Magnetic, geo-electric, and groundwater and soil quality analysis over a landfill from a lead smelter, Cairo, Egypt

Abstract

Abstract A detailed ground magnetic survey, geoelectric vertical electric sounding (VES), and groundwater and soil quality analysis were conducted in the area of the abandoned landfill of the Awadallah lead (Pb) smelter, northeastern Cairo, Egypt. The integration between the applied techniques located successfully the buried solid waste, demarcated the groundwater and its possible contamination, and determined the lead level in soil. Magnetic survey comprised 50 magnetic profiles each 190 m length. Vertical derivatives, wavelength filters, and continuation filters characterized the eastern and central parts of the landfill by high intense magnetic anomalies reflecting metal and lead wastes, whereas the western part was characterized by low intense anomalies indicating change in the landfill composition to non-magnetized material. The geoelectric survey comprised 16 VES with a maximum AB/2 of 100 m. The inverted data demarcated effectively the groundwater aquifer with depth ranged from 11 to 18 m and true resistivities ranged from 96 to 118 Ω·m. The second layer (Holocene-Q3) of semi-permeable silty and sandy clay cap (true resistivities 29 ~ 51 Ω·m and thickness 9–17 m) constituted a considerable role in limiting the possible contamination from the landfill. The analyzed groundwater parameters pH, E h , TDS, SEC, and DO indicated a good water quality with homogenous aquifer characteristics, whereas the lead concentration in groundwater (0.033–0.036 mg/L) was slightly exceeding the safe limits identified by the U.S. EPA (≤ 0.015 mg/L). Lead in soil samples revealed elevated concentrations (3130 mg/L/kg at VES-3) around the Awadallah smelter, whereas a gradual decrease in concentrations was recorded in the northwestern direction.