Urban and industrial surface water pollution and their impacts on the environment. Constantine city case study. North-East of Algeria

Abstract

The study area is located in Constantine, at the North-East of Algeria; it regards the segments of wadi Rhumel and its branch wadi Boumerzoug. It is characterized by a semi-arid climate. This work focused on the assessment of the physical-chemical quality and the level of contamination by hydrocarbons (oils and greases) and metallic trace elements (TMEs) (As, Cd, Cu, Fe, Ni and Zn). 14 samples were collected spread the wadi, and were analyzed. Results show the order of abundance of the cations in the majority of the samples is: Na> Ca> Mg> K. The concentrations ranking is: Na (66.812-396.493 mg/l), Ca (90.11-96.66 mg/l), Mg (18.96-30.52 mg/l), K (9.494-13.988 mg/l). For TMEs, the analyses showed relatively high concentrations. The abundance ranking in most elements is: As > Fe > Cd > Ni > Zn > Cu. The concentrations ranking is: As (1.316-0.436 mg/l), Fe (0.119-0.170 mg/l), Cd (0.054-0.099 mg/l), Ni (0.007-0.043mg/l), Zn (0-0.08 mg/l), Cu (0.008-0.016 mg/l). All analysis shows oils and greases concentrations are extremely high (88.2- 390.6 mg/l). The correlation matrix and the PCA between all metal elements reflect the signature of anthropogenic and domestic inputs at the same time. The SEQ-Water: qualifies very poor quality according As and Cd contents, good to fair for Ni and good quality for Cu and Zn. This situation reveals a direct influence of anthropogenic inputs conveyed by the wadis. Oils and greases, their contents are found to be very high and reflect an intense uncontrolled activity linked to the use of hydrocarbons and derivatives.