Mohamed Fahmy Hussein

Publications

• BTC SOLUTE-TRANSPORT PARAMETERS FOR THREE SEDIMENTS

  M. F. Hussein

  The Bulltine, Fautly of Agri, Cairo Univ., 4th Conference on Recent Technologies in Agriculture, 2009. 01/2009; Special issue, conf, 2009:421-432.

  Solute transport is concerned with irrigation and soil salinization, fertilization and pollution. A locally manufactured fraction-collector was used for BTC runs on three disturbed sediments from Egypt to get transient chloride-transport parameters under steady-state saturated flow. Thirty-cm long c... [more] Solute transport is concerned with irrigation and soil salinization, fertilization and pollution. A locally manufactured fraction-collector was used for BTC runs on three disturbed sediments from Egypt to get transient chloride-transport parameters under steady-state saturated flow. Thirty-cm long columns were packed with dune Sands, Nile-bank sediments, and clayey Calcareous-aggregates. Experimental BTC data were fitted to two analytical solutions in CfitM code that solves the CDE equation corresponding to boundary conditions. The parameters included the retardation factor, Peclet number, longitudinal dispersivity, hydrodynamic dispersion coefficient and tortuosity. RETC was used to get the hydraulic parameters by fitting the samples’ pF data. Sands showed retardation factor of about unity (no reaction), intermediate values for both Peclet number (49-61) and dispersivity (0.49-0.62cm) (moderate leaching-efficiency). Smaller dispersivity (better leaching) would be expected if saturation was realized. Nile-bank sediments monitored high Peclet number (117-180), small dispersivity (0.17-0.26cm) (efficient leaching) and slightly less than unity retardation-factor (some anion exclusion). The Clayey-aggregates have shown wide range of small Peclet numbers (9-34), large dispersivity (0.90-3.4cm) increasing with aggregate size (low leaching in large aggregates) and retardation factor significantly less than unity (rapid exit due to high anion-exclusion). In contrast to Clayey-aggregates, the high Peclet number of the Nile-bank and Sands reflects dominant mass-flow transport compared to dispersive transport.

• IS OT OPE HYD R OGE OCHEMISTRY OF URBAN -ZONE GR OUN D WATER, CENTRAL AFRICA

  M. F. Hussein, A. Islam, S. Gamal, M. Gaetan, Ch. Djebebe

  Bulletine, Fac, of Agric, Cairo Univ, 4th Conference on Recent Technologies in Agriculture ,2009. 01/2009; 4th Conference on Recent Technologies in Agriculture ,2009:539-551.

  The isotope hydrogeochemistry of Bangui City, Central Africa, is discussed. This small city (~0.65 million people on ~20km2) is situated on Oubangui tributary of the Congo River. The urban-zone is highly despoiled and most of its population depends on water supply from the shallow and porous aquifer... [more] The isotope hydrogeochemistry of Bangui City, Central Africa, is discussed. This small city (~0.65 million people on ~20km2) is situated on Oubangui tributary of the Congo River. The urban-zone is highly despoiled and most of its population depends on water supply from the shallow and porous aquifer and/or pumping the deep fractured aquifer. The purpose is to define groundwater chemical and isotope composition in relation to recharge, rock formation and the impact of the awful practices of the indigenous population on groundwater quality. The hydrochemical data demonstrated reaction with biogenic CO2 gas, weathering, cation- exchange and NO3 - pollution of anthropogenic origin. The conjunctive use of the chemical and isotope compositions (18O and 2H) showed the alteration of silicate and carbonate rocks in the zones of dilute and relatively charged groundwater. The isotopes illustrated the role of evaporation and transpiration in the water-balance, with a fraction of the transpired-vapor recycled. The regional “inverse continental isotopeeffect” is attributed to differences in air-temperature, amount and altitude of precipitation, rather than to a claimed movement of humid air masses from Central Africa westward to the Atlantic. Isotope data showed that recharge during the humid-season may not exceed that taking place during the dry-season, and that the overall aquifer-recharge is mediocre. The data helped to distinguish rapid circulation in deep fractured formations northward versus slow one in porous sections southward, and showed that the system is void of evaporites and its carbonates are made-up of Calcite, not Dolomite. Pollution, by nitrate, is noticed downtown, and would extend everywhere in that urban-zone due to its law life-style.