Heavy Metals in Aquatic Organisms

Author(s):  
F. Prosi
1982 ◽  
Vol 14 (12) ◽  
pp. 107-125 ◽  
Author(s):  
Roland Wollast

A comparison of the concentration of dissolved and of particulate heavy metals in the aquatic system indicates that these elements are strongly enriched in the suspended matter. The transfer between the aqueous phase and the solid phase may be due to dissolution-precipitation reactions, adsorption-desorption processes or biological processes. When these processes are identified, it is further possible to develop mathematical models which describe the behaviour of these elements. The enrichment of heavy metals in the particulate phase suspended or deposited and in aquatic organisms constitutes a powerful tool in order to evaluate sources of pollution.


2021 ◽  
Vol 5 (1) ◽  
pp. 223-232
Author(s):  
Mohammed Jr. Kinta ◽  
A. V. Ayanwale ◽  
U. N. Keke ◽  
Y. I. Auta ◽  
B. S. Adama ◽  
...  

Developing countries like Nigeria are faced with increased in generation of domestic, industrial and agricultural wastes, with a large percentage moving. This study evaluates the physico-chemical and some heavy metals concentration in three common species of fish from Tungan Kawo reservoir Kontagora, Nigeria; using standard methods between (July 2018 – February 2019); at four different sampling stations of human activities on the water. Five heavy metals were evaluated (Lead, Copper, Manganese, Iron and Chromium) in the fish samples. Phosphate (0.4 – 2.5) mg/L, Nitrate (3.2 – 7.5) mg/L, Temperature (27 – 32.4) 0C, Dissolved Oxygen (2.4 – 5.2 mg/L), Conductivity (81 – 125 µS/cm), Biochemical Oxygen Demand (1.9 – 4.4 mg/L), Alkalinity (mg/L) and Total Dissolved Solids (117 – 198) ppm were within the standard for drinking water and survival of fish.  However, the pH (6.3 – 9.8) was above the standard for NIS and WHO drinking water but can support aquatic life. Iron (0.64 ± 0.072 mg/kg) was the most highly concentrated in Synodontis clarias while lead (0.01 ± 0.013 mg/kg) was the lowest in Oreochromis niloticus and Coptidon zillii (formerly Tilapia zillii. This current finding indicates that the water is safe for both aquatic life and domestic purpose but not suitable for direct human consumption without being properly treated. However, there is the need for regular monitoring of the heavy metals load in this water body and the aquatic organisms because of the long term effects


2021 ◽  
Author(s):  
Geoffrey Kariuki Kinuthia ◽  
Veronica Ngure ◽  
Luna Kamau

Abstract Background Levels of Mercury (Hg), Lead (Pb), Chromium (Cr), Cadmium (Cd), Thallium (Tl), and Nickel (Ni) in samples of wastewater, filamentous green algae (spirogyra) and urban mosquitoes obtained from open wastewater channels in Nairobi industrial area, Kenya, was established. Industrial wastewater may contain hazardous heavy metals upon exposure. Aquatic organisms in wastewater may accumulate the toxic elements with time. Therefore, human population living in informal settlements in Nairobi industrial area risk exposure to such toxic elements. Biomonitoring using aquatic organisms can be key in metal exposure assessment. Results Pb, Cr, & Ni levels ranged from 3.08 to 15.31 µg/L while Tl, Hg, & Cd levels ranged from 0.05 to 0.12 µg/L in wastewater. Pb, Cr, Ni, & Cd levels were above WHO, Kenya & US EPA limits for wastewater but Hg was not. Metals in tap water (control) which ranged from 0.01 to 0.2 µg/L was below WHO, US EPA, & Kenya standard limits. Pb, Cr, Tl, & Ni levels in assorted field mosquitoes were 1.3 to 2.4 times higher than in assorted laboratory-reared mosquitoes. Hg & Cd concentrations in laboratory-reared mosquitoes (0.26 mg/L & 1.8 mg/L respectively) was higher than in field mosquitoes (0.048 mg/L & 0.12 mg/L respectively). Pb, Cr, Ni, & Cd levels in green filamentous algae were 110.62, 29.75, 14.45, & 0.44 mg/L respectively and above WHO limits for vegetable plants. Hg level in algae samples (0.057 mg/L) was below WHO standard limits but above Kenya & US EPA limits in vegetables. Correlations for Pb & Hg (r = 0.957; P < 0.05); Cd & Cr (r = 0.985; P < 0.05) in algae samples were noted. The metal concentrations in the samples were in the order, wastewater < mosquitoes < filamentous green algae. Conclusion Samples of wastewater, mosquitoes and filamentous green algae from open wastewater channels and immediate vicinity, in Nairobi industrial area (Kenya) contained Hg, Pb, Cr, Cd, Tl, and Ni. Urban mosquitoes and filamentous green algae can play a role of metal biomonitoring in wastewater. The possibility of urban mosquitoes transferring the heavy metals to their hosts when sucking blood should be investigated.


