Browsing by Author "Kitson, James"

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    Conductance based sensing and analysis of soluble phosphates in wastewater
    (Elsevier Science B.V., Amsterdam., 2014-02-15T00:00:00Z) Warwick, C.; Guerreiro, Antonio R.; Gomez-Caballero, Alberto; Wood, Elizabeth; Kitson, James; Robinson, James; Soares, Ana
    The current standard method used for measuring soluble phosphate in environmental water samples is based on a colourimetric approach, developed in the early 1960s. In order to provide an alternative, label free sensing solution, a molecularly imprinted polymer (MIP) was designed to function as a phosphate receptor. A combination of functional monomer (N-allylthiourea), cross-linker and monomer/template ratios were optimised in order to maximise the binding capacity for phosphate. When produced in membrane format, the MIP's ability to produce a reversible change in conductance in the presence of phosphate was explored for fabrication of a sensor which was able to selectively detect the presence of phosphate compared to sulphate, nitrate and chloride. In wastewater samples the sensor had a limit of detection of 0.16 mg P/l, and a linear range between 0.66 and 8 mg P/l. This is below the minimum monitoring level (1 mg P/l) as required by current legislation for wastewater discharges, making the sensor as developed promising for direct quantification of phosphate in environmental monitoring applications.
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    A molecular imprinted polymer based sensor for measuring phosphate in wastewater samples
    (IWA Publishing, 2014-01-31) Warwick, Christopher; Guerreiro, Antonio R.; Wood, Elizabeth; Kitson, James; Robinson, James; Soares, Ana
    Phosphate detection in water samples is still completed using colorimetric standard methods, which have a number of disadvantages, to such as being time consuming, requiring filtration, a number of different reagents, frequent calibration and proper disposal of waste chemicals generated. Hence, a simple cost effective analytical method and instrumentation is highly desirable to aid the optimisation of treatment processes and assist the water industry in their efforts to comply with stringent regulations such as the EU's Water Framework Directive. A sensor based on molecular imprinted polymer (MIP) and a conductance transducer was developed for direct and label-free detection of phosphate in water. The sensor was able to measure the presence of phosphate in wastewater samples with good reproducibility, a linear range of 0.66-8 mg P L-1 and a lower detection limit of 0.16 mg P L-1. The sensor was further tested to measure phosphate concentrations in unfiltered field samples such as domestic wastewater treatment influent and river water and demonstrated a close correlation with reference measurements. The phosphate MIP sensor offers a way forward as either a handheld sensor for use in the field, or as a potential solution for remote, continuous monitoring of phosphate,