Preparation and characterization of nanomuscovite by intercalation method for adsorption of heavy metals from polluted water.

In this study, nanomuscovite adsorbents were prepared by intercalation with various organic intercalates (DTAB-TTAB-DTPA-PA-PN) and used to remove Cd2+ and Pb2+ from polluted water. The best nanomuscovite was prepared using DTPA and muscovite (Muc/DTPA) and characterized by XRD, TEM, EDX, FTIR, and BET surface area. The developed nanoadsorbent was used to remove Cd2+ and Pb2+ from polluted water. The effect of various factors, including contact time, adsorbent dosage, solution pH, and temperature, was investigated. The results reveal that the maximum adsorption of Cd2+ and Pb2+ was 91.5% and 97%, respectively, at the initial metal concentration 50 ppm, adsorbent dosage 0.2 g, contact time 60 min, solution temperature 25 °C, and pH 6 for Pb2+ and pH 7 for Cd2+. Adsorption isotherm models (Freundlich, Langmuir, Dubunin-Radushkevich, and Temkin isotherm models) as well as kinetic models (pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion models) were employed to evaluate the experimental results. The adsorption of Cd2+ and Pb2+ on Muc/DTPA fitted well within the Langmuir isotherm model and followed pseudo-second-order kinetics. Thermodynamics parameters of metal adsorption indicated exothermic and spontaneous processes. Results were applied to the real wastewater that showed high Cd2+ and Pb2+ removal.

Bioenvironmental Trace Elements in Warm Climatic Plant, Pigeon Pea (Cajanus cajan).

Bioenvironmental trace elements play a vital role in plant, animal, and man metabolism. This study aims to determine trace element concentration in different parts (pods, pericarp, seeds, cotyledon, and taste) of the warm climate plant pigeon pea (Cajanus cajan L. Millsp.). The pigeon pea pods were collected from the farms on the shore of the High Dam Lake, Egypt. Elements (Ag, Au, Co, Cr, Sr, Fe, Cu, Ni, Mn, and Zn) in the pods and its different parts were determined by an atomic absorption spectrophotometer. Statistical analysis (cluster, Pearson correlation coefficient, and factor analysis) was applied to trace elements in different parts of pigeon pea. The results reveal that seeds exhibited the highest concentrations of Cu, Ni, Cr, and Zn, while Ag, Co, Pb, and Fe in the pods. Factor and cluster analyses explain a good relationship among the trace elements in pigeon pea. Also, transfer factor of the elements between plant and soil shows that the high transfer factor of most elements was observed for pods and pericarp. The studied elements in the pods and its different parts were in the safety baseline levels for both man and animal uses.

Adsorption and photocatalysis for methyl orange and Cd removal from wastewater using TiO2/sewage sludge-based activated carbon nanocomposites.

Nanocomposite TiO2/ASS (TiO2 nanoparticle coated sewage sludge-based activated carbon) was synthesized by the sol-gel method. The changes in surface properties of the TiO2/ASS nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence. The prepared TiO2/ASS nanocomposite was applied for simultaneous removal of methyl orange dye (MO) and Cd2+ from bi-pollutant solution. The factors influencing photocatalysis (TiO2 : ASS ratios, initial pollutant concentrations, solution pH, nanocomposite dosage and UV irradiation time) were investigated. The results revealed that high removal efficiency of methyl orange dye (MO) and Cd2+ from bi-pollutant solution was achieved with TiO2/ASS at a ratio (1 : 2). The obtained results revealed that degradation of MO dye on the TiO2/ASS nanocomposite was facilitated by surface adsorption and photocatalytic processes. The coupled photocatalysis and adsorption shown by TiO2/ASS nanocomposite resulted in faster and higher degradation of MO as compared to MO removal by ASS adsorbent. The removal efficiency of MO by ASS adsorbent and TiO2/ASS (1 : 2) nanocomposite at optimum pH value 7 were 74.14 and 94.28%, respectively, while for Cd2+ it was more than 90%. The experimental results fitted well with the second-order kinetic reaction.

Animal hair as biological indicator for heavy metal pollution in urban and rural areas.

Animal hair is a good biomonitoring tool for heavy metals assessment and reflects the content of heavy metals in the forage and soil. Heavy metals Fe, Mn, Co and Ni as well as toxic metals Cd and Pb were determined in goat, sheep and camel hair, forage and soil collected from four different environmental urban and rural regions. These regions are Aswan city farms, Allaqi desert pasture, Kalabsha farms and Halaiub desert pasture at far south of Egypt. The results reveal that sheep hair contains the highest levels of Fe and Mn (879 and 55 microg/g, respectively), camel hair contains the highest Pb, whereas for goat Cd and Ni were the highest. Heavy metal concentrations in the studied hair reflect the presence of these metals in the surrounding forage and soil and vary from one area to another, and give knowledge of pollution in the area. Correlation statistics analysis and cluster analysis show a good and significant value between metals in hair and plants.