Effect of bacterial additives on the performance of septic tanks for wastewater treatment in the Upper Egypt rural area

Abstract

A mixture of five selected, adapted, enzyme active producer bacterial species has been used as an additive to septic tanks in order to test its ability to increase treatment efficiency. Regarding the septic tanks receiving waste with medium load, the maximum removal was achieved at day thirty and showed ranges for removal % reaching 91.3-94.4, 93-95.8, 90-91.7, 75-87, and 99.95-99.99 for COD, BOD5, TSS, oil and grease and total coliforms, respectively. Septic tanks without bacterial additives were able to show removal % ranged as 79.3-88.5, 80-85.5, 75.1-83, 28-41.7 and 98.5-99.85 for the same parameters. Septic tanks that receiving influent with high load of pollutants, the maximum removal was achieved during the period of day 36-42 after addition of bacteria. The removal percentages for COD, BOD5, TSS, oil and grease and total coliform were ranged as 93.8-97.2, 94.5-97.0, 94.0-97.9; 64.0-93.8; 99.81-99.99, respectively. Septic tanks without bacterial additives showed percentages of removal ranged as: 64.7-87.2, 73.4- 89.6, 56.7-86.9, 34.6-45, and 92.8-99.28 for COD, BOD5, TSS, oil and grease and total coliforms, respectively. © 2010 WIT Press.