The influence of wastewater temperature on the efficiency of pollutants removal by biological ponds system

The paper presents the impact of the temperature of raw sewage on the effects of poluttants removal in biological treatment plant in Ludwin. The plant includes four ponds: (1) an anaerobic pond, (2A) an aerated pond with biological plunged bed, (2B) an aerated pond, (3) a sediment pond. In the years 2008-2010 organic poluttant removal effeciency, expressed as BOD5 and CODCr indices and total nitrogen and total phosphorus were analyzed. The entire system of wastewa-ter ponds is able to achieve a BOD5 reduction of aproximately 90% anad CODCr reduction 75%. Lower treatment effects for total phosphorus and total nitrogen were found (respectively 65% and 32%). Statistical analysis showed a clear influ-ence of the wastewater temperature on total nitrogen and total phosphorus re-moval. There was no significant correlation beetwen the wastewater temperature and the reduction of BOD5 and CODCr. ...