The filter media from iron and manganese biological removal filter which w- as replaced by new termly can be re-used.The sand filter media was characterized u- sing the SEM and owns developed interspaces.Drying the sand filter media at 110°C,then inspect and analyse its character and mode of defluoridation.The results show as follows.Under the test condition ,the adsorption balance can come out in about 3 hou-rs ,the fluoride sorption on the re-used matured filter media followed pseudo-second kinetics.The effect of defluoridation by the matured filter media will be better within the range of pH 3～7,and best at about pH 4.58.The primary mode of fluoride sorpti- on is chemism,but physical sorption is also in existence ,and the adsorption isother- ms could be described by Langmuir equation.Contact-time is a vary important factor in the continuous-flow column experiment.The effect of fluoride removal is long,as the height of filter column is controlled as 40cm.The filter media from iron and manga- nese biological removal filter possess potential of perfect sorbent,space for deeply study and foreground of practical application.
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