Turbidity removal by conventional and ballasted coagulation with natural coagulants

Kernel of Moringa oleifera and Strychnos potatorum (Nirmali) seeds has the potential for turbidity removal. However, potential of seedkernel naturally dried in trees and that of sun-dried and oven-dried seeds and other parts, such as coat and wing of Moringa oleifera, has not been explored. In the present study, various forms of kernel and parts of Moringa oleifera seed were used to assess the removal of turbidity aided with/without coagulant aid and ballasting agent. Low (<12 NTU), medium (>13<=24 NTU) and high turbidity (>=25<=35 NTU) water samples were used in the present study. Micro-sand and powdered activated carbon (PAC) were used as ballasting agents along with Aloe Vera as a coagulant aid/natural polymer. The kernel from seeds naturally dried in Moringa oleifera tree was found to possess more coagulant property. The optimum dose of Moringa oleifera for medium and high turbidity was found to be 50mg/L and 100mg/L, respectively, with turbidity removal of 90.46% and 88.57%. The optimum dose of Strychnos potatorum was 0.2mg/L, 0.6mg/L, and 0.8mg/L for low, medium and high turbidity, with turbidity removal as 71.42, 64.28 and 57.14%, respectively. Aloe Vera acts as a coagulant aid with the natural coagulants and increases turbidity removal. Ballasting agents micro-sand and PAC, with Aloe Vera and coagulants, increase turbidity removal and reduce the settling time.