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2746 ◽  
Author(s):  
Mojeed A. Agoro ◽  
Abiodun O. Adeniji ◽  
Martins A. Adefisoye ◽  
Omobola O. Okoh

This study assessed the distribution of five heavy metals (Cd, Pb, Cu, Zn, and Fe) across the various stages of treatment in three selected sewage treatment facilities and their receiving waterbodies in the Eastern Cape Province, South Africa. Aqueous and solid (sludge) samples were collected monthly from September 2015 to February 2016. Quantitation was achieved by atomic absorption spectrometry after necessary sample preparations. Concentrations of heavy metal cations in the sludge generally varied from <DL (below detection limit) to 1.17 mg kg−1, <DL to 0.14 mg kg−1, 27.588 to 69.789 mg kg−1, and <DL to 0.099 mg kg−1 for Cu, Cd, Fe and Pb; while Zn was below detection all through. Similarly, the levels of Cu, Cd, and Fe in the influents, effluents, upstream and downstream across the three plants ranged from <DL–6.588 mg L−1, <DL–0.636 mg L−1, <DL–0.878 mg L−1 and <DL–0.711 mg L−1, respectively; Zn and Pb were less than DL in all the matrices and study locations. All the contaminants were below hazardous levels in all the sludge and aqueous samples except Cd which was higher in effluents and surface waters across the board. Wastewater Treatment Plant (WWTP)-A exhibited better removal capacity for Fe (86.6%), compared to WWTP-B (34.7%) and WWTP-C (56.9%). However, the removal of Cu and Zn was very poor in all the treatment facilities studied. Carcinogenic and non-carcinogenic risks evaluated were sufficiently low. This suggests that the levels of contamination, even with respect to Cd, was minimal. Nevertheless, efforts should be made to keep the concentrations of these contaminants at levels safe for humans and aquatic organisms. Furthermore, the use of the effluents from these facilities for irrigation should be discouraged to prevent unnecessary build-up of metals in the soil and plants grown with such, as well as subsequent bioaccumulation and biomagnification in the food chain.


2020 ◽  
Vol 32 (4) ◽  
pp. 827-834
Author(s):  
Muhammad Towhid Moula ◽  
Ranjit K. Nath ◽  
Mh. Mosfeka Chowdhury ◽  
Md. Abu Bakar Siddique

Halda is an important river of Bangladesh, is now polluted in different ways through industrial, agricultural, domestic and sewage disposal. Increased anthropogenic activities have increased the potential pollution of the river and excessive pollutants may be toxic to humans and aquatic fauna. Presence of heavy metals in the river water causes perilous impact on the aquatic organisms. Hence, regular monitoring of pollution levels in the river is indispensable. In this study, we discuss about physico-chemical assessments of water quality parameters viz. pH, dissolve oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solid (TS), total suspended solid (TSS), total dissolved substance (TDS), total alkalinity, turbidity, salinity, electrical conductivity (EC), hardness, chloride and heavy metals in the water of Halda river during rainy and winter seasons, at different points; sources of pollutants in water and their effects given starting from the early research until the current research.


Author(s):  
Min Zhang ◽  
Xiangchun Wang ◽  
Long Yang ◽  
Yangyang Chu

Heavy metals contaminated sediment has become a worldwide environmental issue due to its great harm to human and aquatic organisms. Thus, economical, effective, and environmentally-friendly remediation technologies are urgently needed. Among which, combined remediation technologies have attracted widespread attention for their unique advantages. This paper introduces combined remediation technologies based on physical-, chemical-, and bio-remediation of heavy metal polluted sediments. Firstly, the research progress in physical-chemical, bio-chemical, and inter-organismal (including plants, animals, microorganisms) remediation of heavy metal polluted sediments are summarized. Additionally, the paper analyzes the problems of the process of combined remediation of heavy metals in river sediments and outlooks the future development trends of remediation technologies. Overall, this review provides useful technology references for the control and treatment of heavy metal pollution in river sediments.


2020 ◽  
Author(s):  
Mohammad Ahmad Wahsha ◽  
Tariq Al-Najjar

&lt;p&gt;Heavy metals are considered to be among the most potent environmental contaminants, and their release into the environment is increasing rapidly since the last decades from various sources and activities and may enter into the environment by a wide range of pathways and processes. They can be translocated, disperse in the environment, and bio-concentrate in aquatic organisms, causing increase ecosystem degradation and leading to biodiversity loss. Furthermore, they may enter the food chain, creating health risks for both humans and animals. This study aimed to evaluate the ecotoxicological effects of anthropogenic pressure in semi-enclosed artificial lagoon ecosystems in the Gulf of Aqaba, Red Sea. Our findings with regard to heavy metal contamination showed that the area is contaminated by significant amounts of several potentially toxic heavy metals (such as Cd, Cr, Cu, and Fe). The anthropic intervention in the area impacted heavily the natural environment. We found that the biological test (lipid peroxidation) was a useful assay for assessing the overall health condition and response (stress level) towards natural and anthropogenic forces in the studied areas. The selected marine organisms (&lt;em&gt;Holothuria atra&lt;/em&gt;, &lt;em&gt;Tripneustes gratilla&lt;/em&gt;, &lt;em&gt;Ulva lactuca &lt;/em&gt;and &lt;em&gt;Halophila stipulacea&lt;/em&gt;) have the ability to accumulate several levels of heavy metals in their tissue with different trends of bioaccumulation. Therefore, they can be used as promising bioindicators for such research. The results obtained permit to assess the environmental effects of anthropogenic pressure and can be a useful basis for planning possible remediation projects.&lt;/p&gt;


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