A manner of providing an improved fluid processing arrangement, and bioprocessing in particular, is adapted to agitate the fluid, and also simultaneously provide for the distribution of gas throughout the fluid in order to maintain desirable processing conditions (such as an increased level of dissolved oxygen, in the case of biological applications). In some embodiments, the mixing would be completed without necessitating the use of an external drive motor or the like, such as by using a fluid-driven mixer. Overall, use of the improved arrangement leads to a simplification of the fluid processing operation with improved results and a concomitant reduction in the expense associated with such use.