Fate and distribution of heavy metals in wastewater irrigated calcareous soils.
Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO) amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1) soil was higher than Wadi Dhuleil (WD1) soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective.
Department of Land, Water and Environment, Faculty of Agriculture, The University of Jordan, Amman 11942, Jordan.
Mohammed Hashem
MH
Stietiya
Department of Land, Water and Environment, Faculty of Agriculture, The University of Jordan, Amman 11942, Jordan.
Mohammad
M
Duqqah
School of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409-2122, USA.
Theophilus
T
Udeigwe
Department of Land, Water and Environment, Faculty of Agriculture, The University of Jordan, Amman 11942, Jordan.
Ruba
R
Zubi
Department of Water Resources and Environmental Management, Faculty of Agricultural Technology, Al-Balqa' Applied University, Al-Salt 19117, Jordan.
Tarek
T
Ammari
D002104:Cadmium / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D019216:Metals, Heavy / Q000032:analysis*; D009532:Nickel / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
D002104:Cadmium; D019216:Metals, Heavy; D009532:Nickel; D012987:Soil; D062065:Wastewater; D015032:Zinc