Application of adsorbents derived from waste in contaminated areas remediation is aligned with sustainable development goals and circular economy principles. As chemical activation can result in increased adsorption capacity, it is an alternative to improve the performance of materials and enable their use. This study evaluated whether activated compost derived from the organic fraction of municipal solid waste would be an efficient and low-cost adsorbent. Chemical activation was performed by impregnating 1 mol L-1 of phosphoric acid for 12 h at 25 °C. Characterization and batch equilibrium tests were carried out to confirm if chemical activation would positively affect the retention of lead (Pb) and cadmium (Cd). Surface functional groups and minerals were verified through Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffractometry (XRD) before and after batch equilibrium test. Removal percentages ranged from 52.49 to 91.22% for Pb (initial concentrations of 20.11 to 889.20 mg L-1) and from 13.33 to 87.13% for Cd (initial concentrations from 1.56 to 667.50 mg L-1). Compared to the original material, activation did not increase Cd adsorption capacity. However, was observed an improvement in adsorption performance for Pb between 76.86 and 443.30 mg L-1. The Langmuir isotherm best fitted the experimental data obtained both for Pb and Cd.

Erosión es un problema crítico en todo el mundo. Este documento evalúa las interacciones de los usos del suelo con la dinámica macroscópica y propiedades microscópicas del suelo frente a la susceptibilidad su erosión. Examinamos la reativación de una cárcava recuperada en la ciudad de Nazareno (Brasil), comparando la evaluación de campo con experimentos de laboratorio utilizando dos tipos de suelo (suelo bien desenvuelto y granito-gneiss saprolito). Ambos demostraron que el comportamiento macroscópico de los suelos esta relacionado con las características microscópicas. Suelo bien desenvuelto es más resistente a la erosión que granito-gneiss saprolito, pero los usos de la tierra de los alrededores no respeta estas diferencias. Estos análisis han permitido explicar por qué este y otras cárcavas del municipio aparentemente se estabilizaron, pero las pierdas de suelo siguen ocurriendo. Se ha demostrado que la expansión urbana y rural desempeñó un papel importante en el desencadenamiento de estas erosiones y pierdas de suelo.

Gully erosion is a critical issue worldwide. To correctly understand the association that the environmental data (such as climate, vegetation cover, etc.) has with soil erosion susceptibility and land uses remains a challenge in land management. This paper evaluates land use interactions with macroscopic dynamics and microscopic soil properties in terms of soil's susceptibility to erosion. We examine the reactivation of a stabilized gully in Nazareno (Brazil) by comparing field assessments with laboratory experiments, using two types of soil (well-developed soil and granite-gneiss saprolite). Both of these showed that the macroscopic behavior of soils is connected with microscopic characteristics. Well-developed soil is more erosion resistant than granite-gneiss saprolite, but the surrounding land uses do not respect these differences. These analyses enable us to explain why this and other gullies in the municipality are apparently stabilized, but soil loss continues to occur. This paper demonstrates that urban and rural expansion played a major role in triggering gully and soil losses.