Improvement of drinking water properties using a novel biosorbent material

In the present study, a new material has been discovered in the world of natural coagulants and adsorbents to improve drinking water properties. Flaxseed husk was used as a natural coagulant and adsorbent to remove turbidity, natural organic matter and iron from underground water for several wells in Al-Jouf region in the north of the Kingdom of Saudi Arabia. To remove turbidity and natural organic matter, modified flaxseed husk (MFH) was prepared by addition of aluminum sulfate (AS) to flaxseed husk (FH) after removing mucilage and oil. The characterization of FH shows high specific surface area (125.18 m2/g) with average pore diameter of 26.28 μm. Moreover, FTIR spectra analysis indicated existence of large number of amino groups and another functional group indicated that FH efficiency about removal of turbidity and natural organic matter. The optimum ratio MFH:AS for removal was (80%:40%). Batch experiments were performed as function of process parameters such as slow mixing time, FH dosage and Initial NOM. The removal of turbidity and natural organic matter (NOM) by modified flaxseed husk (MFH) were investigated using a FH dosage of 40 mg.l-1 and 10 mg.l-1 AS which attained a removal efficiency of 98.0 % for turbidity and 99.3 % for NOM at the highest NOM concentration. Also, reduce the iron concentration in drinking water by flaxseed husk ash (FHA) which prepared by burning flaxseed husk at certain temperature was investigated. Batch experiments were performed as function of process parameters such as FHA type, contact time (CT), FHA dosage and initial Fe concentration. The FHA showed a high removal of Fe3+ from aqueous solution. The maximum Fe removal was 90% at FHA200, FHA dose 0.75 g/l and contact time 45 min, The pH value from 7 to 7.8 and the temperature value from 20 to 24 0C. The adsorption equilibrium has been studied by the pseudo first order kinetics model, the pseudo second order kinetics model, Langmuir and Freundlich isotherm, all these models demonstrated the adsorption efficiency of the adsorbent surface behaved in a favorable manner for Fe adsorption .