Index >> Waste Water Microbiology >> Adsorption

Adsorption - Adsorption is the accumulation of molecules from a substance dissolved in a solvent onto the surface of an adsorbent particle (Tebbut, 1992). Adsorption techniques are used to remove soluble organic from drinking waters and wastewaters.

Tiny concentrations of both natural and synthetic organic compounds produce serious taste and odor problems in water. Moreover, long term exposure to these organics may lead to potential health hazards. Thus the needs to remove these organics are becoming important. Although biological treatment processes are very effective in removing organic material, they are not effective in removing small concentrations of organics.

The reason behind this is that the organic matters act as a nutrient source for most microorganisms and they cannot be expected to remove small concentrations of organics. In addition, these processes cannot be used to remove non-biodegradable organic substances which are commonly present in certain industrial wastewaters.

Generally the overall rate of adsorption is governed by the rate of diffusion of solute into the capillary pores of the adsorbent particle. The rate decreases with increasing particle size and increases with increasing solute concentration and temperature. Low molecular weight solutes are more easily adsorbed than the high molecular weight solutes.