【作者】 陈尔余；

【导师】 林峰；

【作者基本信息】 浙江大学 ， 化学， 2006， 硕士

【摘要】 本试验以浙江缙云天然斜发沸石为原料，采用NaOH熔融，并结合水热合成改性制得到Na-Y型改性沸石。它对Ni²⁺的饱和吸附量（37．85mg／g）比天然沸石（3．87mg／g）提高9倍，也远大于Na型沸石（4．46mg/g）、H型沸石（4．59mg／g）、P型沸石（15．54mg/g）。研究了Na-Y型沸石对镍离子的吸附行为，并对其用于实际含镍废水的处理和再生实验进行了探讨。实验结果表明，Na-Y型沸石在水溶液中对镍离子具有较高的吸附能力，表现出“快速吸附，缓慢平衡”的吸附特点，对时间吸附曲线进行拟合，符合班厄姆公式。对Ni²⁺的吸附量随着温度升高和初始浓度的增加而增大，同时也受溶液pH的影响，在pH<4时吸附较小，当pH>8时因溶液中的Ni²⁺会沉淀而无法进行吸附除去，因而，控制溶液的pH范围在4～8之间。Ni²⁺的去除率随着沸石投加量的增加而增大，也与Ni²⁺的初始浓度有关，在初始浓度为196．52mg/L的Ni²⁺溶液中，当沸石投加量为1．8％（重量比）时去除率达90％以上。对吸附量和Ni²⁺浓度的关系进行拟合，符合Langmuir和Freundlich公式。改性沸石的再生实验表明，用0．5mol／L的HCl和NaCl按体积比为1：1混合作为淋洗剂效果最佳，5次再生使用后，改性沸石对Ni²⁺的吸附能力基本不变。实验中选择了四种竞争离子进行实验，发现竞争阳离子的存在降低了沸石对Ni²⁺的吸附量，影响顺序为：Ca²⁺>Co²⁺>Fe³⁺>K⁺。在对实际含镍废水(Pb²⁺、Ni²⁺、Zn²⁺的含量分别为37．2mg／l、25．4 mg／l、30．3mg／l)中，加入Na-Y型沸石0．4％（重量比），在温度为20℃，pH=4．5时，吸附处理2h后溶液中残余的Ni²⁺浓度为0．05mg/l小于国家排放标准（<1mg/l）。更多还原

【Abstract】 The natural zeolite （clinoptilolite） of Zhejiang Jinyun were used as the experimental materiel. The modified Na-Y zeolite was got by combining NaOH melting the natural zeolite with hydro-thermal synthesis method. It was found the saturation exchange capacity （37.85 mg/g） for Ni²⁺on Na-Y zeolite is improved nine multiples than that of the natural zeolite （3.87 mg/g）. The adsorption behavior of Ni²⁺ on the Na-Y zeolite was studied and discussed. The Na-Y zeolite was also applied to study the adsorption behavior and regenerative experiments of water waste that contained Ni²⁺.Experimental results show that the Na-Y zeolite is more high exchange capacity than that of natural zeolite for Ni²⁺ in water solution, and has the characteristic of "quick adsorption, slow equilibrium". The fit curve between time and adsorption amount could be well according with theequation of （?）.The exchange capacity of Ni²⁺) on Na-Y zeolite increase dramatically with the increase of temperature , the initial concentration and pH, but the value of pH is smaller than 4 the exchange capacity is small, while it is larger than 8, because the Ni²⁺ would be precipitated. So the value of pH should be controlled between 4 and 8 during the experiment.The elimination percent of Ni²⁺ increases with the adding amount of zeolite. When the initial concentration is 196.52mg/L and the adding amount of zeolite is 0.45g, The elimination percent is larger than 90%. The fit curve between adsorption and the concentration of Ni²⁺ is well agreement with equations of Langmuir and Freundlich.The regenerative experiments show that the best result is obtained by the mix solutions of 0.5mol/L HCl and NaCl.The modified zeolite has still high exchange capacity after using five times.It was found that the existence of four competitive cations would decrease the exchange capacity for Ni²⁺ on zeolite, and the order of the influence is : Ca²⁺>Co²⁺> Fe³⁺> K⁺.The Na-Y zeolite are applicable in eliminating Ni²⁺ under low concentration. The elimination percent can be achieve 99% when the initial concentration of Ni²⁺ is under 200 mg/L. 0.2g Na-Y zeolite was added to the water waste which containing Pb²⁺, Ni²⁺, Zn²⁺, and their concentrations are 37.2mg/l, 25.4 mg/l, 30.3 mg/l respectively. After 2 h adsorption handing under 20℃and PH=4.5, the concentration of Ni²⁺ is 0.05 mg/l which is lower than the water waste letting standard of our country.（ <1mg/l）更多还原