Study On The Preparation Of Load Materials Of Kelex 100 With High Efficient Extraction And Its Adsorption For Heavy Metal Ions From Waste Aqueous Solution

Trace heavy metal ions discharged in the water environment were enrich through the food chain retention, accumulation, migration and biological amplification in the more advanced organisms, so it destroy the ecological environment and are harmful to human health. In addition, some much-needed metal will only be isolated and refined from lean ore and tailings and electronic waste due to the scarcity of mineral resources. Extraction, one of the most effective methods is preferred for the adsorption of metal ions in wastewater treatment and very dilute aqueous solution. The key factor in the extraction process is the selection of extractive agent with excellent performance. Kelex 100 that is trade name of 7-(4-ethyl-1-methyloctyl)-8-hydroxyquinoline(other name: 7-alkyl-8-hydroxyl-quinoline) has good characteristics such as higher selectivity, stability, extracting speed, extracting rate and eluting rate; Kelex 100 is widely used in the recovery of precious metals and treatment of heavy metal wastewater in occidental places, however, the application is limited in domestic because of it’s complex production process and expensive price. In this dissertation, Kelex 100 was synthesized by using the transfer hydrogenation, novel adsorption materials of Kelex 100 loaded on XAD-2 resin, activated carbon, and hydroxyapatite(HAP) were preparated, and the methods that were used for high efficiency remove trace heavy metals in the wastewater and beneficiate rare metal metal ions from the dilute solution with Kelex 100 loaded on HAP were researched.First, the new technology of synthesizing Kelex 100 was developed. A practical synthetic route of Kelex 100 using the transfer hydrogenation in five steps was explored from n-butyraldehyde and 8-hydroxyquinoline as main raw materials. The self condensation of n-butyraldehyde was carried out, and then cross-condensation with acetone and catalytic hydrogenation to give important intermediate 5-ethyl-2-nonanone, reacted with 8-hydroxyquinoline to obtain 7-alkenyl-8-hydroxyquinoline, sequentially, reduced by direct catalytic hydrogenation or transfer hydrogenation to yield Kelex 100. The transfer hydrogenation process of Kelex 100 can be controlled to avoid over hydrogenation products to realize the complete recovery of Pd/C and reuse of 8-hydroxyquinoline. The effects of feed ratio, catalyst amount, hydrogen pressure, reaction temperature and reaction time on the yield of each step were investigated for the optimal reaction conditions, and the best yield of each step was 99.3%, 93.8%, 94.4%, 93.0% and 99.5%(purity: 97.3%) respectively. The purity was tested with GC and HPLC, and the stuctures were characterized through IR, 1H-NMR, GC-MS, LC-MS and MS for intermediates and Kelex 100. This method simplify the production technology as well as reduce the cost and pollutantemission.Liquid-liquid extraction and elution of metal ions with Kelex 100. Liquid-liquid extraction and elution of Zn(II), Cu(II), Co(II) and Ni(II) were investigated using organic phase containing Kelex 100, decanol and kerosene. The optimal procedure of extraction was studied with the orthogonal experiment. The extraction rates of Zn(II), Cu(II), Co(II) and Ni(II) were 68.1%、98.7%、24.7% and 4.8% respectively, Zn(II) and Cu(II) chelates of Kelex 100 were eluted with hydrochloric acid, the elution rate were 72.1% and 84% in turn, and the recovery rates were 49.4% and 82.7% respectively. Experiments show that Zn(II) and Cu(II) can be selectively extracted with the extraction system of Kelex 100. Under the optimal conditions for the extraction of Cu(II), liquid-liquid extraction with Kelex 100 was used in treatment of trace residues of Cu(II) in electroplating wastewater, which had been pretreated with chemical precipitation, the detectable rate was lower than the national standards for the discharge of pollutants from electroplating.Secondly, the novel