[Sorption of phenolic compounds by suspended particulates]

Sorption properties of phenol, o-chlorophenol, 2, 4-dichlorophenol on four kinds of suspended particles sampled from Changjiang Estuary and Hangzhou Bay were investigated. Experiments show that sorption equilibrium can be achieved in 12h for these phenolic compounds. As the content of chlorine in phenolic ring increases, the sorption amount on the samples enhances. For phenol, sorption amount on the samples are much less than the other two phenolic compounds and no distinct differences are obtained between different samples. The sorption ability of suspended particles has close relation with their particle size distribution, specific surface area and organic content. It is shown that when the initial phenolic concentration is smaller than 2.0 mg/L, Freundlich isotherm is suggested as the most appropriated fitting type. Sorption constants Koc calculated from Freundlich isotherm for these three phenolic compounds are 622-1,410, 3,287-3,707, 6,444-8,787 respectively. As limited by the national discharge standard, volatile phenols discharge concentration can't exceed 0.5 mg/L. Suspended particles can absorb them effectively under this concentration range, but high salinity has a negative effect.