Testing Capabilites

Loss on Ignition (LOI)

PWT’s Membrane Forensics’ LOI Test is used to determine the relative percentages by weight of organic portion to inorganic portion of the foulant.

During the LOI test, our technicians dry the foulant sample at 110ºC and heat the foulant to 550ºC. This procedure destroys the organic material in the sample. A weight loss on ignition is then calculated from foulant weights measured before and after exposure to the higher temperature.

The LOI is referred to as a percentage of the foulant sample and is representative of the organic portion of the foulant. The remaining percentage (that which is not burned off) percentage is the inorganic portion of the sample.

Targeted Energy Dispersive X-Ray Analysis (T-EDXA)

PWT’s T-EDXA service utilizes scanning electron microscope (SEM) imagery to identify inorganic foulant components. X-rays are directed to specific targets in the sample, producing spectra, which then identify the specific chemical elements of the sample. This test is useful in discovering key inorganic foulants and scale so that pretreatment and cleaning efforts may be optimized.

Scanning Electron Microscopy (SEM)

This highly specialized test provides a visual representation of membrane foulants and the surrounding area which is useful in determining particle size and morphology.

In addition to a standard SEM, PWT’s backscatter electron imaging (BSE) capabilities give technicians a unique advantage in evaluating particle structures. BSE imaging distinguishes between particles based on atomic weight (the darker the particle image, the heavier the atomic weight).

SEM and BSE, when combined with our unique Targeted Energy Dispersion X-Ray Analysis , is a valuable tool in determining specific membrane scale and foulants so that membrane cleaning and pretreatment may be optimized.

For more information on our testing capabilities, please contact us.

For more information on our testing capabilities, please contact us.

High Sensitivity Biological Analysis

Our Membrane Forensics’ technicians provide standardized biological analyses to identify specific types of biological growth and its relative aggressiveness. The standardized testing, when used in conjunction with professional microscopic analysis, is used to identify heterotrophic aerobic bacteria, slime forming bacteria, iron-reducing bacteria, sulfate-reducing bacteria, fluorescent psuedomonads, and other microbiological growth. Such information is valuable for optimizing a cleaning regimen and pretreatment methods for membrane separation processes.

Fourier Transform Infrared (FTIR)

FTIR analysis is used to identify organic compounds in membrane foulant samples by measuring vibrations of functional groups and highly polar bonds.

Determining these frequencies allows identification of the samples’ chemical characteristics, since chemical functional groups are known to absorb light at specific frequencies.

An infrared absorbance spectrum is produced creating a “fingerprint” from the vibrational features of the sample components. The spectrum is compared to a 75,000 sample spectral library and subject to spectral interpretation.

Gas Chromatography – Mass Spectrometry (GCMS)

GC/MS is useful in identifying specific organic constituents in a foulant mass. GC utilizes a vaporized sample which is carried by an inert gas through a column which separates the sample components. Each component is then eluted from the column, through a detector and is identified. MS is then used to isolate constituents into molecular ions and other fragments. The fragments are then passed through an electric and/or magnetic field that separate them according to their mass-to-charge ratio to identify the components.

For more information on our testing capabilities, please contact us.

Backscatter Analysis

PWT offers backscatter electron imaging (BSE) services, a unique test designed to distinguish between particles in a foulant mass based on atomic weight. BSE and SEM imaging, when combined with our Targeted Energy Dispersion X-Ray Analysis services, are valuable tools in determining specific membrane scale and foulants so membrane cleaning and pretreatment may be optimized.

Microscopic Analysis

PWT’s Membrane Forensics’ technicians use microscopic analysis in conjunction with other analyses such as SEM, T-EDXA, and biological analyses to identify membrane foulants.

Once membrane foulants have been identified, optimum cleaning methodology and chemicals may be tested. Further, ideal membrane pretreatment strategies may be implemented to reduce future fouling problems.

For more information on our testing capabilities, please contact us.

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