HORIZONTAL FLOW PILOT CONSTRUCTED WETLAND FOR DAIRY WASTEWATER PURIFICATION
Due to the natural energy sources used in constructed wetlands, minimal energy and chemicals are required for wastewater treatment. For the successful wastewater treatment via constructed wetlands, adequate pretreatment and a sufficient amount of oxygen are crucial. Constructed wetlands can be used to treat industrial wastewater, such as wastewater from the dairy industry, with prior degreasing. This study was conducted on a horizontal flow pilot constructed wetland located on a plot of land used by the Biotechnical Faculty in Bihać. The constructed wetland consisted of two fields planted with rushes (Typha latifolia) and reeds (Phragmites australis). The substrate and plants were not changed during the experimental period. We monitored the efficiency of industrial wastewater treatment (wastewater from the dairy industry) by season, varying the flow rate as well as the hydraulic retention time of the water in the device. The quality of the influent and effluent was monitored by determining analytical parameters. The constructed wetland showed the highest efficiency in the summer period, with a hydraulic retention time of 6 days, with removal efficiencies of 98.03% for ammonia, 98.19% for total nitrogen, 95.27% for total phosphorous, 94.50% for COD and 97.73% for BOD5. The organic substance removal efficiency across all four seasons was 94.68%.