Marcelo Angelo Campagnolo

Chemical Modifications of Cassava Peel as Adsorbent Material for Metals Ions from Wastewater

Residues from the processing of cassava roots (Manihot esculenta Crantz), or cassava peels, are evaluated as chemically modified adsorbents with H2O2, H2SO4, and NaOH, in the removal of metal ions Cd(II), Pb(II), and Cr(III) from contaminated water. Modified adsorbents were chemically characterized for their chemical composition and (point of zero charge), while adsorption tests determined the best conditions of pH, adsorbent mass, and contact time between adsorbent and adsorbate in the process of removal of the metal ions. Isotherms obtained from the preliminary results were linearized by Langmuir’s and Freudlich’s models. The thermodynamic parameters, such as , , and , were also evaluated. The modifying solutions proposed were effective in the modification of adsorbents and resulted in high capacity sorption materials. Equilibrium time between adsorbent and adsorbate for the solutions contaminated with metals is about 40 minutes. The Langmuir model adjusted to most results, indicating monolayers adsorption of Cd(II), Pb(II), and Cr(III). The values obtained for Langmuir show a higher adsorption capacity caused by chemical modifications, with values such as 19.54 mg Cd(II) per g of M. NaOH, 42.46 mg of Pb(II) per g of M. NaOH, and 43.97 mg of Cr(III) per g of M H2O2. Results showed that modified cassava peels are excellent adsorbent, renewable, high availability, and low-cost materials and a feasible alternative in the removal of metals in industries.

Adsorption of Cu (II) and Zn (II) from Water by Jatropha curcas L. as Biosorbent

Abstract The objective of this work was to evaluate the removal of Cu2+ and Zn2+ in water by means of the adsorption process using three biosorbents derived from jatropha biomass (bark, endosperm and endosperm + seed coat). The experiments were performed in batch and evaluated the effect of solution pH, adsorbent mass, contact time, different initial concentrations of the metals Cu2+ and Zn2+, and the temperature of the solution during the adsorptive process. By kinetics, the adsorption isotherms and thermodynamics the mechanisms that control the adsorptive process were evaluated. The optimal conditions for the realization of the adsorptive process for both metals were: solution pH of 5.0 and 8 g L-1 of adsorbent mass per volume of solution, with a contact time between adsorbent and adsorbate of 60 min. According to the Langmuir model, the maximum adsorption capacities for the bark, endosperm and endosperm + seed coat of Jatropha were, respectively, for Cu2+ 11.541, 20.475 and 22.910 mg g-1, and for Zn2+ 14.852; 15.888 and 14.674 mg g-1, with the predominance of chemisorption in monolayer. The three biosorbents derived from the biomass of Jatropha have potential for the remediation of water contaminated with Cu2+ and Zn2+.

Sobrevivência e crescimento do pinhão-manso em função do método de aplicação e formulações de hidrogel

This study compared the effects of formulations and methods of hydrogel application on the survival and initial seedling growth of physic nut (Jatropha curcas L.). The study was conducted in Pato Bragado, PR during 2009 and 2010. The experimental design was in randomized blocks, arranged in a 5 x 2 factorial composed by five formulations of hydrogel (0, 2.5, 5.0, 7.5, and 10.0 g L-1) and two application methods (immersion of roots into hydrogel previously hydrated and application of 0.5 L directly in the planting hole). Measurements included the percentage of survival, seedling height and diameter increments, and number of branches three and eighteen months after planting. The analysis with three months data revealed significant effects (p 0.05) was observed for the application methods or hydrogel formulations. The use of 0.5 L of a 7.0 g L-1 of hydrogel directly into the planting hole favored significantly the establishment of physic nut seedling and formulations above the suggested concentration reduced seedling growth in western Parana.

SOBREVIVÊNCIA E CRESCIMENTO INICIAL DE PINHÃO-MANSO EM FUNÇÃO DA ÉPOCA DE PLANTIO E DO USO DE HIDROGEL

The experiment aimed to compare the effect of hydrogel use and seasonal planting on the survival and initial growth of Jatropha curcas L. seedlings in western Parana state. Treatments included planting of seedlings from three provenances of physic nut (Pedro J. Caballero, Nova Porteirinha and Janauba) subjected or not to root immersion in hydrogel (5.0 g L-1) and four planting seasons (spring, summer, autumn and winter). The experimental used a randomized block design with five repetitions for each planting season. Ninety after planting, the effect of the polymeric hydrogel was quantified by the percentage of survival while the initial growth used morphometric variables such as the increment in seedling height, stem diameter, number of leaves, leaf area, and specific leaf area. The results indicated that root immersion in hydrogel increased percentage of seedling survival for the spring planting season in 6.7%. The use of hydrogel did not propitiate the growth increase especially for the winter planting season. However, a larger growth increase was obtained for the spring planting of Pedro J. Caballero and Nova Porteirinha provenances.

Enraizamento de estacas apicais de figueira Roxo de Valinhos submetidas à estratificação a frio úmido e AIB

Na producao de mudas de figueira a utilizacao de estacas apicais de menor comprimento pode facilitar o manejo no viveiro, entretanto ainda nao foram definidos os protocolos para enraizamento desse tipo de estaca. O objetivo do presente trabalho foi avaliar a acao da estratificacao a frio umido e do tratamento com AIB na rizogenese de estacas apicais de figueira Roxo de Valinhos. As estacas foram coletadas da porcao apical dos ramos no final do periodo hibernal (julho) e padronizadas com 20 cm de comprimento e diâmetro aproximado de 0,7 cm. As estacas foram estratificadas (estacas embrulhadas em jornal umedecido e protegidas com saco plastico a temperatura de 4 oC, em câmara tipo BOD) por diferentes periodos (0, 15, 30, 45 e 60 dias) e, posteriormente, tratadas e nao tratadas com 2.000 mg L-1 de AIB por 10 segundos. Em seguida, as estacas foram enterradas em leito de areia umedecido sob telado constituido de tela de polipropileno preta (sombreamento de 50%). Passados 60 dias de cada periodo de estratificacao, foram mensuradas a percentagem de estacas enraizadas, a percentagem de estacas brotadas e o numero medio de brotacoes e de raizes por estaca. Conclue-se que as estacas apicais de figueira Roxo de Valinhos estratificadas a frio umido por 30 dias e posteriormente tratadas com 2.000 mg L-1 de AIB apresentaram maior potencial de rizogenese.