Biological treatment options for cyanobacteria metabolite removal: a review

Lionel Ho, Emma Sawade and Gayle Newcomb

Is nitrification the only cause of microbiologically induced chloramine decay?

Available online 12 November 2015Abstract not availableEmma Sawade, Paul Monis, David Cook, Mary Drika

Radar-Magnet-Betontest - Eine neue Methode zur Bestimmung der Feuchte und des Chloridgehaltes von Brückenfahrbahnplatten aus Beton

For the assessment of the condition of concrete bridge decks it is important to know the moisture and the salinity of the concrete. In this paper, a novel technique for nondestructive determination of moisture and salinity of concrete through the pavement is presented. Using Ground Penetrating Radar, the transient time of the electromagnetic wave to the upper layer reinforcement bars (rebars) is measured. It depends on the dielectric properties of the intermediate materials. The depth of the rebars is determined by a measurement of the static magnetic field of the premagnetized rebars. This magnetic depth determination technique is independent of the dielectric properties of the materials covering the rebars. Comparison of the Radar delay and the magnetically extracted depth yields the averaged real part of the dielectric permittivity of the intermediate material. The imaginary part is estimated from the reflected Radar amplitude. Then, moisture and salt content of the concrete are derived from calibration curves. The method was verified in the lab using concrete test blocks with and without asphalt cover A Radar-magnetic measurement vehicle was developed and tested on two highway bridge decks. The dielectric permittivity of the concrete close to the surface was mapped on a large area, The technique is well suited for quick and nondestructive scans over large areas in order to identify potentially damaged regions. These conspicuous locations should be analyzed in more detail afterwards

High-performance size exclusion chromatography with a multi-wavelength absorbance detector study on dissolved organic matter characterisation along a water distribution system

Abstract not availableHuiping Huang, Emma Sawade, David Cook, Christopher W.K. Chow, Mary Drikas, Bo Ji

Using amplicon sequencing to characterize and monitor bacterial diversity in drinking water distribution systems

Drinking water assessments use a variety of microbial, physical, and chemical indicators to evaluate water treatment efficiency and product water quality. However, these indicators do not allow the complex biological communities, which can adversely impact the performance of drinking water distribution systems (DWDSs), to be characterized. Entire bacterial communities can be studied quickly and inexpensively using targeted metagenomic amplicon sequencing. Here, amplicon sequencing of the 16S rRNA gene region was performed alongside traditional water quality measures to assess the health, quality, and efficiency of two distinct, full-scale DWDSs: (i) a linear DWDS supplied with unfiltered water subjected to basic disinfection before distribution and (ii) a complex, branching DWDS treated by a four-stage water treatment plant (WTP) prior to disinfection and distribution. In both DWDSs bacterial communities differed significantly after disinfection, demonstrating the effectiveness of both treatment regimes. However, bacterial repopulation occurred further along in the DWDSs, and some end-user samples were more similar to the source water than to the postdisinfection water. Three sample locations appeared to be nitrified, displaying elevated nitrate levels and decreased ammonia levels, and nitrifying bacterial species, such as Nitrospira, were detected. Burkholderiales were abundant in samples containing large amounts of monochloramine, indicating resistance to disinfection. Genera known to contain pathogenic and fecal-associated species were also identified in several locations. From this study, we conclude that metagenomic amplicon sequencing is an informative method to support current compliance-based methods and can be used to reveal bacterial community interactions with the chemical and physical properties of DWDSs.Jennifer L.A. Shaw, Paul Monis, Laura S. Weyrich, Emma Sawade, Mary Drikas, Alan J. Coope

Investigations into the biodegradation of microcystin-LR in wastewaters

Microcystins are potent hepatotoxins that can be produced by cyanobacteria. These organisms can proliferate in wastewaters due to a number of factors including high concentrations of nutrients for growth. As treated wastewaters are now being considered as supplementary drinking water sources, in addition to their frequent use for irrigated agriculture, it is imperative that these wastewaters are free of toxins such as microcystins. This study investigated the potential for biodegradation of microcystin-LR (MCLR) in wastewaters through a biological sand filtration experiment and in static batch reactor experiments. MCLR was effectively removed at a range of concentrations and at various temperatures, with degradation attributed to the action of microorganisms indigenous to the wastewaters. No hepatotoxic by-products were detected following the degradation of MCLR as determined by a protein phosphatase inhibition assay. Using TaqMan polymerase chain reaction, the first gene involved in bacterial degradation of MCLR (mlrA) was detected and the responsible bacteria shown to increase with the amount of MCLR being degraded. This finding suggested that the degradation of MCLR was dependent upon the abundance of MCLR-degrading organisms present within the wastewater, and that MCLR may provide bacteria with a significant carbon source for proliferation; in turn increasing MCLR removal.Lionel Ho, Daniel Hoefel, Sebastien Palazot, Emma Sawade, Gayle Newcombe, Christopher P. Saint, Justin D. Brooke