The Fate of Dissolved Organic Carbon (DOC) in the Wastewater Treatment Process and its Importance in the Removal of Wastewater Contaminants

摘要

Goal, Scope and Background. Dissolved organic carbon (DOC) constitutes a parameter of organic pollution for waters and wastewaters, which is not so often studied, and it is not yet regulated by directives. The term 'DOC is used for the fraction of organics that pass through a 0.45 pm pores' size membrane. The type of wastewater plays an important role in the quality of DOC and it has been shown that DOC may contain aquatic humic substances, hydrophobic bases, hydrophobic neutrals, hydrophilic acids, hydrophilic bases and hydrophilic neutrals. The quality of the DOC is expected to affect its fate in a wastewater treatment plant (WWTP), since a considerable frac tion of DOC is not biodegradable, and it may be released in the aquatic environment together with the treated effluent. In the present study, the occurrence of DOC during the waste-water treatment process is investigated and its removal rates during primary, secondary and overall treatment are being esti mated. Furthermore, a correlation is being attempted between DOC and the concentrations of selected Persistent Organic Pol lutants (POPs) and Heavy Metals (HMs) in the dissolved phase of wastewaters, to examine whether there are common sources for these pollution parameters in WWTPs. Also, DOC is being correlated with the partition coefficients of the above-men tioned pollutants in wastewater, in order to examine the effect of 'solubility enhancement' in WWTPs and to evaluate the re sult of this phenomenon in the efficiency of a WWTP to re move organic pollutants.