Research Of Adsorption Of Cr₂^-O₇^- In Water With Polymer Gel Ball

Alginate molecule contains a large number of hydroxyl and carboxyl, divalent cations can be formed with a variety of polymer, film and into the ball good performance, also has good thermal stability, its internal porous structure makes it a good adsorbent material. This article,sodium alginate and CaCl2 solutions, FeCl3 solution crosslinked, the formation of gel microspheres, Adsorption of water used to Cr2O72-, and discuss that, Adding polymer to it, Polyvinyl alcohol, polyethylene oxide gel ball formation of the two substances together, Cr2O72- for removal of waste water, study the effect and mechanism of removal, to develop high-performance metal remover. Gel ball helps adsorption technology to treat industrial waste water is a gel and absorbed heavy metal ions in solution, and research in this field provides a useful reference.Articles by immobilization conditions on properties of gel beads experiment, sodium alginate, sodium alginate gel beads of three Cr2O72- adsorption experiments, preparation of the gel conditions and Cr2O72- adsorption conditions on the adsorption properties of gel beads, initially set the ball gel adsorption good manufacturing conditions, and from the adsorbent material properties and chemical structure point of view to some extent of adsorption of polymer gel beads in solution adsorption mechanism of heavy metal ions.Discussed in this article make the best conditions for Alginate, with a concentration of 2% sodium alginate solution and the concentration of 5% CaCl2 solution and the concentration of 2% FeCl3 solution for cross-linking, get the ball gel with good elasticity and strong mechanical strength, the gel ball size decreases, with the increase of immobilization time. The prepared alginate-polyvinyl alcohol and sodium alginate-PEO comparison of two gel, conclusion that SA-polyvinyl alcohol gel beads are smaller, higher mechanical strength and tightness.In sodium alginate, sodium alginate-polyvinyl alcohol and sodium alginate-PEO Cr2O72-three kinds of gel beads obtained adsorption experiments that, there's no removal calcium alginate gel beads Cr2O72-,alginate gel beads Cr2O72- iron has a good removal.However, since the formation of cross-linked with FeCl3 solution, gel ball of iron with low mechanical strength, balling effect is poor, easily damaged in the test operation, removal of affected dichromate and after the effect of removing,so developed an alginate calcium-iron gel beads. This gel mechanical strength on the ball much better than iron gel beads and the adsorption capacity is almost the same with the iron ball gel, therefore, this gel will be applied to the ball and polyethylene oxide and polyvinyl alcohol gel mixture preparation on the ball. Experiments show that Cr2O72- removal rate increased with increasing amount of gel beads, when the gel the amount of ball control when in 15-20mL, the highest removal rate of Cr2O72-. When more than 20mL, removal no longer bigger changes. Be attracted to the solution pH value on the gel to remove a greater impact on the ball, to CrO72- removal rate reached the maximum and does not cause precipitation solution, Solution between the pH value control is appropriate in the 4-6. Solution Cr2O72- gel beads faster removal of reaction, to complete the reaction around 80% in 30min, the reaction tends to slow after 90min, reached equilibrium. Removal of up to 97% optimal. Comparison of three kinds of gel beads Cr2O72- absorption capacity, PEO-SA-Ca-Fe> S A-PVA-Ca-Fe>SA-Ca-Fe.Part in the adsorption mechanism of draw that,alginate material as the special structure, The surface and internal pore sizes formed by increasing its absorption surface area, Calcium alginate-iron gel beads surface Fe3+ and the solution CrO72- react, Generated Fe2(Cr2O7)3 gel ball attached to the surface to be removed from the solution.other hand, the adsorbent containing hydroxyl and carboxyl functional groups, possible reactions and complex ion exchange reaction.