Year: 2019
Type: conference-paper
Abstract: E. coli is a common Gram-negative facultative anaerobic bacterium.Its principal habitat has been identified in the intestinal tracts of mammals and birds as well as non-host environment (water/sediments).It is widely used as an indicator bacterium and its detection in water indicates possible pollution with waterborne pathogens.The organism's quantification after post treatment (chlorination) serves to evaluate the performance of a WWTP for microbial reduction.South African General Authorisation and Special standards stipulate that treated sewage effluents must have a limit of 1000 and 0 (zero) E. coli (per 100mL) respectively.This study aims at determining the efficiency of the WWTP in a small town of South Africa in eradicating the presence of E. coli through its contact tank disinfection (chlorination) process.Samples were collected for detection of E. coli using Colilert 18 method, from wastewater before chlorination and final effluent after chlorination.Physicochemical analyses were also conducted from the final effluent discharged to the river (Mooi River).The plant applies an average of 10 KG per hour of chlorine to eradicate E. coli.Since the inception of the study, up to date the plant is at an average of 48 E. coli count detected (8% compliance to zero E. coli) at the final effluent.Suspended solids which enhance the presence of these organisms were within the plant WUL at all time.An average of 3.7 mg/L of turbidity was detected.In comparison with the plant WUL, other physicochemical determinants such as pH, conductivity, nitrate, ammonia, ortho-phosphate and COD were at 100%, 100%, 7%, 97%, 100% and 100% respectively.Nitrate is also one determinant affecting the plant optimal performance.Although the average detected organisms showed to be lower, however the plant efficiency of eradicating the organisms is not efficiently meeting the regulated required limits of the plant.Such investigation is crucial in determining the compliance of the plant to its Water Use License (WUL).
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: bronze
Funder: University of Johannesburg
OpenAlex ID: W4242699975