Kajian adsorpsi dan desorpsi Cr2(SO4)3 dalam limbah cair industri penyamakan kulit pada dan dari adsorben kitin dan asam humat terimobilisasi pada kitin
UTARIANINGRUM, E. Ratna, Dr. Sri Juari Santosa, M.Eng
2005 | Tesis | S2 Ilmu KimiaTelah dipreparasi dua macam adsorben yaitu adsorben kitin (K) dan adsorben asam humat terimobilisasi pada kitin (K-H) untuk adsorpsi Cr2(SO4)3 dalam limbah industri penyamakan kulit. Beberapa parameter adsorpsi seperti laju, energi, kapasitas dan mekanisme adsorpsi serta kondisi keasaman optimum adsorpsi ditentukan. Desorpsi terhadap Cr2(SO4)3 pada adsorben selanjutnya dilakukan secara sekuensial menggunakan beberapa pereaksi untuk mengetahui mekanisme adsorpsi. Penelitian diawali dengan isolasi asam humat dari tanah gambut dan kitin dari cangkang kepiting, imobilisasi asam humat pada kitin dan karakterisasi adsorben K dan K-H. Kondisi optimum adsorpsi dipelajari melalui interaksi Cr2(SO4)3 dalam limbah model dengan adsorben pada variasi pH dari 3 sampai 4,5. Adapun laju adsorpsi dipelajari melalui interaksi Cr2(SO4)3 dalam limbah model dengan adsorben pada variasi waktu dari 2 sampai 180 menit, sedangkan energi dan kapasitas adsorpsi dipelajari melalui interaksi Cr2(SO4)3 dalam limbah model dengan adsorben pada variasi konsentrasi awal dari 2 sampai 50 ppm. Desorpsi dilakukan menggunakan H2O, KNO3 1 M, HNO3 0,5 M, Na2EDTA 1 M, secara berurutan. Adsorpsi Cr2(SO4)3 dalam limbah industri penyamakan kulit pada adsorben dipelajari dengan menggunakan kondisi optimum yang diperoleh pada limbah model. Hasil penelitian menunjukkan bahwa pH 4,1 merupakan kondisi optimum adsorpsi Cr2(SO4)3 dalam limbah model pada adsorben K dan K-H. Adsorpsi Cr2(SO4)3 dalam limbah model merupakan adsorpsi kimia dengan energi adsorpsi untuk adsorben K dan K-H berturut-turut sebesar 21,95 dan 20,60 kJ/mol. Adsorpsi Cr2(SO4)3 dalam limbah model pada adsorben K berlangsung lebih lambat dibandingkan pada adsorben K-H dengan konstanta laju untuk adsorben K dan K-H masing-masing 0,0147 dan 0,0169 menit-1. Kapasitas adsorpsi Cr2(SO4)3 pada adsorben K dan K-H berturut-turut adalah 1,14 dan 1,17 mol/g. Adapun pembentukan ikatan hidrogen dan pembentukan kompleks merupakan mekanisme adsorpsi Cr2(SO4)3 pada adsorben yang dominan, baik untuk limbah model maupun limbah industri penyamakan kulit yang sebenarnya.
Two different types of adsorbents have been prepared for the adsorption of Cr2(SO4)3 in tanning industry wastewater. The adsorbents were chitin (K) and immobilized humic acid on chitin (K-H). Several adsorption parameters such as rate, energy, capacity and mechanism also optimum acidity condition of adsorption were determined. Desorption of Cr2(SO4)3 from adsorbent was then conducted sequentially using some reagents in order to elucidate the mechanism of adsorption. This work was started with isolation of humic acid from peat soil and chitin from crab shell, immobilization of humic acid on chitin, and characterization of adsorbents of K and K-H. Optimum condition was studied by interacting the adsorbents with Cr2(SO4)3 in a synthetic solution on various of pH from 3 to 4,5. Adsorption rate was studied by interacting the adsorbent with Cr2(SO4)3 in the synthetic solution on various time from 2 to 180 minutes. The determination of the energy and the capacity of adsorption were studied by interacting the adsorbent with Cr2(SO4)3 on various initial concentration from 2 to 50 ppm. Moreover, the mechanism of adsorption was studied by applying a sequential desorption using H2O, KNO3 1 M, HNO3 0,5 M, Na2EDTA 1 M. The adsorption of Cr2(SO4)3 in tanning industry wastewater on K and on K-H were studied at the same condition as obtained for the synthetic solution. The result showed that pH 4,1 was the optimum adsorption condition for Cr2(SO4)3 in the synthetic solution on both K and K-H adsorbents. Cr2(SO4)3 in the synthetic solution was chemically adsorbed on K and on K-H, involving energy adsorption of 21,95 - 20,60 kJ/mole. Adsorption of Cr2(SO4)3 on K was more slow than that on K-H with the rate constants for adsorbent K and K-H were 0,0147 and 0,0169 minute-1. Adsorption capacity of Cr2(SO4)3 on K and on K-H were 1,14 and 1,17 mole/g. Respectively the hydrogen bonding and complex forming were the dominant mechanism of adsorption, for syntetic solution or real wastewater of tanning process.
Kata Kunci : Adsorpsi,Penyamakan Kulit,Adsorben K dan K,H, Tanning industry wastewater, Cr2(SO4)3, adsorption, chitin, immobilization, humic acid.
