Search

Dayat Roumi Lake, a vast body of permanent and shallow water in Morocco, is exposed to urban, tourist, and agricultural constraints. This human intervention can lead to microbial pollution of the lake ecosystem, hence the need to assess this contamination. For this reason, we undertook in this study an evaluation of the microbiological quality of the lake's water. Thus, seasonal water samples were taken at eight selected stations, taking into account the reception sites of the tributaries and anthropic activities. The parameters determined were: temperature, pH, dissolved oxygen (DO), electrical conductivity, biological oxygen demand (BOD), chemical oxygen demand (COD), ammonium, nitrates, orthophosphates, total phosphate, total coliforms, fecal coliforms and fecal streptococci. The results reveal: (1) A high water conductivity exceeding the admissible value recommended by the Moroccan standard; (2) A significant presence of coliforms and fecal streptococci, in dry periods, exceeding the standards set by the WHO, which could be attributed to a summer temperature favorable to the development of coliforms. This fecal contamination leads to an increased consumption of dissolved oxygen (high BOD and low DO values) explaining the fish mortality in this period of the year; (3) The principal component analysis identified the sources of water quality degradation as domestic sewage, agricultural run-off, domestic waste, and human and animal excreta; (4) The hierarchical analysis divided the sampling stations into three different clusters. The results of the microbiological quality index classified the waters from not to highly polluted. Station 4 was classified as the most polluted site. The results of the COD/BOD ratio showed a spatial and temporal heterogeneity of the biodegradability of the oxidizable matter present in the lake waters. [ABSTRACT FROM AUTHOR]

Groundwater is one of the most important natural resources that is overexploited and extensively polluted by human activity. Furthermore, drinking this dirty water might have major consequences for human health. Before using groundwater, it is consequently required to conduct a precise and regular assessment of its quality. Furthermore, for five monitoring stations in the Khemisset-Tiflet region, cluster analysis (CA), principal component analysis (PCA), and a fuzzy logic technique were utilized to analyze water quality. The CA classified the sample sites into three categories. The PCA identified temporal characteristics of water quality status. Group I include stations characterized by high temperature and low DO, COD, and BOD5 values. Group II includes stations characterized by high values of pH and low concentrations of NO3 -, Cl-, SO4 2- and turbidity. Group III includes stations characterized by high concentrations of NO3 -, Cl-, SO4 2- and turbidity and low concentrations of pH. In addition, fuzzy logic to reveal more information about groundwater quality. In effect, water quality in spring and winter was the best; the parameters responsible for the deterioration of water quality are NO3 -, Cl-, SO4 2- and turbidity. [ABSTRACT FROM AUTHOR]