تاثير جاذب هاي معدني بر گونه بندي، تحرك و تثبيت آرسنيك در ريز و سفر آفتابگردان ﴿Helianthus annuus. L﴾

چكيده انگليسي :

Abstract One of the main causes of soil pollution especially arsenic is mining The minds provide the basic ingredients for human development On the other hand the mining will cause environmental pollution Therefore some countries have used methods to stabilize and reduce environmental effects of heavy metals in soil surrounding the minds One suitable strategy for stabilizing heavy metals especially arsenic in contaminated soils around mines is using different iron compounds Over the past 100 years of drain water output of a Zarshuran gold mine southern West Azarbaijan province increased accumulation of heavy metals such as arsenic cadmium lead and zinc in the soil and in this area increased many health problems for the people living near the mind The objective of this research was to determine the effect of different sorbents such as raw zeolites and bentonite zeolite and bentonite modified with iron iron filings and iron sulfate on the mobility and bioavailability of arsenic in soil and hydroponic systems The first of study was carried out in sand culture enriched with arsenate and in the presence of sunflower The purpose of this study was to investigate the potential of the sorbents to stabilization of arsenate In this study the natural and modified zeolite and bentonite iron filings and ferric sulfate was added to the pots After harvesting the sunflower plants MINTEQ was used to determine arsenic spices in the sand culture Raw bentonite and zeolite and iron filings increased pH and decreased abundance species of H 2AsO4 in sand cuture Zeolite and bentonite modified with iron and iron sulfate reduced pH and increased abundance species of H 2AsO4 in sand culture In this experiment all sorbents decreased concentrations of arsenic in plant tissues Zeolite and bentonite modified with iron and iron filings via electrostatic adsorption mechanism and ligand exchange caused to decrease concentrations of arsenic in the roots and shoots Iron sulfate via precipitation mechanism and raw bentonite and zeolite by changing in speciation of arsenate in sand culture were decreased concentrations of the arsenic in roots and shoots Iron sulfate and raw zeolite have the greatest and the lowest performance in stabilization of arsenic respectively Iron filings containing 6 mmol Fe 3 by high dry weight and low concentration of As in shoot and root and suitble price was selected the best sorbent in this experiment The second study was carried out in soil and in the presence of sunflower The aim this work was to investigate effect of the mention sorbents on the speciation and stabilization arsenate and arsenite phases changing of arsenic in soil and reducing bioavailability of arsenic in contaminated soil The soil used in this experiment was collected from Zarshuran area The sorbents were added to the soil in various rates and after a month of incubation were were planted using sunflower After harvest soil and plant samples were analyzed and various species of arsenate and arsenite were estimated in solution by using MINTEQ The sorbents no impact on the speciation of arsenate and arsenite and mobility of arsenite in the soil solution Soils treated with raw bentonite and zeolite increased concentrations of soluble arsenate and decreased concentrations of arsenic exchangeable Zeolites modified with iron increased concentration of arsenate in solution Bentonite modified with iron iron filings and iron sulfate were decreased concentrations of soluble arsenate and arsenic exchangeable Finally iron filings containing 354 mmol Fe 3 by suitable price increasing biomass and decreasing concentration of As in plant tissue was selected of the best sorbent for stabilization of As Key words Arsenic Zarshuran Speciation Sorbent Stabilization

شاهمرادي سجاد

تاثير جاذب هاي معدني بر گونه بندي، تحرك و تثبيت آرسنيك در ريز و سفر آفتابگردان ﴿Helianthus annuus. L﴾

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