生物滴滤塔净化苯乙烯废气的强化启动及工艺性能

采用多面空心球与活性炭纤维组合填料构建生物滴滤塔(BTF),接种活性污泥净化苯乙烯废气。采用外加葡萄糖共代谢基质,气液相联合挂膜法启动生物滴滤塔,考察BTF启动及稳定阶段的工艺性能。结果表明,BTF的挂膜时间仅为20 d,实现了BTF的快速启动;适宜的苯乙烯进气浓度为195.2~1478.2 mg/m3,停留时间(EBRT)为57 s,气液比为300:1,系统最大去除负荷可达136.4 g/(m3·h); BTF对喷淋液pH的大幅变化及间歇运行有较强的适应性。     

生物滴滤塔净化苯乙烯废气的实验研究

采用生物滴滤(BTF)系统对含苯乙烯的有机废气进行了生物净化实验并研究该系统VOCs生物降解性能。实验表明,苯乙烯进气浓度低于20 mg/m3时BTF去除效率可达92%以上,出口苯乙烯浓度低于1.6 mg/m3,达到GB14554-1993中规定的排放标准;该BTF装置对苯乙烯的去除负荷在2.0 g/(m3.h)左右;系统稳定运行时循环液COD、浊度和pH等都保持稳定,无脱落生物膜积累现象;生物滴滤塔系统适宜的气液比为300;系统总压降约100 Pa,鲍尔环填料和聚氨酯发泡填料混合装填方式可以降低系统压降并有利于微生物挂膜。     

生物滴滤塔净化甲苯启动性能研究

研究以甲苯为驯导物的生物滴滤塔挂膜启动阶段净化性能的变化。实验结果表明,通过控制pH和湿度得到了真菌滴滤系统,启动周期为14 d,比细菌滴滤塔长7 d;在进化性能方面,在入口负荷、浓度为80 g/(m3.h)、3 000 mg/m3的条件下获得了稳定在98%以上的去除效率;对比2种填料对启动阶段的影响,在较低负荷下(≤80 g/(m3.h))对系统的启动时间和去除效率没有显著影响。     

Co-treatment of hydrogen sulfide and methanol in a single-stage biotrickling filter under acidic conditions

Biofiltration of waste gases is cost-effective and environment-friendly compared to the conventional techniques for treating large flow rates of gas streams with low concentrations of pollutants. Pulp and paper industry off-gases usually contain reduced sulfur compounds, such as hydrogen sulfide and a wide range of volatile organic compounds (VOCs), e.g., methanol. It is desirable to eliminate both of these groups of compounds. Since the co-treatment of inorganic sulfur compounds and VOCs in biotrickling filters is a relatively unexplored area, the simultaneous biotreatment of H2S and methanol as the model VOC was investigated. The results showed that, after adaptation, the elimination capacity of methanol could reach around 236 g m(-3) h(-1) with the simultaneous complete removal (100%) of 12 ppm H2S when the empty bed residence time is 24 s. The pH of the system was around 2. Methanol removal was hardly affected by the presence of hydrogen sulfide, despite the low pH. Conversely, the presence of the VOC in the waste gas reduced the efficiency of H2S biodegradation. The maximal methanol removal decreased somewhat when increasing the gas flow rate. This is the first report on the degradation of methanol at such low pH in a biotrickling filter and on the co-treatment of H2S and VOCs under such conditions.     

生物滴滤法去除低浓度苯乙烯

通过装载改性聚乙烯填料的生物滴滤塔进行废气中的苯乙烯生物降解实验。结果表明,通过快速排泥法挂膜,该反应器可在较短周期内实现微生物的驯化。苯乙烯入口浓度和空床停留时间(EBRT)是影响反应器性能的重要因素,当EBRT分别为60、45、30和15 s以及对应的入口浓度分别为950、430、350和200 mg/m3时,可实现达标排放。循环喷淋液中的硝酸盐(亚硝酸盐)对生物滴滤池的影响十分明显,在初始阶段,亚硝酸根很快被耗尽,硝酸根则相对缓慢。当循环液中的TN从102.63 mg/L下降到24.24 mg/L时,滴滤池的去除效率由94.48%下降到43.16%,部分原因是降低NOx-的浓度减弱了反硝化作用对VOC碳源的利用。     

