Treatment of phenolic wastewaters by resin adsorption with solvent regeneration.

摘要

Various phenolic wastewaters were treated by a fixed bed of polymeric adsorbent. The adsorbent was highly efficient for removing phenol from synthetic phenolic wastewaters and from an actual ammonia-still waste from a by-product coke plant. The adsorbent was shown to be completely regenerable by an organic solvent.; An exhaustive study was conducted showing the effects of concentration, flow rate, phenol type, bed change, and cycle no. on breakthrough curve behavior. Resin capacities and mass transfer zone characteristics were calculated. Elution curves were generated enabling calculation of phenol recoveries.; The adsorption process was described by the film-surface diffusion model. Both the external film and intraparticle surface diffusion resistances were shown to be important to mass transfer. Equilibrium was described by a 3-parameter, nonlinear isotherm.; The kinetic parameters (k{dollar}sb{lcub}rm f{rcub}{dollar}, the film transfer coefficient; and D{dollar}sb{lcub}rm S{rcub}{dollar}, the effective surface diffusivity) were obtained by a batch kinetic study, a microcolumn kinetic study, and a column kinetic study. The column film transfer coefficient was shown to be more accurately determined by the microcolumn study than by the column study. The effective surface diffusivity was shown to be more accurately determined by the batch and microcolumn kinetic studies than the column study. The column study yielded a wider range of values for k{dollar}sb{lcub}rm f{rcub}{dollar} and D{dollar}sb{lcub}rm S{rcub}{dollar} than did the other two studies.; The film-surface diffusion model was used to predict the concentration decay curves for the batch adsorber and the breakthrough curves for the microcolumn and column adsorbers. Use of the best fit kinetic parameters in the model yielded adequate prediction of adsorber behavior.