[Adsorption process of organic contaminant in untreated coking wastewater by powdered activated carbon]

The article investigated the removal of organic contaminant from coking wastewater in adsorption process using powdered activated carbon as adsorbent. The dose of activated carbon, temperature, pH and reaction time were studied, and UV-Vis and GC/MS were used to carry out the qualitative and semiquantitative analysis of organic compositions in wastewater. The results showed that the optimum conditions for pretreatment of coking wastewater were 6 g activated carbon per liter, 30 degrees C, pH = 9 and reaction for 20 min, under which the removal efficiency of organic pollutants are more than 70%. Among the 56 kinds of organic compounds, 45 kinds such as dolichoalkanes, polynucleation aromatic series, azacyclo compounds could be removed, and the removal ratios of amidobenzene, hydroxybenzene, indoleacetic, acid-2-methyl-phenyl-ester are 63.5%, 42.6%, 88.1%, 28.1% respectively, while cresol and xylenol are more than 70% and 85%. In the adsorption process of multi-composition system in wastewater, macromolecules with low-pole and major -delta G0 as polynuclear aromatic hydrocarbons and azacyclo compounds could be adsorbed preferentially and completely in tacho-absorption period, while micromolecule with hadro-pole and inferior -delta G0 as amidobenzene and hydroxybenzene were adsorbed ambly.