Basic HTML Version
International Journal of Aquaculture, 2014, Vol.4, No.06
http://ija.sophiapublisher.com
36
Research Report Open Access
Heavy Metals Concentration in Water, Muscles and Gills of
Oreochromis
niloticus
Collected from the Sewage-Treated Water and the White Nile
Elagba Haj Ali Mohamed
1,
, Abdel-Rahman Osman
2
1. Natural History Museum, University of Khartoum, Sudan
2. Faculty of Animal Production, University of Khartoum, Sudan
Corresponding author email:
elagba2000@yahoo.com
International Journal of Aquaculture, 2014, Vol.4, No.06 doi: 10.5376/ija.2014.04.0006
Received: 15 Dec., 2013
Accepted: 25 Jan., 2014
Published: 23 Feb., 2014
Copyright © 2014
Mohamed and Osman, This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Mohamed and Osman, 2014, Heavy Metals Concentration in Water, Muscles and Gills of
Oreochromis niloticus
Collected from the Sewage-Treated Water and
the White Nile, International Journal of Aquaculture, Vol.4, No.06: 36-42 (doi: 10.5376/ija.2014.04.0006)
Abstract
The concentrations of heavy metals (Cd, Cr, Ni, Pb, Cu, Zn, Fe, and Sr) were detected by ICP-OES in muscle tissues and
gills of Nile
Tilapia (O. niloticus)
collected from the effluent of sewage treatment plant, and the released sewage-treated water into
the White; and in water samples collected from four station along the sewage treatment plant. The highest concentration of the heavy
metal in tissues and gills of was recorded for Sr, followed by Fe, Zn, Cu and Pb, where Sr and Fe recorded higher concentrations in
the muscle compared to fish gills. The same trend was found in the other heavy metals. The range of Fe was (10.6 – 11.6 µg/g) in
water from sampling stations, with no significant difference between the four stations, while, the level was (2.2 - 3.2 µg/g) in muscle
and fish gills. The level of Sr in water was (6.32 – 7.86 µg/g) with increased concentration in station 4, the discharge point of the treated
waste-water into the WN; and (2.1 -3.4 µg/g) in muscle and fish gills. The concentration of lead was (0.11 – 0.2 µg/g) in water with the
highest level in station 3, the discharge point of industrial effluents and (0.2 – 0.3 µg/g). The level of Zn was (0.5 - 0.9 µg/g) in muscle
and fish gills, and (<0.0001 µg/g), but long-term disposal of wastewater into the Nile resulted in high level of Zn and Cu in the tissues
and gills of the fish. In conclusion, the levels heavy metals observed in the fish and water samples can be considered as a serious
matter of concern as it may be consumed and be harmful to human health in the study area. More safe and economic methods for the
elimination of heavy metals from contaminated waters are needed and continuous assessment of the level of pollution of the Nile
waters and fish with heavy metals is also necessary.
Keywords
Heavy metals; Nile Tilapia; Sewage-water; White Nile
1 Introduction
Heavy metals are potentially harmful to most
organisms at some level of exposure and adsorption.
Heavy metals may enter the aquatic systems from
different natural and human activities sources,
including industrial or domestic wastewater,
application of pesticides and inorganic fertilizers,
leaching from landfills, shipping and harbor activities
and atmospheric deposits and geological weathering
of the earth crust (Yilmaz, 2003; Marcovecchio, 2004;
Nadafi and Saeed, 2006; Yilmaz, 2009). Heavy metal
ions do not degrade into harmless end products and
will be toxic to many life forms (Adham et al., 1999;
Gupta et al., 2001; Kadirvelu et al., 2001; Olaifa et al.,
2004; Ajayan et al., 2011; Paulami and Banerjee,
2012). Due to their toxicity and accumulation in biota,
determination the levels of heavy metals in
commercial fish species have received considerable
attention in different countries (Kalfakakon and
Akrida-Demertai, 2000; Papagiannis et al., 2004;
Mohamed and Gad, 2008; Klavins et al., 2009; Ozturk
et al., 2009; Olowu et al., 2010; Ambedkar and
Muniyan, 2011; Wariaghli et al., 2013). There has
been an increasing interest in the utilization of fishes
as bio-indicators of the integrity of aquatic environ-
mental systems in recent years (Rashed, 2001a;
Ogbeibu and Ezeunara, 2002; Tawari and Ekaye,
2007). Fish lie at the top of the aquatic food chain and
may concentrate large amounts of some metals from
the water. Fish take heavy metals from the
surrounding water through their gills which are the
primary route for the uptake of water borne pollutants
and accumulate them in their tissues (Allen and Wilson,
1991). The fish diet is another source of these
pollutants in the tissues. WHO (1996) reported that
copper toxicity in fish is taken up directly from the
water via gills and stored in the liver. Therefore, they
are the most indicative factor for the estimation of