The role of ion pairs and ion activity in classification of ground waters for irrigation in Erbil plain

Effect of Ion Pairs on Decrease the Risk of Using Saline Water for Irrigation

“…The dominate ions in the most waters (81%) of the studied area were Mg and SO 4 , it means having Mg-SO 4 family due to the Fars formation of the studied area (13), while the water of 6 wells having Ca-SO 4 family. For these reasons the series of ions contributed in ion paring were arranged dissentingly as follow: SO 4 > Ca > Mg > HCO 3 > Na > K. The contributing ions in ion pairing especially in saline water decrease the risk of salinity since ion pairs cannot absorb by plant roots or they are not active (8). For this reason the classification of saline water depending on salinity potential (SP) and sodium adsorption ratio (SAR) for irrigation after correcting ion pairs regards as a most important issue.…”

“…On the other hand ion pairing and activity effects on water class especially in saline water. Esmail and Salih (10) indicated to classification of 38 ground waters in Erbil plain, correcting ion pairs and activity only affected on 3 water samples depending on salinity potential, means correcting ion pairs and activity affected on conversion of 5 water samples towards the better class 3 of them changed from bad class to moderate class and 2 of them changed from moderate to good class) which salinity of them ranged between (2.45 -5.65) dS m -1 . While the 33 ground water samples were not affected by correcting ion pairs and activity due to low salinity of them or most of them was non saline water.…”

“…Groundwater caters the agricultural requirement. Some of the ground waters have high EC value or they are saline water at the same time this saline water is using for irrigation by farmer (8). Large quantities of salt are brought into agricultural areas by water of good quality.…”

“…After having addressed the formation of both ion pairs and complexes, it is necessary to reconsider how to calculate ion activities from measured total concentrations. Activity is linked to concentration via activity coefficient as described by (10). a= *c…………………….…”

Limiting Water Resources for Agricultural Uses in Rania District, Sulaimani Governorate

“…The water quality for livestock was classified by Altoviski (1962) as recorded in the table below: Water quality guide for livestock and poultry uses was classified by Ayers and Westcott (1985 The water quality for livestock was classified as mentioned by Ayers and Westcot (1985), which referred to upper limit of heavy metals and other ions as shown in table 9: Many studies have been done at different locations in Kurdistan region on water quality which included both of surface water and ground water by Esmail, 1986,Dohuki ,1997, Mam Rasul 2000, Khwakarim et al, 2010, Esmail and Salih, 2014, Rajab, 2015, Bapir and Ali, 2016and Albarwary et al, 2018. Also numerous studies have been done in Iraq by Alhashimi andMustafa 2012 andAlamar, 2015. ince there are little or no studies in Rania district about different water resources and their uses for different purpose for this reason this study was selected to classify the water of different resources (rivers ,springs and wells ) for irrigation ,livestock and poultry uses and fishing culture.…”