Perfluorinated compounds in environmental matrices of Lake Victoria Gulf [Elektronische Ressource] / vorgelegt von Francis Orata

Informations

• Publié par: johannes_gutenberg-universitat_mainz
• Publié le: 01 janvier 2009
• Nombre de lectures: 19
• Langue: English
• Poids de l'ouvrage: 12 Mo

Extrait

Perfluorinated Compounds in Environmental Matrices of
Lake Victoria Gulf


“Their Management Implications and Degradation Studies of Emerging
Perfluorinated Surfactants Substitutes”






Dissertation zur Erlangung des Grades
„Doktor der Naturwissenschaften“







am Fachbereich Chemie und Pharmazie
der Johannes Gutenberg-Universität Mainz



vorgelegt von Francis Orata
geboren in Kenya



Mainz, 2009 ii
DEDICATION








For Christabell






“..…..In the middle of my work, she gave me
the much needed courage and motivation
to keep on keeping on……”
iii
DECLARATION AND COPYRIGHT












This is my original work and has not been presented for a degree in any other university. No
part of this thesis may be produced, stored in any retrieval system, or transmitted in any form
or means, electronic, mechanical, recording or otherwise without prior written permission of
the author or University of Mainz (Germany) on my behalf



























iv
ABSTRACT
One of the major ecological challenges on Lake Victoria resources is the existence of “hot
spots”, caused by human waste, urban runoff, and industrial effluents. The lake is tending
towards eutrophication which is attributed to the increasing human population in its
watershed. The rate of population growth, estimated at seven per cent within 100 kilometres
around the Lake Victoria catchment area, had outpaced the continental average, reflecting
growing dependence and pressure on the lake’s resources. The population growth around the
continent’s largest lake is significantly higher than the rest of Africa. If Lake Victoria is not
managed properly, it will loss sustainability for the future. The lake is experiencing increasing
anthropogenic loads of pollutants from expanding urban, agricultural and industrial
development. So far, very little or no work has been done to determine the levels or impact of
non-conventional trace organic pollutants in the Lake Victoria. The negative health impacts
caused by some of the trace organic pollutants are well documented in other studies. It is in
this view that the motivation of doing this study arose. The choice of pollutant for this study
was perfluorinated compounds because it is an emerging non-conventional pollutant of
concern worldwide.

A report of the levels of perfluorooctane sulfonate and perfluorooctanoic acid in
environmental matrices of Lake Victoria is presented, and management implication of
perfluorinated compounds and similar potential organic pollutants examined. Report on
degradability of new emerging substitutes for perfluorinated alkyl surfactants and an
alternative method for analysis of perfluorocarboxylic acids are presented.

Two widely consumed and economically important fish species namely Lates niloticus (Nile
perch) and Oreochromis niloticus (Nile tilapia) were obtained from Winam gulf of Lake
Victoria, Kenya, and analysed for perfluorooctane sulfonate and perfluorooctanoic acid in
muscles and liver using liquid chromatography coupled with mass spectroscopy.
Concentrations value of perfluorooctane sulfonate in Nile perch muscles of up to 10.50 and
35.70 ng/g for liver samples were obtained. Nile tilapia concentration values were of up to
12.40 and 23.70 ng/g for muscles and liver samples respectively. The accuracy and precision
of the method were validated, and the effectiveness of the method in determining the contents v
of these two perfluorinated compounds in fish matrices was also demonstrated. The lowest
limit of quantification (LOQ) was 0.5 ng/g for fish samples.

Variability in the concentrations of perfluorooctanoic acid or perfluorooctane sulfonate in
river waters (range perfluorooctanoic acid 0.4 – 96.4 ng/L and perfluorooctane sulfonate < 0.4
– 13.2 ng/L) was higher than for Lake waters (range perfluorooctanoic acid 0.4 – 11.7 ng/L
and perfluorooctane sulfonate < 0.4 – 2.5 ng/L respectively). Both analytes were detected in
Lake and River sediments with concentrations of perfluorooctanoic acid and perfluorooctane
sulfonate ranged from 1.4 – 99.1 ng/g and < 1 – 57.5 ng/g respectively, which was higher
than concentrations obtained from Lake sediments (range perfluorooctanoic acid < 1 – 24.1
ng/g and perfluorooctane sulfonate < 1 – 4.0 ng/g). The results obtained suggested
generalized point sources such as domestic and industrial waste. The lowest limit of
quantification (LOQ) in water samples was 0.4 ng/L for both analytes while for sediments it
was 1 ng/g for both analytes. Typical values for precision obtained were 0.14 – 3.7 % for
water samples. Recovery range obtained for sediments were 78 – 109 %, from spiked
amounts ranging from 1 to 150 ng. Sampling sites within and near sewage and water
treatment facilities gave the highest concentrations of both analytes. Analysis of water and
fish samples from the Rhine river (Germany) for comparison, calibration and as part of
analytical quality management was performed.

