有氧条件下生物滤塔去除NOx的挂膜启动及研究

将优选后的好氧反硝化菌应用于生物过滤系统,用来脱除NOx模拟废气,研究了生物滤床在好氧条件下对NOx的处理效果和不同操作条件下的运行情况,并对NOx去除过程的作用机制进行了探讨.结果表明,生物滤塔经过26 d完成挂膜启动,该工艺系统能有效克服氧对反硝化菌活性的抑制作用,可实现对NOx的高效率脱除.NOx净化主要发生在滤...     

废气生物处理微生物学研究进展

与其它处理技术相比,废气生物处理技术具有处理效率高、成本低及环境友好等优点,因此受到人们广泛的关注。废气生物处理技术的原理是废气中的污染物质在微生物的作用下转化为无害或低害的物质,其中微生物起关键作用。文章从与废气生物处理相关的主要微生物种类、污染物高效降解微生物的筛选与应用、微生物群落结构等方面综述了废气生物处理微生物学的研究进展与现状,并对该领域存在的问题和发展方向进行了展望。     

滤速对慢滤池深度处理生活污水的影响

为进一步提高再生水水质,将慢滤池用于污水二级处理出水的进一步处理。选取浊度、COD、色度和细菌总数4个指标,利用实验室小试装置,研究了0.1、0.3、0.5m/h这3种滤速下慢滤池的性能。结果表明,滤速由0.1m/h升高至0.3m/h时,慢滤池出水水质略有下降。而滤速由0.3m/h升高至0.5m/h时,慢滤池出水水质下降显著。滤速小于等于0.3m/h时,慢滤出水浊度、COD、色度和细菌总数平均为0.4NTU、25.9mg/L、14.9°、5×10^3CFU/mL。慢滤对这4个指标的平均去除率分别为78.6%、36.0%、34.0%、62.3%。为获得优良的水质,建议慢滤池用于污水深度处理时,滤速宜小于0.3m/h。但实际工程中,用户对再生水水质要求不高时,则可适当增大慢滤池滤速。     

填料初始湿度对气态乙酸乙酯生物过滤的影响

以堆肥 珍珠岩作为生物过滤器填料 ,研究了填料初始湿度对去除气态乙酸乙酯的影响 .当进气乙酸乙酯负荷为 2 65—376g (m3·h)时 ,通过 1 2 3h的运行实验 ,发现初始湿度低至 30 % (以重量计 )的填料对乙酸乙酯去除能力较低 ,达到稳定运行状态需要较长时间 .而初始湿度较高的填料 (40 %— 70 % )去除乙酸乙酯能力较强 ,可以较快达到稳定运行状态 ,在稳定状态时对乙酸乙酯的去除率较高 .初始湿度高至 70 %的填料不利于实际操作 .在初始湿度高的填料中 ,微生物细胞总数以及细菌和霉菌数量较多 ,酵母菌和放线菌的含量较少 .填料的初始湿度为 40 %— 60 %比较适宜     

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

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/min. 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/（m^3·h） （16.06 g ether/（m^3·h） ≈ 1.0 kg chemical oxygen demand （COD）/（m^3·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/（m^3·h）. However, when the VOC loading rate was increased to 256 g ether/（m^3·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.     

生物过滤塔降解挥发性有机物动力学模型

提出了挥发性有机物(VOCs)生物降解新机理——吸附传递生物降解机理,建立了模型动力学方程,选择活性炭为滤料,以甲苯为VOCs代表,求取模型参数,获得了VOCs生物降解经验方程,并验证了模型的正确性。      

管式生物过滤器去除乙苯废气

生物过滤由于其良好的成本效益和环境友好性已经成为控制挥发性有机化合物(VOCs)含量和气味气体排放的常规技术。营养物质的均匀分布、生物膜和介质床内的气体流是成就一个性能优良的生物过滤器至关重要的因素。而由本实验室开发的管式生物过滤器(TBFs)已被证明具备此优势。本实验的管式生物过滤器以聚氨酯海绵作为填料,研究在不同有机负荷、气体停留时间(EBCT)、进气量和表面活性剂等条件下乙苯废气的去除效率(RE)。实验同时记录了管式生物过滤器启动阶段的表现。初期使附着在填料上的微生物暴露在浓度为40 mg/m3的乙苯废气中40 d,此时的气体停留时间为15 s,使微生物慢慢适应并逐步降解乙苯废气;然后连续地控制管式生物过滤器的入口乙苯浓度为40、80、120和160 mg/m3,以使有机负荷逐步升高。结果表明,乙苯去除效率随着有机负荷的增大而逐步减小。当气体停留时间从15 s增加到30 s和60 s,而有机负荷控制在38.60 g/(m3·h)时,乙苯废气去除效率略微增加。此外,随着进气量的增大乙苯废气的最大平均去除效率有所下降而此时的降解容量增大,这个过程中乙苯进气浓度保持不变。结果还表明,在营养液中加入聚乙二醇辛基苯基醚这种表面活性剂可以提高乙苯废气的去除效率。     

生物过滤法处理挥发性有机物的模型

介绍了生物过滤法处理挥发性有机物模型的研究现状,论述了过滤机理、污染物传递、生物膜增长与脱落、填料和生物膜表面形态学等方面的模型情况,指出了生物过滤法处理挥发性有机物模型的研究趋势,有助于理解生物过滤过程的内在规律和指导优化生物过滤系统的设计与运行。     

废气生物过滤系统填料层热迁移数值模拟

参考多孔介质体积平均模型和三参数模型.以多孔介质能量守恒方程为基础,建立了废气生物过滤填料层热迁移的数学模型,采用Galerkin有限元法对模型进行一维数值计算.结果表明,填料层热迁移模型计算结果与实验一致,且两者值也基本相符.填料层热迁移与气流特性.生物代谢产能及介质导热特性相关.介质导热性能增强、气流温度和污染物浓度增加、生物代谢产能增大,填料层的热迁移速率提高;气流流速增大,同一时刻沿轴向各填料层热迁移速率降低.     

Performance of biotrickling filters packed with structured or cubic polyurethane sponges for VOC removal

Two identical bench-scale biotrickling filters (BTFs), BTF 1 and BTF 2, were evaluated for toluene removal at various gas empty bed contact times (EBCTs) and organic loadings. BTF 1 and BTF 2 were packed with structured and cubic synthetic polyurethane sponges, respectively. At a constant toluene loading of 16 g/(m3 hr), toluene removal efficiencies decreased from 98.8% to 64.3% for BTF 1 and from 98.4% to 74.1% for BTF 2 as gas EBCT decreased from 30 to 5 sec. When the toluene loading increased from 35 to 140 g/(m3 hr) at a gas EBCT of 30 sec, the removal efficiencies decreased from 99.1% to 77.4% for BTF 1 and from 99.0% to 81.5% for BTF 2. The pressure drop for both BTFs increased with increased air flow rate, and did not significantly vary while the toluene loading was increased under similar operation conditions. BTF 1 and BTF 2 could start up successfully within 19 and 27 days, respectively, when packed with fresh sponge media, and the performances could be restored in 3–7 days after biomass was removed and wasted from the media. BTF 2 displayed higher removal efficiency even under shorter EBCT or higher loading rate than BTF1 when other operation conditions were similar, while it showed lower pressure drop than BTF 1 during the whole period of operation. These results demonstrated that both BTFs could treat waste gas containing toluene effectively.