Three diverse-sized organic acids have distinct effect on P-PO₄³⁻ uptake by HZO-201.

The small-sized GA reduce capacity of P-PO₄³⁻ by competing for sites directly.

The middle-large TA inhibit P-PO₄³⁻ adsorption rate due to pore blockage.

The largest HA pose little impact on P-PO₄³⁻ removal because of size exclusion.

The organic acids compete for R-N⁺(CH₃)₃ of HZO-201 instead of the nano-HZO sites.