The addition of aluminum nitrate (up to 100 ppm A1 on pulp) to a two-stage, acidalkali, hydrogen peroxide bleach of Eucalyptus regnans stone groundwood pulp enhanced the brightness gain of the pulp, over a range of consistencies. It is proposed that the presence of aluminum ions modifies the catalytic behaviour of the transition metal ions present in the pulp, especially manganese, reducing per...

The chemical basis for commercial production and purification of nitrous oxide is outlined and discussed. Nitric oxide is the most likely toxic contaminant but the concentration in the effluent gas from a cylinder diminishes rapidly due to fractionation. Nitric oxide reacts with oxygen but the velocity of the reaction is influenced by concentration and is very slow at concentrations below about...

Divalent metal (Mn, Co, Ni) complexes of the ligand hexamethylenetetramine (HMTA, C6H12N4) with sulfate, nitrate and fluoroborate as counter ions have been synthesized in ethanolic media. Whereas the complexes with BF4 and NO3 as counter ions have two molecules of hexamethylenetetramine, those with SO4 2as counter ion contain just one molecule of hexamethylenetetramine. The complexes have been ...

Extracellular production of metal nanoparticles by several strains of the fungus Fusarium oxysporum was carried out. It was found that aqueous silver ions when exposed to several Fusarium oxysporum strains are reduced in solution, thereby leading to the formation of silver hydrosol. The silver nanoparticles were in the range of 20-50 nm in dimensions. The reduction of the metal ions occurs by a...

Reverse osmosis concentrate from wastewater reclamation contains biorefractory trace organic contaminants that may pose environmental or health hazard. Due to its high conductivity, electrochemical oxidation of brine requires low voltage which is energetically favourable. However, the presence of chloride ions may lead to the formation of chlorinated by-products, which are likely to exert an in...

Phosphoryl containing ligand tri-n-octylphosphine oxide (TOPO) in dichloromethane has been used as an extracting agent for tetravalent thorium and trivalent europium ions from their 1 M sodium nitrates. The equilibrium data reveal that both ions are extracted as the complexes at 1:3 metal/ligand ratio. The values of conditional extraction equilibrium constant (Kex) show the superior extract...

Density functional tight binding (DFTB), which is ∼100-1000 times faster than full density functional theory (DFT), has been used to simulate the structure and properties of protic ionic liquid (IL) ions, clusters of ions and the bulk liquid. Proton affinities for a wide range of IL cations and anions determined using DFTB generally reproduce G3B3 values to within 5-10 kcal/mol. The structures ...

In papers by Wang et al. (1998), Liu et al. (1999), and Liu and Tsay (2003), it was proposed that Arabidopsis thaliana Nitrate Transporter1.1 (AtNRT1.1; CHL1) encodes a dual-affinity nitrate transporter that “plays a major role in high-affinity nitrate uptake.” Here, we evaluate this concept by reexamining the uptake kinetics of Arabidopsis (Arabidopsis thaliana) mutant lines defective in NRT1....

Uptake of uranium (VI) ions using an anion exchanger resin, namely amberlite CG-400, was studied through this work in the presence of sulfate anions. Impact of various parameters including pH, contact time, initial concentration of uranium ions and intrusion with different anion contents (phosphate, chloride,sulfate, nitrate and fluoride) was examined on the sorption performance of the resin. A...