PENGARUH DISOLUSI ABU VULKANIK GUNUNG KELUD DENGAN LARUTAN Na2EDTA TERHADAP KEMAMPUAN ADSORPSINYA PADA ION Pb(II); EFFECT OF DISSOLUTION MOUNT KELUD VOLCANIC ASH WITH Na2EDTA SOLUTION ON ADSORPTION ABILITY TO Pb(II) IONS

Lestari, Novianti Dwi, Endang Tri Wahyuni

2016 | Skripsi | FMIPA

In this research, an efford for increasing adsorption capacity of Mount Kelud volcanic ash to a toxic Pb(II) ions in the solution by using dissolution method with Na2EDTA solution has been studied. This research was initiated by determining its mineral and chemical composition using XRD and AAS respectively. Then, dissolution process of Kelud volcanic ash by using Na2EDTA solution was carried out for removing Ca, Mg, and Fe metals which may cover the active sites of volcanic ash. In the dissolution process, the effect of pH to dissolution effectiveness has been evaluated. The amount of the dissolved metals was determined by using AAS and the cristallinity of volcanic ash after dissolution was detected by using XRD. The next step was Pb(II) ions adsorption by using volcanic ash before and after dissolution. The amount of the adsorbed Pb(II) ions was calculated based on the differential of initial and residual Pb(II) ions. The residual Pb(II) ions concentration was determined by AAS. The result showed that volcanic ash contents of feldspar, quartz, and mullite, with the largest chemical components were SiO2 and Al2O3. Dissolution of volcanic ash with EDTA solution could remove Ca, Mg, and Fe metals and the dissolution effectiveness was influenced by pH of EDTA solution. The large amount of the metal dissolved with relatively small damaged of mullite crystals was achieved at pH 3. It’s also found that the adsorbent mass and initial Pb(II) ions concentration influenced to the adsorption effectiveness. The optimum mass and initial ion concentration of Pb(II) were 75 mg and 75 mg/L respectively with the amount of adsorbed Pb(II) ions was 90.02%. The volcanic ash dissolution using EDTA solution increased the adsorption capacity of the volcanic ash from 15.10 mgPb/g-ash to 21.77 mgPb/g-ash.

Kata Kunci : volcanic ash, adsorption, Pb(II) ions, adsorption capacity.