Surfactant efficiency on pentachlorophenol-contaminated wastewater enhanced by Pseudomonas putida AJ 785569

Abstract

This study aims to evaluate the effect of three surfactants on the removal of PCP (800 mg L^-1) from Secondary Treated Wastewater (STWW) by Pseudomonas putida AJ 785569. The effect of surfactants [sodium lauryl sulfate (SDS) as anionic, Tween 80 (TW80) as non-anionic and cetyltrimethylammonium bromide (CTAB) as cationic] is tested about the three following aspects: (1) bacterial growth, (2) bacterial biofilm formation or development and (3) PCP rate removal. The results showed that strain P. putida AJ 785569 could adsorb around 30 mg L^-1 and remove 600 mg L^-1 of PCP within 168 h of incubation. The SDS developed the growth of bacteria and the removal of PCP. This PCP removal in mineral salt medium (MSM) is around 760 mg L^-1 (95% degradation) higher than the ones registered with CTAB and TW80 with a value 506.75 (63% degradation) and 364.1 mg L^-1 (45% degradation), respectively. The obtained results of chloride concentration showed an important relation with PCP removal during incubation with an important value. Monitoring the development of bacterial biofilm, in MSM medium added with PCP (100 mg L^-1) by strain P. putida AJ 785569, showed a significant increase in the optical density value from 0.9 to 4 at λ = 595 nm, a modification of strain P. putida AJ 785569's morphotype, density and color colonies.

Keywords: Biofilm development; Pentachlorophenol; Pseudomonas putida; Surfactants; Wastewater.