Biodegradation of Polychlorinated Biphenyls (PCBs), Aroclor 1260, in Wastewater by Isolate MD2 (Pseudomonas aeruginosa) from Wastewater from Notwane Sewage Treatment Plant in Gaborone, Botswana

摘要

Notwane Sewage Treatment Plant is situated on the eastern part of Gaborone emptying its effluent into Notwane River which flows along the periphery of Gaborone. The wastewater treatment plant receives wastewater from most major industries, and most of the residential waste water for the city of Gaborone. The wastewater is not recycled despite the great shortage of water in Gaborone and surrounding villages and the drying up of Gaborone dam. Wastewater samples from the treatment plant was collected and taken to Department of Biological Sciences in Mafikeng for analysis of PCB (Aroclor 1260) degradation by bacteria. Biodegradation of polychlorinated biphenyls using MD2 was conducted using Aroclor 1260 added to wastewater obtained from Notwane Sewage Treatment Plant by measuring shift in the wavemax (λmax) nm using Cary 300 UV-visible spectrophotometer, for a period of 96 hours. The presence/absence of the compounds was checked using High Performance Liquid Chromatography (HPLC) UFLC Shimadzu using florescence detector pump RF-20A and system gold column C18 (CTO-20A) after 96 hours. The bacterial strain MD2 was found to have completely degraded the Aroclor1260 in wastewater after 96 hours. A shift in maximum wavelength was observed to be from 224 nm to 270 nm, an indication that Aroclor 1260 was degraded forming a chlorobenzoate derivative. This renders the wastewater free from polychlorinated biphenyls thus can be safely recycled.