The increase of industrial plants is the main cause of various pollution problems and heavy metals are one of the harmful toxins.
One approach to help prevent heavy metals from spilling into nature is to use adsorbent material. The objective of this research is
to study the capacity to adsorb Copper, Nickel and Zinc of the loess as mixed with sodium bentonite using the batch test and column
test. The batch test was used for finding the equilibrium time and adsorption isotherm based on the adsorption isotherm of Langmuir so as to clarify the adsorption. The column test was utilized for conducting the adsorption simulation closely similar to
the actual condition; to release waste water onto the soil and rinse from the rain water. The experimental results showed that in
the batch test, bentonite helps to increase the potential for absorbing heavy metals as well as compared with normal loess, where
the appropriate ratio for adsorption is loess mixed with 40% bentonite. When the time elapsed, the concentration of the heavy
metals solution dramatically decreased until reaching the equilibrium state at 48 hours. The adsorption isotherm of Langmuir
performed the explication of the adsorption efficiently. The adsorption capacities ( ) were ranked as follows: Copper > Zinc >
Nickel: in the column test, it was found that the soil was capable of performing to adsorb heavy metals abundantly in the first
period, and then it gradually decreased and leaching of the distilled water was able to less cleanse the heavy metals. After leaching,
the soil was still able to adsorb the heavy metals but the capacity to adsorb was decreased.
Keywords
Adsorption, Heavy metal, Isotherm, Loess, Bentonite