Abstract: The adsorption characteristics of phenol and p nitrophenol onto natural surface coatings (biofilms and associated minerals, collected in the Nanhu Lake, Changchun, China) and the effect of pH on phenol and p nitrophenol adsorption onto natural surface coatings were examined. The results show that Freundlich and Langmuir models are all fit in with describing the adsorption behavior of phenol and pnitrophenol on naturalsurfaces coatings. During the adsorption procedure, surface coatings showed amphoteric properties and can buffer the acids or alkalis in the solution. With pH from 5 to 9, the sorption amount of phenol increased with increasing pH, however, the sorption amount of pnitrophenol decreased with increasing pH. The variety of pH in solution could affect the species and adsorption of phenol and pnitrophenol.

Key words: natural surface coatings, phenol, pnitrophenol, pH, adsorption