Okkerse W J, Ottengraf S P, Osinga-Kuipers B, Okkerse M
Eindhoven University of Technology, P.O. Box 513, STW 0.35, 5600 MB, The Netherlands.
Biotechnol Bioeng. 1999 May 20;63(4):418-30. doi: 10.1002/(sici)1097-0290(19990520)63:4<418::aid-bit5>3.0.co;2-0.
A dynamic model is developed that describes the degradation of volatile acidifying pollutants in biotrickling filters (BTFs) for waste gas purification. Dynamic modelling enables the engineer to predict the clogging rate of a filter bed and the time it takes the BTF to adapt to changes in its inlet concentration. The most important mechanisms that govern the behaviour of the BTF are incorporated in the model. The time scale of the accumulation of biomass in a filter is investigated, and an approach is presented that can be used to estimate how long a BTF can be operated before its packing has to be cleaned. A three-month experiment was carried out to validate the model, using dichloromethane (DCM) as a model acidifying pollutant. Valuable experimental data about biomass accumulation and liquid hold-up in the reactor were obtained with an experimental set-up that allows the continuous registration of the weight of the BTF. The results show that in BTFs eliminating DCM from a waste gas, clogging is not to be expected up to concentrations of several g/m3. Model calculations based on the measurements also suggest that the maximum carbon load that can safely be applied per unit void packing volume should not exceed 0.5-1.6 C mol/(m3. h), depending on the density of the biofilm formed. The model is a good predictor of the elimination of the pollutant in the system, the axial gas and liquid concentration profiles, the axial biomass distribution, and the response of the system upon a stepwise increase in the DCM inlet concentration. The influence of the buffer concentrations in the liquid phase upon the performance of the BTF is investigated.
开发了一个动态模型，该模型描述了用于废气净化的生物滴滤器（BTF）中挥发性酸化污染物的降解情况。动态建模使工程师能够预测滤床的堵塞速率以及BTF适应其入口浓度变化所需的时间。该模型纳入了控制BTF行为的最重要机制。研究了滤器中生物质积累的时间尺度，并提出了一种方法，可用于估计BTF在其填料必须清洗之前能够运行多长时间。使用二氯甲烷（DCM）作为模型酸化污染物进行了为期三个月的实验，以验证该模型。通过一种允许连续记录BTF重量的实验装置，获得了关于反应器中生物质积累和持液量的宝贵实验数据。结果表明，在从废气中去除DCM的BTF中，在浓度达到几g/m³之前预计不会发生堵塞。基于测量的模型计算还表明，根据形成的生物膜密度，每单位空隙填料体积可安全施加的最大碳负荷不应超过0.5 - 1.6 C mol/(m³·h)。该模型能够很好地预测系统中污染物的去除情况、轴向气体和液体浓度分布、轴向生物质分布以及系统对DCM入口浓度逐步增加的响应。研究了液相中缓冲剂浓度对BTF性能的影响。
