No abstract

Soil and water contaminated with RDX (hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine) pose a serious threat to the environment and human health. Our objective was to determine the potential for using zero‐valent iron (Fe0) to remediate RDX‐contaminated water and soil. Mixing an aqueous solution of 32 mg RDX L−1 (spiked with 14C‐labeled RDX) with 10 g Fe0 L−1 resulted in complete RDX destruction within 72 h. Nitroso derivatives of RDX accounted for approximately 26% of the RDX transformed during the first 24 h; these intermediates disappeared within 96 h and the remaining 14C products were water soluble and not strongly sorbed by iron surfaces. When RDX‐contaminated soil (30 mg RDX kg−1 spiked with 14C‐RDX) was treated with a single amendment of Fe0 (20 g kg−1 soil) in a static soil microcosm, more than 60% of the initial 14C‐RDX was recovered as 14CO2 after 112 d. Treating surface and subsurface soils containing 3600 mg RDX kg−1 with 50 g Fe0 kg−1 at a constant soil water content (0.35–0.40 kg H2O kg−1 soil) resulted in a 52% reduction in extractable RDX following 12 mo of static incubation. A second Fe0 addition at 12 mo further reduced the initial extractable RDX by 71% after 15 mo. These results support the use of zero‐valent iron for in situ remediation of RDX‐contaminated soil.

In broad terms, hydrothermal synthesis is a technology for crystallising materials (chemical compounds) directly from aqueous solution by adept control of thermodynamic variables (temperature, pressure and composition). The objective of this review is to introduce the field of hydrothermal materials synthesis and show how understanding solution thermodynamics of the aqueous medium can be used for engineering hydrothermal crystallisation processes. In this review, powder synthesis, and their applications are introduced. In Section 'Introduction', we will focus on the hydrothermal synthesis as a materials synthesis technology by providing history, process definitions, technological merits and comments on its current implementation in the laboratory. In Section 'Scope of hydrothermal synthesis in future', we will describe the development of hydrothermal technology for materials synthesis, their results and comparison with other methods.

Soils surrounding former munitions production facilities are highly contaminated with 2,4,6‐trinitrotoluene (TNT). Long‐term availability and fate of TNT and its transformation products must be understood to predict environmental impact and develop appropriate remediation strategies. Sorption and transport in surface soil containing solidphase TNT are particularly critical, since nonlinear sorption isotherms indicate greater TNT availability for transport at high concentrations. Our objectives were to determine long‐term sorption and bound residue formation in surface and subsurface Sharpsburg soil (Typic Argiudoll). Prolonged equilibration of 14C‐TNT with the soil revealed a gradual increase in amount sorbed and formation of unextractable (bound) 14C residues. The presence of solid‐phase TNT did not initially affect the amount of 14C sorbed during a 168‐d equilibration. After 168 d, 93% of the added 14C was sorbed by uncontaminated soil, while 79% was sorbed by soil containing solid‐phase TNT. In the absence of solid phase, pools of readily available (extractable with 3 mM CaCl2) and potentially available (CH3CN‐extractable) sorbed TNT decreased rapidly with time and coincided with increased 14C in soil organic matter. More 14C was found in fulvic acid than in the humic acid fraction when no solid‐phase TNT was present. After sequential extractions, including strong alkali and acid, 32 to 40% of the sorbed 14C was irreversibly bound (unextractable) in Sharpsburg surface and subsurface soil. Results provide strong evidence for humification of TNT in soil. This process may represent a significant route for detoxification in the soil‐water environment.

Curcumin, very rightly referred to as "a wonder drug" is proven to be efficacious in a variety of inflammatory disorders including cancers. Antiaging, anti-inflammatory, antioxidant, antitumor, chemosensitizing, P-gp efflux inhibiting, and antiproliferative activity are some of the striking features of curcumin, highlighting its importance in chemotherapy. Curcumin inhibits Bcl-2, Bcl-XL, VEGF, c-Myc, ICAM-1, EGFR, STAT3 phosphorylation, and cyclin D1 genes involved in the various stages of breast, prostate, and gastric cancer proliferation, angiogenesis, invasion, and metastasis. The full therapeutic potential of curcumin however remains under explored mainly due to poor absorption, rapid metabolism and systemic elimination culminating in its poor bioavailability. Furthermore, curcumin is insoluble, unstable at various pH and is also prone to undergo photodegradation. Nanotechnology can help improve the therapeutic potential of drug molecules with compromised biopharmaceutical profiles. Solid lipid nanoparticles (SLNs) are the latest offshoot of nanomedicine with proven advantages of high drug payload, longer shelf life, biocompatibility and biodegradability, and industrial amenability of the production process. We successfully developed CLEN (Curcumin encapsulated lipidic nanoconstructs) containing 15 mg curcumin per ml of the SLN dispersion with highest (till date, to our knowledge) increase in solubility of curcumin in an aqueous system by 1.4 × 10 6 times as compared to its intrinsic solubility of 11 ng/ml and high drug loading (15% w/v with respect to lipid matrix). Zero-order release kinetics observed for CLEN versus first order release for free curcumin establish controlled release nature of the developed CLEN. It showed 69.78 times higher oral bioavailability with respect to free curcumin; 9.00 times higher than a bioavailable marketed formulation (CurcuWIN R). The formulation showed 104, 13.3, and 10-times enhanced stability at pH 6.8, 1.2, and 7.4, respectively. All these factors ensure the efficacy of CLEN in treating cancer and other inflammatory diseases.