اثر زئوليت و سوپر جاذب بر كاهش آبشويي نيترات در يك خاك لوم در شرايط غير اشباع

The Effect of Zeolite and Superabsorbent on Reduction of Nitrate Leaching from a Loamy Soil under Unsaturated Conditions

اﺳﺘﻔﺎده از زﺋﻮﻟﯿﺖ و ﺳﻮﭘﺮﺟﺎذﺑﺪر ﺧﺎك ﻣﯽﺗﻮاﻧﺪ در ﮐﺎﻫﺶ آﻟﻮدﮔﯽ ﻣﻨﺎﺑﻊ آب ﻣﻔﯿﺪ ﺑﺎﺷﺪ. ﺑﺪﯾﻦ ﻣﻨﻈﻮر اﯾﻦ ﺗﺤﻘﯿﻖ در ﺳﺎل 1397 و در ﻗﺎﻟﺐ ﻃﺮح آﻣﺎري ﺑﻠﻮكﻫﺎي ﮐﺎﻣﻼً ﺗﺼﺎدﻓﯽ و ﺑﻪﺻﻮرت دو آزﻣﺎﯾﺶ ﻣﺴﺘﻘﻞ اﻧﺠﺎم ﺷﺪ. ﺗﯿﻤﺎرﻫﺎي ﻣﻮرد اﺳﺘﻔﺎده ﺷﺎﻣﻞ دو ﺗﯿﻤﺎر در ﺳﻪ ﺳﻄﺢ ﻣﺨﺘﻠﻒ و ﭼﻬﺎر ﺗﮑﺮار ﺑﻮد و در ﻣﺠﻤﻮع ﺑﺎ 24 ﻟﻮﻟﻪ ﭘﻠﯽاﺗﯿﻠﻦ ﺑﻪ ﻗﻄﺮ 10/5 ﺳﺎﻧﺘﯽﻣﺘﺮ و ارﺗﻔﺎع 50 ﺳﺎﻧﺘﯽﻣﺘﺮ در ﺷﺮاﯾﻂ ﻏﯿﺮ اﺷﺒﺎع در ﻣﺰرﻋﻪ ﺗﺤﻘﯿﻘﺎﺗﯽ داﻧﺸﮑﺪه ﻣﻬﻨﺪﺳﯽ ﻋﻠﻮم آب داﻧﺸﮕﺎه ﺷﻬﯿﺪ ﭼﻤﺮان اﻫﻮاز اﻧﺠﺎم ﺷﺪ. ﺗﯿﻤﺎرﻫﺎ ﺷﺎﻣﻞ زﺋﻮﻟﯿﺖ ﭘﺘﺎﺳﯿﻤﯽ و ﺳﻮﭘﺮ ﺟﺎذب ﻧﻮع A200 در ﺳﻪ ﺳﻄﺢ ﺻﻔﺮ )ﺷﺎﻫﺪ(، 2 و 5 ﮔﺮم در ﮐﯿﻠﻮﮔﺮم ﺧﺎك ﺑﻮد. ﮐﻮد اوره ﺑﻪﺻﻮرت ﺳﺮك و از ﺑﯿﻦ 15 آﺑﯿﺎري، در آﺑﯿﺎريﻫﺎي 6 ،1 و 12 ﺑﻪ ﺳﺘﻮنﻫﺎي ﺧﺎك اﻋﻤﺎل ﺷﺪ. در ﭘﺎﯾﺎن ﻫﺮ آﺑﯿﺎري ﻧﯿﺘﺮات ﺧﺮوﺟﯽ اﻧﺪازهﮔﯿﺮي ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ اﺛﺮ ﺳﻮﭘﺮﺟﺎذب در ﺗﻤﺎم آﺑﯿﺎريﻫﺎ و زﺋﻮﻟﯿﺖ ﻏﯿﺮ از آﺑﯿﺎري 6 در ﺳﻄﺢ 5 درﺻﺪ ﺑﺮ ﮐﺎﻫﺶ آﺑﺸﻮﯾﯽ ﻧﯿﺘﺮات ﻣﻌﻨﯽدار ﺑﻮد. و ﺗﯿﻤﺎر 2 ﮔﺮم ﺳﻮﭘﺮﺟﺎذب در ﮐﯿﻠﻮﮔﺮم ﺧﺎك ﻏﯿﺮ از آﺑﯿﺎريﻫﺎي 6 و 7ﻧﺴﺒﺖ ﺑﻪ ﺗﯿﻤﺎر 2 ﮔﺮم زﺋﻮﻟﯿﺖ در ﮐﯿﻠﻮﮔﺮم ﺧﺎك ﻋﻤﻠﮑﺮد ﺑﻬﺘﺮي را در ﺟﻠﻮﮔﯿﺮي از آﺑﺸﻮﯾﯽ ﻧﯿﺘﺮات داﺷﺖ. ﺑﻪﻃﻮر ﮐﻠﯽ ﺗﯿﻤﺎرﻫﺎي 2 و 5 ﮔﺮم زﺋﻮﻟﯿﺖ در ﮐﯿﻠﻮﮔﺮم ﺧﺎك ﺑﻪ ﺗﺮﺗﯿﺐ 20و 29 درﺻﺪ و ﺗﯿﻤﺎرﻫﺎي 2 و 5 ﮔﺮم ﺳﻮﭘﺮﺟﺎذب در ﮐﯿﻠﻮﮔﺮم ﺧﺎك ﺑﻪ ﺗﺮﺗﯿﺐ 48 و 64 درﺻﺪ ﻧﺴﺒﺖ ﺑﻪ ﺗﯿﻤﺎر ﺷﺎﻫﺪ در ﺟﻠﻮﮔﯿﺮي از آﺑﺸﻮﯾﯽ ﻧﯿﺘﺮات ﻣﺆﺛﺮ ﺑﻮدﻧﺪ.

The application of zeolite and superabsorbent in the soil can be useful in reducing water pollution. For this purpose, this research was carried out in 2018 with two treatments in a completely randomized block design. Each treatment consists of 3 different levels and 4 replications. Totally 24 polyethylene pipes with 10.5 cm in diameter and 50 cm in height were used under unsaturated conditions at research farm of Faculty of Water Sciencs Engineering, Shahid Chamran University of Ahvaz. Treatments in this study included potassium zeolite and A200 superabsorbent at three levels of 0, 2 and 5 g/kg of soil. Urea fertilizer was applied to the soil in irrigation 1, 6 and 12 from 15 irrigation events. At the end of each irrigation event, nitrate effluent was measured. The results showed a significant reduction (at 5% level) of nitrate leaching in the superabsorbent and zeolite treatments in all irrigation events (with the exception of No. 6 irrigation event in zeolite). Superabsorbent treatment (2g/kg of soil) had better performance than the zeolite treatment (2g/kg of soil) in terms of preventing nitrate leaching, with the exception of irrigation events of 6 and 7. In general, zeolite and superabsorbent treatments (2 and 5 g/kg of soil) reduced nitrate leaching (20 and 29%) and (48 and 64%), respectively, as compared to the control treatments.