生物净化废气技术的进展

生物技术以其能在常温常压下将污染物降解为无毒无害的简单物质、无二次污染、运行费用低等优点,目前已应用于许多废气处理,并已经形成了一套关于可生化气体的净化原理和工业应用经验的重要体系。文中介绍了生物技术处理污水处理厂、养殖场排放的恶臭气体、工厂排放的硫化物的发展,并分析了解决生物膜堵塞的途径,以及分子生物学在废气生物处理中的应用研究,提出生物净化废气技术的发展方向,期待该技术在国内能得到更广泛的应用。     

生物净化废气技术的进展

生物技术以其能在常温常压下将污染物降解为无毒无害的简单物质、无二次污染、运行费用低等优点,目前已应用于许多废气处理,并已经形成了一套关于可生化气体的净化原理和工业应用经验的重要体系。文中介绍了生物技术处理污水处理厂、养殖场排放的恶臭气体、工厂排放的硫化物的发展,并分析了解决生物膜堵塞的途径,以及分子生物学在废气生物处理中的应用研究,提出生物净化废气技术的发展方向,期待该技术在国内能得到更广泛的应用。     

生物滴滤池中废气有机物的生物降解

生物滴滤法是一种经济、有效的有机废气处理方法。从填料的选择、传质过程、微生物的筛选等几个方面介绍了影响生物滴滤池处理效果的几个关键因素。回顾以前的一些研究成果并对某些重要观点进行了总结与分析,希望能为生物滴滤池在有机废气处理的应用开发提供参考。     

生物过滤床净化含乙苯废气的温度影响分析

以两种陶粒作为生物过滤床的填料净化含乙苯废气。主要考察温度变化对生物过滤塔净化含乙苯废气效果的影响。在稳态条件下,在温度为15~25℃时,乙苯的去除效率随运行温度的升高而升高,在25~45℃时,乙苯的去除效率随温度升高而降低。并通过实验得出了温度系数。结果表明,对于零级反应,温度对高入口体积负荷的影响较低入口体积负荷的影响大,而对于一级反应,则出现了相反的结果。同时也表明不同填料对温度系数的影响不显著。     

生物滴滤池处理甲苯废气的研究

以陶粒和活性炭为填料的生物滴滤池系统,对人工合成的甲苯废气进行了净化处理试验,4个多月的运行结果表明(1)添加活性炭能提高填料柱的处理性能,陶粒和活性炭组成的复合填料能有效地处理含有甲苯的废气,当进气浓度为2.35g/m3时,去除率可达95%以上,填料柱对甲苯的去除能力为130g/m3·h;(2)在低浓度下,生物滴滤池的处理性能受传质过程控制;(3)填料柱出气通过循环液曝气处理后,废气中甲苯浓度进一步降低.     

处理甲苯废气的生物滴滤池中微生物生态学研究

利用PCR-DGGE技术分析了处理甲苯废气的生物滴滤池生物多样性,结果表明：在运行过程中,随着生物滴滤池对甲苯去除能力的不断增加,填料当中的微生物种群也发生了明显的变化。在甲苯的选择压力下,随时间的迁延,微生物种类减少,优势种群的相对丰度增加,处于不同层面填料上的微生物分布也趋向于一致。     

处理甲苯废气的生物滴滤池中微生物生态学研究

利用PCR-DGGE技术分析了处理甲苯废气的生物滴滤池生物多样性,结果表明:在运行过程中,随着生物滴滤池对甲苯去除能力的不断增加,填料当中的微生物种群也发生了明显的变化。在甲苯的选择压力下,随时间的迁延,微生物种类减少,优势种群的相对丰度增加,处于不同层面填料上的微生物分布也趋向于一致。     

生物滴滤池处理废气中生物质的积累与控制措施

生物滴滤池在废气处理中具有其无以比拟的优点,但由于其在工业化应用面临的最大难题就是如何解决生物质积累所带来的种种问题。综述分析生物滴滤池处理废气中生物质的积累的危害;以εf和αf为参数探求其积累的机理;生物质积累的控制措施,包括化学法、物理机械法与其他一些方法。     

