Application, design and operation of constructed wetland systems: case studies of systems in the Gdańsk region, Poland

Constructed wetland systems in Poland are applied to provide secondary treatment of domestic wastewater, protection of surface water and treatment of landfill leachate. Due to climatic conditions vegetated submerged beds (VSB) are most commonly applied for sewage and leachate treatment. For water protection systems with FWS or with mixed flow are more commonly used. The objective of the study was to recognize the efficiency and operation conditions of existing constructed wetland in Poland. It was concluded that discharging of too high loads of contaminations as well as too high hydraulic loadings leads to beds clogging and to the decrease of treatment efficiency in consequence. The average rates of organic matter and total nitrogen decomposition rates at the CW Wiklino were twice higher for the HF-CW II in comparison to corresponding rates for HF-CW I. The constants were dependent not only on temperature of sewage but on loads of contamination in the sewage as well.