A pilot study for rapid water clarification by V-shaped nested tubes

The emergency water treatment technology supplies water when the quality of raw water becomes temporarily unpleasant due to an incident. Removing the factors producing turbidity is very important because of different issues, such as protecting microorganisms during disinfection. Thus, it is one of the priorities of water treatment in emergency conditions. The present study aimed at surveying the function of tube settlers in water treatment, especially for removing turbidity, in emergency conditions. This cross-sectional study was done by making a pilot using polyvinyl chloride material and a sedimentation tank as the control pilot. The performance of these settlers was surveyed during three different steps; without using any coagulants, using coagulants, and using coagulants and a slow sand filter. The efficiency of the tube and the control pilot were surveyed at three inlet turbidities (100, 200, and 300 NTU) at 10, 20, and 30 min retention times in each of the three steps. The samples were gathered from designated places according to the above-mentioned retention times. The best efficiency was gained at 300 NTU inlet turbidity and 30 min retention time. The average efficiency was 45.3% for the control pilot, 89.9% for the tube pilot using coagulants, 57.2% for the tube pilot without using any coagulants, and 99.4% for the tube pilot using coagulants and a slow sand filter. The results demonstrated the high efficiency of the tube pilot in removing turbidity compared to the control pilot.