scholarly journals SEASONAL VARIATION OF HEAVY METAL CONCENTRATIONS IN WATER AND SEDIMENT SAMPLES OF ERELU RESERVOIR (OYO TOWN, NIGERIA) AND THEIR EFFECTS ON ITS MACRO-INVERTEBRATES

Author(s):  
Amusat A.I.
Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1840 ◽  
Author(s):  
Lei Huang ◽  
Hongwei Fang ◽  
Ke Ni ◽  
Wenjun Yang ◽  
Weihua Zhao ◽  
...  

In this study, surface sediment samples were taken from the Three Gorges Reservoir (TGR) in June 2015 to estimate the spatial distribution and potential risk of Cu, Zn, Cd, Pb, Cr, and Ni (34 sites from the mainstream and 9 sites from the major tributaries), and correlations with environmental variables were analyzed (e.g., median sediment size, water depth, turbidity, dissolved oxygen of the bottom water samples, and total organic carbon, total nitrogen, and total phosphorus of the surface sediment samples). Results show that the heavy metal concentrations in the sediments have increased over the last few decades, especially for Cd and Pb; and the sites in the downstream area, e.g., Badong (BD) and Wushan (WS), have had greater increments of heavy metal concentrations. The sampling sites from S6 to S12-WS are identified as hot spots for heavy metal distribution and have relatively high heavy metal concentrations, and there are also high values for the sites affected by urban cities (e.g., the concentrations of Zn, Cd, Cr and Ni for the site S12-WS). Overall, the heavy metal concentrations increased slightly along the mainstream due to pollutants discharged along the Yangtze River and sediment sorting in the reservoir, and the values in the mainstream were greater than those in the tributaries. Meanwhile, the heavy metal concentrations were generally positively correlated with water depth (especially for Ni), while negatively correlated with dissolved oxygen, turbidity, and median sediment size. These environmental variables have a great impact on the partition of heavy metals between the sediment and overlying water. According to the risk assessment, the heavy metals in the surface sediments of TGR give a low to moderate level of pollution.


2016 ◽  
Vol 2 (7) ◽  
pp. 146
Author(s):  
C. Vinothini ◽  
R. Ravikumar

The levels of physiochemical, heavy metal and microbiological pollution in different oil contaminated regions of Tiruchirappalli city were reported in the study. The water and sediment samples from four different oil contaminated regions in Tiruchirappalli city were collected during monsoon 2015. The sampling regions were divided into two category such as heavy oil contaminated regions (oil shed / oil washed regions) and bus stand regions. In oil contaminated water sample, counts of TVC, TC, TS, FC, FS, VC, SAC, SHC and PC were in the range of 21300 126000, 1620 13200, 240 1050, 250 1130, 100 250, 120 180, 80 160, 130 200 and 260 560 CFU/mL, respectively. In soil sample, the TVC, TC, TS, FC, FS, VLO, SC and PC ranges were 56000 218000, 3100 14800, 350 1260, 330 1420, 150 300, 110 240, 120 200, 160 260 and 410 1060 CFU/g, respectively. The results of this study indicated that oil shed regions gor higher pollutions tha bus stand regions. This study gave a special emphasis on the determination of the levels of pollution and also identified the vulnerable regions. Hence, throughout impoundment and continuous monitoring is needed.


2020 ◽  
Vol 1 (2) ◽  
pp. 01-08
Author(s):  
V. O. Ashaolu

There are thirty-five (35) metals with public health implications due to occupational or residential exposure; twenty-three (23) of these are called heavy elements or metals. They are Antimony, Arsenic, Bismuth, Cadmium, Cerium, Chromium, Cobalt, Copper, Gallium, Gold, Iron, Lead, Manganese, Mercury, Nickel, Platinum, Silver, Tellurium, Thallium, Tin, Uranium, Vanadium, and Zinc. Interestingly, minute amount of these elements are common in our environment and diet and are actually necessary for a balanced health, but increased consumption may cause acute or chronic toxicity (poisoning). Allergies are not uncommon and repeated long-term exposure to these metals such as Zinc, Lead, Chromium, Selenium, Nickel, Cobalt and Cadmium may cause cancer. The alarming perceived increase of these pollutants around the south-western regions of Nigeria have necessitated the need to evaluate water and sediment samples of Osun river, popularly known for its cultural practices and activities. The physicochemical properties of samples such as pH, TDS EC, Total Dissolved Solid (TDS), Conductivity, Total Hardness, Sodium, Potassium, Phosphate, Nitrate, Chloride were analyzed and result showed compliance with recommended WHO standards. Trace and heavy metal composition in water using standard methods indicates the presence of Calcium (5.11±0.04ppm), Magnesium (0.54±0.004ppm), Potassium (1.28±0.01ppm) and Iron (0.05±0.00ppm) while sediment sample contained high composition of Zinc (21.99±2.67ppm), Iron (261.6±2.00ppm) and Manganese (105.6+0.50ppm).  Results obtained from proximate analysis of both water and sediment samples, shows that there are no heavy metals presence in Osun River that could pose a threat to public health. Rather, there are more minerals and nutrients in availability which implies that water sample lacks considerable pollutants and can be certified healthy for moderate consumption and domestic uses which is within permissible value limits of WHO standards. Ashaolu V. O. | Research Scholar, Department of Chemistry, LIFE, Loyola College, Chennai-600034


2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lestari Lestari ◽  
Fitri Budiyanto

Gresik coastal waters is one of the areas that have a potential risk for environmental damage due to anthropogenic activities. Water and sediment samples were collected to determin  metals concentration and to identify sediment quality in February 2012. Twelve samples were collected for analysis of mercury (Hg) and four other metals (Cd, Cu, Pb, and Zn). Mercury was analyzed using USEPA method 7471B with Flameless-AAS (Atomic Absorption Spectrophotometer) varian type SpectarAA VGA 20-76 and the other metals were analyzed using USEPA 30050B with Flame-AAS. Results showed that ranges and average concentrations of Hg were 0.04-0.33 (0.13) mg/kg, Cd 0.08-3.05 (0.64) mg/kg, Cu 23.7-234.0 (85.5) mg/kg, Pb 1.74-12.7 (4.29) mg/kg, and Zn 77.0-405.0 (133.0) mg/kg. Metals with high concentrations were detected in some places and by SQG-Q, surface sediment showed a moderate impact level of biological adverse effects in aquatic sediments. Keywords: mercury, heavy metal, sediment, Gresik.


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