Spectrophotometric studies on the removal of some metal ions and methylene blue dye from their aqueous solutions using new absorbents

In the current work, carboxy methyl starch graft copolymerized with acrylamide (CMS-g-PAAm) and CMS-g-PAAm silver nanoparticles composite (CMS-g-PAAm-AgNPs) prepared in previous works were used as novel absorbents for the removal of Cu2+, Co2+, Ni2+ ions and methylene blue dye from their aqueous solutions. Reaction kinetics and % removal of the metal ions and methylene blue using CMS-g-PAAm and CMS-g-PAAm-AgNPs were studied. Metal ions and methylene blue removal were determined by measuring the absorbance of the colored solution of Cu2+, Co2+, Ni2+ ions and methylene blue dye before and after treatment with CMS-g-PAAm and CMS-g-PAAm-AgNPs using spectrophotometer. Results showed that the % removal of Cu++, Co++, and Ni++ is very high at the first 30 min then slowly increased. The % removal of ion for Cu++, Co++, and Ni++ reached up to 81.2%, 79.88, 77.97 respectively. Study also showed that the % of methylene blue removal using both CMS-g-PAAm-AgNPs and CMS-g-PAAm reached up to 99.7 and 99.33% respectively. The novel absorbents were found promising for use in waste-water treatments applications.