Synthesis Of Novel Adsorption Materials And Their Adsorption Properties For Trace Elements And Organic Dyes

With the rapid development in science and technology and proceeding industrialization, the consumption and draining of heavy metals and organic substance are increasing daily. The pollution caused by heavy metals and poisonous organic substance become more severe, which is also a dominant factor for jeopardizing the public health and preventing social economical development of our country. Thus, to efficiently monitor those pollutants has become one major task for environmental scientists and analytical chemists. Because of high complexity of classification and concentration of pollutants and samples, extreme low concentration of analytes and severe interference caused by matrix effects, traditional analytical methods weren't competent for the challenging. Although many instrument analysis methods possessing higher sensitivity and selectivity have been developed recently, pre-concentration and analysis of trace elements is still necessary before the more accurate measurement by analytical instruments in reality. The pre-concentration and analysis of trace elements will depend on different adsorption materials with higher selectivity and bigger adsorption and appropriate separation methods. In this research paper, new adsorption materials are synthesized in order to establish new methods by which the pre-concentration and separation of trace heavy metals and organic substance can be separated completely. The synthesis of new adsorption methods and their adsorption and selectivity characteristics for trace heavy metals and organic dye have been investigated systematically. The more detailed novelty of this research can be categorized as following:1. The imprinted and non imprinted copolymers for Hg(â…¡) and Pd(â…¡) was obtained by a surface imprinting technique for selective solid-phase extraction (SPE) of Hg (â…¡) and Pd(â…¡) prior to its determination by ICP-OES. The relatively selective factor (α_r) values of Hg²⁺, Pd²⁺ were 3.85 and 2.94, which were greater than 1. Compared with the traditional solid sorbents and non-imprinted polymer particles, the ion-imprinted polymers (IIPs) had higher adsorption capacity and selectivity for Hg(â…¡) and Pd(â…¡). The detection limit (3σ) of the method was 0.32μgL^-1 and 0.36μg L^-1, respectively. The developed method was also successfully applied to the determination of trace mercury and palladium in Chinese traditional medicine, in geological samples andwater samples with satisfactory results.2. A molecularly imprinted polymer was prepared by molecular imprinting technique using acrylamide as monomer, sudan red â…¢, morin and rhodamine 6G, respectively as template molecule, a large excess of ethyleneglycol dimethacrylate as the cross-linking agent and 2, 2-Azobisisobutyronitrile (AIBN) as the initiator. The bulk polymer obtained was investigated in equilibrium binding experiments toevaluate the molecular recognition and binding characteristics of the sudan red III, morin and rhodamine 6G molecularly imprinted polymer. The substrate selectivity of imprinted polymer and non-imprinted polymer was investigated. The results showed that the imprinted polymer exhibited much higher affinity for sudan red III, morin and rhodamine 6G among the tested compounds. It is possible to be a good adsorption and binding material in the selective enrichment and determination of trace sudan red III, morin and rhodamine 6G in complex biosamples.3. Nanometer TiO2 was modified with diethyldithiocarbamate (DDTC), sulfanilamide and diphenylthiourea under the activation of surfactant (SLS) and used for preconcentration and separation of trace amounts of metal ions from solution samples with reliable and satisfactory results. Compared with untreated nanometer TiO2, the DDTC-surfactant-modified nanometer TiO2 (DDTC-surfactant-TiO2), sulfanilamide-surfactant-modified nanometer TiO2 (sulfanilamide-surfactant-TiO2) and diphenylthiourea-surfactant-modified nanometer TiO2 (diphenylthiourea-surfactant-TiO2) show the higher selection and adsorption capacities for preconcentration and separation of trace heavy ions, and the metal ions can be enriched on the surface of modified adsorbents at lower pH which prevented metals ions from hydrolyzing. The separation / preconcentration conditions of analytes, which include the effects of the pH, the sample flow rate and volume, the elution condition, detection limits and precision and the interfering ions on the recovery of the analytes were investigated in detail. The accuracy of the proposed each method was checked by analyzing standard reference material with satisfactory results. In addition, some biological and natural water samples were analyzed using the standard addition method, the recoveries of trace analyzed ions added to these samples are 95-102 %. XRD patterns show that the synthesized nanometer TiO2 possesses classical anatase structure. FT-IR analyzing show that the nanometer TiO2 has been successfully modified by DDTC under the activation of surfactant.4. The novel poly(acryl-/?-toluenesulfonamideamidine-/7-toluenesulfonyl-amide) chelating fiber was firstly synthesized through one-step reaction of polyacrylonitrile fiber with /7-toluenesulfonamide and used for pre-concentration and separation of trace Ru(III), Rh(IH)> Au(III)> Pd(II)^ Sn(rV> V(V)^ Bi(III), Mo(VI), Zr(IV) and Mn(II) ions from solution samples. Using the FT-IR spectrometry and elemental analyzer, we got the structure of the chelating fiber and its elements' percentages. The acidity, rate, desorbed conditions, reuse, adsorption capacity, rate constant, interference on the adsorption of ions and mechanism on this chelating fiber were investigated in detail. The precision and the accuracy of the proposed method were achieved by analysis of wastewater, alloy samples and ore samples with satisfactory.