In the present study, a tailor-made plug-flow reactor with 3D-printed parts and a multi-position monitoring of the pH-value, conductivity and ORP at the inlet, center and outlet part is introduced and applied in anaerobic digestion in order to investigate whether i) the formation of gradients can be detected, ii) ideal single or multiple spots for the location of sensors during an acidification process can be identified, and iii) the spatial gradient acquisition allows for an indirect monitoring of process performance measures, e.g. the accumulation of short-chain carboxylic acids.

During the acidification of a full digestion and in dark fermentation with maize and grass silage, the multi-position monitoring of the liquid phase revealed that the local monitoring of conductivity at the inlet and center, the ORP at the center and outlet and the pH-value at the outlet are relevant to gain information of the process performance, while the spatial gradient monitoring of the conductivity between the inlet and center and of the ORP between the center and outlet are relevant for the early detection of process disturbances.

在本研究中，介绍了一种定制的带 3D 打印部件的活塞流反应器，并在入口、中心和出口部分对 pH 值、电导率和 ORP 进行多位置监测，并将其应用于厌氧消化，以便研究是否 i) 可以检测到梯度的形成，ii) 可以确定酸化过程中传感器位置的理想单个或多个点，以及 iii) 空间梯度采集允许间接监测过程性能测量，例如，短链羧酸的积累。

在玉米和牧草青贮饲料的全消化和暗发酵酸化过程中，液相的多位置监测显示，入口和中心的电导率、中心和出口的 ORP 以及 pH-出口处的值与获得过程性能信息相关，而入口和中心之间的电导率以及中心和出口之间的 ORP 的空间梯度监测与过程扰动的早期检测相关。