In order to investigate the influence of the plants and hydraulic loading on nitrogen removal in constructed wetlands built with horizontal sub-surface flow (HFSS. abbreviation in Spanish) for domestic wastewater treatment. twelve laboratory-scale (microcosm) HFSS were constructed using gravel substrate. Six of these were planted with Heliconia psittacorum and six were not (controls). https://parisnaturalfoodes.shop/product-category/proscalp-itch-relief/