HEAVY-METALS IN SOME WATER-IRRIGATED AND WASTE-WATER-IRRIGATED SOILS OF OMAN

Limited water resources and increased demands have triggered a nationwide campaign for water conservation and augmentation in the Sultanate of Oman. Renovated wastewater use is sought as part of the National Conservation Strategy being drafted by the authorities in the country. About 10 million cubic meters of wastewater is treated annually and primarily used for amenity along the main roads. Social, health, and environmental considerations have necessitated setting guidelines and regulations to accord with the most stringent international practices attaining at the time. Soil and water samples collected from different sites, using industrial and domestic treated effluent and potable underground water, and analysed for copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) revealed the effectiveness of such stringent but costly regulations, reflected by the low level of concentrations detected. No signs of toxicity to the plants were visible, some showing Zn-deficiency symptoms, and a separate study disclosed insignificant levels in the plants as well. Using treated and regulated wastewater for agricultural production has proved to be chemically safe and poses as a partial solution for conserving significant amounts of water, at a time when every drop counts.