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The objective of the present study was to gather information on the effects of liming on changes in soil physical attributes. Soil acidity, caused by natural ways, such as rain, weathering and decomposition of organic matter and by human interference, by the use of nitrogen fertilizer mainly ammonia and urea fertilizer contribute to the acidification of the soil. In this context liming is perform to correct soil pH and neutralize the effect of toxic elements. Numerous benefits of liming are known, but their influence on soil physical attributes is poorly studied. Liming directly affects some physical properties of the soil, such as flocculation, aggregates, density and porosity. Flocculation of soil particles initially is smallest, which promotes greater particle dispersion. However, it changes over time, since H+ and Al3+ ions tend to be subsumed by Ca2+ and Mg2+ increasing particle flocculation power which favors its approximation and aggregate formation. For soil aggregates, surface liming in improves soil aggregation by increasing the mean aggregate diameter with positive responses as dose increases. Density and porosity of soil also undergo changes. It is important to point out that liming also has the potential to alter the porous structure of the soil. Porosity liming promotes soil density reduction and increase influenced reducing macroporosity values and increase of total porosity and micropores values. The results of studies carried out present divergent and similar results according to the evaluated physical attributes. This is possibly due to the dynamics between liming under different edaphoclimatic conditions.

The pollution of water has been one of the greatest problems faced by the modern society, due to industrialization and urban growth. Rivers, lakes and seas have been continually suffering from the rising concentration of various pollutants, especially toxic elements. This study aimed to evaluate the use of cashew nut shell (Anacardium occidentale) (CNS), after chemical modification with H 2 O 2 , H 2 SO 4 and NaOH, as an new and renewable adsorbent material, for the removal of metals Cd 2+ , Pb 2+ and Cr 3+ in aqueous medium. The adsorbents were characterized by its chemical constitution, structure, infrared spectroscopy, morphology, by means of scanning electron microscopy, determination of the point of zero charge, thermogravimetrical analysis and porosimetry assessments. Tests were conducted to determine the optimal conditions (pH vs. adsorbent mass) for adsorption, by means of multivariate analysis using a central composite design. The adsorption kinetics was evaluated by models of pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion, while adsorption isotherms were linearized by Langmuir, Freundlich and Dubinin-Radushkevich. The effect of initial concentration, temperature and desorption was also performed. The adsorbents exhibited irregular, spongy and heterogeneous structure. FTIR analysis confirms the presence of hydroxyl, aliphatic, phenolic and carboxylic acid groups, which are favorable adsorption characteristics. The pH PZC of adsorbent is 4.35, 2.50 e 6.92, respectively, for CNS H 2 O 2 , H 2 SO 4 and NaOH. The optimum adsorption conditions were as follows: pH 5.0; relation of adsorbent mass/volume of water: 4 g L −1 ; 40 min of contact time for reaching the equilibration. Results suggest the predominance of chemisorption of Cd 2+ and Cr 3+ . Most of biosorbents exhibited good fit by Langmuir and Freundlich, suggesting the occurrence of adsorption on mono-and multilayers. The adsorbents of cashew nut shell exhibited high removal efficiency of Cd, Pb and Cr from waters.

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The aim of this work was to evaluate the removal of Cd (II) from water using three biosorbents originated from the biomass of jatropha (bark, endosperm, and endosperm ? tegument). For that, batch tests were performed to verify the effect of solution pH, adsorbent mass, contact time, initial concentration of Cd (II), and the temperature of the process. The adsorption process was evaluated by the studies of kinetics, isotherms, and thermodynamics. The ideal conditions of solution pH were 5.5 and 8 g L-1 of adsorbent mass of biosorbents by solution volume, with an equilibrium time of 60 min. According to the Langmuir model, the maximum adsorption capacity for bark, endosperm, and bark ? endosperm of jatropha was, respectively, 29.665, 19.562, and 34.674 mg g-1 , predominating chemisorption in monolayers. The biosorbents presented potential for the remediation of waters contaminated with Cd (II).

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