Status of heavy metals in water and bed sediments of river Gomti--a tributary of the Ganga River, India

Water quality assessment of river Hindon at Ghaziabad, India: impact of industrial and urban wastewater

River Hindon is a major source of water to the highly populated and predominantly rural population of western Uttar Pradesh, India. The main goal of the present study was to assess the impact of urban and industrial activities on the water quality of river Hindon at the Ghaziabad. For this, river water samples were collected from six different sites all along the route of Hindon main streamline and its branch and were analyzed for pH, turbidity, electrical conductivity (EC), total dissolved solids (TDS), total alkalinity (TA), total hardness (TH) and calcium hardness (Ca-H), chemical oxygen (COD) demand, biochemical oxygen demand (BOD), dissolved oxygen (D.O.), sulphate (as SO(4)(2-)), nitrate (as NO(3)(-)) and chloride (Cl-) levels. There were drastic variations for EC (0.83-5.04 ms), turbidity (28.7-109.3 NTU), TDS (222.2-2426.3 mg l(-1)), SO(4) (36.4-162.4 mg l(-1)), NO(3) (106-245 mg l(-1)), TA (347.0-596.3 mg l(-1)), TH (235.1-459.9 mg l(-1)), Ca-H (64.5-402.2 mg l(-1)), BOD (27-51 mg l(-1)) and COD (85.0-337.4 mg l(-1)) levels at different sites. Water pollution indicating parameters were manifold higher than the prescribed limit by the National Pollution Control Agency, i.e. CPCB. This is the first study on itself and the interrelationship of human activities and river water quality makes the study significant and interesting to assess the pollution load discharges in catchments of Hindon at Ghaziabad. Overall, the water quality of Hindon was relatively poor with respect to its use for domestic purposes.

Sediment load and bioconcentration of heavy metals by shrimp (Peaneus notalis) from Epe Lagoon, Nigeria

In many developing countries, surface waters, especially rivers and lagoons, have become deposition sites for all sorts of wastes. Three sampling sites located trigonally on Epe lagoon, Lagos, Nigeria were identified, and water, sediment, and commonly farmed shrimp, Peaneus notalis, were sampled and assessed for heavy metal concentrations. Zn, Pb, Ni, Cu, Cr, Cd, and Mn were determined in the aqua regia digests of the samples by means of Perkin Elmer AAnalyst 200 atomic absorption spectrophotometer. Heavy metals occurred above detection limits at all sites. The highest load of these trace elements was found in sediment samples followed by the water samples. The levels observed in the shrimp samples, however, were much lower than WHO levels. In the distribution, zinc was the highest metal found in the samples ranging from 17.94 +/- 2.60 mg/L in water to 37.85 +/- 9.35 microg/g in sediments. The least was Cd 0.03 +/- 0.01 mg/L in water and 0.28 +/- 0.04 microg/g in sediments. Lead was the most widely varied metal in shrimp with a 84.38% coefficient of variation. Apart from Cr, the metals appeared to be fairly and evenly distributed in the sediment, with coefficient of variation ranging from 14.29% (Cd) to 24.76% (Mn) The variations were between 14.49% (Zn) and 66.67% (Cr) in the water samples. The paired t test carried out between water and sediment, water and shrimp, and shrimp and sediment was significant at p = 0.05. Three-factor analysis of variance did not reveal any significant difference in metal burdens among the trigonally located sites under investigation. Shrimp samples showed evidence of bioaccumulation but are still below internationally established levels.

Water quality assessment near an industrial site of Damodar River, India

An assessment on the water quality parameters coliform including the bacterial abundance from a point source of river Damodar (24 degrees 26(') N and 86 degrees 53(') E), West Bengal, India was carried out during the period of 2004-2007. The site received mining and industrial effluents from the collieries and industries. The water samples collected on a monthly basis revealed the presence of the coliform bacteria Escherichia coli and Streptococcus sp., between 2,600 and 20,000 colony-forming unit/100 ml throughout the study period with peak abundance during the months of September to December, the post-monsoon period. The relative abundance of the two bacterial species was found to be y(E. coli) = 1.41x (Streptococcus) - 8.07 and were positively correlated (r = + 0.868, df = 34). Principal component analysis revealed three factors to clarify for the observed variance of the environmental variables. The mean values of the physicochemical parameters of the river water at the sampling sites were consistently higher than the levels specified by WHO and other regulatory bodies and qualify as polluted water. The presence of the coliform bacteria in these water samples warrants for proper measure to reduce the pollution at the point source and proper remediation strategies to combat contamination in the domestic water usage from river Damodar from this site and downstream.

