Ceb, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal 1  
[PERSON]  
1 Graduate Program in Environmental Technology and Management, IFCE, Federal institute of Ceara, Fortaleza-Ceari 60000-000, Brazil; [EMAIL_ADDRESS] (A.P.F. ); [EMAIL_ADDRESS] (K.R. ); [EMAIL_ADDRESS] (W.E.M. ); [EMAIL_ADDRESS] (S.M.P.R.R. ); [EMAIL_ADDRESS] (G.M.M.S.) Ceb, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal 1  
[PERSON]  
1 Graduate Program in Environmental Technology and Management, IFCE, Federal institute of Ceara, Fortaleza-Ceari 60000-000, Brazil; [EMAIL_ADDRESS] (A.P.F. ); [EMAIL_ADDRESS] (K.R. ); [EMAIL_ADDRESS] (W.E.M. ); [EMAIL_ADDRESS] (S.M.P.R.R. ); [EMAIL_ADDRESS] (G.M.M.S.) Ceb, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal 1  
[PERSON]  
1 Graduate Program in Environmental Technology and Management, IFCE, Federal institute of Ceara, Fortaleza-Ceari 60000-000, Brazil; [EMAIL_ADDRESS] (A.P.F. ); [EMAIL_ADDRESS] (K.R. ); [EMAIL_ADDRESS] (W.E.M. ); [EMAIL_ADDRESS] (S.M.P.R.R. ); [EMAIL_ADDRESS] (G.M.M.S.) Ceb, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal 1
Water scarcity exacerbates this precarious situation, as water is an essential resource for life. Sustainable management of water resources has become one of the most critical issues of the 21 st century, directly impacting water availability [2; 3]. Many challenges associated with water scarcity stem from inadequate conservation and protection of water sources. In addition to the deforestation of springs and riparian forests, the pollution of water bodies, particularly through the discharge of untreated or partially treated sewage into natural waters, is identified as the primary contributor to the degradation of water quality [3; 4]. Therefore, investing in sanitation and sewage treatment is a crucial strategy for enhancing water supply. Wastewater treatment plants (WWTPs) are designed to replicate, within a compact space and timeframe, the natural self-purification processes of watercourses [2; 4]. Various technologies have been developed to treat water resources, aiming to restore and preserve their physical, chemical, and biological characteristics. Among these, constructed wetland (CW) systems are particularly notable due to their sustainability [5]. CW systems are sustainable and decentralized technologies, effective in improving water quality, and can treat a range of effluents, including domestic sewage, storm water, leachate, and industrial wastewater [5]. They offer significant advantages, such as lower costs for implementation, operation, and maintenance compared to traditional treatment methods. The recent review by [PERSON] et al. [5] examined the impact of substrate type, plant selection, and operational criteria such as hydraulic load and hydraulic retention time (HRT) on CW performance, highlighting the promising use of construction waste and biochar as effective, cost-efficient alternatives due to their adsorption properties and ease of use to enhance efficiency. Their review also provides key insights into how design and operational choices affect CW effectiveness. The selection of appropriate substrates in wetland systems is crucial for optimizing treatment efficiency, as these substrates play a significant role in biofilm formation [5]. While sand and gravel are commonly used, alternative substrates such as waste materials--specifically, ceramic bricks from construction and seashells from shellfish farming--offer a means to recycle these by-products [5]. Shellfish farming by-products have demonstrated potential for treating wastewater, especially those with high phosphorus content. However, research on using seashells in effluent treatment technologies, particularly within nature-based systems, remains limited [6].