Sustainable Application of Chitosan for Water Purification

ABSTRACT

Alum (potassium aluminum sulfate-K+Al3+ (SO42-) 2), ferrous sulfate (Fe2+ SO42-), ferric chloride (Fe2+2Cl-) and ferric chloro-sulfate (Fe2+Cl-SO42-) were commonly used as coagulants. However, a possible link of Alzheimer’s disease with conventional aluminum based coagulants and other adverse bioaccumulation cases associated with heavy metal have become an issue in wastewater treatment. Hence, special attention has shift towards using biodegradable polymer like chitosan in treatment, which are more environmental friendly. Moreover, chitosan is natural organic polyelectrolyte of high molecular weight and high charge density which obtained from deacetylation of chitin. In this work, chitosan was produced from snail shells and experiments were carried out on Jesse river water sample by analyzing water criteria parameters before and after treatment of the water sample with the produced chitosan and alum in order to investigate the purification performance of chitosan in comparison to alum in terms of their ability of boasting water quality and safety as expressed by parameters reduction or increment after treatment. The results obtained shown that chitosan is more effective in boasting water quality relatively to alum as turbidity, total solids, conductivity, total hardness, nitrate, BOD5, COD, Al3+ etc. were reduced by 44.23%, 30.61%, 64.63%, 35.51%, 10.64%, 32.46%, 75.34%, 25% while alum reduced same parameters by 17.30%, 17.76%, 33.33%, 21.56%, 7.30%, 27.98%, 71.56% respectively. Also, chitosan boast DO by 72.52% and increased the pH from 6.20 to 7.8 but alum yielded 46.03% and reduced pH from 6.20 to 5.8. Hence, chitosan is an effective coagulant, which can reduce the turbidity, total solids, conductivity, total hardness, nitrate, BOD5, COD, Al3+ etc. wastewater and maybe substituted for alum at the coagulation/flocculation stage of a water treatment process, especially for domestic use.