated cells were adsorbed on diatomaceous earth, where they grew actively forming a biofilm of short filaments. Immobilization protected cells against phenol and resulted in a remarkable enhancement of their respiratory activity and a shorter lag phase preceding active phenol degradation. Under optimum operation conditions in a laboratory-scale air-stirred reactor, the immobilized cells were able to completely degrade phenol in synthetic wastewater at a volumetric productivity of 11.5 kg phenol m(-3) day(-1). Phenol biodegradation was also tested in two different industrial wastewaters (WW1 and WW2) obtained from local resin manufacturing companies, which contained both phenols and formaldehyde. In this case, after wastewater conditioning (i.e., dilution, pH, nitrogen and phosphorous sources and micronutrient amendments) the immobilized cells were able to completely remove the formaldehyde present in both waters. Moreover, they biodegraded phenols completely at a rate of 0.5 kg phenol m(-3) day(-1) in the case of WW1 and partially (but at concentrations lower than 50 mg l(-1)) at 0.1 and 1.0 kg phenol m(-3) day(-1) in the cases of WW2 and WW1, respectively. 相似文献
6.
Recirculation of fully nitrified effluent from a laboratory horizontal-flow biofilm reactor (HFBR) to a mixed pre-denitrification reactor (DR) was used to remove organic carbon and nitrogen from synthetic dairy wastewater. Three recirculation ratios of 2, 4, and 6 were examined in this study and the average filtered chemical oxygen demand (CODf) and total nitrogen (TN) removals were up to 97.4% and 85.5%, respectively, at 11 degrees C. In the DR, the nitrate nitrogen removal efficiencies and rates were 86-96% and 22-34 g N/m3 d. In the HFBR, the ammonium nitrogen removal rates were 293-337 mg N/m2 d. 相似文献
7.
Leachate from a municipal waste landfill site was treated using an activated sludge bioreactor, a fluidized bed biofilm reactor and a packed-bed column reactor (trickling filter). The leachate contained high organic matter (2.0–2.6 g/l of COD), high ammonium (300–700 mg/l) and sulphide (200–800 mg/l) concentrations, as well as low metal concentrations. The continuously operating reactors were employed to study the effects of TOC loading on the removal of TOC as well as on the nitrification and denitrification processes. Among the three biological treatment technologies investigated, the fluidized bed biofilm reactor was best with respect to removing ammonia and TOC. More than 90% of TOC and 99% of ammonia were removed when TOC loading was less than 0.5 kg/m3 × d. At a TOC loading of 4 kg/m3 × d, the removal of TOC and ammonia was 80% and 99%, respectively. In contrast, the treatment of leachate with the packed-bed reactor was successful in TOC removing only at TOC loading less than 0.3 kg/m3 × d (TOC elimination decreased from 86% at 0.06 kg/m3 × d to 60% at 0.3 kg/m3 × d). However, the reactor was active in nitrification even at a higher TOC loading (more than a 98% ammonia elimination at a TOC loading of 0.5 kg/m3 × d). Leachate was processed in the activated sludge reactor when TOC loading was less than 0.5 kg/m3 × d (with a removal of TOC and ammonia up to 83% and 99%, respectively). The activated sludge reactor was also effective in TOC removal at a higher TOC loading (e.g. a 74% TOC removal at a TOC loading of 1 kg/m3 × d), but for ammonia elimination, the activity continuously decreased (less than 60% ammonia removal at a TOC loading of 1 kg/m3 × d). Overloading in the activated sludge system was indicated by a high concentration of ammonia and nitrite in the effluent. In the packed bed reactor, overloading was characterized by a progressively incomplete TOC removal. No significant overloading was found in the fluidized bed reactor up to a TOC loading of 4 kg/m3 × d. 相似文献
8.
