TY  - JOUR
ID  - epos1722
UR  - http://doi.org/10.1016/j.scitotenv.2014.10.103
A1  - Klamerth, Nikolaus
A1  - Moreira, Jesús
A1  - Li, Chao
A1  - Singh, Arvinder
A1  - McPhedran, Kerry N.
A1  - Chelme-Ayala, Pamela
A1  - Belosevic, Miodrag
A1  - Gamal El-Din, Mohamed
Y1  - 2015/02//
N2  - The presence of naphthenic acids (NAs) and other organic constituents in oil sands process-affected water (OSPW) stored in tailings ponds, poses a serious environmental threat due to their potential toxicity to aquatic organisms and wild life. In this work, four fractions of OSPW, extracted by dichloromethane at different pHs, were ozonated to determine the ozone impact on NAs degradation. Extracts distributions showed that high carbon number NAs (14?22) were associated with higher pH fractions (pH > 7) and smaller carbon number NAs (7?13) with lower pH fractions (pH ? 7). Extracts showed similar hydrogen deficiency (Z-number) patterns centered on Z = 6. Analysis of the speciation of NAs and oxidized NAs in the four fractions showed that ozonation degraded most NAs (55% to 98%). Despite the high degradation levels, there was still significant toxicity of the fractions toward goldfish macrophages and measurable toxicity toward Vibrio fischeri. The toxicity of such a complex matrix as OSPW may be attributed to other organic compounds and degradation by-products not currently detected. Thus, there is a need to elucidate which compounds are responsible for the remaining OSPW toxicity and to determine if combined processes, such as ozonation followed by biological treatment, are able to completely detoxify OSPW. This work is taking the first steps into this direction, narrowing down the range of compounds which might be responsible for the toxicity.
PB  - Elsevier
JF  - Science of The Total Environment
VL  - 506-50
SN  - 0048-9697
TI  - Effect of ozonation on the naphthenic acids' speciation and toxicity of pH-dependent organic extracts of oil sands process-affected water
SP  - 66
AV  - none
EP  - 75
ER  -