生物焦炭滴滤塔降解苯乙烯废气的中试启动研究

苯乙烯废气既是一种挥发性有机化合物（VOCs），又属于我国恶臭气体控制的范围之内。其作为一种化工原料和有机溶剂广泛应用于工业生产中。生物法处理有机废气具有运行费用低和没有二次污染等优点。采用焦炭填料滴滤塔对苯乙烯废气的处理进行了中试启动研究。启动过程中，进气浓度范围是50—114mg／m^3，去除率为30％～45％左右，最高可达90％左右。所采用的焦炭填料可以认为是一种环境友好型填料，废弃后可作为燃料，值得推广。     

生物焦炭滴滤塔降解苯乙烯废气的中试启动研究

苯乙烯废气既是一种挥发性有机化合物(VOCs),又属于我国恶臭气体控制的范围之内。其作为一种化工原料和有机溶剂广泛应用于工业生产中。生物法处理有机废气具有运行费用低和没有二次污染等优点。采用焦炭填料滴滤塔对苯乙烯废气的处理进行了中试启动研究。启动过程中,进气浓度范围是50~114 mg/m3,去除率为30%~45%左右,最高可达90%左右。所采用的焦炭填料可以认为是一种环境友好型填料,废弃后可作为燃料,值得推广。     

PCR-DGGE技术用于处理苯乙烯废气的生物滴滤塔中微生物优势菌种解析

采用生物滴滤塔能够有效去除含苯乙烯恶臭气体,塔内微生物中含有大量的球菌和杆状菌。采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术研究处理苯乙烯恶臭气体的生物滴滤塔填料表面的微生物,结果表明,去除苯乙烯生物滴滤塔中有5种菌为降解苯乙烯的优势菌种;通过16S rDNA基因扩增测序同源性比对,结果显示嗜甲基杆菌属(methylophilus)丰度为50.5%,2种变形菌属(alpha proteobacterium、delta proteobacterium)相对丰度分别为16.9%和11.6%。     

Effect of metabolic uncouplers on the performance of toluene-degrading biotrickling filter

Environmental Science and Pollution Research - The biomass control potential of three metabolic uncouplers (carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP), carbonyl cyanide...     

矿物棉填料孔隙率对生物滴滤池水处理效果的影响

针对生物滴滤池因接触时间短而导致出水不达标的问题,采用3种容重(80、100、120 kg·m−3)的矿物棉作为滤池填料,考察了填料孔隙率对保水性的影响,分析了不同容重填料的生物滴滤池去除污染物的效能,探究了填料孔隙率对微生物群落特征的影响。结果表明,矿物棉载体的吸水、保水性能随其孔隙率增加呈现先增加后减小的趋势;孔隙率较小的矿物棉载体在稳定运行后对COD、${\rm{NH}}_4^ + $-N有更好的去除效果,平均去除率分别可达99%和72%,且具有一定的抗冲击负荷能力。高通量测序结果显示,随着矿物棉载体孔隙率的减小,微生物群落物种丰富度增加,而其多样性减少。比较而言,当容重为100 kg·m−3时,矿物棉的吸、保水性高,微生物种群结构适宜,出水水质可达一级A标准,且具有一定的抗冲击负荷能力。     

Simulating accumulation of biofilms in biotrickling filter

Accumulations and spatial and dynamic variations of biofilms in the media of a biotrickling filter were simulated using mathematical models for Volatile Organic Compound (VOC) removal. Toluene was selected as the model VOC. Effects of toluene concentration and gas Empty Bed Contact Time (EBCT) on VOC removal were also investigated. Results showed that biofilm thickness increased with increased operation duration and the growth rate of biofilms increased with increased inlet toluene concentration and EBCT at a constant toluene loading. The profiles of the thickness and growth rate of biofilms along the medium depth dropped gradually at a certain time.     

