Manganese impregnated biochar deriving from wheat straw were synthesized to treat heavy metal contamination. Nitrogen adsorption-desorption isotherms, scanning electron microscopy-energy dispersive X-Ray spectroscopy (SEM-EDS), and X-ray diffraction (XRD) were used to determine the characteristics of adsorbents. Batch adsorption experiments demonstrated a fit Langmuir model with the maximum adsorption capacity of 0.216 mmol g-1 for As (III) and a suitable Freundlich model for Cr (VI) respectively. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were measured to explore probable adsorption mechanisms involving As and Cr adsorption, which indicated that the Lewis acid-base interactions play a more important role in arsenic adsorption while electrostatic interaction along with the reduction Cr (VI) to Cr (III) contribute primarily to chromium adsorption.

Studies on the bioavailability of As, Cr, Cu, Pb, Mn and Cd of impacted soils; the As bioaccesibility in the edible parts of carrots, beets and quinoa growing in these polluted soils thought “in vitro” gastrointestinal process; the As speciation both in the edible parts of vegetables and in their gastrointestinal extracts have been performed. Elemental analysis and As speciation have been performed by ICP-MS and LC-ICP-MS, respectively. The high As contents in the interchangeable and oxidized fractions of soil may be responsible for the high As species content in these high vegetables consumption. The Arsenic recovery after the in vitro gastrointestinal digestion was from 98, 90 and 40% for carrots, beets and quinoa, respectively; with no significant transformation of original As species. These studies provide a clearer understanding of the impact that As and other contaminant elements may present in the population of this high polluted Chilean region

Heavy metals are common pollutants in River mainly due to traffic emissions to it. The present project work was focused to study Mn, Cr, Cd and Pb concentrations in Kulufo River, Arba Minch, Gamo Gofa. In the present work, the water sample was collected from Kulufo River randomly and analyzed for the concentrations of Mn, Cr, Cd and Pb. The concentrations of Mn, Cr, Cd and Pb were analyzed with the help of Flame Atomic Absorption Spectrometry (FAAS). The levels of Mn, Cr, Cd and Pb in the studied River water ranges from (0.420-520, 0.012-0.023, 0.106-0.201 and 0.050-0.108) mg L-1 respectively. From these concentrations, all the concentration obtained for Mn, Cr, Cd and Pb were greater than the concentration reported by World Health Organization (WHO). This shows that the presence of Mn, Cr, Cd and Pb in the study area has a significant influence to health. Especially, Pb, and Cd exhibited high significance toxicity effect even at lower concentration.