Assessment of Sediment Contamination by Heavy Metals in the Water of Mgoua Catchment in the Industrial Zone of Douala (Cameroon)
Josephine Ndjama,
Raoul Gustave Nkoue Ndondo,
Gloria Takem Eyong,
Eric Belmond Biram Ngon,
Alain Fouepe Takounjou,
Georges Mafany,
Clarisse Mfopou Mewouo
Issue:
Volume 9, Issue 3, September 2021
Pages:
58-67
Received:
11 May 2021
Accepted:
9 June 2021
Published:
13 July 2021
Abstract: Aquatic ecosystems are increasingly affected by human activities, notably urban sewage and industrial effluent discharges, particularly in rivers. This study assesses heavy metals contamination of sediments of the Mgoua River in Douala, Cameroon. The Geoaccumulation Index (Igeo), the Contamination Factor (FC), the Sediment Pollution Index (SPI), the Enrichment Factor (EF) and the Pollution Load Index (PLI) were used to assess the contamination risk. The mean concentration of Ti, V, Cr, Co, Ni, Cu, As, Cd, Zn, Pb, U, Rb, Sr, Y, Zr, Mo, Mn, Fe, Cs and Ba in sediments was 12601.08, 111.96, 151.93, 9.47, 65.43, 161.81, 7.55, 2.27, 419.30, 248.30, 49.30, 12.65, 89.50, 39.69, 3017.52, 5.95, 313.26, 39667.32, 0.97 and 243.19 µg/l, respectively. Heavy metals concentrations in sediments creased in the following order: U < Cs < Cd < Mo < As < Co < Rb < Y < Ni < Sr < V < Cr < Cu < Ba < Pb < Mn < Zn < Ti < Fe. The Igeo, CF and EF indicate a polymetallic contamination dominated by Cu, Cd and Pb being the most important in all studied sites. The value of SPI varied between 10.95 and 37.84, suggesting that the sediments are moderately to highly polluted, with PLI higher than 1. These indices reveal that the sediments of Mgoua river catchment were polluted with most of the heavy metals. The high concentrations of some of the metals were due to anthropogenic sources particularly the discharge of untreated industrial wastes in to watercourses. This study can therefore be used as a reference to monitor the quality of sediments of the Mgoua river.
Abstract: Aquatic ecosystems are increasingly affected by human activities, notably urban sewage and industrial effluent discharges, particularly in rivers. This study assesses heavy metals contamination of sediments of the Mgoua River in Douala, Cameroon. The Geoaccumulation Index (Igeo), the Contamination Factor (FC), the Sediment Pollution Index (SPI), th...
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Equilibrium Constant, Concentrations Study of p-Aminobenzoic Acid in Anionic, Cationic and Non-ionic Surfactants
Albert Antony Muthu Prabhu,
Narayanasamy Rajendiran,
Kasi Sathiyaseelan
Issue:
Volume 9, Issue 3, September 2021
Pages:
68-76
Received:
18 August 2021
Accepted:
13 September 2021
Published:
12 October 2021
Abstract: p-aminobenzoic acid (pABA) was used as a probe to study the equilibrium constant in ground and excited state and concentrations of anionic surfactant, cationic surfactant and non-ionic surfactant. The absorption and fluorescence spectral characteristics of pABA were reported in aqueous micellar environments (SDS, CTAB and TW 80) at different pHs. The neutral and monoanion form of pABA is present at both pHs 3 and 7 respectively. The blue shifted fluorescence maximum was accompanied by a great raise in intensity at pH 3 whereas at pH 7 the emission intensity a little increase with increasing micelles concentration. In the acidic medium, the CMC value is increased when compared to neutral solution. The strength of interaction between pABA-micelles at both pHs was estimated using Hirose - Sepulveda equation and these calculated values was further used to estimate the free energy change of the interaction from the fluorescence data. These results from the absorption and fluorescence spectra of pABA well explained that the nature of force and location of probe in ionic micelles and non-ionic micelles at different pHs.
Abstract: p-aminobenzoic acid (pABA) was used as a probe to study the equilibrium constant in ground and excited state and concentrations of anionic surfactant, cationic surfactant and non-ionic surfactant. The absorption and fluorescence spectral characteristics of pABA were reported in aqueous micellar environments (SDS, CTAB and TW 80) at different pHs. T...
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