Physicochemical and Biological Characteristics of Shrimp Pond Sludge in the Thua Thien Hue Province, Vietnam

Abstract

This study has been carried out to analyze the physical and biological indicators of shrimp pond sludge samples obtained from the Phu Vang and Phu Loc districts of the Thua Thien Hue Province, Vietnam. All standard methodologies have been used to analyze the selected parameters like pH, organic carbon, total nitrogen, total phosphate, and microbial density. The results of the study revealed that the sludge was characterized by a neutral to alkaline pH (6.9 - 7.5), and the total organic carbon content was in the range of 103.8–173.5 mg/kg. The sludge was rich in organic matter (17.8–29.9%), total nitrogen (13.5–32.5 g/kg), and total phosphate (7.9-20.1 g/kg). Further, in the case of the microbial density of pathogenic microorganisms, the density of total bacteria, coliform, E.coli, Salmonella spp., Vibrio spp., and Clostridium spp. was also estimated at two opposing weather conditions (spring, February to March; summer, June to July). The microbial community increased rapidly during the cool spring months. The total bacterial levels were recorded as 8.77 log10 CFU/mL in the Phu Loc district and 9.11 log10 CFU/mL in the Phu Vang district. The levels decreased during the hot summer months, and the level of total bacteria, Coliform, E.coli, Salmonella spp., and Vibrio was reported 2.57, 1.49, 1.06, 0.56, and l2.54 log10 CFU/mL respectively from the Phu Loc district of Vietnam. The results obtained using the anaerobic decomposition model showed that on the 60th day, the amount of CH4 generated at the high output value for the Phu Vang district was 22385 ppm. The results reported here revealed that CH4 gas can be potentially produced from shrimp waste sludge in this province.