Removal of lead and chromium from solution by organic peels: effect of particle size and bio-adsorbent

Efficient removal of Cr(VI) contaminant using recoverable silica from volcanic ash as natural adsorbent: Synthesis and activity in the mechanism and kinetic adsorption

Modification of silica purified from the Merapi volcanic ash with magnetic material of Fe3O4 and attachment of cetyl triamine bromide (CTA-Br) on the magnetic cored has been performed to provide recoverable and positive surfaced of natural adsorbent. The magnetic cored was prepared via co-precipitation and CTA-Br attachment was conducted by a facile strategy. Then, the modified adsorbents were characterized by SEM, TEM, XRD, and FTIR instruments and examined for removing anionic Cr(VI) from the water media. The characterization data confirmed that crystals of Fe3O4 coated by SiO2 that has been bound with CTA-Br have been successfully formed. Additionally, increasing CTA-Br loaded gives thicker lamination on Fe3O4@SiO2/CTA-Br, but the CTA-Br loaded with higher than 0.25 mmol, leads to the coating peeled out. It is also demonstrated that Fe3O4@SiO2/CTA-Br prepared with CTA-Br 0.25 mmol is ideal for Cr(VI) anionic removal, regarding to the highest adsorption and very good separation or recovery process. Moreover, the optimal dose of Fe3O4@SiO2/CTA-Br in the Cr(VI) removal was observed at 0.25 g/20 mL under condition of pH 3 for 60 min. The adsorption of Cr(VI) well fits the Langmuir isotherm model with an adsorption capacity of 3.38 mg g-1 and is in a good agreement with pseudo-second order giving kinetic constant at 0.005 g mg-1 min-1. Thus, it is clear that the natural adsorbent material with recoverable properties for more efficient and wider application of removal Cr(VI) contaminant was expected from this study.

Phytochemistry, nutritional composition, health benefits and future prospects of Passiflora: A review

Passiflora, also known as "passion fruit", is widely grown in tropical and subtropical regions. It is not only eaten raw but is also widely used in processed foods. Various extracts, juices and isolated compounds show a wide range of health effects and biological activities, such as antioxidant, anti-inflammatory, sedative, and neuroprotective effects. In this review, we not only review the phytochemical properties of Passiflora but also highlight the potential of Passiflora for food applications and the use of all parts as a source of ingredients for medicines and cosmetics that promote health and well-being. This will provide theoretical support for the integrated use of such natural products.

A review of important heavy metals toxicity with special emphasis on nephrotoxicity and its management in cattle

Toxicity with heavy metals has proven to be a significant hazard with several health problems linked to it. Heavy metals bioaccumulate in living organisms, pollute the food chain, and possibly threaten the health of animals. Many industries, fertilizers, traffic, automobile, paint, groundwater, and animal feed are sources of contamination of heavy metals. Few metals, such as aluminum (Al), may be eliminated by the elimination processes, but other metals like lead (Pb), arsenic (As), and cadmium (Ca) accumulate in the body and food chain, leading to chronic toxicity in animals. Even if these metals have no biological purpose, their toxic effects are still present in some form that is damaging to the animal body and its appropriate functioning. Cadmium (Cd) and Pb have negative impacts on a number of physiological and biochemical processes when exposed to sub-lethal doses. The nephrotoxic effects of Pb, As, and Cd are well known, and high amounts of naturally occurring environmental metals as well as occupational populations with high exposures have an adverse relationship between kidney damage and toxic metal exposure. Metal toxicity is determined by the absorbed dosage, the route of exposure, and the duration of exposure, whether acute or chronic. This can lead to numerous disorders and can also result in excessive damage due to oxidative stress generated by free radical production. Heavy metals concentration can be decreased through various procedures including bioremediation, pyrolysis, phytoremediation, rhizofiltration, biochar, and thermal process. This review discusses few heavy metals, their toxicity mechanisms, and their health impacts on cattle with special emphasis on the kidneys.

Removal of As(V) and Cr(VI) with Low-Cost Novel Virgin and Iron-Impregnated Banana Peduncle-Activated Carbons

This work reports the investigation of activated carbons from virgin banana peduncle (ZR1) and iron-impregnated banana peduncle (ZR2) as adsorbents for the removal of As(V) and Cr(VI) ions from aqueous solutions. Both adsorbents were characterized through the point of zero charge, powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray, Brunauer-Emmett-Teller, and Fourier transform infrared spectroscopic techniques. The effects of initial pH, contact time, temperature, and initial concentration on metal ion adsorption were investigated. Adsorbents existed as both crystalline and amorphous species having homogeneous surface cavities and surface area of 749.73 and 369.66 m²/g for ZR1 and ZR2, respectively. The maximum As(V) removal of 79.32 and 69.08% was obtained using ZR1 and ZR2, respectively, whereas the maximum Cr(VI) removal was calculated as 69.73% for ZR1 and 73.78% for ZR2. Kinetic modeling data were found to be best fitted for the pseudo-second-order reaction, and rate constants were calculated. The theoretical adsorption capacities (q _m) of ZR1 and ZR2 were calculated through Langmuir and Freundlich models. The maximum As(V) adsorption capacities calculated for ZR1 and ZR2 were 13.33 and 9.066 mg/g, respectively, whereas the maximum Cr(VI) adsorption capacity for both was 13.26 mg/g at 298-328 K. The reaction was endothermic with decreased randomness at the solid-liquid interface due to positive entropy and enthalpy values. All kinetic and thermodynamic parameters showed the feasibility of the adsorption process, and characterization after adsorption indicated ZR1 and ZR2 novel activated carbons as efficient and cheapest biosorbents for removing As(V) and Cr(VI).