B. DO of water samples after treatment
Study the effect of EM balls on properties of water sample
after treatment of waste water treatment plant
Bangkokthonburi University found that the dissolved oxygen
before treatment of three sets of trials have very similar values
are 6.08, 5.96 and 5.70 for set A, B and C, respectively. The
dissolved oxygen after treatment with EM ball in the first
week of treatment B and C series of experiments, down from
the original and is equal to 0 mg/L. Because the water is dirty
from addition EM ball that is organic bran and rice bran used
in the process, it needs oxygen to decompose organic matter
by bacteria. When the organic decomposition occurs during
the first week, the dissolved oxygen was decreased. Fig. 2
show the DO of water sample after treatment of three sets in
four weeks. The results shows that DO are not significantly
changed in set A, while set B and C were increased
continuously for four week. And found that the dissolved oxygen was increased from a 0 mg/L to 0.25, 0.13 in the set of
experiments B and C, respectively after the addition of EM
ball in two weeks. In third week and fourth week were
increased rapidly to 1.20, 1.38 and 3.05, 2.75 mg/L of a set of
experiments B and C, respectively. These results may caused
the organic matter in the water sample was digested as low.
Oxygen is used in the process of oxidizing the organic matter
less. As a result, the diffusion of oxygen from the air in a
water sample is dissolved in water to rise in test for the set A.
It was found that the dissolved oxygen increased markedly
during the first and second week of 7.85 and 8.00 mg/L and
will reduce slightly over third to fourth weeks (7.80 to 7.88). It
can be concluded that EM ball can enhance the DO of waste
water after addition EM ball for two weeks up.