Shift of microbial diversity and function in high-efficiency performance biotrickling filter for gaseous xylene treatment

ABSTRACT

Xylene is the main component of many volatile industrial pollution sources, and the use of biotechnology to remove volatile organic compounds (VOCs) has become a growing trend. In this study, a biotrickling filter for gaseous xylene treatment was developed using activated sludge as raw material to study the biodegradation process of xylene. Reaction conditions were optimized, and long-term operation was performed. The optimal pH was 7.0, gas-liquid ratio was 15:1 (v/v), and temperature was 25 °C. High-throughput sequencing technique was carried out to analyze microbial communities in the top, middle, and bottom layers of the reactor. Characteristics of microbial diversity were elucidated, and microbial functions were predicted. The result showed that the removal efficiency (RE) was stable at 86%–91%, the maximum elimination capacity (EC) was 303.61 g·m^?3·hr^?1, residence time was 33.75 sec, and the initial inlet xylene concentration was 3000 mg·m^?3, which was the highest known degradation concentration reported. Kinetic analysis of the xylene degradation indicated that it was a very high-efficiency-activity bioprocess. The r_max was 1059.8 g·m^?3·hr^?1, and K_s value was 4.78 g·m^?3 in stationary phase. In addition, microbial community structures in the bottom and top layers were significantly different: Pseudomonas was the dominant genus in the bottom layer, whereas Sphingobium was dominant in the top layer. The results showed that intermediate metabolites of xylene could affect the distribution of community structure. Pseudomonas sp. can adapt to high concentration xylene–contaminated environments.

Implications: We combined domesticated active sludge and reinforced microbial agent on biotrickling filter. This system performed continuously under a reduced residence time at 33.75 sec and high elimination capacity at 303.61 g·m^?3·hr^?1 in the biotrickling reactor for about 260 days. In this case, predomestication combined with reinforcing of microorganisms was very important to obtaining high-efficiency results. Analysis of microbial diversity and functional prediction indicated a gradient distribution along with the concentration of xylene. This implied a rational design of microbial reagent and optimizing the inoculation of different sites of reactor could reduce the preparation period of the technology.     

The treatment of waste air containing phenol vapors in biotrickling filter

This research aimed at investigating the biodegradation of phenol contaminated-air streams in biotrickling filter. The effect of inlet concentration (200-1000 ppmv) and empty bed contact time (EBCT) (15-60 s) were investigated under steady state, transient and shock loading, and shutdown periods. Upon rapid start up operation, inlet phenol concentrations of up to 1000 ppmv did not significantly affect the performance of the biotrickling filter at EBCT of 60 s, so that removal efficiency was well greater than 99%. In addition, the EBCT as low as 30 s did not have detrimental effects on the efficiency of the bioreactor and phenol removal was greater than 99%. Decreasing the EBCT to 15s reduced the removal efficiency to around 92%. The maximum elimination capacity obtained in the biotrickling filter was 642 g(phenol) m(-3) h(-1), where the removal efficiency was only 57%. Results from the transient loading experiments revealed that the biotrickling filter could effectively handle the variations of the inlet loads without the phenol removal capacity being significantly affected.     

Removal of nitric oxide in a biotrickling filter under thermophilic condition using Chelatococcus daeguensis

