2
Abstract
Treatment efficiency in wastewater treatment plant of Hat-Yai municipality,
which consists of
stabilization ponds and constructed wetlands, was assessed using fecal coliform (FC)
monitoring
. The wastewater
treatment plant has the capacity to treat influent loading (138,000 m
3
/day). The wastewater samples were collected
from 7 ponds as follows: primary or anaerobic pond (2 points: P1A and P1B), facultative pond (F), maturation pond
(M), constructed wetlands (W1, W2 and W3) and treated wastewater pond (S1). The percentage reduction of FC
was
found ranging from
84.56 (F) > 76.24 (P1A and P1B) >70.89 (W1) )> 68.23 (M) > 68.05 (W3) > 53.44 (W2) >
30.02 (S).
Overall, the wastewater system could reduce 90.26% of the FC. Following physico-chemical properties,
temperature, pH, dissolved oxygen (DO), light intensity and chlorophyll
a
, which affected on amount of FC, were
also investigated. The best FC removal was found in the facultative pond, thereby only the correlation between
amount of FC and physico-chemical properties of this pond
was
shown. It was found that only DO had a medium
negative correlation with FC (r= 0.40,
p
< 0.05).
Keywords
: Removal of fecal coliform, stabilization ponds, constructed wetlands, dissolved oxygen