Significant correlations were tested between perfluorinated compounds levels in sediments,
fish and water. Wastewater treatment plants and other anthropogenic sources have been
identified as significant sources or pathways for the introduction of perfluoroalkyl compounds
into Lake Victoria ecosystem. In this study, elevated concentrations of perfluorooctanoic acid
and perfluorooctane sulfonate was found in two wastewater treatment plants (WWTPs) in
Kisumu, City of Kenya.

An alternative analytical method to liquid chromatography/ mass spectroscopy for analysis of
perfluorocarboxylic acids in abiotic and biotic matrices where high concentrations are
expected is also presented. Derivatisation of the acid group to form a suitable alkyl ester
provided a suitable compound for mass spectroscopy detection coupled to gas
chromatography instrumental analysis. The acid is esterified by an alkyl halide i.e benzyl
bromide as the alkylating agent for Perfluorocarboxylic acids quantification. vi

The study also involved degradability measurements of emerging perfluorinated surfactants
substitutes. The stability of the substitutes of perfluorinated surfactants was tested by
employing advanced oxidation processes (AOP), which was based on the degradation by ultra
violet (UV)-Lamp, hydrogen peroxide (H O ) or both, followed by conventional tests, among 2 2
them an automated method based on the manometric respirometry test [OECD 301 F] – Oxi-
Top-, Closed bottle test- CBT [OECD 301 D] and standardized fix bed bioreactor [FBBR] on
perfluorobutane sulfonate (PFBS), a fluoroethylene polymer, fluorosurfactant (Zonyl), two
fluoraliphaticesters (NOVEC ™ FC4430 and NOVEC ™ FC4432) and 10-(trifluoromethoxy)
decane-sulfonate. Most of these new surfactants are well-established in the market and have
been used in several applications as alternatives to PFOS and PFOA based surfactants.
The perfluorinated compounds concentrations obtained in water, sediments, and fish in this
study are mostly lower than those obtained previously in various study areas around the globe
for all matrices analysed. Specifically, the perfluorinated compounds levels in water observed
in this study fall much below the known health based guide standards, for example the guide
standards in Germany. The results of this study can be used as pioneer information for further
studies on the sources, behaviour and fate of PFOA and PFOS and other related compounds in
both abiotic and biota compartments of Lake Victoria and other lakes. The data obtained in
this study can particularly be considered when formulating policies and management
measures for preservation and sustainability of Lake Victoria resources.



















vii
This thesis has in parts been published and presented in the following papers and conferences.

Francis Orata, Natalia Quinete, Friedrich Werres, Rolf-Dieter Wilken. Determination of
Perfluorooctanoic Acid and Perfluorooctane Sulfonate in Lake Victoria Gulf Water. Bull Environ
Contam Toxicol. 2008. Volume 82, Issue2 (2009), Page 218.

Orata Francis, Quinete Natalia, Maes Anke, Werres Friedrich, Wilken Rolf-Dieter.
Perfluorooctanoic acid and perfluorooctane sulfonate in Nile Perch and tilapia from gulf of Lake
Victoria. Pure and Applied Chemistry Vol. 2 (8), pp. 075-079, August, 2008

Francis Orata, Natalia Quinete, Rolf-Dieter Wilken. Long Chain Perfluorinated alkyl acids
Derivatisation and Identification in Biota and Abiota Matrices using Gas Chromatography. Bull
Environ Contam Toxicol. DOI : 10.1007/s00128-009-9756-y
Francis Orata, Anke Maes, Friedrich Werres, Rolf Dieter Wilken. Perfluorinated Compounds
Mapping and Source Identification in Lake Victoria Gulf Basin by Sediments Analysis. S