生物滴滤池处理甲苯废气的研究*

以陶粒和活性炭为填料的生物滴滤池系统,对人工合成的甲苯废气进行了净化处理试验,4个多月的运行结果表明:(1)添加活性炭能提高填料柱的处理性能,陶粒和活性炭组成的复合填料能有效地处理含有甲苯的废气,当进气浓度为2·35g/m³时,去除率可达95%以上,填料柱对甲苯的去除能力为130g/m³·h;(2)在低浓度下,生物滴滤池的处理性能受传质过程控制;(3)填料柱出气通过循环液曝气处理后,废气中甲苯浓度进一步降低。     

生物滴滤池中废气有机物的生物降解*

生物滴滤法是一种经济、有效的有机废气处理方法。从填料的选择、传质过程、微生物的筛选等几个方面介绍了影响生物滴滤池处理效果的几个关键因素。回顾以前的一些研究成果并对某些重要观点进行了总结与分析,希望能为生物滴滤池在有机废气处理的应用开发提供参考。     

Feasibility of atmospheric methane removal using methanotrophic biotrickling filters

Methane is a potent greenhouse gas with a global warming potential ~23 times that of carbon dioxide. Here, we describe the modeling of a biotrickling filtration system composed of methane-consuming bacteria, i.e., methanotrophs, to assess the utility of these systems in removing methane from the atmosphere. Model results indicate that assuming the global average atmospheric concentration of methane, 1.7 ppmv, methane removal is ineffective using these methanotrophic biofilters as the methane concentration is too low to enable cell survival. If the concentration is increased to 500–6,000 ppmv, however, similar to that found above landfills and in concentrated animal feeding operations (factory farms), 4.98–35.7 tons of methane can be removed per biofilter per year assuming biotrickling filters of typical size (3.66 m in diameter and 11.5 m in height). Using reported ranges of capital, operational, and maintenance costs, the cost of the equivalent ton of CO₂ removal using these systems is $90–$910 ($2,070–$20,900 per ton of methane), depending on the influent concentration of methane and if heating is required. The use of methanotrophic biofilters for controlling methane emissions is technically feasible and, provided that either the costs of biofilter construction and operation are reduced or the value of CO₂ credits is increased, can also be economically attractive.     

Modelling adsorption and biological degradation of nutrients on peat

A dynamic mathematical and numerical model of adsorption and biological degradation of nutrients in an organic perfusion column with recycle has been developed. This model has applicability to industrial applications of biodegradation of nutrients in wastewater such as biofilters and biotrickling filters where concentrations are dilute and solid surface coverage is low. It successfully predicts that adsorption has the effect of masking a ‘true' rate of biological degradation behind an ‘observed' rate of degradation in the liquid phase. This is due to the adsorptive capacity of peat which provides a buffer for surges in loading and makes peat a useful carrier for engineered biological systems. Four dimensionless parameters were identified to totally describe the physical system without biological activity and a further two were identified for the system with biological activity. Analytical solutions to simplifications of the model were justified by showing that the assumption of a negligible concentration gradient in the column was valid after an initial perturbation in nutrient concentration had passed.     

Changes in the potential functional diversity of the bacterial community in biofilters

The bacterial community structure in a biofilter treating ethanol was investigated using community level physiological profiling. Laboratory scale biofilters of two sizes (5 or 11.5 cm internal diameter with 30 or 67 cm packed height, respectively) were packed with compost and a humidified airstream loaded with ethanol passed through them. Good removal efficiencies (82–100%) and elimination capacities (49–205 g ethanol m^− 3 h^− 1) were observed in all units. Compost packing media samples were extracted and the community level physiological profiles assayed using Biolog Ecoplates. The community structure was found to be similar over a range of a few centimetres. No differences were observed between sample sizes of 0.5–1 and 6 g, and therefore, the smaller sample size (typical of that used in previous studies) is appropriate for use in the future. Two studies of parallel systems showed that the community structure diverged during the acclimation period (10 days) in one pair, but in another pair, no divergence was observed and a similar shift in community profile was observed in both units between 25 and 40 days of operation. Community level physiological profiling with Biolog Ecoplates is a useful method for detecting differences between and changes within the bacterial communities in biofilters.