Study On Carboxyl Modification Of Jute And Its Adsorption Behavior For Copper Ions In Simulated Water Pollution

Heavy metals and their compounds are widely exists in the mining, metal smelting,machinery manufacturing, electroplating and other industries.Industrial production canproduce a large number of poisonous and harmful waste water what is adverse to theaquatic environment and aquatic organisms and even bring a serious threat to humanhealth. With the continuous development of industrial technology, the heavymetal sudden water accidents occurs frequently.Jute as renewable natural polymers,possesses the advantages of good performance, high strength, and the environmentalbenefits without bagging in treatment of sudden water pollution accident, the strongapplicability, easy to recycle.This paper developed a modified jute fiber adsorptionmaterials.The goal pollutant is heavy metal cation-bivalence copper (Cu(Ⅱ)). Thispaper studied the processes of the modified jute adsorption treatment Cu(Ⅱ) in wastewater. The reaction mechanism of the modified jute with pyromellitic dianhydride andthe adsorption mechanism of modified jute for Cu(Ⅱ) are discussed in this paper.The modification taked advantage of the esterification between pyromelliticdianhydride and hydroxyl of jute fiber. The adsorption capacity to Cu(Ⅱ) served asevaluation index.Using single factor and orthogonal experiment the optimumpreparation conditions of material as follows: pretreat jute with15%NaOH solutionfor10min, the quality ratio of the jute and pyromellitic dianhydride by2:1, adjust thetemperature of the constant temperature water bath90℃, reaction time is0.5h, finallyafter a series of post processing get product adsorption material.With Cu(Ⅱ) as treatment object, this paper studied the static adsorptiontechnology of the modified jute disposing Cu(Ⅱ) in waste water. Static process, in theconstant temperature water bath, the optimum adsorption conditions as follows:0.1~0.2g modified jute materials, environment temperature, solution pH condition, theadsorption quantity is the highest after15min. The modified jute has wide applicationrange. The interference ions influence order of the adsorption quantity of Cu(Ⅱ) underthe condition of optimal adsorption process: Ca(Ⅱ)> Mg(Ⅱ)> K(Ⅰ)> Na(Ⅰ);Thebigger the calcium ion concentration, the greater influence on the adsorption quantityof Cu(Ⅱ).The regeneration experiment of the material by EDTA-2Na has goodreproducibility. Repeated use make the Cu(Ⅱ) enrichment and recovery, has the verygood application prospect.The adsorption behaviour of modified jute can be discribedby Langmuir model, and obeys the formation of single-molecular layer adsorption.Boththe pseudo-second-order equation and Arrhenius equation of fitting indicate that theadsorption of chemical adsorption.The thermodynamic parameters demonstrate that theadsorption was a spontaneous endothermic process, with physical adsorption. Studied the dynamic adsorption process of modified jute disposing Cu(Ⅱ) inwaste water within adsorption column. The results showed that the shorter columnpacking height, the larger the initial concentration and the higher penetration rate, theshorter the time of break-through; Modified jute has better treatment effect than jute, inaccordance with static experiment results. Thomas and Yoon-Nelson model can fit wellmodified jute dynamic adsorption behavior. The related parameters of models and thecurve fitting for materials can provide reliable design parameter information to theapplication of sudden pollution of heavy metals. Open channel simulation test benchresults show that the modified jute have significant treatment effect for sudden Cu(Ⅱ)wastewater.But above all, the modified jute fiber adsorption materials in this paper has a broadapplication prospect when purify heavy metal cations in wastewater.