RO plant experiences with high silica waters in the Canary Islands

80,000h operational experience and performance analysis of a brackish water reverse osmosis desalination plant. Assessment of membrane replacement cost

“…However Mingheng Li [27][28][29] took into consideration that factor in his model, when the membrane capacity decreases or the pressure drop increases, a higher recovery and a greater applied pressure gives the lowest normalized SEC. But in BWRO desalination plants the scaling usually plays an important role being sometimes the limiting factor in the RO system recovery [30][31][32]. The plant is operating with a fractional water recovery of about 0.6 due to silica scaling issues.…”

Elemental composition of membrane foulant layers using EDS, XPS, and RBS

“…Important objectives in the characterization of foulant layers and membrane surfaces are the quantification of their elemental composition, and estimation of foulant layer thickness, as these objectives allow conclusions to be drawn related to the types of foulants comprising foulant layers and the severity of fouling. Three techniques that have been used to accomplish these objectives are energy-dispersive X-ray spectroscopy (EDS) [8][9][10][11][12], X-ray photoelectron spectroscopy (XPS) [7,[13][14][15][16][17], and more recently Rutherford backscattering spectrometry (RBS) [14,[18][19][20][21][22][23]. EDS, XPS and RBS give, in principle, the same information about the sample analyzed, specifically its relative elemental composition.…”

Silica removal from newsprint mill effluents with aluminum salts

“…Preventive methods interact and modify silica so as not to allow it to deposit on membranes but they do not remove it. The use of antiscalants is probably the most common method [8,9], although their efficiency in highly contaminant waters is low. Besides, when treated water is reused in other process stages, as the process conditions can change significantly, scaling problems could appear once again.…”