ZEOLITE APPLICATION TO SEA WATER FOR AMMONIA ABSORBTION AND ITS EFFECTS ON GROWTH AND SURVIVAL OF PENAEUS INDICUS

We evaluated Zeolite efficiency in absorbtion of ammonia from sea water. Three phases including ammonia movement through Zeolite column, application of Zeolite powder and granule in closed containers filled with ammonia solution and dispersion of Zeolite in shrimp culture tanks were implemented in the study. For the first phase, ammonia solution in two concentrations (4.8 and 2.42mg/lit) and a water salinity of 42 ppt (sea water) was passed through the Zeolite column (400g of granule Clinoptilolite) in three replications.
Concentration of ammonia in outlet solution was between 0.2-5.4mg/lit in the first replication and 0.0 to 5.5, 0.0 to 2.6mg/lit in the 2nd and 3rd replication, respectively. At the second phase, volume and levels of ammonia concentration left in the closed jug of ammonia solution was different. The concentration of ammonia was measured at various time periods in four replications. The results showed that ion exchange in seawater is not a one way process, so that ammonia concentrations in the jugs with Zeolite fluctuated with time, contrary to its stable concentration in control treatments. At the third phase, Zeolite in granule and powder forms was added to culture tanks of shrimp juveniles (Penaeus indicus) weighting on average 0.2g each for 79 days of culture period and a stoking density of 16 individuals per square meter. Thus, we provided three treatments, using Zeolite granules, powder and one control. A Duncan's test of the growth and survival rate of the cultured shrimps showed no significant difference among the treatments (P>0.01).