Abstract: The physicochemical characterization of water of the peri-urban area of Douala city was carried out from 04 springs and 21 wells in February 2013 and August 2013 corresponding to the dry season and the rainy season respectively. For bacteriological analyzes, thirteen water points were sampled, including 4 sources, 08 wells in the rainy and dry season. All the water points yielded pH values below 7,0 and were classified as acidic water. Electrical conductivity ranged between 44.30-483μm/cm and then waters are poor mineralized. The relative abundance of major ions (mg/l) was Ca2+> Na+> K+> Mg2+ for cations in dry season whereas and Na+> K+> Ca2+>Mg2+ in the rainy season. For the anions, HCO3-> Cl->SO42-> NO3- in the dry season whereas in the rainy season HCO3- > Cl- > NO3- > SO42-. Major ion concentrations were within the WHO guidelines for drinking water, but a few points have a concentrations below the WHO limits. Main water types in the both seasons were Ca-Mg-HCO3 and Ca-Mg-Cl. Bacteriological analysis revealed that all water points sampled during the rainy season and some (67%) during dry season contain feacal contamination control germs. Bacteriological contamination of the water is of human and animal origin. Human origin is linked outflow from latrines used by the population. The spring and well waters analysed are not suitable for drinking and domestic purposes except two springs in the dry season.Abstract: The physicochemical characterization of water of the peri-urban area of Douala city was carried out from 04 springs and 21 wells in February 2013 and August 2013 corresponding to the dry season and the rainy season respectively. For bacteriological analyzes, thirteen water points were sampled, including 4 sources, 08 wells in the rainy and dry seas...Show More
Abstract: The present study is a diagnosis of the level of degradation of Cavally River in Côte d'Ivoire. Several abiotic indicators such as physico-chemical parameters were appreciated. These abiotic indicators were supported by biotic indicators sensitive to some variations in quality of water. That is the use of benthic macro-invertebrates as some species of freshwater shrimps of the genus Macrobrachium. Sampling was made between September 2015 and August 2016 on the upper course of Cavally River and the area on either side of the mining zone "Ity". Measures of physico-chemical parameters such as dissolved oxygen, temperature of water, hydrogen potential, electrical conductivity, mercury rate and water transparency were made by season using multi parameters. Shrimps were caught monthly using dip nets and keep nets. The extreme value of physicochemical parameters is for dissolved oxygen value were 4.90 mg/l, temperature of water (25.55°C), hydrogen potential (8.48), electrical conductivity (53.14 μS/cm), mercury rate (5.75.10-3 mg/kg) and water transparency (27.06 cm). In general, the results showed that the extreme values of physico-chemical parameters were recorded in areas with high concentrations of anthropogenic activities. In the mining areas, high levels of mercury have been recorded above those of the WHO guideline for surface water. In total, M. vollenhovenii was the most abundant species with 383 individuals out of 879 specimens caught (43.57%). It is followed by M. dux with 321 individuals (36.51%) and M. macrobrachion with an abundance of 175 individuals (19.90%). Spatially, these species have been more abundant in the upstream and downstream areas which are more or less conserved environments. However, they were less abundant in mining areas. These results show that the upper course of the Cavally River is deteriorating. That constitutes a real threat to aquatic organisms and biodiversity.Abstract: The present study is a diagnosis of the level of degradation of Cavally River in Côte d'Ivoire. Several abiotic indicators such as physico-chemical parameters were appreciated. These abiotic indicators were supported by biotic indicators sensitive to some variations in quality of water. That is the use of benthic macro-invertebrates as some species...Show More