Design Blueprint: Village Defluoridation Kiosk (Activated Alumina, 1,000 L/day) — Build Specification Derived from the Working-Point Defluoridation Pricing Paper

DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT. A complete build specification for a village defluoridation kiosk treating 1,000 L/day of groundwater at a 5 mg/L design feed fluoride concentration to a 1.0 mg/L target by adsorption on activated alumina. Derived from the source paper: https://doi.org/10.5281/zenodo.24109228. Design basis: usable alumina capacity of 2.58 mg/g taken from a Langmuir isotherm evaluated at the working point (pH 6), two alternating beds of 11 kg each (13.75 L bed volume, 0.20 m internal diameter vessel, 0.438 m settled bed depth), fresh-bed breakthrough of 7,087.5 L and a 7.09-day regeneration interval shortening over 14 cycles to a media life of 72.62 m3 per bed, regeneration charged in full at 0.55 kg caustic soda and 151.25 L of discharge per event, running cost USD 0.864 per m3, and 4.23 operator hours per week. Adsorption is the source paper's winning route at the 5 and 10 mg/L feeds because Nalgonda precipitation breaches the 0.2 mg/L residual-aluminium limit there (0.389 and 0.875 mg/L); at a 2 mg/L feed precipitation wins and this kiosk is not the recommended build. Running unadjusted at pH 7.5 destroys 55.9% of capacity at the design feed. The blueprint gives dimensions and layout, a bill of materials in generic specification classes, an assembly and commissioning sequence, the operating envelope, critical fits tied to the source figures, failure modes and mitigations, a maintenance schedule, and the measurements a first build must make — above all effluent fluoride and aluminium at the working point. Nothing has been built or measured; every derived quantity is reproducible from the accompanying compute.py.