Microsoft PowerPoint - IERO promising future of Optiflux.ppt by mirit35


									                      >95% recovery RO with Optiflux®
Introduct ion
Commonly known Nanofiltration and           possible to make operation of the
Reverse O smosis systems typically          membranes      more    efficient  while
work at recoveries between 75-85%           scaling danger is totally eliminated.
and in a flux range of 20-30 l/(m2.h).      Removing of all bivalent cations can
This common design range is defined         easily be achieved by Cation Exchange.
by (prevention of) scaling. When            The membrane system can now be
fluxes and/or recoveries become to          operated at much higher recovery
high, precipitation of bivalent ions will   (>95%) and much higer flux (40-60
occur on the membrane surface (e.g.         l/m2.h). This concept of combining Ion
BaSO 4, CaCO 3, CaSO 4).                    Exchange – NF/RO is called IERO .

Another disadvantage of this common         Benef its of IERO
design is the high concentrate loss.        The IERO concept has many benefits:
This concentrate can not be used and          Minimising capital costs (high flux)
needs to be disposed. When anaerobic          Minimising water use (high recovery)
Nanofiltration or RO is implied,              Minimising concentrate discharge
treatment of the concentrate before           Minimising pre-treatment c osts
disposal is necessary in order to             No antiscalants needed
prevent negative effects on s urface
water flora and fauna (oxygen demand        IERO: only possible wit h Opt if lux®
of un-oxidised iron). It is commonly        O peration at high flux, needs a
                                                                                        The Optiflux® pressure vess el offers a
known that concentrate treatment,           different hydraulic design. T he current
                                            hydraulic design (6 elements in series      clear advantage in the IERO concept!
transport (to discharge point) and
discharge c an be responsible for 20-       in pressure vessels) would give an
                                                                                        IERO at WTP Engelse Werk
40% of the total annual costs!              unequally flux over the different
                                            membrane elements . At the present          In future the capacity of NF/RO at
                                                                                        Engelse Werk possibly needs to be
IERO (Ion Exchange - RO):                   low fluxes of about 20-30 l/(m2 .h),
                                            hydraulic losses are already 1-3 bar        expanded. For this reason the c urrent
higher re covery, highe r f lux                                                         installation is already prepared to use
Vitens and DHV however, believe that        per vessel. As hydraulic loss ~ flow2, a
                                            higher flux will give a dramatically        IERO . Used materials for housing,
they can contribute in this field by                                                    piping and piping connections can
minimising the concentrate discharge        increase of the hydraulic losses up to
                                                                                        resist a higher feed pressure (up to 20
and operation costs at the same time.       4-5 bar per vessel! Consequently,
                                            success fully optimisation of flux and      bar).     D iameters      and    pumping
By removing all positive bivalent ions                                                  capacities are       also   suitable  for
before entering a Nanofiltration or         recovery of N F/RO is not possible
                                            without the O ptiflux ® c oncept.           operating at higher pressure and
Reverse O smosis membrane it is                                                         capacities.
                                                                        Ion Exchange: regenerat e solut ion
 Conventional design
                                                                        Vitens and DHV have developed and investigated this
                       NF                                               IERO -concept. Specific field of investigation was the
       Feed                                            Product          reuse of salt. The Ion Exchange columns for cation
       100%                                            80%              removal need to be regenerated by a 10% NaCl
                                                                        solution. The spent regenerate contains high levels of
                               Concentrate                              bivalent positive ions, but it also contains a remaining
                                                                        Na concentration (ca. 50%).
                                                                        By treating spent regenerate with dead-end NF or
 IERO-concept                                                           Electro Dialysis (ED) over 80% of Na in spent
 Feed                                                                   regenerate can be s eparated for reus e, thus reducing
                                                                        total s alt cos ts of the I on Exchange by 40%!
        IEX                                            Product          IERO is a patented concept, developed by Vitens and
                                                       97%              DHV Water


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