comparison of water turbidity removal efficiencies of descurainia sophia seed extract and ferric chloride

background; turbidity removal using inorganic coagulants such as iron and aluminum salts in water treatment processes causes environmental and human health concern. historically, the use of natural coagulant to purify turbid water has been practiced for a long time. recent research indicates that descurainia sophia seed can be effectively used as a natural coagulant to remove water turbidity. method; in this work, turbidity removal efficiency of descurainia sophia seed extract was compared with ferric chloride. experiments were performed in laboratory scale. the coagulation experiments were done with kaolin as a model soil to produce turbidity in distilled water. the turbidity removal efficiency of descurainia sophia seed extract and ferric chloride were conducted with jar test apparatus. in all experiments, initial turbidity was kept constant 100(ntu). optimum combination of independent variables was used to compare two different types of coagulants. result; the obtained results showed that ferric chloride could remove 89.75% of the initial turbidity, while in case of descurainia sophia this value was 43.13%. the total organic carbon (toc) analysis of the treated water using seed extract showed an increased concentration of toc equal to 0.99 mg/l. conclusions; this research has shown that descurainia sophia seed extract has an acceptable potential in the coagulation/flocculation process to treat turbid water.