Abstract
Coagulation-precipitation treatment using ferric chloride was carried out in wastewater taken from a solid waste incinerator wet scrubbing system. The treated wastewater was fractionated with 1 μm and 0.1μm filter, and the dioxin concentration in each fraction was determinde. The isomer profiles indicated that 1) dioxin concentration in the “<0.1μm” fraction decreased, and 2) dioxin in the “≥0.1,<1μm” fraction between temproary increased by the conagulation process. Hence, it become clear that dioxin particle size increases and dioxin can be removed with conagulation-precipitation treatment. The relationship between dioxin isomer concentrations in montreated warte (X) and treatde water (Y), and Flocculant concentration (A) is expressed by the following regression formula. Y=2.3×1010×(X/A)+1.8 This result suggests that a dioxin concentration of more than 1,000 pg TEQ·l-1 in highly contaminated wastewater can be reduced to below the wastewater effluent regulation value (10 pg TEQ·l-1) by a combination of coagulation-precipitation treatment and membrane filtration.
