TITLE:
Assessment of Endotoxin Removal from Reclaimed Wastewater Using Coagulation-Flocculation
AUTHORS:
M. Guizani, M. A. Lopez Zavala, N. Funamizu
KEYWORDS:
LPS Endotoxins, Wastewater, Coagulation-Flocculation, Potable Reuse
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.8 No.9,
August
15,
2016
ABSTRACT: Following
biological treatment, wastewater continues to have endotoxic active materials.
However, because there is a trend of potable reuse and because endotoxic active
materials potentially have harmful effects on human health, their removal from
water is crucial. Lipopolysaccharide endotoxin has hydrophobic groups, and
their removal using a coagulation-flocculation alternative is believed to be
efficient. Thus, their removal from reclaimed wastewater using the coagulation-flocculation process was assessed. Secondary effluent samples from a wastewater
treatment plant located in Sapporo, Japan, were investigated. It was found that
this process gave satisfactory results in removing endotoxins, with an optimum
removal rate of up to 40.5%. The endotoxin removal was maximized by adjusting
the pH at the low range 4 - 5.5, with an aluminum sulfate dose of 80 mg/L.
Further increases of the coagulant dose did not improve the removal efficiency.
DOC and turbidity removal were at their optimum at higher pH range 5.5 - 6.5.
Thus coagulation and flocculation could be considered as the first barrier and
should be followed by other treatments to safely reuse reclaimed wastewater.