Towards effective phosphorus recycling from wastewater: quantity and quality.

Precipitation in the Mg-Ca-NH3-PO4 system has been explored to improve understanding of likely phases recoverable from complex wastewaters. Over a range of Mg/Ca combinations (0-100%) and pH 5-11, at least seven identifiable crystalline phases could be precipitated from artificial wastewater including: struvite, hydroxylapatite, newberyite, brushite, merrilite/whitlockite, octocalcium phosphate, and monetite. This experimental study has outlined the physicochemical conditions required to produce various phosphate products from synthetic wastewater, and found that large differences exist between experimentally formed phases and thermodynamical predictions. Struvite formation is the most desirable precipitate for the recovery of phosphate based upon purity, growth characteristics, dewatering properties, phosphate removal efficiency, and its ability to simultaneously remove ammonia. This study has also demonstrated that in specific cases the preliminary precipitation of brushite is a possible means of decreasing calcium content such that subsequent struvite formation could achieve higher-purity. Utilising experimental results and information on current commodity prices, discussion on the choice of Mg and Ca sources for phosphorus recovery provides guidance on appropriate means to optimise the formation and yield of high quality cost-optimised products.

[Preclinical studies of live intranasal H5N1 influenza vaccine with the deleted HS1 gene].

The paper gives the results of evaluating the efficiency of deINS1 pandemic H5N1 vaccine candidate VN1203delNS1 which was constructed by reverse genetics on the basis of influenza virus strain A/Vietnam/1203/04. The safety, immunogenicity and cross-protection of the vaccine strain against different H5N1 virus clades were demonstrated in mouse and macaque models. The results showed the possibility of designing a new-generation replication-deficient intranasal influenza vaccine, by applying an approach to deleting the NS1 pathogenicity factor, an antagonist of the interferon system.