This work examined 19 carbon samples prepared by acid and thermal activation of various agro-residues viz. bagasse, bagasse flyash, sawdust, wood ash and rice husk ash for color removal from biomethanated distillery effluent. Phosphoric acid carbonized bagasse B (PH) showed the maximum color removal (50%). However, commercial activated carbons AC (ME) and AC (LB) showed better performance of over 80% color removal. Besides color removal, activated carbon treatment also showed reduction in chemical oxygen demand (COD), total organic carbon (TOC), phenol and total Kjeldahl nitrogen (TKN). The performance was related to the characteristics of the investigated samples. Further, adsorption isotherms for melanoidins, which is the primary coloring compound in distillery spentwash, followed the Langmuir isotherm implying monolayer adsorption. 相似文献
9.
The N2-fixing bacterium, Azotobacter vinelandii, was used both in single culture and in combination with activated sludge culture for the treatment of nitrogen-deficient wastewaters as an alternative to external nitrogen supplementation. Azotobacter-supplemented activated sludge culture removed more total organic carbon (TOC), especially at low initial TN/COD (total nitrogen/chemical oxygen demand) ratios, than the Azotobacter-free culture. Up to 95% TOC removal efficiencies were obtained with synthetic media of TN/COD<4 when Azotobacter was used singly or with activated sludge. The results indicated clear advantage of using Azotobacter in the activated sludge to improve TOC removal from nitrogen-deficient wastewaters. 相似文献
10.
Bioaugmentation of cyanide-degrading microorganisms in a full-scale cokes wastewater treatment facility 总被引:7,自引:0,他引:7
To enhance biological removal efficiency of total cyanides, bioaugmentation was applied to a full-scale cokes wastewaters treatment process. After a laboratorial-scale cultivation (up to 1.2 m(3)) of a cyanide-degrading yeast (Cryptococcus humicolus) and unidentified cyanide-degrading microorganisms, the microbial consortium was inoculated into a fluidized-bed type process (1280 m(3)), and then enriched for two months with a huge supply of glucose, KCN and other nutrients. Target wastewater was effluent of a biological pre-denitrification process for treating cokes wastewater, and contained about 14 mg/L of total cyanides in the form of ferric cyanide. This may be a first or rare report on the full-scale bioaugmentation of specialized-microorganisms. However, continuous operation of the full-scale cyanides-degrading bioprocess showed poor removal efficiency than expected owing to poor settling performance of microbial flocs, slow biodegradation rate of ferric cyanide and lack of organic carbon sources within the wastewater. Therefore, there is a need for further studies on how to solve these operating problems in full-scale bioaugmentation approach. 相似文献
11.
Biodegradation of phenolic industrial wastewater in a fluidized bed bioreactor with immobilized cells of Pseudomonas putida 总被引:10,自引:0,他引:10
The paper presents the main results obtained from the study of the biodegradation of phenolic industrial wastewaters by a pure culture of immobilized cells of Pseudomonas putida ATCC 17484. The experiments were carried out in batch and continuous mode. The maximum degradation capacity and the influence of the adaptation of the microorganism to the substrate were studied in batch mode. Industrial wastewater with a phenol concentration of 1000 mg/l was degraded when the microorganism was adapted to the toxic chemical. The presence in the wastewater of compounds other than phenol was noted and it was found that Pseudomonas putida was able to degrade these compounds. In continuous mode, a fluidized-bed bioreactor was operated and the influence of the organic loading rate on the removal efficiency of phenol was studied. The bioreactor showed phenol degradation efficiencies higher than 90%, even for a phenol loading rate of 0.5 g phenol/ld (corresponding to 0.54 g TOC/ld). 相似文献
12.
E. Posadas S. Bochon M. Coca M.C. García-González P.A. García-Encina R. Muñoz 《Journal of applied phycology》2014,26(6):2335-2345
The potential of algal–bacterial symbiosis for the removal of carbon, nitrogen and phosphorus from five agro-industrial wastewaters was investigated in enclosed batch biodegradation tests using a mixed microalgae consortium and activated sludge as model microorganisms. The target wastewaters were obtained from potato processing (PW), fish processing (FW), animal feed production (MW), coffee manufacturing (CW) and yeast production (YW). The initial C/N/P ratio of the agro-industrial wastewater was correlated with its biodegradability. Thus, the highest removals of total organic carbon (TOC) and nitrogen were recorded in two fold diluted FW (64?±?2 % and 85?±?1 %, respectively), while the maximum P-PO4 3? removal achieved was 89?±?1 % in undiluted PW. The biodegradable TOC was in most cases the limiting component in the treatment of the wastewaters evaluated. This study confirmed the potential of coupling carbon and nutrient recovery from agro-industrial effluents with the production of a valuable algal–bacterial biomass, despite their poor biodegradability. 相似文献
13.
