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11.
This study investigated the removal of hydrophobic trichloroethylene (TCE) in the presence of methanol (co-metabolite) in a biotrickling filter, which was seeded with fungi at pH 4. Starvation was chosen as the biomass control strategy. Two systems, Biofilter I (methanol:TCE 70:30) and Biofilter II (methanol:TCE 80:20) were run in parallel, each with varying composition ratios. The TCE loading rates for both biofilters ranged from 3.22 to 12.88 g/m3/hr. Depending on the ratio, methanol concentrations varied from 4.08 to 27.95 g/m3/hr. The performance of the systems was evaluated and compared by calculating removal kinetics, carbon mass balance, efficiencies and elimination capacities. Methanol was observed to enhance TCE removal during the initial loading rate. However, methanol later inhibited TCE degradation above 6.44 g TCE/m3/hr (Biofilter I) and 3.22 g TCE/m3/hr (Biofilter II). Conversely, TCE did not impede methanol removal because over 95% methanol elimination was consistently achieved. Overall, Biofilter I was able to outperform Biofilter II due to its greater resistance towards methanol competition. 相似文献
12.
Zhangli Cai George A. Sorial Kai Zhang Pascal Saikaly Maher M. Zein Daniel B. Oerther 《Water, Air, & Soil Pollution: Focus》2008,8(3-4):311-321
Microbial communities in trickle bed air biofilters (TBABs) were evaluated under conditions of interchanging the feed volatile
organic compounds (VOCs) and VOC mixtures. Three independent TBABs (Biofilter “A,” “B,” and “C”) were run under interchanging
VOCs conditions with different initial VOCs. Two aromatic compounds (toluene and styrene) and two oxygenated compounds (methyl
ethyl ketone (MEK) and methyl isobutyl ketone (MIBK)) were interchanged as single solutes. Two other TBABs “D” and “E” were
run for two VOC mixtures. Biofilter “D” had a VOC mixture with equal molar ratio of the four components and Biofilter “E”
received a VOC mixture with its composition based on EPA 2003 emission report. Denaturing gradient gel electrophoresis (DGGE)
analysis of 16S rRNA genes was used to assess the microbial richness in TBABs for treating the VOC mixtures and the impact
of interchanging VOCs on the bacterial community structure in the biofilters. The results from DGGE indicated that the microbial
community structure in the biofilter was different after each interchange of VOCs. Some bands of microbial species faded and
some bands were strengthened. For the two TBABs treating VOC mixtures, the microbial species did not show significant difference,
but the richness among these species was different from each other. 相似文献
13.
Jianwei Liu Peng Yue Nana Zang Chen Lu Xinyue Chen 《Frontiers of Environmental Science & Engineering》2021,15(3):48
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Alvarez-Hornos FJ Izquierdo M Martínez-Soria V Penya-Roja JM Sempere F Gabaldón C 《Journal of environmental management》2011,92(8):1978-1985
The effect of using ground tire rubber (GTR) as an adsorptive material in the removal of a 2:1:1 weight mixture of n-butyl acetate, toluene and m-xylene by using a peat biofilter under different intermittent conditions was investigated. The performance of two identical size biofilters, one packed with fibrous peat alone and the other with a 3:1 (vol) fibrous peat and GTR mixture, was examined for a period of four months. Partition coefficients of both materials were measured. Values of 53, 118 and 402 L kg(-1) were determined for n-butyl acetate, toluene and m-xylene in peat, respectively; and values of 40, 609 and 3035 L kg(-1) were measured for the same compounds in GTR. Intermittent load feeding of 16 h per day, 5 days per week working at an EBRT of 60 s and an inlet VOC concentration of 0.3 g C m(-1), resulted in removal efficiencies higher than 90% for both biofilters, indicating that the addition of GTR did not adversely affect the behavior of the bioreactor. Full removal of n-butyl acetate was obtained for both biofilters. GTR improved the removal of the aromatics in the first part of the biofilter, facilitating lower penetration of the toluene and m-xylene into the bed. A 31-day starvation period was applied and intermittent operation subsequently restarted. In both biofilters, high removal efficiencies after a re-acclimation period of two days were achieved. A shock loading test related to 1-h peaks of three- and four-fold increases in its baseline concentration (0.30 g C m(-3)) was applied in both biofilters. For the biofilter packed with the peat and GTR mixture, attenuation greater than 60% was observed in the maximum outlet concentration when compared to the biofilter packed with peat alone. 相似文献
16.
随着生物技术在水处理工业中的推广应用,人们逐渐认识到生物除铁是将来替代接触氧化法除铁的新一代除铁方法。本文在国内外生物除铁研究的基础上,通过较低pH值条件培养铁细菌,最终检测不同实验条件下的过滤效果,以达到研究不同粒径滤料、pH值、溶解氧等条件对生物除铁的影响。实验结果表明:小粒径滤料有利于过滤过程的进行;生物除铁的效果不明显,尤其在高pH值和溶解氧条件下几乎没有差别;随着pH值和溶解氧浓度的增加,亚铁的氧化效果加强了,但是生物除铁的效果却减弱了。 相似文献