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

Abstrak. Penelitian ini bertujuan untuk mengetahui karakteristik kimia bentonit teknis sebelum dan sesudahdiaktivasi serta untuk mengetahui kemampuan adsorpsinya terhadap ion Cd2+. Aktivasi bentonit teknisdilakukan dengan menggunakan larutan HCl 0,5 M dan memvariasi suhu pemanasan 100, 140, 200 dan 400oC. Parameter adsorpsi meliputi konsentrasi sampel, massa adsorben, waktu kontak serta bentonit teknissebelum dan sesudah aktivas dengan HCl/suhu dengan sistem “batch shaker”. Karakteristik kimia bentonitteknis sebelum dan sesudah diaktivasi menunjukkan terjadinya pergeseran bilangan gelombang danperubahan 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. Hasiladsorpsi menunjukkan bahwa konsentrasi sampel optimum yaitu 25 ppm, massa adsorben optimum pada0,3 gram, waktu kontak optimum selama 80 menit. Adsorpsi bentonit teknis terhadap ion Cd2+ mengikutipola 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 adsorpsiAbstract. This research aimed to investigate the characteristic of chemistry technical bentonite before andafter activated and to investigate the adsorption ability of ion Cd2+. Activation of technical bentoniteperformed 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 technicalbentonite before and after activated with HCl/temperature with a "batch shaker". Characteristics ofchemistry technical bentonite before and after activated showed the movement of wavelength number and thefriction 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 adsorptionshowed that sample concentration optimum was 25 ppm, adsorbent mass optimum at 0.3 grams, contact timeoptimum for 80 minutes. Adsorption of technical bentonite for ion Cd2+ fitted well to Langmuir isothermmodel was R2 = 0.997 with capasity of adsorption was 2,3148 mg/g.Keywords: Technical bentonite, characteristic of chemistry, activation, and capacity of adsorptio