KAPASITAS ADSORPSI BENTONIT TEKNIS SEBAGAI ADSORBEN ION Cd2+CAPACITY OF ADSORPTION TECHNICAL BENTONITE AS ADSORBENT Cd2+ IONS

Abstract

Abstrak. Penelitian ini bertujuan untuk mengetahui karakteristik kimia bentonit teknis sebelum dan sesudah
diaktivasi serta untuk mengetahui kemampuan adsorpsinya terhadap ion Cd2+. Aktivasi bentonit teknis
dilakukan dengan menggunakan larutan HCl 0,5 M dan memvariasi suhu pemanasan 100, 140, 200 dan 400
oC. Parameter adsorpsi meliputi konsentrasi sampel, massa adsorben, waktu kontak serta bentonit teknis
sebelum dan sesudah aktivas dengan HCl/suhu dengan sistem “batch shaker”. Karakteristik kimia bentonit
teknis sebelum dan sesudah diaktivasi menunjukkan terjadinya pergeseran bilangan gelombang dan
perubahan puncak yaitu pada vibrasi ulur OH, tekuk H-O-H dari air yang teradsorpsi, ulur Si-O, tekuk Al-
Al-OH dan tekuk Si-O-Al yang menunjukan kandungan terbesar bentonit yaitu montmorillonit. Hasil
adsorpsi menunjukkan bahwa konsentrasi sampel optimum yaitu 25 ppm, massa adsorben optimum pada
0,3 gram, waktu kontak optimum selama 80 menit. Adsorpsi bentonit teknis terhadap ion Cd2+ mengikuti
pola adsorpsi isoterm Langmuir dengan nilai R2 sebesar 0,997 dengan nilai kapaistas adorpsi 2,3148 mg/g.
Kata-kata kunci: Bentonit teknis, karakteristik kimia, aktivasi, dan kapasitas adsorpsi
Abstract. This research aimed to investigate the characteristic of chemistry technical bentonite before and
after activated and to investigate the adsorption ability of ion Cd2+. Activation of technical bentonite
performed using solution of HCl 0,5 M and varying the heating temperature of 100, 140, 200 and 400 oC.
Parameters of adsorption include sample concentration, adsorbent mass, contact time and technical
bentonite before and after activated with HCl/temperature with a "batch shaker". Characteristics of
chemistry technical bentonite before and after activated showed the movement of wavelength number and the
friction of peak, that were stretching OH, bending HOH of water adsorbed, stretching Si-O, bending Al-Al-
OH and bending Si-O showed the largest content of bentonite is montmorillonit. The results of adsorption
showed that sample concentration optimum was 25 ppm, adsorbent mass optimum at 0.3 grams, contact time
optimum for 80 minutes. Adsorption of technical bentonite for ion Cd2+ fitted well to Langmuir isotherm
model was R2 = 0.997 with capasity of adsorption was 2,3148 mg/g.
Keywords: Technical bentonite, characteristic of chemistry, activation, and capacity of adsorption