The prospective of table olive debittering & washing Effluent (DWE) as feed stock wastewater for anaerobic digestion (AD) systems was investigated in batch and continuous systems together with cattle and pig manures. While DWE considered unsuitable for biological treatment methods due to its unbalanced nature, the co-digestion of the wastewaters resulted in a 50% increase in the methane production/gram volatile solidsadded (CH4/gVSadded), accompanied by 30% phenol reduction and 80% total organic carbon removal (TOC). pH increase during the co-digestion period was not identified as an inhibitory factor and all reactors were able to withstand this operational condition change. Moreover, no volatile fatty acid (VFA) accumulation was observed, indicating that the reactors were not operating under stress-overloading state. Under thermophilic conditions a 7% increase on the TOC removal efficiency was achieved when compared to the mesophilic systems while, under mesophilic conditions phenolic compounds reduction was 10% higher compared to the thermophilic systems. 相似文献
14.
Hamna Saleem Khadeeja Rehman Muhammad Afzal 《International journal of phytoremediation》2018,20(7):692-698
Phenol is a commonly found organic pollutant in industrial wastewaters. Its ecotoxicological significance is well known and, therefore, the compound is often required to be removed prior to discharge. In this study, plant-bacterial synergism was established in floating treatment wetlands (FTWs) in an attempt to maximize the removal of phenol from contaminated water. A common wetland plant, Typha domingensis, was vegetated on a floating mat and augmented with three phenol-degrading bacterial strains, Acinetobacter lwofii ACRH76, Bacillus cereus LORH97, and Pseudomonas sp. LCRH90, to develop FTWs for the remediation of water contaminated with phenol. All of the strains are known to have phenol-reducing properties, and grow well in FTWs. Results showed that T. domingensis was able to remove a small amount of phenol from the contaminated water; however, bacterial augmentation enhanced the removal potential significantly, i.e., 0.146 g/m2/day vs. 0.166 g/m2/day, respectively. Plant biomass also increased in the presence of bacterial consortia; and inoculated bacteria displayed successful colonization/survival in the rhizosphere, root interior and shoot interior of the plant. Similarly, highest reduction in chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and total organic carbon (TOC) was achieved by the combined application of plants and bacteria. The study demonstrates that the plant-bacterial synergism in a FTW may be a more effective approach for the remediation of phenol-contaminated water. 相似文献
15.
In this study, a biological nitrogen removal process using a vertically moving biofilm system was used to treat synthetic wastewater. The process consisted of two pre-denitrification units, one combined carbonaceous removal/nitrification unit and three nitrification units. Each unit employed biofilm growth on a plastic module. In the anoxic units, the modules were vertically moved, while always submerged, in the bulk fluid; in the aerobic units, they were moved vertically up into the air and down into the wastewater. Three small-scale experiments, having different recirculation ratios and influent loadings, were conducted at a controlled temperature of 11 degrees C. In this system, the carbonaceous removal efficiency was in the range of 94-96% and the total nitrogen removal efficiency was 77-82%. In the anoxic units, the denitrification efficiency was 94-98% and the areal denitrification rates, based on the surface area of the biofilm modules, were 2.9-3.8 g NO3-N/(m2 x d). The nitrification efficiency occurring in the aerobic tanks was up to 95% and the maximum areal ammonium removal rates were 1.3-1.8 g NH4-N/(m2 x d). 相似文献
16.
