FUNDAMENTALS OF ELECTROSORPTION ON ACTIVATED CARBON FOR WASTE-WATER TREATMENT OF INDUSTRIAL EFFLUENTS

The potential of electroadsorption/desorption on activated carbon for waste water treatment of industrial effluents is studied. Adsorption i sotherms of hydrophobic differently charged model substances on activa ted carbon were measured in order to obtain specific information about the influence of the charge (+1, -1 and 0) on the adsorbability of co mparable, aromatic species and the influence of the bed potential on t he adsorption equilibria. In all these cases the adsorption equilibria show a dependence on applied potential in electrolyte of approximatel y 1 M ionic strength. With electrosorption from aqueous solution, a fi vefold enhancement of the concentration in one potential controlled ad sorption/desorption cycle is achievable. The use of the solvent methan ol instead of water for desorption allows for a concentration enhancem ent by a factor of hundred in the desorptive step. The adsorption capa city of the activated carbon changes only slightly with cycle number. Two cell designs for the performance of potential controlled adsorptio n/desorption cycles on the large scale are discussed.