a quick method for evaluating the suitability of activated carbon adsorption for wastewaters

to day, the activated carbon is being used to treat the industrial and domestic wastewaters. the suitability of activated carbon for treatment of industrial wastewaters can be quickly predicted by consideration of wastewater characteristics. the results of this paper represent a first step in determining suitability of activated carbon for treatment of wastewaters or effluent of treatment plants containing carboxyl, hydroxyl, and amine functional groups as a function of aromaticity , molecular size, and ph. relative adsorbability of uncharged sulstituted groups to activated carbon followed the order : acids>ampiline>phenol, and for aliphatic organics in the uncharged state followed the order: acids alcohols)amines. since these groups of aromatic and aliphatic compounds were in the same molecular weight range. the respective order of uncharged organics compound up take is: aromatic acids>aliphatic acids and alcohols> aniline aliphaticamines>phenol. the degree of adsorption was dependent on organic solubility and acid dissociation constant. adsorbality increased as solubility decreased and when the organic compound was in an uncharged state. solubility decreased with increasing carbon length which tended to decrease functional group influence. the importance of the number of functional groups per molecule on solubility and sorbability was demonstrated from the results of the acidic polymer (polymethylacrylic) and amine polymer (polyethylenimine) studies: organics containing carboxyl groups adsorbed better in their uncharged state (usually in acidic solutions). the respective carbon adsorption in acidic and basic environments followed the order: benzoic acid (h )valeric acid (h )polymethylacriylic acid(h ),propionic acid (h )valeric acid (oh-)benzoic acid (oh )propionic acid (oh ) polymethlacrylic acid (oh ). organic substituted with hydroxyl groups demonstrated little affect in adsorption with changing ph (with the exception of pentanol). respective relative adsorbability to activated carbon follow the sequence: phentanol(h )phenol(oh and h )penta- nol (oh )>propanol (h and oh ). organics substituted with amine groups adsorbed better in the uncharged state at ph values above thier pka, (usually in basic solution). respective adsorbability of these compounds in acidic and basic environments follow the sequence: aniline (oh )po1yethylenimine (oh )>pentylamine (oh )> nony1anmine (h )>hepthylamine (h )>pyridine (oh ) >aniline (h )>polyethylenimine (h ) >pyridine (h ) . on the basis of this experiment, it is recommended that four wastewater characteristics to be investigated to predict euitability of activated carbon for wastewater treatment. these characterictics are as follows: measurement of total organic carbon, acidity ,organic nitrogen and aromatic compounds .the application of these organic wastewater characteristics can aid in predicting suitability of activated carbon for wastewater treatment and answerd to various questions about the design of treatment plant.