الفهرس 
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Abstract
The main purpose of this study was to provide oxygen requirements and assess the aquatic environment during the growing season of fish, using two aeration systems. The first one was to simulate nozzle spray by using micro-sprinkler and the other one was to simulate bubble aeration by using porous pipes. The study was conducted during the period from 19th October till 12 December 2021 at a private house in Kafr Saad city, Damietta governorate.Initial experiments were conducted to investigate suitable operation conditions for the two systems. One sprinkler was installed with four different pressures that were used as follows: 15, 18, 20 and 25 m. A porous pipe operated at different air speeds namely 0.5, 0.8, 1.0 and 1.5 m/s were tested at three different heights of 200, 400 and 600 mm from the bottom operating of the tank. Primary experiments for both systems showed that the maximum obtained Oxygen Transfer Rate (OTR) was 7.5 mg/h for micro-sprinkler at 25 m, while it reached 57 mg/h using an air velocity of 1.5 m/s at used at 200 mm height from the bottom of the tank in the porous pipes ventilation system.
Micro-sprinkler aeration system, SAE was 5.0 kg O2/kW.h, while SAE in porous pipes aeration system was 2.1 kg O2/kW.h. The total costs in micro-sprinkler aeration system amounted to 156 L.E which led to the B/C ratio reached 0.26, while in porous pipes aeration system were was119.82 L.E, then the B/C ratio was 0.27. The mortality rate in micro-sprinkler aeration system reached 20%. While reached 33.3% in porous pipes aeration system. Results indicated that both systems could be used for fish ponds aeration, whether indoor or open-air ponds, considering the variation in operation procedures.