This article discusses new Smopex^® ion exchange materials which have been developed by Johnson Matthey Water Technologies, and highlights their performance relative to other commercially available materials for the removal of selenocyanate, selenate and selenite ions from aqueous solutions. The ion exchange mechanisms by which these materials sorb these ions are also explained and modelled in order to highlight the additional benefits that these materials offer that non ion-exchange materials do not, such as the ability to achieve the full material exchange capacities at feed concentrations lower than 1 mg l^–1 selenium. The unique characteristics of these fibrous type materials are also discussed, including fast sorption kinetics, facile regeneration and enhanced selectivity for selenium ions against competing sulfate ions. Finally, the performance of these materials in a continuous stirred tank reactor setup is demonstrated, showing that performance levels as high as in fixed bed processes can be achieved, due to the high selectivity and mass transfer kinetics of Smopex^® materials.

Many gold ore bodies contain high levels of mercury which are co-extracted with the gold. This mercury then travels through the process circuit to pose health, environmental and technical issues. This article highlights a method to selectively remove the mercury whilst leaving the gold to be processed as normal. The removal of mercury from the circuit mitigates the need for retorting of the produced gold, reduces the potential environmental impact of any waste solutions and decreases any potential mercury exposure to plant workers.

The solid bound thiol species used have been shown by inductively coupled plasma optical emission spectrometry (ICP-OES) to reduce the mercury to undetectable levels whilst having no measurable effect on the gold concentration. The control of the cyanide concentration at the adsorption step has been shown to be key to ensuring that the mercury removal is achieved selectively. This in turn ensures that no precious metal value is lost in the mercury removal process. The process has been shown to be applicable to both batch and continuous operation which will allow the technology to be applied to a variety of flow rates and applications.

1. Introduction Jointly organised by the Aseanian Membrane Society, the European Membrane Society and the North American Membrane Society, the 10th International Congress on Membrane and Membrane Processes (ICOM) was held at Suzhou, China from 20th to 25th July 2014. ICOM is a highly regarded triennial conference in the membrane community, attracting scientists from around the world for...

Microemulsions were used to develop a catalyst with high selectivity towards ethylene and ethane while maintaining considerable methane (CH₄) conversion. The use of this technique to produce lanthanum nanoparticles was studied under different conditions. Temperature was shown to have the most significant effect on the final material properties providing a minimum crystallite size at 25°C. The morphology observed for all the samples was flake or needle like materials containing nanocrystallites. To obtain the catalytically active materials a thermal treatment was needed and this was studied using in situ X-ray diffraction (XRD). This analysis demonstrated that the materials exhibited significant changes in phase and crystallite size when submitted to thermal treatment and these were shown to be difficult to control, meaning that the microemulsion synthesis method is a challenging route to produce La nanoparticles in a reproducible manner. The materials were tested for oxidative coupling of methane (OCM) and no correlation could be observed between the ‘as synthesised’ crystallite size and activity. However, the presence of La carbonates in the materials produced was deemed to be crucial to ensure an adequate OCM activity.

Hydrogen production from methanol oxidation over silver-gold/zinc oxide (AgAu/ZnO) catalysts was investigated. Bimetallic catalysts produced higher hydrogen yield and lower carbon monoxide and water yields than Ag/ZnO catalyst without deactivation during 72 h on stream at 250°C. In addition, the presence of Au in the bimetallic catalyst facilitated the preferential oxidation of CO to CO₂. Structural analysis of bimetallic catalysts indicated that the strong interaction between Ag and Au particles in the nano-range (4.2 nm–7.2 nm) efficiently enhanced the reducibility of non-selective silver oxide (Ag₂O) species. Furthermore dispersion of metal particles in bimetallic AgAu/ZnO catalysts did not significantly change after reaction; however, dispersion of Ag species in Ag/ZnO catalyst was remarkably decreased.

The main objective of this study was to evaluate the performance of a self-developed filler micro-embedded with Pseudomonas putida (P. putida) for toluene removal in a biofilter under various loading rates. The results show that the biofilter could reach 85% removal efficiency (RE) on the eighth day and remain above 90% RE when the empty bed residence time (EBRT) was 18 s and the inlet loading was not higher than 41.4 g m⁻³ h⁻¹. Moreover, the biofilter could tolerate substantial transient shock loadings. After two shut-down experiments, the removal efficiency could be restored to above 80% after a recovery period of three days and six days, respectively. Sequence analysis of the 16S rRNA gene of fillers in four operating periods revealed that the highly efficient bacterial colonies in fillers mainly included Firmicutes, Actinobacteria and Proteobacteria and that the abundance of Bacteroidetes increased significantly during the re-start period.