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The emissions of two types of organic solutes during the coagulation process were simulated using Jar Test equipment and two additives, coagulant and polymer, to evaluate the volatilization characteristics under various operating conditions. The solute volatilization rates were found to be a function of the liquid mixing intensity, the chemical properties of the additives, and the properties of solutes, including molecular weight (M), Henry's law constant (H), and water solubility (S). The volatilization rates of the high H solutes increased sharply as the mixing intensity increased. Moreover, the volatilization rates of selected compounds were only slightly dependent on the coagulant concentrations due to the inorganic property of the coagulant. On the other hand, the effective volatilization reduction of the high H solutes in the existence of organic flocculant was a result of the enhancement of solutes solubility in water solutions. However, the above inhibition effects decreased significantly when the mixing intensity increased. Finally, the emission rates of the low H solutes were weakly correlated with both the solution properties and the operating parameters, due to their high affinity with the solution and the major volatilization resistance existing in the gas phase. Two different approaches, i.e., the two-film theory and the modified Knudsen diffusion equation, were used to explain the solute volatilization characteristics in the simulation process. CE Database subject headings: Coagulation; Volatile organic chemicals; Volatilization; Polymers; Emissions; Organic compounds.

Nonionic surfactant-modified clay is a useful absorbent material that effectively removes hydrophobic organic compounds from soil/groundwater. We developed a novel material by applying an immobilized fungal laccase onto nonionic surfactant-modified clay. Low-water-solubility polycyclic aromatic hydrocarbons (PAHs) (naphthalene/phenanthrene) were degraded in the presence of this bioactive material. PAH degradation by free laccase was higher than degradation by immobilized laccase when the surfactant concentration was allowed to form micelles. PAH degradation by immobilized laccase on TX-100-modified clay was higher than on Brij35-modified clay. Strong laccase degradation of PAH can be maintained by adding surfactant monomers or micelles. The physical adsorption of nonionic surfactants onto clay plays an important role in PAH degradation by laccase, which can be explained by the structure and molecular interactions of the surfactant with the clay and enzyme. A system where laccase is immobilized onto TX-100-monomer-modified clay is a good candidate bioactive material for in situ PAHs bioremediation. [ABSTRACT FROM AUTHOR]