Carbonaceous biochemical oxygen demand and nitrification oxygen demand of the sediments of Penaeus monodon culture ponds

Abstract

Five-day carbonaceous biochemical oxygen demand (CBOD₅) of Penaeus monodon pond sediments varied between 10.0 and 40.8 mg/g dry weight. Ultimate carbonaceous BOD of the sediments varied between 16.3 and 61.5 mg/g dry weight. Average CBOD₅ of the sediments was 23.2 mg/g dry weight and average ultimate carbonaceous BOD of the sediment was 33.1 mg/g dry weight. CBOD₅ of the sediments were 64.9 to 84.7 percent of ultimate CBOD. Rate of biochemical oxidation (k) of shrimp pond sediments varied between 0.09 and 0.15 per day with an average k valu of 0.11. Nitrification oxygen demand of shrimp pond sediments varied between 0 and 1.0 mg/g dry weight at 5 days, 2.0 and 4.8 mg/g at 10 days and 4 and 5.6 mg/g at 20 days. Combined oxygen demand of shrimp pond sediments varied between 11.0 and 35.4 mg/g at 5 days, 14.7 and 47.8 mg/g dry weight at 10 days, and 17.7 and 55.1 mg/g dry weight at 20 days. Average twenty-day nitrification oxygen demand of shrimp pond sediments was 5.8 mg/g dry weight. At 20 days. nitrification oxygen demand were 15.6 to 25.6 percent of combined oxygen demand. Results of laboratory scale investigation indicated that aeration of overlying water together with periodically stirring of the sediment can significantly increase reduction rate of BOD₅ of shrimp pond sediments.