LED light use for the improvement of wastewater treatment in the hydroponic system

Effective removal of nitrogen and phosphorus from sewage before its discharge to the receiving water body is now a key task for scientists and technologists around the world. The widespread problem of eutrophication in the watercourses as well as in the seas and oceans obliges to take actions leading to more effective protection of water resources and implementation of sustainable development principles. One of the methods of increased wastewater treatment from nutrients is the use of a third stage of treatment with the use of macrophytes for the uptake of nitrogen and phosphorus. These systems, called hydroponic, under moderate climate conditions show little effectiveness due to the lack of sufficient light intensifying the growth of aquatic plants. The aim of this study was to evaluate the reduction of biogenic compounds concentrations in wastewater where additional lighting of plants was provided by the use of LED (Light Emitting Diodes), in two different conditions of experiment: with aeration and with carbon dioxide supplementation. Analyses show that the effectiveness of purification was higher in the wastewater supplemented with CO₂ and artificial lighting had no significant influence on the reduction of nitrogen forms concentrations. In wastewater with aeration, higher effectiveness of nitrogen removal was observed in the tank with artificial lighting. In both cases, aeration or CO₂ supplementation as well as artificial lighting or its lack, had no influence on total phosphorus and phosphates removal.