Constructed Wetlands for Nature-Based Treatment of Domestic Wastewater on Large-Scale in Mexico.

These initiatives mark significant progress in Constructed Wetland (CW) technology, expanding towards larger and more complex applications. Our recent work establishes a new type of nature-based wastewater treatment plant. Our recent work introduces a novel approach to natural wastewater treatment facilities. Designed for technical and ecological efficiency, our plants employ low-tech processes encompassing primary and secondary treatment, natural sludge mineralization and final polishing via Constructed Wetland Technology. The technical reliability of these plants ensures robust operation with minimal risk of malfunction. They are straightforward to operate and maintain, requiring fewer personnel compared to similar facilities. Moreover, they offer low energy consumption and cost-efficiency without the need for chemical additives.
Our design philosophy places a strong emphasis on ecological and social considerations. Ecologically, the integration of plants, flowers, and enhanced water resources fosters diverse habitats for local insects, birds, and reptiles, thereby promoting biodiversity. Additionally, the cultivation of flowers on biological filters provides income opportunities for the community. The purified water supports agricultural irrigation, bolstering local food production and economic growth.
Our recent projects in Mexico are:

Rayón Nature-Based Treatment Plant, State of México: Under construction and expected to be completed by early 2025. Located near Mexico City, this facility is designed to treat wastewater from a population equivalent of over 23.000 individuals, processing approximately 3,5 million liters per day (144 m³/h). The plant features 6 vertical-flow constructed wetlands (VFCW) covering nearly 15.000 square meters. Additionally, a surface-flow constructed wetland (SFCW), approximately the same size, enhances the treated wastewater quality and provides habitat for wildlife, including a birdwatching shelter for visitors. The treatment process begins with pretreatment facilities such as sand traps, sedimentation chambers with automated sludge removal, leveling and homogenization lagoons, ensuring efficient removal of solids and oils before entering the CW stages. Removed sewage sludge undergoes stabilization and mineralization processes in two dedicated wetlands designed for this purpose. Within these wetlands, solids accumulate on the surface and gradually transform into fertile soil through microbial activity. Percolation water returns to the treatment plant for further processing. You can find regular updates on the project on our LinkedIn page https://www.linkedin.com/company/janisch-schulz.

Mexicali Treatment Plant, State of Lower California: Currently under construction, with completion expected by the end of 2024. Located in the arid northern part of Mexico near the US border, this project expands an existing treatment plant with two additional CW-based purification stages. It includes eight vertical-flow CW modules covering a total surface area of 12.800 m² and a surface-flow wetland spanning 14.000 m². This innovative configuration will achieve a high-level purification with minimal energy consumption and enhances ecological value for the region.

Cihuatlán Nature-Based Treatment Plant, State of Jalisco: Completed in 2021, this is our first complete multi-stage treatment plant built on the tropical Pacific coast. Serving a population of over 20.000, the plant incorporates primary treatment through sand traps, screens, and Imhoff Tanks, followed by secondary treatment in two lung-shaped Vertical-Flow Constructed Wetlands covering 9.000 m² each. The purified water is collected in a natural-shaped pond, providing additional habitat for wildlife. This treated water can be used for irrigation, supporting surrounding coconut and banana farming. You can see a 5-minute video on Youtube explaining many details of this project https://www.youtube.com/…