@misc{10481/98313,
year = {2007},
month = {6},
url = {https://hdl.handle.net/10481/98313},
abstract = {This paper concerns the primary biodegradation
of different commercial fatty-alcohol ethoxylate surfactants
(FAEs), applying the OECD 301 E test for ready
biodegradability. Changes were made both in the carbonchain
length of the surfactants as well as in the number of
units of ethylene oxide (EO) in its molecule. The biodegradation
were monitored, analysing the colony-forming
units (CFU) formed during this process. From the biodegradation
profiles drawn for the FAEs, parameters
characteristic of the biodegradation process were defined:
latency time (tL), biodegradability at 50 h of assay (B),
half-life (t1/2), mean biodegradation rate until reaching
biodegradability of 85% (VM), and the residual concentration
of the surfactant (SR). The analysis of these
parameters enabled the establishment of the influence of
surfactant concentration and structure during the biodegradation
process. The increase in the surfactant concentration
lowered the rate of the biodegradation process and
the biodegradability of the surfactant in addition to the
half-life and residual concentration of the surfactant. The
mean biodegradation rate, VM, for fatty-alcohol ethoxylates
increased with the number of EO units and molecular
weight of the surfactant. At low initial test concentrations
(less than 25 mg/L), the concentration of the residual surfactant
rapidly diminished with biodegradation time. For
higher concentrations, after an adaptation period of the
microorganisms, the surfactant concentration declined
exponentially and the biodegradation rate became far
slower for all the surfactants. The parameters characteristic
of the growth curves: specific growth-rate, k, and the yield
of biomass production per gram of surfactant, Yap, made
possible the quantification and corroboration of the results
during the biodegradation process.},
publisher = {American Oil Chemists' Society (AOCS)},
title = {Primary Biodegradation of Commercial Fatty-Alcohol Ethoxylate Surfactants: Characteristic Parameters},
doi = {10.1007/s11743-007-1027-5},
author = {Núñez Olea, Josefa},
}