3.3. Changes in TN, NH4
+
–N, and NO3
–N
Although composting is a process of biochemical degradation
of organic matter, it is also accompanied by an obvious nitration
reaction. During this process, NH3 is released from the degradation of nitrogen components and then absorbed through microbial assimilation, oxidized to become nitrite or nitrate by
nitrogen-fixing microorganisms, or liberated into the atmosphere
(loss of nitrogen). In the present study, the emission patterns of
NH4
+
–N were similar in both solar and greenhouse reactors
(Fig. 4a). During the first 5 days of composting, NH4
+
–N concentrations sharply increased and reached high values in all three reactors, which was most likely due to the intensive degradation of