Monitoring and investigation of water and effluent conditions in greenhouse desalination devices in Isfahan province

The decline in quality and quantity of water resources has created a great challenge in the production of greenhouse agricultural products in Iran. Considering the increasing use of water desalination systems in the greenhouses, a research was conducted in Isfahan province (Falawarjan, Isfahan, Mobarakeh and Shahreza counties). Therefore, after visiting and observing various aspects of the use of these devices, samples were taken from well water, desalinated water and the condensed effluent of desalination systems and the methods of effluent disposing of the devices were studied. The results showed that the highest amount of well water salinity was observed in Falawarjan, with an average of 12.41 dS/m and the lowest in Shahreza, with an average of 4.09 dS/m. For condensed effluent of devices, the highest amount of salinity was also observed in Falawarjan, with an average of 16.63 dS/m and the lowest in Shahreza, with an average of 5.41 dS/m. The average salt removal from feed water (returned salt) in all investigated greenhouses in Isfahan province was 73%. In addition, the values of Sodium Absorption Ratio (SAR), Calcium-Magnesium Ratio, Chlorine and Bicarbonate level in water samples was also carried out. Regarding the condensed effluent discharge, the main option with 46% belonged to the release of effluent in the surrounding lands (environment), followed by combined use with well water for open-air agriculture with 27%, discharge to local wells with 18%, and discharge to trenches and the infiltration ponds with 9%, respectively. Due to the lack of monitoring of the implementation and use of these devices and the lack of consideration in waste disposal, a suitable situation was not observed, and with the continuation of the current process, the spread of contamination of water and soil resources is not far from expected.