9210

8512

كارشناسي ارشد

خاكشناسي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1393

دوازده،80ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

مهران شيرواني

محمود كلباسي، ژاله ورشوساز

30/7/93

حسين شريعتمداري، جهانگير عابدي كوپايي

مهندسي كشاورزي

ID8512

80Release Pattern of Zinc and Copper From Alginate zeolite Matrices Pegah Razavi p razavi@ag iut ac ir 15 July 2014 Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiAssoc Prof M Shirvani@cc iut ac irAbstractExcessive use of chemical fertilizers typically leads to solution nutrient concentration higher than optimalfor the plant and results in a potential for leaching losses or precipitation of nutrients One of the effectivemethods to overcome this problem is the development of slow release fertilizers Biopolymers are themost suitable compounds for synthesis of the slow release systems of nutrients In this study alginatewith and without combination with zeolite clay in zeolite alginate ratios of 1 4 and 1 8 were used toproduce slow release systems of zinc Zn and copper Cu To load the systems with Zn or Cu thesynthesized systems were put in solutions of zinc sulfate and copper sulfate with concentration of 300 and200 mg l 1 respectively For the release experiments specified amounts of loaded matrixes in two forms dried or moist were transferred into vessels containing 0 01 M CaCl 2 solutions and the amounts ofreleased Zn or Cu were measured from 24 hours to 58 days Results showed that releases of Zn and Cufrom the moist systems were greater than those form the dried ones Release of Cu from the moistsystems continued for 58 days while release of Zn lasted for 17 days Releasing time of Zn from thedried systems however was considerably longer than that from the moist systems Time dependent Cuand Zn release data was sufficiently explained by pseudo first order power function and parabolicdiffusion kinetic models Pure alginate systems showed the greatest amounts of releasable Cu and Zn asestimated by the pseudo first order model Moreover rate of Zn and Cu release from pure alginate systemwas greater than those of the zeolite alginate systems showing the role of zeolite clay in decreasing therelease of nutrients from alginate Diffusion rate constants k i derived from parabolic diffusion modelswere also higher for pure alginate as compared to zeolite alginate systems Overall alginate andzeoite alginate hybrids can be applied as an environment friendly products for synthesis of slow releasesystems of Zn and Cu Key words Alginate Biopolymer Zeolite Kinetics Micronutrients Slow release

مهران شيرواني

محمود كلباسي، ژاله ورشوساز

حسين شريعتمداري، جهانگير عابدي كوپايي