Treatment of water turbidity and bacteria by using a coagulant extracted from Plantago ovata

A biocoagulant was successfully extracted from Plantago ovata by using an FeCl3-induced crude extract (FCE). The potential of FCE to act as a natural coagulant was tested for clarification using the turbid water of a river. Experimental tests were performed to evaluate the effects of turbidity concentration, coagulant quantity, water pH, and humic acid concentration on the coagulation of water turbidity by FCE. The maximum turbidity removal was occurred at water pH<8. At the optimum dosage of FCE, only 0.8 mg/L of dissolved organic carbon was released to the treated water. An increase in the humic acid led to the promotion of the water turbidity removal. Results demonstrated that the FCE removed more than 95.6% of all initial turbidity concentrations (50–300 NTU). High bacteriological quality was achieved in the treated water. FCE as an eco-friendly biocoagulant was revealed to be a very efficient coagulant for removing turbidity from waters.