The development of a thermophilic biotrickling filter (BTF) system to inoculate a newly isolated strain of Chelatococcus daeguensis TAD1 for the effective treatment of nitric oxide (NO) is described. A bench-scale BTF was run under high concentrations of NO and 8% O2 in thermophilic aerobic environment. A novel aerobic denitrifier Chelatococcus daeguensis TAD1 was isolated from the biofilm of an on-site biotrickling filter and it showed a denitrifying capability of 96.1% nitrate removal rate in a 24 h period in aerobic environment at 50 degrees C, with no nitrite accumulation. The inlet NO concentration fluctuated between approximately 133.9 and 669.6 mg m-3 and kept on a steady NOx removal rate above 80% in an oxygen stream of 8%. The BTF system was able to consistently remove 80-93.7% NO when the inlet NO was 535.7 mg m-3 in an oxygen stream of 2-20%. The biological removal efficiency of NO at 50 degrees C is higher than that at 25 degrees C, suggesting that the aerobic denitrifier TAD1 display well denitrification performance under thermophilic condition. Starvation for 2, 4 and 8 days resulted in the re-acclimation times of Chelatococcus daeguensis TAD1 ranging between 4 and 16 hours. A longer recovery time than that for weekend shutdown will be required when a longer starvation occurs. The results presented here demonstrate the feasibility of biotrickling filter for the thermophilic removal of NOx from gas streams. Implications: A novel denitrifier Chelatococcus daeguensis TAD1 was isolated from an on-site biotrickling filter in aerobic environment at 50 degrees C. To date, C. daeguensis has not been previously reported to be an aerobic denitrifier. In this study, a thermophilic biotrickling filter system inoculated with Chelatococcus daeguensis TADI for treatment of nitric oxide is developed. In coal-fired power plants, influent flue gas stream for nitrogen oxides (NOx) removal typically exhibit temperatures between 50 and 60 degrees C. Traditionally, cooling gases to below 40 degrees C prior to biological treatment is inevitable, which is costly. Therefore, the application ofthermophilic microorganisms for the removal of nitric oxide (NO) at this temperature range would offer great savings and would greatly extend the applicability ofbiofilters and biotrickling filters. Until now there has not been any study published about thermophilic biological treatment of NO under aerobic condition.     

Removal of nitric oxide in a biotrickling filter under thermophilic condition using Chelatococcus daeguensis

The development of a thermophilic biotrickling ?lter (BTF) system to inoculate a newly isolated strain of Chelatococcus daeguensis TAD1 for the effective treatment of nitric oxide (NO) is described. A bench-scale BTF was run under high concentrations of NO and 8% O₂ in thermophilic aerobic environment. A novel aerobic denitrifier Chelatococcus daeguensis TAD1 was isolated from the biofilm of an on-site biotrickling filter and it showed a denitrifying capability of 96.1% nitrate removal rate in a 24 h period in aerobic environment at 50 °C, with no nitrite accumulation. The inlet NO concentration fluctuated between approximately 133.9 and 669.6 mg m-3 and kept on a steady NOx removal rate above 80% in an oxygen stream of 8%. The BTF system was able to consistently remove 80–93.7% NO when the inlet NO was 535.7 mg m-3 in an oxygen stream of 2–20%. The biological removal efficiency of NO at 50 °C is higher than that at 25 °C, suggesting that the aerobic denitri?er TAD1 display well denitrification performance under thermophilic condition. Starvation for 2, 4 and 8 days resulted in the re-acclimation times of Chelatococcus daeguensis TAD1 ranging between 4 and 16 hours. A longer recovery time than that for weekend shutdown will be required when a longer starvation occurs. The results presented here demonstrate the feasibility of biotrickling ?lter for the thermophilic removal of NOx from gas streams.

Implications A novel denitrifier Chelatococcus daeguensis TAD1 was isolated from an on-site biotrickling filter in aerobic environment at 50 °C. To date, C. daeguensis has not been previously reported to be an aerobic denitrifier. In this study, a thermophilic biotrickling ?lter system inoculated with Chelatococcus daeguensis TAD1 for treatment of nitric oxide is developed. In coal-fired power plants, influent flue gas stream for nitrogen oxides (NO_x) removal typically exhibit temperatures between 50 and 60 °C. Traditionally, cooling gases to below 40 °C prior to biological treatment is inevitable, which is costly. Therefore, the application of thermophilic microorganisms for the removal of nitric oxide (NO) at this temperature range would offer great savings and would greatly extend the applicability of biofilters and biotrickling filters. Until now there has not been any study published about thermophilic biological treatment of NO under aerobic condition.     

生物膜填料塔处理高流量负荷下低浓度甲苯废气的初探

采用净化甲苯专用菌种对生物膜填料塔净化处理高流量负荷下低浓度甲苯废气的技术进行了初步实验研究。实验结果表明 ,当气体流量在 0 8m3 /h、进口浓度为 10 5mg/m3 、停留时间 18 3s时 ,甲苯的去除率可达到 6 1 90 % ,出口甲苯浓度低于国家对现有企业的排放标准 (≤ 6 0mg/m3 )。适宜的操作温度应控制在 19～ 2 5℃之间 ,氮磷营养添加量的配比应控制为C∶N∶P =2 0 0∶5∶1,操作压降与气体流量呈线性关系。结合实验数据 ,对相关的基础理论进行了初步探讨。     

