Reutilization of waste biomass from sugarcane bagasse and orange peel to obtain carbon foams: Applications in the metal ions removal.

The high levels of heavy metals contained in residual water and the pollution generated by a large amount of unexploited agro-industrial waste are a serious problem for the environment and mankind. Therefore, in the present work, with the aim of treating and reducing the pollution caused by heavy metal ions (Pb, Cd, Zn and Cu), activated carbons (ACs) were synthesized from sugarcane bagasse (SCB) and orange peel (OP) by means of physical - chemical activation method in an acid medium (H3PO4, 85 wt%) followed by an activation at high temperature (500 and 700 °C). Thereafter, these materials were used to produce carbon foams (CF) by the replica method and to evaluate their adsorbent capacity for the removal of heavy metals from synthetic water. XRD, FTIR, DLS, BET, Zeta Potential (ζ), SEM-EDS and AAS were used to investigate their structures, surface area, pore size, morphology, and adsorption capacity. The results show that as-prepared CF have a second level mesoporous structure and AC present a micro-mesoporous structure with a pore diameter between 3 and 4 nm. The experimental adsorption capacities of heavy metals showed that the CF from OP present a better elimination of heavy metals compared to the AC; exhibiting a removal capacity of 95.2 ± 3.96% (Pb) and 94.7 ± 4.88% (Cu) at pH = 5. The adsorption values showed that the optimal parameters to reach a high metal removal are pH values above 5. In the best of cases, the minimum remaining concentration of lead and copper were 2.4 and 2.6 mg L-1, respectively. The experimental data for carbon adsorbents are in accordance with the Langmuir and BET isotherms, with R2 = 0.99 and the maximum homogenous biosorption capacity for lead and copper was Qmax = 968.72 and 754.14 mg g-1, respectively. This study showed that agro-industrial wastes can be effectively retrieved to produce adsorbents materials for wastewater treatment applications.

Data that support the use of agro-industrial residues from orange peel and sugarcane bagasse for the production of carbonaceous structures and their application in the removal of metal ions.

This document contains additional information for the production of activated carbons (AC) and carbon foams (CF) from agroindustrial wastes, orange peel (OP) and sugarcane bagasse (SCB). In particular, a set of data is presented for the characterization of carbonaceous structures (AC and CF) and their application in the removal of metallic ions contained in polluted waters. The adsorbent materials were obtained combining chemical and physical activation processes. Data presented here included characterization of AC and CF using dynamic light scattering (DLS), BET (Brunauer, Emmet and Teller) surface area analysis, Barrett-Joyner-Halenda (BJH) method to assess pore size distribution and zeta potential (ζ) to evaluate electrokinetic potential of carbonaceous structures. In addition, energy dispersive spectroscopy (SEM/EDS) to identify heavy metals on the surface of carbonaceous materials is shown and complementary adsorption capacity data for metal ion removal are presented in the paper. The data can be used as a reference to promote reuse of agroindustrial wastes and provide added value; particularly for the synthesis of carbonaceous structures applied to the water purification.

Observer agreement in toenail disorders: implications for diagnosis and clinical research.

BACKGROUND: Toenail disorders are frequent, especially onychomycosis. The interobserver variability of nail signs needs to be known before these signs can be confidently applied for diagnosis. OBJECTIVES: To describe observer agreement in toenail findings as described by dermatologists in standard clinical practice, focusing on signs that could be useful for diagnosis of onychomycosis. METHODS: Prospective cross-sectional study in five dermatology departments. Eighty-six patients with abnormal toenails that could have onychomycosis as a differential diagnosis were independently examined by a pair of dermatologists using a predefined questionnaire, to describe the presence of 10 findings on previous history and 14 physical signs. RESULTS: Agreement was fine for previous history findings: it was very good (kappa > 0.81) for previous diagnosis of diabetes, smoking and use of public dressing rooms or swimming pools. Agreement was good (kappa 0.61-0.80) for immune suppression (drugs or cancer), previous diagnosis of fungal disease and worsening in the last year. It was moderate (kappa 0.41-0.60) for previous diagnosis of arterial disease, trauma induced by work or sports, and distal vs. proximal or lateral vs. central start of the lesion. Agreement was worse for physical signs: we found good agreement for the presence of the same disease in fingernails, abnormal plantar desquamation, deformity causing nail trauma, and subungual hyperkeratosis. It was moderate for the presence of nail destruction, tinea interdigitalis, onycholysis, and the type of material obtained by subungual curettage (dust vs. hard). Agreement was fair (kappa 0.21-0.40) for the presence of longitudinal or transverse striae, trachyonychia, pachyonychia, and change in colour of the nail plate. Pitting was too infrequent to allow for kappa calculation. Chance expected agreement was between 51% and 84% for all signs except pitting. CONCLUSIONS: Agreement is adequate for most signs. It is low for the presence of longitudinal or transverse striae, trachyonychia, and change in colour of the nail plate. Pitting is rare in toenails.

Hydrogen peroxide and flavan-3-ols in storage roots of cassava (Manihot esculenta crantz) during postharvest deterioration.

Cassava storage roots are an important staple food throughout the lowland humid tropics. However, cassava suffers from a poorly understood storage disorder, known as postharvest physiological deterioration (PPD), which constrains its exploitation. In an attempt to broaden the understanding of PPD, nine different cassava cultivars were analyzed for specific compounds accumulating during the process. The production of hydrogen peroxide (H(2)O(2)) is involved in the early stages of PPD in cassava roots. H(2)O(2) was quantified and localized histochemically at the tissue and cell level in deteriorating roots. This reactive oxygen species accumulated during the first 24 h after harvest, especially in the inner parenchymatic tissue. Three flavan-3-ols, (+)-catechin, (+)-catechin gallate, and (+)-gallocatechin, accumulated during the storage of cassava roots. However, these potential antioxidants cannot be related to early storage disorders or wound responses because they start to accumulate only after 4-6 days.