ASTM on Data Normalisation

ASTM D4516 - Standard Practice for Standardizing Reverse Osmosis Performance Data

Membrane performance (flux and salt passage) is affected by: water temperature, feed conductivity, and flux rate. If the operating arameters remain constant the system will perform fairly steadily over a long period of time. However, these operating conditions will eventually change. Normalisation is a technique that allows the user to standardise the data to a constant set of conditions (or to a reference), and may be used with SCADA for online diagnostics.

Flow or flux performance

Specific flux

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \operatorname{Specific Flux} = \frac{Flux \times TCF}{NDP} }

Where: Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \operatorname{TCF} = e^{x} }

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle x = u\left( \frac{1}{T+273} - \frac{1}{298}\right ) }

NDP = Net Driving Pressure

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle NDP = P_{feed}-\Delta \pi-\frac{\Delta P}{n+1}-P_{permeate} }

$P_{feed}=$ RO feed pressure

$\Delta \pi =$ Osmotic Pressure

$\Delta P=$ Feed/Brine Differential Pressure

$n+1=$ Number of membrane stages

$P_{permeate}=$ Permeate back pressure

$\pi =0.006\times$ Average feed / brine conductivity

${\text{Average feed / brine conductivity}}={\text{Conductivity of feed}}\times \left[{\frac {\ln \left({\frac {1}{1-Y}}\right)}{Y}}\right]$

$Y={\text{Recovery}}={\frac {\text{Permeate flow}}{{\text{Concentrate flow}}+{\text{Permeate flow}}}}$

Normalised Flow

${\text{Normalised Permeate Flow}}={\frac {\left(NDPs\right)\left(TCFs\right)}{\left(NDPa\right)\left(TCFa\right)}}{\text{Actual Flow}}$

$a={\text{actual}}$
Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle s = \text {standard} }

Calculators/spreadsheets

Dow http://www.dowwaterandprocess.com/en/resources/normalization_of_membrane_systems

Hydronautics http://membranes.com/index.php?pagename=rodata