Effects of bacteria on nitrogen and phosphorus release from river sediment
WU Qunhe , ZHANG Renduo , HUANG Shan , ZHANG Hengjun
DOI:
Received June 12, 2007,Revised August 28, 2007, Accepted , Available online
Volume 20,2008,Pages 404-412
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To better understand the mechanisms of eutrophication, we addressed the microbial processes that influence many key aspects
of water-sediment systems. In this study, a large column experiment was conducted for 30 d. Along the column, solution samples
were collected at di erent locations at di erent time. The samples were analyzed for physical, chemical, and biological properties
of the sediment and overlying water. The results showed that the amount of nitrogen transforming bacteria was higher than that
of phosphorous bacteria. The amount of nitrogen transforming bacteria was in the order: ammonifier > denitrifying bacteria >
nitrobacteria and nitrosomonas. Principal component analysis indicated that the three main factors accounted for more than 90%
overall contributions for bacterium growth, which represented nutrition, organics and oxygen, and pH and redox potential (Eh) of
the environment. Corresponding to the bacteria, the concentrations of nitrogen in the system was in the order: ammonia (NH4
+-N)
> nitrate (NO3??-N) > nitrite (NO2??-N). The fluxes of N and P clearly showed a temporal release and adsorption processes in the
water-sediment system. The large magnitude of N fluxes suggested that N might act as an important contamination source for the water
quality. However, P exchange between the sediment and overlying water was less intensive during the experiment.
