Supporting constructed wetlands in P removal efficiency from surface water.

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Wastewater Management

Background:

• Constructed wetlands (CWs) are crucial for phosphorus (P) removal.
• Enhancing P removal efficiency in CWs is an ongoing challenge.
• Autoclaved aerated concrete (AAC) shows potential as a reactive material (RM).

Purpose of the Study:

• To investigate the efficacy of suspended reactive filters utilizing AAC for phosphorus removal.
• To determine the optimal mass-to-volume ratio of AAC for P removal in a laboratory setting.
• To predict the P removal efficiency of CWs with AAC filters for a specific river.

Main Methods:

• Laboratory experiment using 10 L artificial P solutions.
• Four variants: AAC mass to volume ratios of 1:1, 5:1, 10:1 (g:L), and a control (0:1 g:L).
• AAC was suspended in filter bags within the solutions for 30 days.

Main Results:

• AAC significantly reduced P-PO4 concentration from 2.972 mg·L⁻¹.
• Reductions to 0.341, 0.006, and 0.004 mgPO4-P·L⁻¹ were achieved with 10g, 50g, and 100g AAC, respectively.
• Unit sorption varied from 2.53 to 0.30 mgP-PO4·g⁻¹ with increasing AAC mass.

Conclusions:

• Suspended AAC filters are effective in enhancing phosphorus removal in CW systems.
• The study provides data for dimensioning CW filters to achieve target outflow concentrations (e.g., 0.01 mg·L⁻¹).
• P removal efficiency was predicted for the Cetynia River, Poland.