『Abstract
Different substrates were evaluated to investigate their effect
on nitrate removal and denitrifying bacterial community in soils
obtained from wetland. Serial batch kinetic tests were conducted
on soils obtained from wetland mixed with glucose and sawdust
using KNO3 solution. Column tests were also
conducted on soils obtained from wetland mixed with three different
substrates (glucose, sawdust, and scoria coated with zero-valent
iron) using KNO3 solution. For the batch
tests, the nitrate removal efficiency for soil mixed with glucose
was comparable to that for soil mixed with sawdust, but the nitrate
removal rate for soil mixed with glucose (23.3 NO3--N
mg/L-d) was approximately eight times higher than that for soil
mixed with sawdust (2.8 NO3--N
mg/L-d). For column tests among soil samples, nitrate removal
efficiency was highest in soil mixed with glucose, which is an
easily biodegradable carbon source. Removal efficiency increased
with increasing incubation time for both soil samples with glucose
and sawdust. A phylogenetic analysis based on nitrate reductase
gene demonstrated that the different carbon sources affected both
the diversity and compositions of the denitrifying bacterial in
soil samples.
Keywords: Nitrate; Denitrification; Substrates; Denitrifying bacteria』
1. Introduction
2. Materials and methods
2.1. Soils
2.2. Substrates
2.3. Batch tests
2.4. Column tests
2.5. Chemical analyses
2.6. Biological analyses
3. Results and discussion
3.1. Batch tests
3.2. Column tests
3.2.1. Denitrification characteristics
3.2.2. Denitrifying bacterial populations
4. Conclusions
Acknowledgement
References