Characterization of organic matter and disinfection by-products in membrane backwash water from drinking water treatment

ABSTRACTRecent studies suggest the involvement of water in the epidemiology ofCyclospora cayetanensisand some microsporidia. A total of 223 samples from four drinking water treatment plants (DWTPs), seven wastewater treatment plants (WWTPs), and six locations of influence (LI) on four river basins from Madrid, Spain, were analyzed from spring 2008 to winter 2009. Microsporidia were detected in 49% of samples (109/223),Cyclosporaspp. were detected in 9% (20/223), and both parasites were found in 5.4% (12/223) of samples. Human-pathogenic microsporidia were detected, includingEnterocytozoon bieneusi(C, D, and D-like genotypes),Encephalitozoon intestinalis,Encephalitozoon cuniculi(genotypes I and III), andAnncaliia algerae.C. cayetanensiswas identified in 17 of 20 samples. To our knowledge, this is the first study that shows a year-long longitudinal study ofC. cayetanensisin drinking water treatment plants. Additionally, data about the presence and molecular characterization of the human-pathogenic microsporidia in drinking water, wastewater, and locations of influence during 1 year in Spain are shown. It is noteworthy that although the DWTPs and WWTPs studied meet European and national regulations on water sanitary quality, both parasites were found in water samples from these plants, supporting the idea that new and appropriate controls and regulations for drinking water, wastewater, and recreational waters should be proposed to avoid health risks from these pathogens.

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Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane

Drinking Water Engineering and Science ◽

10.5194/dwes-6-1-2013 ◽

2013 ◽

Vol 6 (1) ◽

pp. 1-10 ◽

Cited By ~ 29

Author(s):

A. Grefte ◽

M. Dignum ◽

E. R. Cornelissen ◽

L. C. Rietveld

Keyword(s):

Water Quality ◽

Drinking Water ◽

Organic Matter ◽

Water Treatment ◽

Organic Carbon ◽

Natural Organic Matter ◽

Drinking Water Treatment ◽

Biological Stability ◽

Sand Filtration ◽

Slow Sand Filtration

Abstract. To guarantee a good water quality at the customers tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research was to improve the biological stability of the produced water by incorporating anion exchange (IEX) for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration) and two IEX configurations (MIEX® and fluidized IEX (FIX)) were compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. Both, MIEX® and FIX were able to remove NOM (mainly the HS fraction) to a high extent. NOM removal can be done efficiently before ozonation and after slow sand filtration. The biological stability, in terms of assimilable organic carbon, biofilm formation rate and dissolved organic carbon, was improved by incorporating IEX for NOM removal. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The total costs for IEX for the three positions were approximately equal (0.0631 € m−3), however the savings on following treatment processes caused a cost reduction for the IEX positions before coagulation and before ozonation compared to IEX positioned after slow sand filtration. IEX positioned before ozonation was most cost effective and improved the biological stability of the treated water.

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