Dairy Wastewater Treatment with Constructed Wetlands: Experiences from Belgium, the Netherlands and Greece

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.…”

“…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.…”

Potential Nutrient Conversion Using Nature-Based Solutions in Cities and Utilization Concepts to Create Circular Urban Food Systems

“…If N:P:K ratios in recovered nutrient supply sources and specific crop field demand are considered, crop selection and/or dimensioning of the system could be adapted to N:P:K ratios in the fertigation water (TW effluent), or fertilizer (digestate) in order to maximize the production achieved from applying only recovered nutrients, and/or to maximize the replacement of synthetic fertilizer. The calculations for this study were conducted with average net nutrient requirements of different crop species within each product group (1)(2)(3). When applying this to a specific field case, the specific crop nutrient requirements could be considered and secondary nutrient input sources tapped adequately.…”

“…TW for wastewater treatment are wellestablished NBS [51]. They can treat wastewater from a wide range of sources besides domestic wastewater, such as industrial (e.g., [11,21,31,32]and agricultural wastewater (e.g., [2,3,49]) or landfill leachate [36], and have been successfully implemented in different climate zones around the world [19]. The systems are characterized by low external energy demand, comparatively low cost, and easy operation and maintenance as well as the possibility to use local materials and labor.…”

“…In combination, TW and biogas plants can efficiently treat liquid and solid fractions of wastewater, respectively, and the solid wastewater fraction (sewage sludge) co-digested with kitchen waste. Appropriate agricultural residues and industrial effluents, such as food and drink processing wastewater [21,31,32], wood, leather, and textiles wastewater [2,3,20,29,37], could be added as well. TW fed with solid-free wastewater can function with reduced space and innovative setups which can be integrated into the built environment, such as green walls (e.g., [54]).…”