Conductance based sensing and analysis of soluble phosphates in wastewater.
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.
Cranfield Water Sciences Institute, School of Applied Sciences, Cranfield University, Cranfield MK43 0AL, UK.
Christopher
C
Warwick
Antonio
A
Guerreiro
Alberto
A
Gomez-Caballero
Elizabeth
E
Wood
James
J
Kitson
James
J
Robinson
Ana
A
Soares
D015374:Biosensing Techniques / Q000379:methods*; D004784:Environmental Monitoring; D010710:Phosphates / Q000302:isolation & purification*; D011108:Polymers / Q000737:chemistry; D012995:Solubility; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D010710:Phosphates; D011108:Polymers; D062065:Wastewater; D014874:Water Pollutants, Chemical
Conductance; MIP; Phosphate; Sensor; Thiourea; Wastewater