Arsenic and Other Irrigation Water Quality Indicators of Groundwater in an Agricultural Area of Qorveh Plain, Kurdistan, Iran

摘要

One of the most important agriculture areas in Kurdistan province in west of Iran, is the Qorveh Plain. Naturally-occurring arsenic (As) pollution along with agricultural drain waters are the great challenges to quality of water resources in this area. Therefore, 64 agricultural groundwater samples (depth on average 75 m) were collected from this area in September 2009. Water samples were analyzed for pH, water electrical conductivity (Ec ), As, Mn, Fe, Ca, Mg, Na, K, NO ¨CN, P, Cl, HCO , CO , SO ¨CS, Si, total hardness (TH), total w 3 3 3 4 alkalinity (TA), total dissolved solids (TDS), sodium adsorption ratio (SAR) and adjusted SAR. The results showed that surveyed groundwaters for irrigation purposes have a high salinity hazard (92%, C3 class), low alkalinity hazard (100%, excellent class), mildly acidic in nature, rich in bicarbonate ions (increasing alkalinity hazard) and are very hard. Furthermore, the toxicities of arsenic (range: 11.0-149.1, mean: 48.1 ppb), nitrate (range: 1.6-79.0, mean: 39.4 ppm) and phosphorus (range: 0.02-0.46, mean: 0.13 ppm) were found in the groundwaters. The results also indicated that the amount of nutrient ions such as N, P, K and S in the water samples were considerable. Thus, to minimize soil and groundwater degradation and cost of cultivation, the amount of these ions should be subtracted from the recommended fertilizers in this area. In general, the quality of the groundwaters is not suitable for sustainable crop production and soil health without appropriate remediation.