D2.1 - EU Project Neptune

NEPTUNE · Contract-No. 036845 Deliverable 2.1
Figure 3.2 Oxidative elimination of selected micropollutants during treatment of a
secondary wastewater effluent as a function of the Fe(VI) dose (0.25 −5.0 mg Fe L –1 ).
Experimental conditions: [micropollutants] 0 = 0.1 − 1 µM, [PO 4 ] 0 = 3.5 mg P L –1 , [DOC]
= 5.1 mg C L –1 , pH = 7 and T = 23±2 °C.
In addition, the combined process of micropollutants elimination and phosphate removal
(Figure 3.3) was investigated. It could be shown that Fe(VI) doses needed to eliminate
micropollutants containing electron rich moieties (5 mg Fe L -1 ) are lower than those needed
to reduce phosphate concentrations from 3.5 to 0.2 mg P L -1 (> 8 mg Fe L -1 ). Hence, the
combined use of (Fe(VI)) and the less expensive Fe(III) could be of economic interest. The
comparison of different forms of iron (Fe(VI), Fe(III), Fe(II)) revealed that Fe(VI) is as efficient
as Fe(III) in terms of phosphate removal (Figure 3.3a).
Figure 3.3 (a) Oxidative elimination of selected micropollutants and subsequent
removal of phosphate during treatment of secondary wastewater effluent as a function
of the Fe(VI) dose (1.0 − 15 mg Fe L –1 ) and (b) Comparison of phosphate removal
efficiency for various forms of iron. Experimental conditions: [micropollutants] 0 = 0.5
− 1 µM, [PO 4 ] 0 = 3.5 mg P L –1 , [DOC] = 5.1 mg C L –1 , pH = 7 and T = 23±2 °C.
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