1. Thirdly, considering the nature of Bidirectional pedestrian flow, a modified crossing time model based on the drag force theory is formulated as a function of the number of pedestrians, the directional ratio, and the crosswalk width.

2. The system also has a processor coupled to the agitator and configured to create at least a minimum self-cleaning drag force between drilling sludge passing through the enclosed flow zone and the combined at least one type of biological microorganism and the at least one bio-suspension element.