Risk assessment modelling of N2O production for eco-activated sludge process optimization

We structured atmospheric methane sources and sinks into a well-organized network of 49 nodes and 302 links. In the network, reactions (including substrates and products) are considered as nodes and their pathways as links. Our directed network keeps sources and sinks independent of each other such that changes in the number or type of methane sources does not affect the findings related to sinks. Tracking the structure of methane sources and sinks not only provides valuable, and perhaps universal, information about the network structure, but also can lead to a better understanding of the dynamic processes that generate the network. Additionally, this network model may represent a common blueprint for the reactions (sources and sinks) of other greenhouse gases.