حذف فلزات سنگين سرب و كادميم از محلول هاي آبي با استفاده از بقاياي گياهي كلزا و خاك

چكيده انگليسي :

Removal of Pb II and Cd II Ions From Aqueous Solution Using the Brassica Napus Residues and Soil Maedeh Khademi Hedayat m khademihedayat@ag iut ac ir January 21 2013 Department of Water Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi S F Mousavi mousavi@cc iut ac ir J Abedi Koupai koupai@cc iut ac ir Abstract The natural asset of water source of life and origin of major civilizations of the world in the 21st century is known as the cause of many regional conflicts and serious challenges between countries According to the fiftieth constitution principle environment protection in which today and future s generations should have a growing life has been regarded as a public duty Therefore activities that are involved with pollution and environmental degradation are prohibited Due to the large volume of produced wastewater it is necessary to achieve the proper method of sewage disposal Thus a wastewater treatment method that can be justified in terms of economic efficiency is definitely required Lead Pb metal is one of the most widely used metals in the world with consumption of over 7 million tons per year Also about 25 000 tons of cadmium Cd is introduced annually into the environment Forest fires and volcanoes human activities such as industrial wastes and synthetic phosphate fertilizers are important sources of released Cd Hence in this study the residues of canola rapeseed plant which is abundantly planted in Iran and has not been yet researched as a heavy metal adsorbent is selected to remove the heavy metals of Pb and Cd from aqueous solutions Also a comparison between maximum amount of adsorption of these elements with residues of canola and silty clay soil of Jar area Isfahan province Iran was conducted Functionality of these materials as an adsorbent while changing initial concentrations of Pb and Cd the amount of adsorbent pollutant s solution pH and contact time was investigated The greatest amount of Pb and Cd adsorption by rapeseed plant residues was 39 8 and 25 21 mg gr respectively for a solution with pH of 5 5 in optimal contact time of 60 minutes This amount for soil was 21 06 and 15 8 mg gr respectively for a solution with pH of 5 and optimum contact time of 50 minutes Techniques such as FTIR SEM and BET were performed to characterize the adsorbent attribute of the residues of rapeseed To complete the studies presented on the introduced adsorbent column adsorption experiments were performed at two stages This was to check the performance of the adsorbent during multiple courses of entering soluble contaminants drying column and consecutive entering of aqueous solutions of Pb and Cd into the column until the adsorbent has been saturated Results showed that the concentration of Pb outflow at the end of ten times adding two pore volumes of Pb and Cd solution to the columns containing soil and rapeseed was not detectable with atomic adsorption device Results for columns with continuous inflow indicated that maximum capacity of adsorption of Cd ion at 50 breakthrough curve was 9 47 mg g for a column height of 30 cm of canola residues and input concentration of 15 mg L This amount for removing the Pb ions in 50 breakthrough curve was 13 22 mg g for a column height of 20 cm of canola residues and input concentration of 8 mg L The results of this study showed that the soil of Jar region has high capability in adsorbing Pb and Cd heavy elements and dumping of these elements into the soil will cause soil pollution Also the crushed residues of canola can remove heavy metal elements such as Pb and Cd from aquatic environments Keywords Lead cadmium adsorption batch adsorbent column experiment

خادمي هدايت، مائده

حذف فلزات سنگين سرب و كادميم از محلول هاي آبي با استفاده از بقاياي گياهي كلزا و خاك

جذب , آزمايش پيمانه اي , آزمايش ستوني