Speciation of Biochemical Oxygen Demand (BOD) for wastewater and surface water / Norizan Abdullah

The Biochemical Oxygen Demand (BOD) test has been a standard test method to
quantify the amount of biodegradable organic matter present in a water sample. The
test is typically conducted over a 5-day period (BODs), with the sample being
incubated at 20°C. This study aims to speciate the two organic fractions under two
distinct categories termed slow-BOD and fast-BOD. Furthermore, the cBOD test also
being conducted. The speciation is done by filtering the samples with filter size of
0.12 pm to separate the dissolved and particulates fractions. Twenty four of samples
from variety sources have been collected and tested. The samples have been divided
into five category which are discharge from sewage treatment plant (STP), industrial
discharge, sullage, leachate and river water. The results showed that the speciation of
slowly biodegradable fraction and fast biodegradable fraction are obviously shown in
the BOD and cBOD reaction. It also has been found that five samples out of twenty
four samples showed that the degradation of organic matter present is between 70-80
% in 5 days. The rest of the sample showed the degradation of the organic matter is
below than 70%. Furthermore, the kinetic reaction parameter of BOD had been
calculated through four different methods which are Thomas, Least-square, Fujitomo
and Slope methods. From the observation, least-square is the best method followed by
slope, Fujitomo and Thomas method. The kinetic reactions support the finding which
the speciation of slow-BOD and fast-BOD are obviously shown in this study.