Summary:

The paper attempts to evaluate effectiveness of treatment of wastewater in sewage treatment plant in Paczków which is used in hydroponic technology. In order to determine the efficiency of wastewater treatment for the removal of nitrogen, phosphorus, suspended solids, BOD5 and COD, results of analyses of wastewater collected at the inlet of the treatment plant and at the outlet of the object were analyzed. Research period covered the years 2009 to 2011. Analysis of the data showed that the purification efficiency related to all parameters did not drop below 77.0%. The biggest effectiveness of sewage treatment was observed for total suspended solids (99.0%) for BOD and phosphorus it was at least 98.0% and 98.1%, and for COD - 94.8%. The lowest efficacy of treatment (but not less than 77.0%) was found for total nitrogen, which allowed concentration in sewage at the outlet from wastewater treatment plant has been exceeded several times during the study period. Based on the results of analyzes and literature studies was found that the hydroponic block which is tertiary step of urban wastewater treatment allows for considerable reduction of values of individual pollutants in discharged wastewater to make it possible to reach at the outlet values of BOD less than 4.8 mgO2/dm3, COD in the range 24.2-33.0 mgO2/dm3, total suspended solids below 3.4 mg/dm3, total phosphorus less than 0.3 mgP/dm3 and total nitrogen below the 20.4 mgN/dm3. Obtained results indicate that macrophytes and other hydroponic plants inhabiting the lagoon, have the ability to reduce the concentrations of nutrients in the wastewater, which allows drainage to receiver water of a better quality than the water flowing.