4.4 Variation of AVS (AVS) in different kinds of sediment
Figure 5 illustrates that the AVS value varied with time in all types of
sediment. The river sediment showed a lower value of AVS is probably due
to the size of the sediment during the starting of the experiment. The
larger particle size of the river sediment can be one of the reasons why
the AVS is lower value. The another probable reason of the lower AVS in
river sediment is due to the pollution level of the river water. The
various human activities such as using the chemical products to grow the
sea weed in the sea is one of the main reasons of the higher AVS in the
sea sediment. However, AVS reduced for all the samples from the
1st week of the experiment and after 3 weeks, SMFC 1,
2 and 3 showed a dramatic reduction of the sulfide content.
Nevertheless, all of the 4 samples showed that the sulfide content
reduction trend after using the SMFCs compare to blank sediment (without
using the SMFC). The probable reason of AVS reduction in the SMFC is
that the electron movement is frequent in the SMFC and this condition is
favorable for the geo-bacteria who work in the bioelectricity generation
from the polluted sediments which was discussed in the earlier research
(Moqsud 2020).