Tag: nitrogen

Waste Water Treatment Plant Sankey

An area of application for Sankey diagrams that has (so far) received little attention here on the blog is waste water treatment. The article ‘Nitrogen Recovery from Wastewater: Possibilities, Competition with Other Resources, and Adaptation Pathways’ by Van der Hoek, J.P.; Duijff, R.; Reinstra, O. In: Sustainability 2018, 10(12), 4605 has two Sankey diagrams that merit being featured here.

The first one visualizes the absolute flows through the process in mio m³ per year (volume streams). Data is from the Amsterdam-West waste water treatment plant (WWTP). The main loop leads water from the clarification stage back to the biological treatment stage.

The second Sankey diagram uses exactly the same process structure, but flows are displayed in tons of nitrogen per year. Most of the nitrogen leaves the system as a gaseous effluent. In contrast to the above, the loop of nitrogen loads is in the reject water from the digester fed back to the primary settling stage.

Anyone in for calculating the concentrations? Read the full article here for details.

Pimp my nitrogen Sankey

Below is an example of a Sankey diagram showing a nitrogen metabolism. The original diagram is from a Japanese publication (‘White Paper on Quality of the Environment in Japan 1994’), even though the diagram represents nitrogen loads (in 1000 tons N) in the Netherlands in 1990.

A pimped version of this diagram can be found in the e!Sankey download gallery. I don’t like the color very much, but the overall aspect of the diagram is much better than in the b/w version, I think.

They seemed to have struggled with inconsistencies in the original diagram, as an annotation suggests. Also the denitrification due to accumulation in the bottom sediment, or nitrogen ending up in durable goods (shown in black in the original) are not represented in the remake. For the rest it pretty much sticks to the original.

Thinking about a new tag “pimp my Sankey”…