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Passive treatment wetlands are conventionally designed with the primary objective of purifying contaminated mine water; any benefit of enhanced biodiversity is ancillary. We propose a new approach that incorporates enhanced biodiversity as an explicit objective. In this approach, treatment units are selected based on water flows and chemistry and the ecological requirements of key species are identified. Elements of the wetland design that meet these distinct requirements are selected and sized, then merged within the constraints imposed by site geomorphology and hydrology. This concept is illustrated with the wetland design for the Los Bronces Mine in Chile, where aspects of treatment, biodiversity, and water management were developed separately, and then integrated into a holistic design. The treatment wetlands are integrated within the local ecology. This approach adheres more closely to the objective of designing wetlands that offer ecosystem services and also meets the requirements for long-term water treatment. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the sorption characteristics of NH 4 + -N and PO 4 3 − -P onto the surface of natural zeolites coming from Chile and their potential application in the subsurface-flow treatment wetlands for wastewater treatment in rural areas. For this purpose, adsorption experiments onto the zeolite were developed in batch assays. The effects of the adsorbent quantity (20 g and 50 g) and particle size (0.2–1.0 mm; 1.5–3.0 mm, and 5.0–8.0 mm) were evaluated in terms of adsorption capacity at different NH4+-N and PO4−3-P concentrations. Then, the obtained laboratory results were adjusted to theoretical models: Saturation-growth-rate and Langmuir. The saturation adsorption of NH4+-N on the zeolite increases at the same time that the initial concentration increases for the same zeolite quantity; however, the saturation values were similar between the different zeolite sizes tested. For PO4−3-P, the adsorption did not have a direct relationship with the initial concentration nor zeolite quantity and better results were only achieved for zeolite sizes of 1.5–3.0 mm. Regarding the Langmuir model, sizes of 1.5–3.0 mm had the best adsorption characteristics, with the maximum adsorption capacity of up to 1.58 mg/g for NH4+-N and up to 0.08 mg/g for PO4−3-P. Therefore, a new material—a natural zeolite from the Maule Region of Chile—is described as a potential support medium for treatment wetlands. [ABSTRACT FROM AUTHOR]