A collection device for various-sized microparticles that uses four serial acoustic separations: Working toward microplastic emission prevention
A collection device for various-sized microparticles that uses four serial acoustic separations: Working toward microplastic emission prevention
复制标题
采用四个连续声学分离的各种尺寸微粒的收集装置：致力于防止微塑料排放
DOI：
10.1016/j.seppur.2023.123697
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发表时间：
2023
影响因子：
8.6
通讯作者：
Akiyama Yoshitake
中科院分区：
文献类型：
--
作者：
Jonai Tatsuki;Ohori Yuimaru;Fujii Tadahiko;Nakayama Akemi;Moriwaki Hiroshi;Akiyama Yoshitake
尺寸小于5毫米的小塑料碎片被称为微塑料（MPs），是一个新兴的全球生态问题。本研究开发了一种高富集微流控装置，利用四次连续声分离来收集不同大小的微颗粒。为了使该装置用于高达200µm的MPs，通过降低激励频率来拓宽微通道。设计的微流控装置在每个结处富集3.2倍，在四个结处富集105倍。该装置的微流控网络是在液压-电类比的基础上设计的，即使只有一个泵，没有多个精确的流量控制器，它也能工作。该装置的收集性能是根据总收集率来评估的，而总收集率又基于四个节点的微观观察和实际收集率以及通过测量出口流出物获得的实际富集比。首先，分别使用直径为5、10、15、25、50和200µm的微粒对该装置进行评估。总收集率超过90%，除了5µm的微粒似乎太小，无法在较低的频率下进行声学操作。最后，用两种样品混合物对该装置进行了评估，这些样品混合物代表了200µm到25µm的小MPs和25µm到10µm的非常小的MPs。总回收率和实际回收率都在70%到90%之间。然而，实际的富集比范围从设计值105的一半到设计值本身，因为一些微粒被减慢，一些微粒似乎被声辐射力困住并附着在微通道壁上。因此，判断微流控装置适用于粗网预过滤后的MP去除应用，而MP分析应用则需要改进，以抑制用于二维聚焦的微粒附着。综上所述，连续声分离是一种很有前途的方法，可以从环境样品中高度富集和去除各种大小的MPs。
Small plastic debris particles less than 5 mm in size called microplastics (MPs) are an emerging global ecological issue. This study developed a high enrichment microfluidic device to collect various-sized microparticles that uses four serial acoustic separations. To adopt the device for use with up to 200-µm MPs, the microchannel was widened by lowering the excitation frequency. The microfluidic device was designed for a 3.2-fold enrichment at each junction and a total 105-fold enrichment at the four junctions. The microfluidic network of the device was designed on the basis of a hydraulic-electric analogy and it worked even though only a single pump was used without multiple precise flow controllers. The collection performance of the device was evaluated based on the total collection rate that in turn was based on microscopic observations at the four junctions and the actual collection rate and the actual enrichment ratio obtained by measuring the effluents from the outlets. First, the device was evaluated separately using microparticles of 5, 10, 15, 25, 50, and 200 µm in diameter. The total collection rates were over 90% except for the 5-µm microparticles which seemed to be too small to manipulate acoustically at the lowered frequency. Finally, the device was evaluated with two example mixtures representing small MPs ranging from 200 µm down to 25 µm and very small MPs ranging from 25 µm down to 10 µm. Both the total collection rates and the actual collection rates ranged from 70% to 90%. However, the actual enrichment ratios ranged from half the designed value of 105 to the design value itself as some microparticles were slowed down and a few seemed to become trapped and attached to the microchannel walls by acoustic radiation force. Therefore, the microfluidic device was judged to be applicable to MP removal applications after prefiltration through a coarse mesh, while the MP analysis applications were judged to require improvement to inhibit the microparticle attachment used in 2D focusing. In conclusion, the serial acoustic separations could be a promising approach to highly enrich and remove various-sized MPs from environmental samples.