Hi,

I have conducted a 4 months test run using 8 units of subsurface constructed wetlands (1.53x0.76m) planted with phragmites australis using actual produced water from onshore terminal with boron measured at 53mg/L. It was interesting to find out that the boron removal efficiency decreases over time as showed in the chart attached in this post. It is not responding to any variables tested such as HRT or type of constructed wetland. I wonder has anyone have a similar observation before? The other contaminants have relatively high removal rate and does not show a declining trend like boron.

I appreciate your view on this finding as well.

Thank you.