Comparison of the purification performance and microbial community functional diversity in flow-directional-switching and unidirectional-flow biotrickling filters

Because of the characteristics of low operating cost and convenient operation, the biotrickling filter is extensively researched and used to treat low concentration waste gas contaminated by volatile organic compounds (VOCs) and other odors. In this paper, two laboratory-scale biotrickling filters were constructed and toluene was selected as the sole carbon source, and the effects of different waste-gas flow configuration patterns on the purification capacity and the microbial community functional diversity of biotrickling filters were evaluated. The results indicated that the flow-directional-switching (FDS) biotrickling filter had better purification performance, and the maximum elimination capacity reached 480 g·m^?3·hr^?1, which was 17.1% higher than conventional unidirectional-flow (UF) biotrickling filter. Comparing the purification capacities of different sections in two biotrickling filters, the maximum toluene elimination capacity of section III in FDS system could reach 542 g·m^?3·hr^?1, which was 2.8 times as great as that in UF system, which resulted from the difference of elimination capacity in two systems. By analyzing the metabolic activity of two systems by community-level physiological profiling (CLPP) with Biolog (Biolog Inc., Hayward, CA) ECO-plate technique, metabolic activity in three sections of FDS system was higher than that of UF system. The metabolic activity was the highest in section III of FDS system and 46.8% higher than that of UF system. Shannon index and McIntosh index of section III in FDS system were 6.2% and 31.5% higher, respectively, than those of UF system.

Implications: The flow-directional-switching (FDS) biotrickling filter had a better purification performance than unidirectional-flow (UF) biotrickling filter at high inlet loadings, because FDS produced a more uniform distribution of biomass and microbial metabolic capacity along the length of the packed bed without diminishing activity and removal capacity in the inlet section.     

Evaluation of trickle-bed air biofilter performance under periodic stressed operating conditions as a function of styrene loading

Trickle-bed air biofilters (TBABs) are suitable for treating volatile organic compounds (VOCs) at a significantly high practical loading because of their controlled environmental conditions. The application of TBAB for treating styrene-contaminated air under periodic backwashing and cyclical nonuse periods at a styrene loading of 0.64-3.17 kg chemical oxygen demand (COD)/m3 x day was the main focus of this study. Consistent long-term efficient performance of TBAB strongly depended on biomass control. A periodic in situ upflow with nutrient solution under media fluidization, that is, backwashing, was approached in this study. Two different nonuse periods were employed to simulate a shutdown for equipment repair or during weekends and holidays. The first is a starvation period without styrene loading, and the second is a stagnant period, which reflects no flow passing through the biofilter. For styrene loadings up to 1.9 kg COD/m3 x day, removal efficiencies consistently above 99% were achieved by conducting a coordinated biomass control strategy, that is, backwashing for 1 hr once per week. Under cyclical nonuse periods for styrene loadings up to 1.27 kg COD/m3 x day, stable long-term performance of the biofilter was maintained at more than 99% removal without employing backwashing. No substantial impact of nonuse periods on the biofilter performance was revealed. However, a coordinated biomass control by backwashing subsequently was unavoidable for attaining consistently high removal efficiency at a styrene loading of 3.17 kg COD/m3 x day. As styrene loading was increased, reacclimation of the biofilter to reach the 99% removal efficiency following backwashing or the nonuse periods was delayed. After the non-use periods, the response of the biofilter was a strong function of the biomass in the bed. No significant difference between the effects of the two different nonuse periods on TBAB performance was observed during the study period.     

生物滴滤床废气净化技术及应用

生物滴滤床是一种高效的废气净化装置 ,但其运行受诸多因素影响 ,采用传统的传质理论和传统的生物膜理论进行描述 ,难以取得满意结果 ,因此应从多方面来理解生物滴滤床的设计和运行 ,以开发高效的反应器和合理的运行处理系统。在分析中 ,综述了生物滴滤床净化有机废气的原理及运行中的多种影响因素 ,阐述了生物滴滤床的研究现状及相关应用。