Novel Helical or Coiled Flocculator for Turbidity Reduction in Drinking Water Treatment: a Performance Study Gede H. Cahyana (1) Puji Suwandhi (2) Tri Mulyani (3)
(1)(3)Environmental Engineering, Kebangsaan University
(2)Soreang Hospital, Bandung Regency, West Java Province
Abstract
Helical or spiral coiled flocculator have not been applied in drinking water treatment yet in Indonesia. There were only a few articles discussed it with different themes like hydrodynamic, floc characteristic, and performance. This study was done to know the efficiency (performance) of helical flocculator with parameters velocity gradient, pipe and helical diameter, flowrate, detention time, coagulant dose. The study was divided into two steps: Jar test to determine the optimum dose of coagulant and flocculation experiments to evaluate the helical flocculator efficiency. Efficiencies were in the range of medium to high. On flowrate 13 ml/second was obtained good results for two pipe sizes but different in helical diameters. In 0.5 inch pipe with 0.8 m helical diameter the turbidity reduction efficiencies were 72.4% and 73.9% and sediment volume were 18.3 ml and 20.0 ml. In 0.625 inch pipe with 0.4 m helical diameter the turbidity reduction efficiencies were 76.7% and 78.5% and sediment volume were 14.3 ml and 19.7 ml. The optimum velocity gradient about 64.9-69.6 persecond and detention time about 438-649 seconds. The results showed that helical flocculator was effective for floc formation. Flowrate, pipe diameter, helical diameter were three key parameters to perform helical flocculator.
