Page 14 - ro membanes

ABBREVIATIONS AND UNITS xiii
mg/L Micrograms per liter
mm Micrometer
mS/cm Microsiemens per centimeter N Nitrogen
Na Sodium
Na2S2O4 Sodium hydrosulfite
Na2S2O5 Sodium metabisulfite
NaHSO3 Sodium bisulfite
NaOH Sodium hydroxide
NDMA N-nitrosodimethylamine
NDP Net driving pressure
Nepv Number of elements per RO vessel
NF Nanofiltration
Ni Nickel
NL No leaks (for membrane integrity)
NOM Natural organic matter
NPDES National pollutant discharge elimination system
Nt Number of RO trains
NTU Nephelometric turbidity unit
Nvpt Number of vessels per RO train
O&M Operation and maintenance
Op Average osmotic pressure
ORP Ooxidation-reduction potential
P Phosphorus
PA Polyamide
PACL Polyaluminum chloride
Pd Pressure drop
PE Polyethylene
PES Polyethersulfone
pH Indication of acidity or basicity of solution
Pp Permeate pressure
ppt Part per thousand (1 ppt 1⁄4 1000 mg/L)
Pr Permeate recovery rate
psi Pounds per square inch (unit of pressure)
PTFE Polytetrafluoroethylene
PVC Polyvinyl chloride
PVDF Polyvinylidene difluoride
PVP Polyvinilpyrrolidone
PX Pressure exchanger
Qbw Daily volume of backwash water
Qc Daily volume of desalination plant concentrate
Qf Saline source water daily flow
Qp Volume of the plant fresh-water production (daily permeate flow) Qs Volume of the saline source water (daily flow)
R Plant recovery
Rnew Resistance of new membranes
RO Reverse osmosis
Rt Membrane resistance after given time of operation
s Second
S Membrane area of an element
SBS Sodium bisulfite
SCADA Supervisory control and data acquisition
SDI Silt density index