Levels and distribution of persistent organochlorine pesticide residues in water and sediments of Gomti River (India)--a tributary of the Ganges River

This study reports the concentration levels and distribution pattern of the persistent organochlorine pesticide (OCPs) residues in the water and bed-sediments of the Gomti River collected seasonally over a period of 2 years. The water and bed-sediment samples were collected from eight different sites and analyzed for aldrin, dieldrin, endrin, HCB, HCH isomers, DDT isomers/metabolites, endosulfan isomers (alpha and beta), endosulfan sulfate, heptachlor and its metabolites, alpha-chlordane, gamma-chlordane and methoxychlor. In the river water and sediments SigmaOCPs residues ranged between 2.16 and 567.49 ng l(-1) and 0.92 and 813.59 ng g(-1), respectively. The results, further, suggested that source of DDT contamination is from the aged and weathered agricultural soils with signature of recently used DDT in the river catchments. To assess any adverse effect of OCPs contamination on river's biological component, the threshold effect level (TEL) was used. The results revealed that bed-sediments of the Gomti River are contaminated with lindane, endrin, heptachlor epoxides and DDT, particularly at site-4 and may contribute to sediment toxicity in the freshwater ecosystem of the river.

Content, distribution and fate of 33 elements in sediments of rivers receiving wastewater in Hanoi, Vietnam

Untreated industrial and domestic wastewater from Hanoi city is discharged into rivers that supply water for various agricultural and aqua-cultural food production systems. The aim of this study was to assess the content, distribution and fate of 33 elements in the sediment and pore water of the main wastewater receiving rivers. The sediment was polluted with potentially toxic elements (PTEs) with maximum concentrations of 73 As, 427 Cd, 281 Cr, 240 Cu, 218 Ni, 363 Pb, 12.5 Sb and 1240 Zn mg kg(-1) d.w. Observed distribution coefficients (log(10) K(d,obs)) were calculated as the ratio between sediment (mg kg(-1) d.w.) and pore water (mg L(-1)) concentrations. Maxima log(10) K(d,obs) were >4.26 Cd, >6.60 Cu, 4.78 Ni, 7.01 Pb and 6.62 Zn. The high values show a strong PTE retention and indicate the importance of both sorption and precipitation as retention mechanisms. Sulphide precipitation was a likely mechanism due to highly reduced conditions.

Determination of levels of Mn, As, and other metals in water, sediment, and biota from Phayao Lake, Northern Thailand, and assessment of dietary exposure

This study was undertaken to determine levels of contamination of toxic metals in water, sediment, and consumed fishery products from Phayao freshwater lake located in northern Thailand, which is a major water resource for drinking water, agriculture, and household use. Concentrations of Mn, As, and other metals were determined in water, sediment, fish tissues (Puntius gonionotus) and pond snails (Filopaludina martensi). Sampling was carried out in 3 periods (February, May, and August) in 2005. Metal analysis was performed by using inductively coupled plasma mass spectrometer (ICP-MS). Concentrations of Mn and As in lakewater ranged from 40-382 and 0.68-8.79 microg L(- 1) whereas the USEPA (Mn) and WHO (As) guidelines for drinking water are 50 and 10 microg L(- 1), respectively. Concentrations of some metals (Al, Cr, Mn, and Fe) in water were found to be higher in the area where water flowed into the lake from a small river than in other areas. The highest metal concentrations were found in the period of the dry season (May 2005). Among different sampling sites, the patterns of metal accumulations were different. Estimated fishery product consumption from the lake was calculated and the results indicated that the concentrations of metals in these products were lower than the recommended average daily dietary intake. Therefore, the consumption of fish and pond snail from this water resource may not pose a risk of metal toxicity. However, monitoring of the levels of Mn and As in lakewater should be carried out routinely so that appropriate prevention of contamination from these toxic metals can be implemented.

Chromatographic separation of certain metal ions using a bifunctional quaternary ammonium-sulfonate mixed bed ion-exchanger

The separation behaviour of Pb(2+), Cu(2+), Cd(2+), Co(2+), Zn(2+) and Ni(2+) on bifunctional quaternary ammonium-sulfonate mixed ion-exchangers (Dionex, IonPac CS5 and CG5) was studied using different eluents including solutions of oxalic acid, potassium oxalate, sodium oxalate and ammonium oxalate. Separated metal ions were followed by using 4-(2-pyridylazo) resorcinol (PAR) as post-colouring complex. The retention factors of different ions proved to be dependent on the pH, concentration, nature of each complexing agent, and to less extent on eluent flow rate. The retention behaviour and separation mechanism of complexed metal analytes are discussed in the light of the stability of metal complexes and the ligand complexing ability of used eluent. Comparison between various mobile phases is evaluated, and both sodium and potassium oxalate can be used successfully for simultaneous separation of studied metals with good resolution within short elution periods. The method can be used in different applications including analysis of bottled water from different resources.