PERFORMANCE EVALUATION OF SAND AND CHITOSAN AS DUAL FILTER MEDIA

摘要

Nuisance due to suspended and colloidal particles causing turbidity has become widespread, severe problem due to urban population and industrial activities. The consequences of turbidity are presence of microorganisms, reduction of dissolved oxygen, etc. Consumption of such water is known to cause water borne diseases. Available water treatment methods for the removal of turbidity and pathogens are coagulation, filtration and disinfection. The common filter media used are sand, activated carbon etc. Chitosan has been used as a coagulant aid and adsorbent. Chitosan when used as a filter media causes the colloidal particles to bind together and is subsequently removed during the process. The column studies using Chitosan in combination with conventional sand filter was carried out in a borosilicate glass column. Chitosan was placed on top of sand layer and constant down flow pattern of 100mL/min was followed. Dual filter media was effective in the reducing turbidity by 93%.