Fish Hatchery Management - fisheries & aquaculture

FISH HATCHL,RY MANAGEMEN'IWASTE SLUDGECHLORINEBREAKPOINTCHLORINATIONNITROGEN GASACT I VAT EDCA R BONADSORPTIONCHLORAMINES,EXCESS CHLORINEAND DISSOLVEDORGAN ICSAE RATI ONIItRECONDITIONEDWATERFtcunn .10. Schematic diagram of breakpoint chlorination removalof ammonia from hatchery waste water.its practicality in hatcheries. An advantage of this system is that all treatedwater is sterilized.Oxidation ponds or lagoons can remove 35-U5'il of the ammonia inwastewater through microbial denitrification in the pond bottom andthrough uptake by algae. This method requires considerable land area andextended retention time of the wastewater in the lagoon. Oxidationlagoons work best in southern climates. Cold weather significantly reducesbiological activity.ESTIMATION O!'AMMONIABecause of the importance of ammonia to fish production total ammonia inhatchery water should be measured directly on a regular basis. However,rough estimates of total ammonia can be made from an empirical formula,if necessary. Although ammonia can be contributed by source water and by