Model adsorpsi dan distribusi logam dalam sedimen perairan Kali Code, Yogyakarta

WARDANI, Rini Jati, Prof.Dr. Narsito

2008 | Tesis | S2 Ilmu Kimia

Telah dilakukan penelitian tentang model adsorpsi dan distribusi logam dalam sedimen perairan Kali Code, Yogyakarta. Pengambilan sampel berupa air dan sedimen dilakukan pada musim kemarau tahun 2006 di 11 titik lokasi dari hulu hingga hilir Kali Code dimulai dari mata air Turgo, Boyong, Ngentak, Ring Road Utara, Sarjito, Tukangan, Tungkak, Karang Kajen, Ring Road Selatan, Ngoto, dan Pacar. Logam yang dianalisis yaitu logam Mg, Ti, Mn, V, Al, Cr, Cd, Hg, As, dan Co menggunakan metode Analisis Aktivasi Neutron (AAN) dari reaktor Kartini PTAPB-Batan Yogyakarta yang dilakukan secara serentak. Olah data menggunakan metode perbandingan harga koefisien determination (R2) dari masing-masing model adsorpsi (model Partisi, model Freundlich, model Langmuir). Hasil penelitian menunjukkan bahwa logam Mg, Ti, Mn, V, Al, Cr, Cd, Hg, As, dan Co pada tingkat konsentrasi yang relatif rendah, konsentrasi logam di dalam sedimen berbanding lurus dengan konsentrasi logam di dalam air. Pada konsentrasi tertentu mulai terjadi hubungan non linier, artinya bahwa pola adsorpsi pada titik tersebut mulai mengikuti model adsorpsi Freundlich atau Langmuir. Logam kationik yaitu Mg, Ti, Cd, Hg dan Co lebih sesuai dengan pola adsorpsi Langmuir kecuali logam Cd dan Hg, sedangkan logam yang memiliki sifat anionik yaitu logam Mn, V, Al, Cr, dan As sesuai untuk pola adsorpsi Langmuir kecuali logam As. Distribusi logam dari badan air ke dalam sedimen melibatkan padatan tersuspensi dengan nilai hubungan linier antara padatan tersuspensi dengan konsentrasi logam di sedimen 0,789< R2 <0,967.

A research about adsorption models and metals distribution in the sediment at Kali Code, Yogyakarta has been conducted. Water and sediment sampling were conducted in dry season on August, 2006 at 11 locations started from Turgo, Boyong, Ngentak, Ring Road North, Sardjito, Tukangan, Tungkak, Karangkajen, Ring Road South, Ngoto, to Pacar. The metals which have been analyzed by Neutron Activation Analysis (AAN) method included Mg, Ti, Mn, V, Al, Cr, Cd, Hg, As and Co. Data analysis was carried out by comparing the value of determination coefficient (R2) of adsorption models (Partition model, Freundlich model, Langmuir model). The result of analysis showed that metals such as Mg, Ti, Mn, V, Al, Cr, Cd, Hg, As and Co at low concentration, has a linear correlation between those found in sediment and those in water. At a higher metal concentration, correlation between sediment metal concentration and metal concentration in water becomes non linear. This indicates that adsorption model at higher concentration followed Freundlich or Langmuir adsorption. Futhermore, cationic metals such as Mg, Ti, Cd, Hg and Co follows Langmuir adsorption except Cd and Hg, while anionic metals such as Mn, V, Al, Cr, and As follows Langmuir adsorption except As. Metals distribution from water to sediment system involving Suspended Solid (SS) as indicated by significant correlation between SS and metal concentrations in sediment which is in the range of 0,789< R2 <0,967.

Kata Kunci : Adsorpsi,Distribusi Logam,Logam Air,Sedimen,adsorption models, metal distribution, suspended solid