流加菌种对厌氧氨氧化工艺的影响 总被引:7,自引:0,他引:7
厌氧氨氧化工艺具有很高的容积氮去除速率,现已成功应用于污泥压滤液等含氨废水的脱氮处理,容积氮去除速率高达9.5 kg/(m3·d)。但由于厌氧氨氧化菌为自养型细菌,生长缓慢,对环境条件敏感,致使厌氧氨氧化工艺启动时间过长,运行容易失稳,并且不适合处理有机含氨废水和毒性含氨废水,极大地限制了该工艺的进一步推广应用。为了克服厌氧氨氧化工艺实际应用中存在的问题,结合发酵工业中常用的菌种流加技术,提出了一种新型的菌种流加式厌氧氨氧化工艺,研究了该新型工艺在厌氧氨氧化工艺的启动过程、稳定运行以及处理有机含氨废水和毒性含氨废水等方面的应用情况。结果表明,通过向反应器内补加优质厌氧氨氧化菌种,可提高厌氧氨氧化菌数量及其在菌群中的比例,强化厌氧氨氧化功能。据此研发的菌种流加式厌氧氨氧化工艺不仅可以实现快速启动,而且可以稳定运行,并突破了有机物和毒物所致的运行障碍,拓展了厌氧氨氧化工艺的应用范围。 相似文献
17.
Phenol removal using HRP and hematin as a biomimetic of HRP has been studied under various conditions at room temperature. The best results were obtained with treatment in two steps, with double addition of HRP or hematin and a final treatment with activated carbon. This two-step treatment achieved a minimum of 90% conversion of the initial phenol, under conditions commonly found in wastewaters (from 400 up to 1500 ppm phenol). Other additives such as chitosan, cellulose or polyethylene glycol (PEG) gave no satisfactory results.
Hematin and magnetite-supported hematin showed comparable activities in phenol removal from aqueous solution. The supported hematin is an interesting alternative to HRP for practical application of a biomimetic catalyst for phenol removal. 相似文献
Hematin and magnetite-supported hematin showed comparable activities in phenol removal from aqueous solution. The supported hematin is an interesting alternative to HRP for practical application of a biomimetic catalyst for phenol removal. 相似文献
18.
Removal of total lipids and fatty acids from sunflower oil factory effluent by UASB reactor 总被引:2,自引:0,他引:2
In this study wastewaters of a sunflower oil factory in Elazig (Turkey) were investigated in a pilot-scale mesophilic upflow anaerobic sludge blanket (UASB) reactor by determination of removal of total lipids (TL) and fatty acids (FA). The removal efficiencies of TL and FA (linoleic, oleic, myristic, palmitic, stearic, arashidic, behenic and other FA) were above 70% at organic loading rates (OLR) between 1.6 and 7.8 kg COD/m(3)d and at optimum hydraulic retention times of 2.0 and 2.8 day. The conversion rate of removed COD to methane was between 0.16 and 0.354 m(3) CH(4)/kg COD. 相似文献
19.
Bacillus coagulans strain isolated from contaminated soil was immobilised on activated carbon for degradation of pyridine, toluene and methylene chloride containing synthetic wastewaters. Pyridine was supplied as the only source of nitrogen in the wastewaters. Continuous runs in a packed bed laboratory reactor showed that immobilized B. coagulans can degrade pyridine along with other organics rapidly and the effluent ammonia is also controlled in presence of “organic carbon”. About 644?mg/l of influent TOC was efficiently degraded (82.85%) at 64.05?mg/l/hr loading. 相似文献
20.
Ingrid Hauser Aslak Einbu Kjetill Østgaard Hallvard F. Svendsen Francisco J. Cervantes 《Biotechnology letters》2013,35(2):219-224
Nitrogen and organic matter removal from reclaimer waste of a monoethanolamine (MEA) based CO2-capture plant was demonstrated in a pre-denitrification biofilm system. The reclaimer waste was generated from a 30 % (w/w) MEA solvent used for capturing CO2 from flue gas from a coal-fired power plant. MEA, N-(2-hydroxylethyl)glycine (HEGly) and 2-hydroxyethylformamide (HEF) were the major contaminants treated. Hydrolysis of MEA to ammonia and further oxidation of organic intermediates readily occurred in the pre-denitrification system with a hydraulic retention time of 7 h. The biofilm system achieved 98 ± 1 % removal of MEA and 72 ± 16 % removal of total nitrogen. This is the first demonstration of efficient biodegradation of real amine waste from a post-combustion CO2 capture facility by pre-denitrification without external electron donor. 相似文献