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The Loch Katrine water supply to Glasgow was unfiltered until a new treatment works was completed in 2007. Disinfection observations on the unfiltered supply are reported here for the decade 1995-2004. On one half of the supply, raw water contamination by gulls led to annual final water microbiological failure rates up to 2.7%, which fell below 0.4% after introducing revised gull control measures. Seasonality in gull contamination contributed to marked seasonality in observed final water microbiological failure rates. A 14-min chlorine contact time at pH 5.8 realised all the effective disinfection; a longer second stage contact time at pH 8.6 provided no significant ( P > 0.05) improvement. For a range of raw water Escherichia coli counts, a logistic regression model predicted probabilities of a final water E. coli failure that varied with quarterly period; this was consistent with seasonal factors, aside from raw water quality, contributing to probability of these failures. [ABSTRACT FROM AUTHOR]

The Li-O 2 battery has attracted substantial attention due to its high theoretical energy density. In particular, high-efficiency oxygen catalysts are very important for the design of practical Li-O 2 batteries. Herein, we have synthesized heterogeneous crystalline-coated partially crystalline bimetallic organic coordination polymers (PC@C-BMOCPs), which are further pyrolyzed to obtain Co- and Fe-based nanoparticles embedded within rodlike N-doped carbon (Co/Fe@NC) as a bifunctional oxygen reduction reaction/oxygen evolution reaction (ORR/OER) catalyst used in the Li-O 2 battery. Owing to excellent ORR/OER catalytic ability, the Co/Fe@NC bifunctional catalyst exhibits an efficient reversible reaction between O 2 and Li 2 O 2 . Additionally, a large number of mesoporous channels are present in the core-shell Co/Fe@NC nanoparticles. These channels not only promote the diffusion of Li + and O 2 , but also create ample room to store insoluble discharge product Li 2 O 2 . The Li-O 2 batteries utilizing the bifunctional Co/Fe@NC oxygen electrode exhibit a large capacity of 17,326 mAh g -1 , a long cycling life of more than 250 cycles, and excellent reversibility. This work provides a universally applicable strategy for designing nonnoble metal ORR/OER catalysts with excellent electrochemical performance for metal-air batteries.