STUDI ADSORPSI – DESORPSI KALIUM PADA HUMUS SINTETIS DALAM KONDISI LINGKUNGAN ASAM; STUDY OF POTASSIUM ADSORPTION – DESORPTION ON SYNTHETIC HUMUS IN ACIDIC ENVIROMNMENT

Andjartyassih, Kadek, Agus Harjoko

2015 | Skripsi | FMIPA

Study of potassium adsorption desorption by synthetic humus in acidic environment has been conducted. The purposes of this research are to characterize synthetic humus in acidic solution, determine its addition effect for solution pH value, and evaluate potassium adsorption desorption by synthetic humus. The research started with isolation of synthetic humus in acidic solution with pH value 4 and characterization using IR spectrometer. Determination of synthetic humus addition effect for solution pH value was done by varying the amount of synthetic humus added to pH 4 solution. Potassium adsorption desorption studies were done by interacting synthetic humus with potassium solution. Concentration of potassium left in solutions were measured using AAS instrument. Characterization using IR spectrometer shows humin is the most stable component of synthetic humus in acidic environment. Synthetic humus is proven in increasing solution pH through H+ ion binding by fenolic–OH and –NH2 group, and also hydrolysis of metal oxide (MxO). Potassium adsorption by synthetic humus follows pseudo-first kinetic order with value of k1 and qe are 0,0484 minute-1 and 19,0 mg g-1 respectively. Adsorption is suitable with isotherm Langmuir model with parameters value Kl 0.2343 L mg-1 and qm 16,9 mg g-1. Potassium desorption is a slow released system and follows first order kinetic with k value is 0,0006 second-1. The equilibrium point of potassium in synthetic humus is reached at weight 0,0175 g in potassium solution 40 mg L-1.

Kata Kunci : synthetic humus; adsorption; desorption; potassium; acidic environment