Common oak (Quercus robur) acorn as a source of natural coagulants for water turbidity removal

The potential of whole fruit of acorn and its cotyledons and coat to be used as sources of coagulation active components was studied. Water extracts of whole fruit, cotyledons and coat were the most efficient at 35 NTU. Crude extracts of acorn cotyledons and coat prepared with 1 mol/L and 0.5 mol/L NaCl as solvents, respectively, exhibited their highest coagulation activities 27% and 42%, respectively, at pH 9. Partially purified protein fractions from whole fruit showed maximal potential for turbidity removal at dosages equal or less than 2.5 μg/L. Results of protein precipitation from crude extract of cotyledons indicated that other extracted biomolecules besides protein can be active in coagulation process at applied conditions. Organic load in water treated by crude extract from coat lower than that of blank indicated this part of acorn as promising source of natural coagulant whose extraction and conditions of usage should be further investigated.