adsorption materials of Kelex 100 were prepared. Based on large pore network structure of XAD-2 resin, pore structure of activated carbon, and interfacial adsorption, micro hole adsorption, hydroxyl chelating adsorption of HAP, synergistic effect of adsorption-coordination was formed with the strong chelating interaction of Kelex 100. Kelex 100 loading on the resin, activated carbon and HAP were studied with impregnation method to obtain novel adsorption materials, and the load rates that were tested via increases weight method was 30.0%, 35.3% and 21.5% respectively. IR shows that the non polar part of the alkyl chain is adsorbed on the surface of the carrier to obtain a stable novel adsorption material of Kelex 100, while the hydroxyl and quinoline ring in molecular of Kelex 100 still retain the necessary flexibility that play a role in chleation. SEM of load material showed that there was no obvious difference of appearance and morphology for the three kinds of carrier materials and Kelex 100. The original structure of the carrier and Kelex 100 is not affected by whether or not the load and the chelating metal ions.Solid-liquid extraction and elution of metal ions with novel adsorption materials. Using the novel adsorption material of Kelex 100 loaded on the resin, activated carbon and hydroxyapatite, the optimum adsorption conditions for capturing Pb(II), Cu(II), Zn(II), Ga(III) and Ce(III) in aqueous solution were carried out with the aid of the single factor experiment and orthogonal experiment. The metal ions that were adsorbed on resin-Kelex 100 or activated carbon-Kelex 100 were eluted by hydrochloric acid solution containing Kelex 100 concentration of 15.0 mg/L, the optimum elution conditions were determined with the aid of the single factor experiment and orthogonal experiment. Using resin-Kelex 100, the adsorption rates of Ga(III), Ce(III), Pb(II), Cu(II) and Zn(II) were 95.7%, 96.8%, 97.2%, 99.1% and 98.8% respectively, and the elution rate was 94.9%, 97.6%, 94.2%, 96.9% and 95.7% respectively. Making use of activate carbon-Kelex100, the adsorption rates of Ga(III), Ce(III), Pb(II), Cu(II) and Zn(II) in aqueous solution were 97.9%, 96.1%, 98.4%, 99.6% and 99.0% respectively, and the elution rate was 98.0%, 98.9%, 98.5%, 98.7% and 98.9% respectively. The adsorption rates of Ga(III), Ce(III), Pb(II), Cu(II) and Zn(II) in aqueous solution were all 100.0% utilizing HAP-Kelex 100. The optimum competitive adsorption conditions of three novel adsorption materials for mixture aqueous solution of Cu(II) and Zn(II) were investigated using the single factor experiment and orthogonal experiment. Changing p H of aqueous phase, Cu(II) and Zn(II) were selectively removed under optimal conditions, however, XAD-2 resin, activated carbon and HAP that were used as the control group have too low competitive adsorption rate for capturing Cu(II) and Zn(II) in aqueous solution to be used as absorbent of deep treatment Cu(II) and Zn(II) under like conditions.Lastly, the methods of high efficiency removal trace heavy metals were researched with HAP-Kelex 100. The interfacial adsorption, adsorption of micro hole and hydroxyl chelating adsorption of hydroxyapatite can reduce coordination number of Kelex 100 for heavy metal ion chelating, and the coordination of Kelex 100 is able to enhance the stability of interfacial adsorption, micro hole adsorption and hydroxyl chelating adsorption of hydroxyapatite, so the synergistic effect of adsorptionchelation-coordination was formed. The Cu(II) contained in industrial wastewater that was treated by chemical precipitation in an electroplating factory was not up to the standard. After treatment of HAP-Kelex 100, the Cu(II) concentration was almost zero, and was lower than measured limit of the atomic adsorption spectrometer and ICP-AES. The adsorbed performance of Kelex 100 loading on hydroxyapatite is the excellent, which is expected to be used in the complete treatment of drinking water, pharmaceutical water, enrich metal ions in dilute solution and other industries.