Study On Preparation Of Modified Polymers And The Adsorption Properties For Heavy Metal Ions

In recent years,with the development and progress of society,environmental pollution has become a problem can not be ignored,of which water pollution accounts for a large proportion.Heavy metals will cause a lot of impact of water resource,if not to control,heavy metal ions will eventually enter the animal and plant body,causing poisoning or some other hazards.The excessive amount of heavy metal content in water is one of the most important topics of concern.Compared with many methods of treating heavy metals,the simple adsorption method is suitable for practical application,and its low cost and biodegradable adsorbent have a wide application prospect in water treatment.In this paper,modified polymers and water treatment,the main work done the following:1.The hydroxamic acid chelate fibers were prepared by converting sodium carboxymethyl cellulose into acid-type carboxymethyl cellulose which was insoluble in water in acidic medium and modified with hydroxylamine hydrochloride.The structure of the modified material was characterized by infrared,thermogravimetric and scanning electron microscopy.The effects of various disturbances on the adsorption properties of hydroxamic acid chelate fibers were investigated in detail.Under the same conditions,the maximum adsorbents of the adsorbents were 100mg/L Pb²⁺,Cu²⁺and Ni²⁺solutions were 97.9 mg/g,68.9 mg/g and 42.5 mg/g,respectively,higher than sodium carboxymethyl cellulose's adsorption capacity of Pb²⁺,Cu²⁺and Ni²⁺was 70.0 mg/g,22.1 mg/g and 19.4 mg/g.At the same time,the adsorption thermodynamics and kinetic model were analyzed.The results show that the adsorption process is in good agreement with the quasi-second-order kinetic model,and the chemical adsorption is in the dominant position.The thermodynamic simulationresultsaccordwiththeLangmuirequation.Adsorbent adsorption-desorption test results show that hydroxamic acid chelate fiber has a better re-use performance.2?The walnut shell powder and 2-bromoisobutyryl bromide were reacted to form macromolecular initiator,and the acrylamide and methyl methacrylate were grafted with polyacrylamide and polymethyl methacrylate under certain conditions.The structure and morphology of two walnut shell modified materials were characterized by FTIR,thermogravimetric and scanning electron microscopy.Their adsorption on Pb²⁺was studied.293K,walnut shell-g-polyacrylamide,walnut shell-g-polymethyl methacrylate 10 mg,the initial concentration of 100 mg/L Pb²⁺solution?pH=5.0?,the oscillation time of 30 min,the largest The adsorption capacity was 40.2 mg/g and53.7 mg/g,respectively,which was higher than that of walnut shell.The isothermal adsorption process of the two materials can be described by the Langmuir equation.The kinetic fitting results conform to the second-order kinetics,indicating that the chemical adsorption is the main rate-limiting step.