Which type of treatment process involves rapid chemical reaction due to recycled materials?

The solids-contact basin treatment process involves a rapid chemical reaction that enhances water treatment by utilizing recycled materials, particularly sludge. In this system, the treated water interacts with recycled sludge, which contains a concentration of activated solids from previous treatment stages. This interaction promotes a rapid flocculation process, where fine particles clump together to form larger aggregates called flocs.

The inclusion of recycled materials allows for an increase in the surface area of solids available for interaction and reaction with contaminants, leading to improved settling and a more efficient removal of pollutants from the water. The solids-contact basin process effectively combines the functions of flocculation and sedimentation in one system, making it a highly efficient method for treating water.

Other options, like flocculation, chlorination, and filtration, do not primarily hinge on the rapid reaction facilitated by recycled materials. Flocculation is a process meant for the agglomeration of particles but does not incorporate the same intense chemical interaction with recycled solids as seen in solids-contact basins. Chlorination is primarily a disinfection step rather than a primary treatment process involving chemical reactions with recycled materials. Filtration serves to physically remove contaminants from water but does not involve the same rapid chemical reactions or adjustments using recycled materials.