Flotation of suspended solid by introducing coagulant and fine bubbles in the mobile wastewater treatment plant

Abstract

Turbidity is an essential process variable in water treatment processes for clean water. This study reports the development of a mobile mini wastewater treatment plant (WTTP) intended to provide clean water in flooding incidents, where access to clean water is demanding. The mobile mini-WTTP employed with a fine bubbles generator aims to provide micro and nano bubbles with longer residence in the water expected to promote an effective flotation process. The system was evaluated in removing suspended solid capability to reduce total suspended solids (TSS) or water turbidity. The system consists of a mesh trap, chemical flocculation, dissolved air flotation chamber, and activated carbon–zeolite as a mineral filter. The system was tested on the suspended solid from homogenized clay resulted from a turbid tap water effluent with adjusted turbidity up to 500 FNU on the storage tank. Alum solution with a dosage of 200 mg/L was used as a coagulant agent. In the flotation process was introduced a fine bubbles generator with a pressurized mechanism. The effluent was pumped from a storage tank into a treatment plant with a flow rate of 200 L/h, and the samples were obtained after the separation from the corresponding sub-system at the condition of steady state of water flow. A digital water quality measurement was operated to evaluate the effluent after the separation process. The results show that the separation of turbidity up to 98% was obtained at the end of the processing system. The successful flotation of the suspended solid due to the zeta potential turn to zero up on the addition of flocculants lead to effective fine bubbles flotation. Finally, clean water was achieved in the performance test of mobile mini WTTP utilized with fine bubbles.