Universal Forest Products

About: Universal Forest Products is a based out in . It is known for research contribution in the topics: Population & Adsorption. The organization has 1765 authors who have published 1391 publications receiving 8421 citations.

Organophilic bentonites obtained by microwave heating as adsorbents for anionic dyes

Abstract: Organobentonites were prepared using three cationic surfactants tetradecyl- (C14), hexadecyl- (C16) and octadecyltrimethylammonium (C18) bromides in the proportions of 100% and 200% of the cationic exchange capacity (CEC) at 323 K under microwave irradiation for 5 min. The XRD patterns indicated the formation of intercalated hybrids with d values in the range 1.83–2.00 nm. CHN elemental analysis showed better organofunctionalization of the clay matrix for the organobentonites obtained with 200% of the CEC and longer organic alkyl chains and agreed with thermogravimetric analysis. Infrared spectroscopy suggested the presence of the organic moieties on organobentonites, showing typical absorptions of CH2 and CH3 groups. The solids were applied for Remazol blue RN dye removal from a single and synthetic effluent sample. The influences of the pH, adsorbent dosage, contact time and initial dye concentration were systematically investigated. The data were fitted to different kinetic and equilibrium models. All of the adsorption processes were adjusted to pseudo-second order and Langmuir models. The organobentonites showed good performance in dye removal at a pH of 2 for the solids obtained with 100% of the CEC, and the dye removal was independent of the pH for the other solids, which is in agreement with the zeta potential measurements. The optimal reaction time was 60 min, except for Bent-C16-200%. The best dye removal efficiency (100%–211 mg g−1) for the Bent-C14-200% sample with 500 mg/L of dye concentration.

Biomassa microbiana e estoques de C e N do solo em diferentes sistemas de manejo, no Cerrado do Estado do Piauí

Abstract: The aim of this study was to verify the effects of different soil tillage systems on microbial biomass and the total organic C and N stocks in an Oxisol. The soil tillage systems evaluated were: no-tillage (PD) and conventional tillage (PC). A deforested area (ARD) and another with native vegetation (AVN) were used as references. The soil samples were collected in the 0-5, 5-10 and 10-20 cm depths, and in these soil samples were quantified the contents and total stocks of C and N, basal respiration, microbial biomass C (Cmic), and microbial (Cmic/COT) and metabolic (qCO2) quotients. The values of microbial biomass C (Cmic) in the soil under PD were higher than those observed in PC and ARD in all depths. The area under no-tillage (PD) showed larger contents of C and N, and stocks of C on the surface of the soil. For the stocks of N, there were no differences among the evaluated areas, in all depths. No-tillage adoption provides an increase in the soil microbial biomass and total C and N stocks, indicating improvement in soil quality.

Estimativas de parâmetros genéticos em genótipos de feijão-caupi avaliados para feijão fresco

Abstract: The aim of this work was to estimate genetic parameters in traits associated with the production of fresh southern pea in 14 cowpea genotypes of purple pod and white grains. Three experiments were carried out: two under irrigation (2004 and 2005) and one in rainfed conditions (2005), at Embrapa Mid-North experimental field, in a randomized complete block design with four replications. The correlations, genetic variation and determination coefficients were estimated for the following traits: number of days for the harvest of fresh seed (NDHFS), fresh pod length (FPL), number of seeds for fresh pod (NSFP), weight of one hundred fresh seed (WHFS), fresh pod yield (FPY), fresh seed yield (FSY), fresh seed index (FSI), value of crop (VC) and plant type (PT). The genotypic correlations were superior to phenotypic and environment correlations, being distinguished the correlations between VC and FPY (100%). The genetic variation coefficient varied from 6.58% (FSI) to 31.62% (FSY), with highlight also for FPY (30.16%). All characters showed high genetic component in the expression of the character, with highlight for the FPL (98.72%). There is a high genetic component in the phenotypic expression of all the traits studied, with a high probability of genetic gains in additional cycles of selection based on phenotype. Selection of cowpea genotypes for high yield and early is easier than selection of genotypes with high yield and late in the fresh southern pea breeding.

Potential of Cellulose Functionalized with Carboxylic Acid as Biosorbent for the Removal of Cationic Dyes in Aqueous Solution

Abstract: In the last decade, adsorption has been used to minimize the pollution caused by dyes, which represents a serious environmental problem. In this context, this work reports the preparation of phthalic anhydride-modified cellulose (PhCel), through the reaction of cellulose (Cel) with phthalic anhydride (Ph). The efficiency of the reaction was observed by elemental analysis, Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermogravimetry/derivative thermogravimetry (TG/DTG). The adsorbent matrix (Cel and PhCel) was used in the removal of crystal violet (CV) and methylene blue (MB) dyes in aqueous medium. In the kinetic study, the experimental data obtained had the best fit to the pseudo-first-order model. In general, the isotherms obtained at different temperatures had a best fit to the model proposed by Langmuir, and the CV and MB adsorption process in adsorbent matrixes can be favored strictly by hydrogen bonds and/or electrostatic interactions for Cel and electrostatic interactions for PhCel.