PODS FROM ALBIZIA LEBBEK AS A NOVEL WATER SOFTENING BIOSORBENT

The paper presents the results of a preliminary investigation into the use of Albizia lebbek seed pods for water softening by the adsorption of calcium. These results show that at 25 degrees C, the adsorption i ncreased with the pH value. An analysis of the adsorption rates by thr ee different techniques suggested that the sorption of the calcium ion s was the rate limiting stage in the overall process. The data were fo und to conform to both the Langmuir and the Freundlich equations and t he values of the equation constants confirmed that a better adsorption was achieved at a pH value of 10.82 than at one of 5.95. The maximum specific adsorption (Q(o)) derived from the Langmuir equation was 63.3 6 mg Ca/g at the higher pH value of 10.82