Mountain dairy wastewater treatment with the use of a ‘irregularly shaped’ constructed wetland (Aosta Valley, Italy)

Abstract

In mountain areas, economical activities related to milk processing represent both a key source of income\ud and job opportunities. One of the main characteristics of cheese production is the seasonal variability in\ud the volume of milk processed and wastewater production that tend to limit the capacity of ecosystems to\ud absorb their inputs. In alpine environment, the scarcity of plain surfaces and the climatic conditions\ud results in the need for high CW performances of variable nutrient inputs in different seasons. By\ud evaluating a CW seasonal efficiency for dairy wastewaters in a mountain region (Aosta Valley-NW Italy),\ud this research was aimed to understand how performances of nutrient removal could be affected by\ud seasonal shift in temperature and loadings. Results indicate that the “irregularly shaped” CW, designed to\ud fit the natural landscape, shows best organic removal efficiency in winter (93 and 96% mass removal for\ud BOD5 in summer and winter respectively), in presence of high organic loadings and low temperatures.\ud Even if nitrate removal is more variable during seasons (71 and 33% mass removal in summer and winter\ud respectively) and differently affected by environmental conditions, overall performance meet the need of high removal efficiency

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

“…Researchers found high removal rates for COD RE (93-96.00%) [55]. In southern Europe, in various studies [12,[27][28][29][31][32][33], the authors reported average values of BOD 5 RE ranging between 70% and 94% depending on various factors, such as the size of the CW and the wastewater pretreatment. In this study, at inlet of the HSSFs CW, the ratio between BOD 5 and COD was found to be 0.40, on average.…”

Domestic Wastewater Depuration Using a Horizontal Subsurface Flow Constructed Wetland and Theoretical Surface Optimization: A Case Study under Dry Mediterranean Climate

“…When P abatement is required, it is necessary to incorporate an alternative treatment. Different alternatives like the use of slags, which have been studied recently, remove P mainly via CaO-slag dissolution followed by Ca 2+ phosphate precipitation [14] or the use of an "irregularly shaped" HF-CW as described by Gorra et al [65].…”

Seasonal Considerations for Year-Round Operation of On-Farm Wetlands in Temperate Climates: A Review

“…A study by Gorra et al (2014) found that a consistent snow cover during the winter months maintained a temperature close to 0 o C of the substrata (Gorra et al, 2014). The snow cover had been shown to protect the soil by maintaining unfrozen conditions between 1 and -3 o C, and therefore sustained high biological activity in temperatures approaching sub-zero (Gorra et al, 2014).…”

“…They maintained a 5-10 cm water level below the surface to prevent heat loss and allowed a snow layer to persist throughout the winter as an insulating layer (Grebenshchykova et al, 2020). A study by Gorra et al (2014) found that a consistent snow cover during the winter months maintained a temperature close to 0 o C of the substrata (Gorra et al, 2014). The snow cover had been shown to protect the soil by maintaining unfrozen conditions between 1 and -3 o C, and therefore sustained high biological activity in temperatures approaching sub-zero (Gorra et al, 2014).…”