ADSORPSI ION FOSFAT DALAM AIR TAWAR DAN AIR LAUT MENGGUNAKAN BENTONIT ALAM KOMERSIAL YANG TERJERAP PADA Fe-ALGINAT DAN Ca-ALGINAT; ADSORPTION OF PHOSPHATE ION IN FRESHWATER AND SEAWATER USING COMMERCIAL NATURAL BENTONITE ENTRAPPED IN Fe-ALGINATE AND Ca-ALGINATE

SHINTA DEWI ANGGRAENI, Nurul Hidayat Aprilita

2014 | Disertasi | PROGRAM STUDI S2 ILMU KIMIA

The phosphate ion adsorption by commercial natural bentonite entrapped in Fe-alginate and Ca-alginate has been studied. The first step of this research was characterization of commercial natural bentonite from Magelang using XRD and AAS. The particle of bentonite-Fe-alginate (B-Fe-A) and bentonite-Ca-alginate (B-Ca-A) were synthesized with a ratio of bentonite:alginate (1:1) by extrusion method. Adsorption process of phosphate ion by B-Fe-A and B-Ca-A particle was carried out in fresh water and sea water by batch system at room temperature with variation of pH, contact time, and adsorbate concentration. The results of the XRD analysis from commercial natural bentonite showed 3 dominant peaks at diffraction angle (2?) with d-value of 26.65°(3.34Å); 24.03°(3.70Å); 20.86°(4.25Å), while calcium content was 0.60% bigger than Na indicated the bentonite was Ca-bentonite. pH optimum B-Fe-A on the adsorption of phosphate ions in fresh water obtained at pH 3. The adsorption of phosphate ion in fresh water by B-Fe-A particle followed pseudo-first order (Lagergren) with k1 4.0x10-3 min-1. The particle of B-Fe-A in fresh water gave value of KF 2.2x10-3 L.mg-1and 1/n 6.6x10-1. The adsorption of phosphate ion by B-Fe-A and B-Ca-A particle from fresh water and sea water fit to Freundlich adsorption isotherm.

Kata Kunci : fosfat; bentonit; Fe-alginat; Ca-alginat; isoterm Freundlich