Activated zeolite and bentonite as adsorbents of heavy metal ions for polluted groundwater :: Case study Yogyakarta urban area, Indonesia

BUNCHOEUN, Pich, Dr. Ir. I Wayan Warmada

2008 | Tesis | S2 Teknik Geologi

Mengacu pada aktivitas manusia, seperti industri batik rumah tangga, rumah pemotongan hewah dan industri penyamakan kulit, keberadaan logam berat dalam air tanah telah diketahui sebagai penyebab pencemaran air tanah di kota Yogyakarta. Untuk menyehatkan air tanah pada studi kasus daerah kota Yogyakarta, telah dilakukan sejumlah percobaan adsorpsi dengan menggunakan zeolit dan bentonit dari daerah Sidomulyo dan Bandung. Sebelum treatment, dilakukan karakterisasi zeolit dan bentonit dengan menggunakan analisa XRD, SEM/EDX, dan ICP, dan dilakukan modifikasi untuk menaikkan nilai KPK zeolit dan bentonit melalui proses aktivasi termal, sedangkan air tanah pada awalnya dianalisa untuk kandungan logam-logam berat tertentu, seperti Cd, Cr, Cu, Fe, Zn, Pb, Mn. Selama perlakuan, tepung zeolit dan bentonit teraktivasi, dalam jumlah yang sama, secara terpisah dimasukkan ke dalam 250mL sampel air tanah murni. Selanjutnya semua larutan dicampur dengan menggunakan pengaduk magnetik (magnetic stirrer) dan didiamkan selama 24 jam untuk mencapai kondisi setimbang. Hal ini dilakukan sebanyak 3 kali agar dapat dibuat korelasi untuk interpretasi hasil. Setelah treatment, air tanah tersebut dianalisa ulang untuk jenis logam-logam berat yang sama seperti pada kondisi awal. Dari hasil tersebut, kapasitas adsorbsi zeolit dan bentonit dapat diinterpretasikan dalam bentuk kurva adsorbsi. Zeolit Sidomulyo dan bentonit Bandung berturut-turut dominan tersusun oleh klinoptilolit dan mordenit serta montmorilonit–Ca dan illite (dari hasil analisa karakteristik), kedua bahan tersebut mengandung konsentrasi beberapa unit logam berat dalam jumlah yang signifikan (dari hasil analisa komposisi kimia), namun bahan-bahan tersebut mempunyai kemampuan untuk menyerap ion-ion logam berat dari air tanah di Yogyakarta yang tercemar .

Due to human activities such as batik home industries, abattoirs, and tanneries, the existence of heavy metals in groundwater has been known as the cause of groundwater pollution in the Yogyakarta city. To treat this groundwater for this case study of Yogyakarta Urban Area, a batch adsorption experiment by utilizing the zeolite and bentonite respectively from the Sidomulyo and Bandung areas has been carried out. Prior to the treatment, the zeolite and bentonite were characterized by means of XRD, SEM/EDX, and ICP and modified to improve their CECs by thermal activation process, whereas the groundwater was initially analyzed for certain heavy metals like Cd, Cr, Cu, Fe, Zn, Pb, Mn. In the course of treatment, the activated zeolite and bentonite powders at the same amount of 1 g, 2 g, 4 g, 8 g, and 15 g were separately put into the natural groundwater sample of 250 mL; all the solutions were afterwards mixed by magnetic stirrer and kept for 24 hours to reach the equilibrium condition. This was performed three times to make correlation for result interpretation. After the treatment, the groundwater was reanalyzed for the same kinds of heavy metals as the initial condition; therefore the adsorption capacity of zeolite and bentonite could be interpreted in forms of adsorption curves. The study showed that although the Sidomulyo zeolite and the Bandung bentonite which were found composed of abundantly clinoptilolite and mordenite and mostly Camontmorillonite and illite, respectively (from characteristics analyses) contain significant concentrations of some kinds of heavy metals set in the study (from chemical composition analyses), they have their capabilities in adsorbing heavy metal ions from the Yogyakarta polluted groundwater and from themselves.

Kata Kunci : Zeolit,Bentonit,Air tanah,Logam berat,Adsorpsi, zeolite, bentonite, groundwater, heavy metal, adsorption