Proporty Of Thiolated Cellulose Materials For Preconcentration And Separation Of Ag(Ⅰ)

In this study, corn stalk and waster paper were modified to prepare different characteristics of adsorbents, and then the separation and preconcentration of Ag(Ⅰ) with adsorbents were investigated systematically. In the same time, Ag(Ⅰ) existed in the form of AgCl43-coordination anion in single and mixture solution, instead of Ag+ positive ion usually in several sources.And the detailed result of experiment and analysis were as follows:The adsorbent was synthesized based on the carbonize corn stalk (OCS) modified by ammonia (NH3)-thiosemicarbazide (TSC), and it was abbreviated as TSC-NH3-OCS. In the case of the Ag(Ⅰ) single system and nickel-plated mixture system, it could be observed that about 97%([H+]=0.1～2 mol L-1) and 91.26% ([H+]=0.1～0.5 mol L-1) adsorption of Ag(I) was achieved, while Cu(Ⅱ) and Ni(Ⅱ) were scarcely adsorbed no matter the acid concentration was high or low. Additionally, the maximum adsorption capacity in the Ag(Ⅰ) single and Ag(I)-Cu(Ⅱ)-Ni(Ⅱ) ternary system were obtained and calculated as 153.54 and 46.69 mg g-1. The adsorption mechanism was believed to be electrostatic interaction of the protonated bands of AgCl43- with protonated thiol form of the thioamide units by FTIR and XPS analysis. The adsorption process fitted Langmuir isotherm model and pseudo-second order kinetics. In addition, three successive sorption/desorption cycle runs from ternary system were performed which indicated that the TSC-NH3-OCS adsorbent has a good performance for recovery Ag(Ⅰ) from simulate nickel electrolyte.The pre-treated paper was chemically modified with potassium periodate (OX) and ethylenediamine (EDA), and then hydrosulphonyl was introduced in the adsorbents and gained PWP-OX-TSC, in addition PWP-OX-TSC has a high maximum adsorption capacity in the Ag(Ⅰ) single and Ag(Ⅰ)-Cu(Ⅱ)-Ni(Ⅱ) ternary system which was calculated as 171.16 and 49.89 mg g-1 by comparison to other adsorbents which was modified by thiourea and formaldehyde. FTIR, XPS, SEM and EDX was used to evaluate the structure, composition and adsorption mechanism.Adsorption mechanism of Ag(I) onto the gel in acid medium could be expressed by electrostatic interaction. The adsorption process fitted Langmuir isotherm and pseudo-second order kinetics model. Regeneration and durability of the adsorbant towards the successive cycles were clarified.The novel adsorbent (PWP-C1-TSC) which was synthesized by chlorination、 amination and thiolation of the waste paper as a solid phase extractant has been developed for preconcentration of trace Ag(I) from high-concentration salt solution prior to the determination by atomic adsorption spectrometry. The result showed that the optimum acidity for the adsorption of Ag(I) on the adsorbent was 0.1-2 mol L-1 and the maximum adsorption capacity of the adsorbent at optimum conditions was found to be 177.02 mg g-1, Ag(I) was eluted off from the adsorbent with 2.5 mL mixture of 0.73 mol L-1 of thiourea and 0.2 mol L-1 HCl. In addition, the enrichment factors for Ag is 16.7, The limits of detection are 1.74 ng mL"1 for Ag, with relative standard deviations (for n=8) of 6.48%, The accuracy of the method was validated using practical samples (wastewater from nickel plating factory and lian hua shan water).