Study On The Modification Of Straw Stalks And Its Adsorption Properties Of Hexavalent Chromium Ion

Nowadays,environmental pollution and energy shortage have become serious problems,which hinders the social development,we as a big agricultural country,The yield of straw is about 230 million t every year,but the mainly utilize pattern still are burning、composting、feeding.And other way of utilization is relatively scarce.Therefore,exploring an effective way to improve the utilization rate of straw has a very important significance.With the development of industry,huge number of industrial wastewater which containing chromium had been produced.Chromium pollution could cause great harm to human health,and it has become an important pollution source in ecological environment.So looking for a wide-source and low-cost agricultural wastes to prepare efficient cellulosic-based adsorbent,Treating with heavy metal ions pollution waste waters in order to achieve the purpose of using waste treat waste.This paper through modification of fiber cellulose structure,prepared the higher capacity absorbent.Then applied the modified straw stalk to study the adsorption of the simulate Cr(VI)waste water.The study of contents and results are as follows:Washing and drying the crushed straw,using tartaric acid、triethanolamine、ammonium citrate、sodium hydroxide modified straw,and characterized by SEM,TG,FTIR.The main experiments contents include:1)effect of pH;2)Effect of particle size;3)effect of temperature;4)effect of time;5)effect of initial concentration;6)the adsorption rate of low concentrations of Cr(VI)under the best conditions;7)Analysis of Kinetic Model;8)Analysis of Isotherm model.The results of experiment show that when pH=2,the adsorption is best,Temperature and particle size has little effect on the adsorption.When reached equilibrium,the adsorption capacity of straw immersed in water,tartaric acid modified,triethanolamine modified,ammonium citrate modified,sodium hydroxide modified are 2.18 mg/g,4.01 mg/g,3.69 mg/g,3.52 mg/g,3.02 mg/g,And their adsorption rates at low concentration are 78.4%,91%,86.6%,82.6%,81.4%.Showing that the adsorption capacity of modified straw are better than nature materials.