Starch Base Metals Amplification Of Capture Agent Test And Performance Study

The heavy metal pollution is a kind of environmental pollutions thatcaused by the heavy metal or the chemical compounds with heavy metalions. With the industrialization process，more and more heavy metalpollution arisen from industrial waste water has affected human life bothphysically and mentally．Modified starch heavy metal chelating agentshas strong ability to chelate the heavy metal ions．What’s more,thecapturing product is biodegradable that can be landfill isposaled withoutsecondary pollution.The scale up test for synthesis of starch-based heavy metalchelating agents（AMS）was accomplished on the basis of the technologic-cal conditions adopted in the former test，a sufficiently stable，efficient，mature and suitable for industrial production process formula and processroute was identified. To test the adsorbability of AMS synthesised by thescale up test，it was used to capature the heavy metal ions．The main workwere as follows：optimize the parameter of lab-scaleï¼›many stabilityexperiments under the best experimental conditionsï¼›characterize thestructure of AMS，with a feasibility study report for the production of200ton AMS per year．At general conditions,the small-scale experiments can not certainlysimulate the scale up test．The emulsion polymerization with strong exothermic is a heterogeneous chemical reaction，while the influence ofthe pH and stirring rate on the enlarged product is predominant．As one ofthe most important chemical raw materials，EDA has highly volatibilityand stimulating．Based on the shortcoming of the technology with lowutilization efficiency and no convenient to operate in industral product，the effects of pH values in the solution，reaction time，stirring rate and thesolvents selection were discussed．The results showed that reaction timeand quantity of materials have been decreased, while is beneficial toimproving the efficiency and reducing cost of production，at the sametime，the influence of the pH and stirring rate on the enlarged product ispredominant．It was found that the total nitrogen content of AMS comesto11.46%at this optimum process conditions．By changing the varietiesof the solvents，the reaction time was shorten and the efficiency wasenhanced.When the optimal conditions for AMS was adopted in20m3multi functional stirring reactors,the heat transfer efficiency is high,andthe technological process is operational， which offer the basis ofcommercial production up till the present moment.The treatment of simulated and actual wastewater by AMS wasinvestigated, the effects of reaction temperature, reaction time, theamount of AMS used and other related factors on the adsorption wereinvestigated to obtain the optimal reaction conditions. The effect ofheating and EDTA on stability of capturing products and the performance of oxidation degradation were studied．The results indicated that thehigher nitrogen contains of AMS，the stronger ability to capture heavymetal ions．Meanwhile，the influence of the chelating agents content, pH,reaction time, reaction temperature on removing heavy metal ions ispredominant. It was also found that the adsorption of heavy metal ion onAMS at single-specie heavy metal ion solution is good． At theconcentration of30mg·L^-1 of heavy metal ions in solution，the removalrate of Cu²⁺, Pb²⁺,Cr³⁺, Cd²⁺, Ni²⁺were up to98%． When theelectroplating wastewater containing more than five kinds of heavy metalions，the removal rate also can achieve95%．The AMS-X(X concludsCu²⁺、Pb²⁺、Zn²⁺、Cr³⁺、Cd²⁺、Ni²⁺)can be oxidation degradation by H₂O₂，while it has some thermal and EDTA stability.Finally, the surface and internal structure of the products werecharacterized by FTIR、XRD、SEM．It has been proved that glycidylmethacrylete grafted into the base of starch and grate copolymer（St-g-GMA） was modified by ethylenediamine successfully．The surfaceof AMS was the major degradation area，meanwhile，it is infiltrating tothe internal gradually.