Biodegradation of Polyethoxylated Nonylphenols
Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEO x ), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEO x and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO 15 , as unique carbon source, is described. The most efficient NPEO 15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO 15 medium. The NPEO 15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO 15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h(-1) and 96.3 h, respectively.
Application of surfactants to increase the mobility of hydrophobic contaminants in soils will create a secondary aqueous waste stream containing mobilized contaminant and surfactant that may be biodegraded. Previous research on surfactant biodegradation focused on low surfactant concentrations, typically less than 0.01 % (weightlweight). The goal of this project was to investigate the effect of...متن کامل
Synthesis of nonionic-anionic colloidal systems based on alkaline and ammonium β-nonylphenol polyethyleneoxy (n = 3-20) propionates/dodecylbenzenesulfonates with prospects for food hygiene
UNLABELLED BACKGROUND The main objective of this work was to obtain a binary system of surface-active components (nonionic soap - alkaline and/or ammonium dodecylbenzenesulfonate) with potential competences in food hygiene, by accessing a scheme of classical reactions (cyanoethylation, total acid hydrolysis and stoichiometric neutralization with inorganic alkaline and/or organic ammonium bas...متن کامل
Influence of operating parameters on the biodegradation of steroid estrogens and nonylphenolic compounds during biological wastewater treatment processes.
This study investigated operational factors influencing the removal of steroid estrogens and nonylphenolic compounds in two sewage treatment works, one a nitrifying/denitrifying activated sludge plant and the other a nitrifying/denitrifying activated sludge plant with phosphorus removal. Removal efficiencies of >90% for steroid estrogens and for longer chain nonylphenol ethoxylates (NP4-12EO) w...متن کامل
Natural attenuation of priority and emerging contaminants during river bank filtration and artificial recharge
The fate of various emerging contaminants as well as priority pollutants from the European Union Water Framework directive was examined along a complex combination of natural and engineered processes used to produce drinking water downstream of a major metropolitan area. The sampling points examined comprised Seine river water downstream of the Paris area, water from a primary well after bank f...متن کامل
Influence of Hydrophobe Type and Extent of Branching on Environmental Response Factors of Nonionic Surfactants
A number of ethoxylated nonionic surfactants differing in hydrophobe branching and chain lengths have been evaluated for environmental responses. Screening biodegradation tests show those non-ionics having more than one methyl group per hy-drophobe degrade considerably slower than those having less extensive branching. Continuous flow-through activated sludge tests, simulating actual waste trea...متن کامل