Biswas Ishita, Sadrzadeh Mohtada, Kumar Aloke
Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8, Canada.
Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560012, India.
Biomicrofluidics. 2018 Aug 20;12(4):044116. doi: 10.1063/1.5025359. eCollection 2018 Jul.
We investigate the effect of biofouling in a microfluidic filtration system. The microfluidic platform consists of cylindrical microposts with a pore-spacing of 2 m, which act as the filtration section of the device. One of our key findings is that there exists a critical pressure difference above which pronounced streamer formation is observed, which eventually leads to rapid clogging of the device with an accompanying exponential decrease in permeate flow. Moreover, when streamers do form, de-clogging of pores also occurs intermittently, which leads to small time scale fluctuations [O(10 s)] superimposed upon the large time scale [O(10 min)] clogging of the system. These de-clogging phenomena lead to a sharp increase in water permeation through the microfluidic filtration device but rates the water quality as biomass debris is transported in the permeate. Streamer-based clogging shares similarities with various fouling mechanisms typically associated with membranes. Finally, we also show that the pH of the feed strongly affects biofouling of the microfluidic filtration system.
我们研究了微流控过滤系统中生物污垢的影响。该微流控平台由孔隙间距为2μm的圆柱形微柱组成，这些微柱作为设备的过滤部分。我们的一个关键发现是，存在一个临界压差，高于该压差时会观察到明显的流光形成，这最终会导致设备迅速堵塞，同时渗透流呈指数下降。此外，当流光形成时，孔隙的解堵塞也会间歇性发生，这会导致在系统的大时间尺度[O(10分钟)]堵塞之上叠加小时间尺度[O(10秒)]的波动。这些解堵塞现象导致通过微流控过滤设备的水渗透急剧增加，但由于生物质碎片在渗透物中传输，水质变差。基于流光的堵塞与通常与膜相关的各种污垢机制有相似之处。最后，我们还表明，进料的pH值强烈影响微流控过滤系统的生物污垢。
