Disinfection of stabilization pond effluent by peracetic acid and sodium hypochlorite

Abstract

Aims: In this study, the efficiency of peracetic acid (PAA), sodium hypochlorite (NaOCl) and combination of both disinfectants for disinfection of stabilization pond effluent was assessed. Materials and Methods: The samples was collected during four months. All samples were analyzed as triplicate according to the Standard Methods. Microbial tests were carried out to total coliform (TC), fecal coliform (FC) and fecal streptococci (FS) . Also, the physical characteristics such as the total suspended solids, and also chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were analyzed. Results : In this study, the application of combined disinfectants lead to reduction of total coliform, fecal coliform and fecal streptococci from 2.8×10 5 , 2.2×10 5 and 7.1×10 4 to 1.6×10 3 , 5×10 1 and 1.9×10 2 MPN/100 ml, correspondence to 2.55, 3.64 and 1.83 log removal value (LRV), respectively. Conclusions: The study demonstrated that application of combined PAA and NaOCl in disinfecting the effluent of the stabilization pond will promote the efficiency of disinfection process in inactivating the coliform group bacteria and fecal streptococci.

Keywords

• Disinfection
• fecal coliform
• fecal streptococci
• NaOCl
• PAA
• total coliform