Dairy Wastewater Treatment by a Horizontal Subsurface Flow Constructed Wetland in Southern Italy

Treatment of Combined Dairy and Domestic Wastewater with Constructed Wetland System in Sicily (Italy). Pollutant Removal Efficiency and Effect of Vegetation

“…TSS RE was found to be almost identical in the two planted units. These values were inside the range of those observed in HSSFs CW for the DWW treatment, which varied between 75% and 85% [13,24,27,40,44]. In Italy, some authors [28,30] reported TSS RE values of above 90%, however when using different pre-treatment systems and applying hybrid CWs.…”

“…Tables 1 and 2 show the average influent and effluent concentrations of chemical and physical parameters, as well as RE percentages of the HSSFs CW. As reported by various authors [13][14][15]43], the levels of the main parameters in the study were different throughout the year and varied mainly due to seasonal changes in dairy activities.…”

“…For pH measurements, literature [11,13,44] shows ranging between 3.5 and 11, depending on the dairy activities and the use of alkaline and acid cleaners. In our study, in both planted units, influent values were found to be slightly alkaline, significantly higher than effluent values.…”

“…The high average RE values of BOD 5 and COD can be explained by considering the role of plants, substrate and microorganisms in a CW and their interaction. Many authors [12,13,24,27,44,53] highlight, in fact, that filtration and sedimentation carried out by plants and substrate, together with microbiological degradation, are the main physical and chemical processes required for the elimination of organic matter in a CW. However, taking the functional and construction characteristics of HSSFs into consideration, it is not possible to conclude that the removal rate of organic compounds depends only on oxygen levels in the rhizosphere.…”

Green sustainable technology for biotreatment of actual dairy wastewater in constructed wetland

“…To address the need to maintain and preserve public health and hygiene from the risks of discharging this type of wastewater to natural aquatic systems without treatment, there are various conventional treatment methods such as coagulation/flocculation, oxidation process, activated sludge process, membrane bioreactors and membrane separation. However, these methods are considered not feasible, owing to their complication, high cost required for operation and maintenance, and their input requirements of electrical energy and chemicals, and resulting in massive byproducts in the form of chemical sludge 8–10 . Accordingly, the use of green infrastructure systems as natural‐based processes is the optimal sustainable solution for wastewater treatment rather than the traditional methods 11–16 .…”