Theobroma cacao agro-industrial waste (WTC) has been characterized and tested as an effective biosorbent to remove Cd(II) from aqueous media. At the optimum pH of 5.0, a maximum adsorption capacity of q_e,max = 58.5 mg g⁻¹ was determined. The structural and morphological characterization have been conducted by FTIR, SEM/EDX, and TGA measurements. The SEM/EDX results confirmed that the metals are adsorbed on the surface. C-O-C, OH, CH, NH, and C=O functional groups were identified by FTIR. TGA results were consistent with the presence of hemicellulose. Biosorption kinetics were rapid during the first 30 min and then reached equilibrium. The corresponding experimental data were well fitted to pseudo-first and -second order models, the latter being the best. The biosorption isotherm data were also well fitted to Temkin, Langmuir, and Freundlich models, showing that several sorption mechanisms may be involved in the Cd(II) biosorption process, which was characterized as exothermic (ΔH⁰ < 0), feasible, and spontaneous (ΔG⁰ < 0). In binary (Cd–Pb and Cd–Cu) and ternary (Cd–Pb–Cu) systems, Cu(II) and particularly Pb(II) co-cations exert strong antagonistic effects. Using HNO₃, effective good regeneration of WTC was obtained to efficiently remove Cd(II) up to three times.

This study quantifies long-term surface urban heat island (SUHI) dynamics (2001–2016) in three climatically diverse South American metropolises—Buenos Aires (temperate), Bogotá (tropical highland), and Lima (arid coastal)—using MODIS data (0.05° resolution), comparing Streutker’s Gaussian model with a quantile-based approach (SUHI = 95th urban LST percentile—rural LST median). Method performance varied with surface heterogeneity: Gaussian modeling underestimated SUHI in coastal cities (nocturnal bias = +1.5 °C in Buenos Aires; R² ≤ 0.17 in Lima) due to non-Gaussian LST distributions driven by oceanic moisture advection, while quantile-based estimation proved robust in complex terrains (Bogotá agreement: day R² = 0.67, night R² = 0.53). Distinct SUHI signatures emerged: Buenos Aires exhibited stronger nocturnal SUHI (max 3.79 °C, linked to reduced rural evaporative cooling), Lima showed winter daytime Urban Cool Islands (−1.5 °C) from higher heat absorption in semi-desert surroundings, and Bogotá peaked in October (7.27 °C daytime SUHI) with altitudinal suppression of convective rainfall. Vegetation strongly modulated surface fluxes, with urban NDVI/EVI correlations (R² ≤ 0.29) confirming evaporative regulation’s role in halving thermal amplitudes (10 °C urban vs. 5 °C rural), while rural coupling varied with moisture availability (R² ≤ 0.65). Coastal proximity and elevation were key divergence drivers, disrupting surface energy partitioning. We recommend quantile methods for moisture-heterogeneous regions and advocate hydrometeorologically informed mitigation: optimizing green infrastructure for latent heat flux (Buenos Aires), leveraging nocturnal drainage flows (Bogotá), and integrating natural cool-island dynamics into water-sensitive design (Lima).

In the annex of Viñas, Pampas district, Tayacaja Province, Huancavelica department, Peru, they lack the benefit of a drinking water treatment plant and consume water directly from the river, which is also used for livestock and agricultural activities, and waste is dumped, Therefore, the...