Occurrence and probabilistic risk assessment of PAHs in water and sediment samples of the Diep River, South Africa

The objective of this study was to determine and assess niclosamide residue levels in the Nan Ji Shan island within Poyang Lake Region, from March to June, September, October and December of 2012. Water and sediment samples from the Nan Ji Shan island were extracted with alkaline ethylacetate,and were detected by high performance liquid chromatography (HPLC). Niclosamide residues were detected in all water and sediment samples in varying concentrations during the two periods using molluscicide, niclosamide residues concentration water samples ranged from 0.01 to 0.038 mg/L, and from 0.1 to 0.473 mg/kg in sediments. According to the guidelines for potential risk assessment drawn up by the US Environmental Protection Agency, the risk of niclosamide residue was assessed. The results indicated that it would cause greater effect on fish, invertebrates and aquatic plants, but the influence on human and avian was relatively smaller.

Download Full-text

Distribution of heavy metals in water and sediment of an urban river in a developing country: A probabilistic risk assessment

International Journal of Sediment Research ◽

10.1016/j.ijsrc.2021.09.002 ◽

2021 ◽

Author(s):

Mir Mohammad Ali ◽

Saima Rahman ◽

Md Saiful Islam ◽

Md Refat Jahan Rakib ◽

Shaharior Hossen ◽

...

Keyword(s):

Heavy Metals ◽

Risk Assessment ◽

Developing Country ◽

Probabilistic Risk Assessment ◽

Urban River ◽

Water And Sediment ◽

Probabilistic Risk

Download Full-text

Occurrence of polycyclic aromatic hydrocarbons in water and sediment samples from KwaZulu Natal Province, South Africa

Water and Environment Journal ◽

10.1111/wej.12598 ◽

2020 ◽

Author(s):

Ayanda Ngubo ◽

Precious N. Mahlambi ◽

Stephen O. Ojwach

Keyword(s):

South Africa ◽

Polycyclic Aromatic Hydrocarbons ◽

Aromatic Hydrocarbons ◽

Sediment Samples ◽

Water And Sediment ◽

Kwazulu Natal ◽

Polycyclic Aromatic ◽

Water And Sediment Samples

Download Full-text

Petroleum Hydrocarbon Fingerprints of Water and Sediment Samples of Buffalo River Estuary in the Eastern Cape Province, South Africa

Journal of Analytical Methods in Chemistry ◽

10.1155/2017/2629365 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 8

Author(s):

A. O. Adeniji ◽

O. O. Okoh ◽

A. I. Okoh

Keyword(s):

South Africa ◽

Petroleum Hydrocarbon ◽

River Estuary ◽

Anthropogenic Sources ◽

Source Tracking ◽

Environmental Matrices ◽

Sediment Samples ◽

Water And Sediment ◽

Buffalo River ◽

Water And Sediment Samples

Petroleum hydrocarbon status of the Buffalo River Estuary in East London, South Africa, was evaluated from January to May, 2016. Surface water and sediment samples were collected from five points in the estuary and extracted using standard methods. The extracts were subsequently analyzed by gas chromatography-flame ionization detection. Results showed that total petroleum hydrocarbon (TPH) varied from 7.65 to 477 μg/L in the water and 12.59 to 1,100 mg/kg in the sediments, with mean values of 146.50 ± 27.96 μg/L and 209.81 ± 63.82 mg/kg, respectively. Concentrations of TPH in the sediments correlated significantly with organic carbon (OC) in both seasons. TPH and OC levels were slightly lower in summer than in autumn in the two environmental matrices, and the average amount of TPH in the water samples collected from all the sampling stations was generally lower than the EU standard limit of 300 μg/L. However, the levels in the sediments exceeded the EGASPIN target value (50 mg/kg) for mineral oil but were below the intervention value (5,000 mg/kg), indicating a serious impact of industrial growth and urbanization on the area, although the n-alkane ratios and indexes used for source tracking revealed excessive flow from both natural and anthropogenic sources.

Download Full-text

Investigation into the bacterial pollution levels at various sites along the Diep and Plankenburg river systems, 3 Western Cape, South Africa

Water Science & Technology ◽

10.2166/wst.2016.054 ◽

2016 ◽

Vol 73 (11) ◽

pp. 2590-2599

Author(s):

O. O. Alegbeleye ◽

B. O. Opeolu ◽

V. A. Jackson

Keyword(s):

