Synthesis of Curcumin Nanoparticles from Raw Turmeric Rhizome

Turmeric (Curcuma longa L.) has been used as a spice and a medicinal herb since ancient times. The main active ingredient of turmeric is curcumin, a polyphenol that helps prevent and control neurological, respiratory, cardiovascular, metabolic, inflammatory, and autoimmune diseases and some cancers. However, curcumin has drawbacks such as low water-solubility, poor absorption, fast metabolism, quick systemic elimination, low bioavailability, poor pharmacokinetics, low stability, and low penetration targeting efficacy. To overcome these drawbacks, a common method used is encapsulating curcumin in nanocarriers for targeted delivery. However, the degraded products of nanocarriers have raised concerns. In this research, we synthesized nanoparticles of curcumin, nanocurcumin without using nanocarriers. To do so, curcumin was soxhlet extracted from raw turmeric rhizome. The stock solutions of different curcumin concentrations prepared in dichloromethane were added to boiling water at different flow rates and sonicated for different time intervals. An average particle size of 82 ± 04 nm was obtained with 5.00 mg/mL stock solution concentration, at 0.10 mL/min flow rate and 30 min sonication time. The particle size tends to increase with the flow rate and the concentration of curcumin in the stock solution but decreases with the sonication time. X-ray diffraction shows sharp and intense diffraction peaks for curcumin, indicating its identity and high crystallinity, but nanocurcumins are amorphous. Fourier-transform infrared spectroscopy spectra confirm the presence of all the functional groups of curcumin in nanocurcumin. Transmission electron microscopy and scanning electron microscopy images show the perfectly spherical morphology of nanocurcumin. Although curcumin is not water-soluble, nano-curcumin formulations are freely dispersible in water.

Removal of uranium(VI) from water using hydroxyapatite coated activated carbon powder nanocomposite

Synthesis of hydroxyapatite coated activated carbon nanocomposite was carried out by in-situ chemical precipitation method. Different characterizations confirm that, hydroxyapatite successfully coated over activated carbon powder. Extensive sorption studies of U(VI) on the nanocomposite were conducted to know the effect of contact time, humic acid, carbonate, ionic strength and pH. The study revealed that, the composite material is a more efficient sorbent for U(VI) compared to precursors, which removes U(VI) ion without altering physicochemical properties of water. Sorption exhibits multilayer adsorption on heterogeneous surface and follows chemisorptions. Practical applicability of the material was demonsteted by spiking tap water with U(VI) ion at three different initial concentrations (50, 100 and 150 µg L^-1) and the tap water was allowed to passed through a cartridge packed with composite. It was observed that, the concentration of U(VI) ion in eluted water reduced to 98.28%, 96.20% and 97.40%, respectively. This revealed that, the material possesses a huge potential for sequestrating dissolved U(VI) ion and can be used as alternate filtering material for dissolved U(VI) in complex natural water system.

Carbon Nanomaterials for the Treatment of Heavy Metal-Contaminated Water and Environmental Remediation

Nanotechnology is an advanced field of science having the ability to solve the variety of environmental challenges by controlling the size and shape of the materials at a nanoscale. Carbon nanomaterials are unique because of their nontoxic nature, high surface area, easier biodegradation, and particularly useful environmental remediation. Heavy metal contamination in water is a major problem and poses a great risk to human health. Carbon nanomaterials are getting more and more attention due to their superior physicochemical properties that can be exploited for advanced treatment of heavy metal-contaminated water. Carbon nanomaterials namely carbon nanotubes, fullerenes, graphene, graphene oxide, and activated carbon have great potential for removal of heavy metals from water because of their large surface area, nanoscale size, and availability of different functionalities and they are easier to be chemically modified and recycled. In this article, we have reviewed the recent advancements in the applications of these carbon nanomaterials in the treatment of heavy metal-contaminated water and have also highlighted their application in environmental remediation. Toxicological aspects of carbon-based nanomaterials have also been discussed.

Synthesis of multifunctional activated carbon nanocomposite comprising biocompatible flake nano hydroxyapatite and natural turmeric extract for the removal of bacteria and lead ions from aqueous solution

Clean water, which is free from pathogens and toxic chemicals, is vital to human health. The blue planet is encountering remarkable challenges in meeting the ever-increasing demands of clean water. The intention of this research study was to develop a water filter material that is capable of removing bacterial contaminants and heavy metals from fresh water using cost effective and easily fabricated biocompatible filter material. For this purpose, granular activated carbon (GAC) was coated with both hydroxyapatite (HAP) nanoflakes and turmeric extract (TE) (HAP/TE/GAC) which had been extracted from natural turmeric powder. In addition, GAC was coated only with HAP nanoflakes to synthesize HAP coated GAC (HAP/GAC) composite. Prepared HAP/GAC and HAP/TE/GAC were characterized using Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy and UV–visible spectrophotometry. Antibacterial effect of the prepared nanocomposites, HAP/GAC and HAP/TE/GAC was compared with neat GAC using Gram-negative bacteria Escherichia coli. Results showed that antibacterial studies of the synthesized nanocomposites exhibit effective antibacterial activity against E. coli compared with neat GAC alone. However, the composite HAP/TE/GAC revealed better activity than HAP/GAC. Heavy metal adsorption ability of the synthesized composites was carried out using Pb²⁺ ions at room temperature at different time intervals and different pH levels. The equilibrium adsorption data were assessed via Langmuir and Freundlich adsorption isotherm models for neat GAC, HAP/GAC and HAP/TE/GAC at pH 6. The equilibrium adsorption data for GAC, HAP/GAC and HAP/TE/GAC were well fitted with both Freundlich and Langmuir isotherm models in the given Pb²⁺ concentrations. The HAP/TE/GAC composite is capable of maintaining the natural function of GAC in addition to removal of bacterial contaminants and heavy metals, which can be used as a point-of-use water filter material.

Natural polysaccharides leading to super adsorbent hydroxyapatite nanoparticles for the removal of heavy metals and dyes from aqueous solutions

Water pollution has created a major impact on the environment mainly due to contaminated industrial effluents with toxic substances such as heavy metals and textile dyes.