Apply modified cotton by m-DMDHEU and choline cloride to separate ion CrO4 2- , H2AsO4 - in water solution

Abstract

In this article, cotton is modified by m- DMDHEU and choline chloride. The modified cotton can adsorb and ion exchange ion CrO4 2- , H2AsO4 - in water solution as effectively as anionit resin. The material are activated by soaking in 24 h with mixed m-DMDHEU and choline chloride, then dried and activated in 1 h at 140 oC, all residual reactants was removed by water. Adsorption and ion exchange process were studied with a model solution contained ion CrO4 2- , H2AsO4 - in different conditions. Results showed that the modified cotton is able to adsorb ion CrO4 2- , H2AsO4 - of the model, solution is nearly completely, respectively 99,95 % and 99,60 %; the values of anionit resin is respectively 97,99 % and 97,60 % at pH=7,0.

Modification of Lignocellulosic Materials with a Mixture of m-DMDHEU/Choline Chloride to Remove CrO42–, NO3–, and H2AsO4– in Aqueous Solution

“…Fourier transform infrared spectroscopy (FT-IR) spectra of modified lignocellulosic materials show an additional peak at wavenumber 1708 cm –1 , these results confirmed the presence of the CO group in the N–CO–N urea group. − On the other hand, solid-state 13 C CP-MAS NMR spectra of cotton after modification also show the speciality peak of the CO group in the N–CO–N urea group at 159 ppm (shown in Figure ). These results revealed that a chemical linkage was formed between m -DMDHEU and hydroxyl groups of the cellulose chain or CC. − …”

“…Activation time and liquor ratio were chosen suitably for the modification process, respectively, as 1 h and 1:60 in our heretofore survey results. , Cotton, sawdust, and coconut shell powder were processed according to the modification process above, m -DMDHEU concentration ranging from 5 to 15 wt % and CC concentration ranging from 2 to 10 wt %. After being rinsed with distilled water, the materials were dried at room conditions and then the materials were weighed to determine the mass increase level of materials, and ion exchange capacity of the materials was also examined using 200 mL of 200 mg/L chromate solution at pH = 7.6 and room temperature (28 ± 5 °C).…”

“…Ion exchange capacity of modified lignocellulosic materials with a chromate solution was the best in acidic conditions and dropped significantly in base conditions. − The results could be explained by two reasons: first, OH – ions and dichromate (Cr 2 O 7 2– ) ions were present in adsorbate solutions at different conditions; second, characteristic of modified material surface changed about charge, this matter could be checked by using the pH PZC value. When pH < pH PZC , materials’ surface was charged positive and when pH > pH PZC , materials’ surface was charged negative.…”