South Africa ◽

Surface Water ◽

Sampling Time ◽

Western Cape ◽

River Systems ◽

Bacterial Counts ◽

Sediment Samples ◽

Microbial Counts ◽

Water And Sediment ◽

Water And Sediment Samples

This study sought to investigate and compare bacterial contamination levels at six different sites along the Diep and Plankenburg river systems in the Western Cape, South Africa. Surface water and sediment samples were collected monthly from the six selected sampling sites along both river courses between January 2014 and December 2014 and were evaluated for bacterial contaminants. Microbial isolation, characterisation and identification were done using conventional techniques (serial dilution, Gram staining, and biochemical testing) and molecular identification techniques (polymerase chain reaction and DNA sequencing). A total of 19 bacterial isolates belonging to the genera Raoultella, Bacillus, Pseudomonas, Klebsiella, Escherichia, Enterobacter, Exiguobacterium, Acinetobacter, Serratia, Aeromonas, Staphylococcus and Citrobacter were isolated from the surface water and sediment samples at the end of the survey. Higher microbial load was obtained from sediment samples compared to surface water samples. Seasonal variation was also observed in terms of microbial counts. Higher microbial counts were obtained during summer sampling time compared to winter sampling time. The most contaminated site was located on Plankenburg River with average bacterial counts ranging between 3.1 × 105–6.9 × 108 CFU/ml and 3.9 × 106–2.88 × 109 CFU/ml from surface water and sediment, respectively, recorded at this site during winter and summer. Although lower microbial counts were recorded along the Diep River course, most of the bacterial counts recorded along both rivers exceeded the acceptable maximum limits for river water.

Download Full-text

Heavy Metals Analysis and Health Risk Assessment of Three Fish Species, Surface Water and Sediment Samples in Ogbaru Axis of River Niger, Anambra State, Nigeria

Asian Journal of Applied Chemistry Research ◽

10.9734/ajacr/2021/v9i130205 ◽

2021 ◽

pp. 64-81

Author(s):

Opeyemi F. Ojaniyi ◽

Patrice A. C. Okoye ◽

Daniel O. Omokpariola

Keyword(s):

Heavy Metals ◽

Risk Assessment ◽

Surface Water ◽

Fish Species ◽

Dry Season ◽

Sediment Samples ◽

Anambra State ◽

Water And Sediment ◽

River Niger ◽

Water And Sediment Samples

Human activities on environmental resources have negatively affected floras and faunas in maintaining fair balance. In this research study, selected heavy metals (Al, As, Cd, Cr, Cu, Fe, Hg, Pb, Ni, Zn) concentration in three fish species (Clarias gariepinus, Heterotis niloticus and Anguilla labiate), surface water and sediment samples in Ogbaru axis of River Niger, Anambra State, Nigeria. We evaluated the samples using atomic absorption spectrophotometer (AAS). The result of heavy metals (Cu, Fe, Zn, Ni, Pb, Cd, Al, Cd) analysis in fish samples showed that Cr was detected in Clarias garipinus and Anguilla labiate with a concentration of 0.001mg/kg in both species but was not detected in Heterotis niloticus. Hg and Al were not detected in Anguilla labiate but both metals were detected in the other fish species with a mean concentration of 0.311mg/kg and 0.019mg/kg respectively for Clarias garipinus and 0.001mg/kg and 0.005mg/kg respectively for Heterotis niloticus. In decreasing order, the heavy metal concentration in Clarias garipinus in increasing order of Cu >Fe > Ni > Hg > Pb > Zn > As > Cd > Al > Cr, while Heterotis niloticus followed the order Cu > Zn > Fe > Ni > Pb > Cd > Al > As > Hg > Cr, and Anguilla labiate followed the pattern of Cu > Fe > Zn > Ni > Pb > Cd > Cr > As > Hg > Al. For surface water, As (0.005mg/l), Cd (0.032 mg/l), Cr (0.099 mg/l), Cu (0.186 mg/l), Fe (2.308 mg/l), Hg (1.501 mg/l) and Pb (0.724 mg/l) showed high concentration for the raining season compared to dry season, as Al (0.246 mg/l), Ni (0.773 mg/l) and Zn (2.903 mg/l) were dominant during dry season, while sediment samples of Cr (0.112 mg/kg), Cu (0.029 mg/kg), Ni (0.945 mg/kg) and Pb (0.039 mg/kg) concentration in raining season were higher than dry season and vice versa for other As, Cd, Fe, Hg, Zn. Correlation matrices showed positive value showing that heavy metals were from a similar source with migration route and vice versa for negative correlation. Health and exposure risk assessment was conducted for carcinogenic and non-carcinogenic exposure in adults and children, where the cumulative cancer risk was within USEPA regulatory standard (1.0E-6 – 1.0E-04) and cumulative hazard index were above 1 for adults (2.02) and children (4.93), implying that children are at risk of having adverse health issues compared to adults. Therefore, there is a need for regulatory advocacy and special care to mitigate anthropogenic release and safeguard the environment.

Download Full-text