The use of constructed wetlands for the treatment of agro-industrial wastewater – A case study in a dairy-cattle farm in Sicily (Italy)

Wastewaters generated by agro-industrial operations often represent an unsustainable cost for farms due to high wastewater-treatment management costs. The wastewater produced by dairies, wineries or oil mills may vary in quantity and in quality depending on the time of the year, making the use of a conventional treatment system less efficient and more costly. Constructed wetland systems (CWs) provide low-cost technology and an efficient solution in the treatment of a number of wastewaters from agriculture. They are simple to build, have low maintenance costs and are sustainable compared to conventional treatment methods. This paper shows a case study that was carried out on a dairy-cattle farm, located in the West of Sicily (Italy). The aim of the study was to evaluate the pollutant removal efficiency of an horizontal subsurface flow system (HSSFs) for the treatment of dairy parlor wastewater (DWWs). An HSSFs was planted with Phragmitesaustralis (Cav.) Trin. ex Steud. DWWs were initially pre-treated with a degreaser and two Imhoff septic tanks were used for the removal of suspended solids. The results showed a significant removal rate of organic pollutants by the HSSFs. The system was efficient in the treatment of DWWs and represents an artificial engineering system that corresponds well to Italian legislation requirements concerning the management of agricultural wastewaters from dairy-cattle farms.