Water treatment process

An improved water softening process is provided which also reduces anion content. A first stream of water is passed through an anion-exchange unit to remove undesirable anions and raise the pH. The first stream of water is then provided to reactor/clarifier water softening equipment, where it acts as a source of hydroxyl ions. Preferably a second stream of water which did not pass through an anion-exchange unit is also provided to the water softening equipment. The streams of water are combined and processed through the softening equipment, where hardness ions are precipitated out, yielding softened water with reduced anion content. The anion-exchange system utilized preferably has a counter-current continuous resin train and a counter-current continuous resin regeneration unit.

FIELD OF THE INVENTION 
The invention relates generally to water treatment and more particularly to 
an improved process for softening water while reducing anion content. 
DESCRIPTION OF RELATED ART 
Hardness in water is a common problem. Hardness in water is due primarily 
to the presence of Ca.sup.2+ and Mg.sup.2+, and also to the presence of 
Ba.sup.2+ and Sr.sup.2+, all of these being hardness ions. Water is said 
to be "softened" when these cations are removed, such as by water 
softening equipment. For large-scale or large volume water softening, the 
traditional process is called cold lime or cold lime-soda softening. In 
this process the lime can be either hydrated lime (Ca(OH).sub.2) or 
quicklime (CaO). In large systems the lime source is stored in a storage 
vessel. If quicklime is used, it must first be converted to hydrated lime 
(Ca(OH).sub.2) by being slaked, that is, combined with water. In any 
event, Ca(OH).sub.2 is provided and is diluted in a lime slurry, where the 
Ca(OH).sub.2 dissociates into Ca.sup.2+ and 20H.sup.-. This lime slurry 
is then fed to the reaction section of the lime softening equipment, where 
the OH.sup.- combines with Mg.sup.2+ to form Mg(OH).sub.2, which 
precipitates out. The original Ca.sup.2+ hardness in the water, and the 
Ca.sup.2+ introduced via dissolved lime, are removed by a different 
reaction. If there is sufficient natural bicarbonate (HCO.sub.3.sup.-) in 
the water, some of the OH.sup.- will react therewith to yield carbonate 
(CO.sub.3.sup.2-), which will combine with the Ca.sup.2+ to form 
CaCO.sub.3, which precipitates out. If there is insufficient natural 
bicarbonate, soda ash (Na.sub.2 CO.sub.3) is added (which converts to 
2Na.sup.+ and CO.sub.3.sup.2-) and again the CaCO.sub.3 forms and 
precipitates out. (Soda ash usage unfortunately adds substantial Na.sup.+ 
to the finished water). As an alternative to using Ca(OH).sub.2 as the 
source of OH.sup.-, sodium hydroxide (caustic soda) (NaOH) has been and is 
used. Sodium hydroxide also adds significant quantities of sodium ion to 
the final water and removes essentially no anions other than bicarbonate. 
The traditional lime process generates considerable sludge, being 
CaCO.sub.3 and Mg(OH).sub.2, and does little if anything to reduce 
chloride content and has limited capability to reduce any of the other 
anion content (sulfate, phosphate, nitrate) of the initial water. When it 
is necessary to use soda ash (due to low influent bicarbonate content), 
the traditional process increases the sodium content of the final 
effluent. 
As can be seen, the key to removing hardness is the introduction of 
OH.sup.-. The OH.sup.- converts Mg.sup.2+ to Mg(OH).sub.2, and converts 
HCO.sub.3.sup.- to CO.sub.3.sup.2-, which then reacts with Ca.sup.2+ to 
form CaCO.sub.3. (If there is insufficient natural HCO.sub.3.sup.-, 
Na.sub.2 CO.sub.3 is added). In the traditional hydrated lime treatment 
process, the OH.sup.- is supplied via Ca(OH).sub.2. It is also 
traditional to use NaOH as the OH.sup.- source with the lime treatment 
equipment. 
There is a need for an improved water softening process which eliminates or 
reduces the drawbacks of the traditional lime softening process. 
SUMMARY OF THE INVENTION 
A process for softening water comprising the steps of 
(a) passing a first stream of water through an anion-exchange unit to raise 
the pH of said first stream and provide a second stream of water having a 
pH of at least 9.5; 
(b) providing said second stream of water to water softening equipment 
comprising reactor and clarifier sections, said second stream of water 
being used as a source of hydroxyl ions in said water softening equipment; 
(c) processing a fourth stream of water through said water softening 
equipment, said fourth stream comprising said second stream; and 
(d) operating said water softening equipment on said fourth stream of water 
to remove via precipitation reactions hardness ions from said fourth 
stream and to provide thereby a fifth stream of water. 
An anion-exchange system comprising a counter-current continuous resin 
regeneration unit is also provided.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
As used herein, parts are parts by weight unless otherwise indicated and 
parts per million (ppm) and parts per billion (ppb) are parts by weight. 
When a preferred range such as 5-25 is given, this means preferably at 
least 5 and preferably not more than 25. 
With reference to FIG. 1 the diagram includes a conventional lime/soda 
water softening equipment or contact solids water treatment unit or 
portion or system (reactor/clarifier) which is basically operated as water 
softening equipment in the conventional manner except as noted. This water 
softening equipment consists essentially of a first stage mixing tank or 
reaction zone or section 20, an optional second stage mixing tank or 
reaction zone or section 21 and a clarifier or clarifier section 33 having 
a flocculation zone 35 and a settling zone 36. Other conventional cold or 
hot process lime or lime/soda water softening equipment or contact solids 
reactor/clarifier can be used. Influent water (typically pH 6-8 or about 
7) to be treated comes in via line 23 at a flow rate of preferably 
20-5000, more preferably 50-1000, more preferably 100-800, optionally 
200-600, gallons per minute; some or all (preferably 10-100%, more 
preferably 25-50%, more preferably 30-40%, more preferably about 33%) of 
the influent water passes through line 30 to the anion-exchange unit 38 
for anion-exchange and the remainder of the influent water passes through 
line 32 directly to mixing tank 20, lines 30 and 32 each being portions of 
line 23. This is preferably controlled by pH controller 25 or similar 
device sensing tank 20 and controlling valves 43 and/or 44. Preferably pH 
controller 25 senses the pH of tank 20 and controls the valves 43 and/or 
44 so as to maintain the pH of tank 20 at a pH of at least 9.5, more 
preferably at least 9.8, more preferably at least 10, more preferably at 
least 10.3, more preferably at least 10.6, more preferably at least 10.9, 
optionally at least 11.3. The pH of tank 20 is preferably 10-12.5, more 
preferably 10.3-12, more preferably 10.3-11.6, more preferably 10.6-11.2. 
The preferred method is to control the flow through line 32; less 
preferred is to control the flow of water through line 30. If all the 
influent water is diverted through the anion-exchange unit, this usually 
results in the water in tank 20 being too caustic; however, in some 
situations all the influent water can go through the anion-exchange unit, 
so the pH of the effluent from the anion-exchange unit is the pH of the 
water in tank 20. The preferred maximum pH of the effluent from the 
anion-exchange unit is 13.3 or, more preferably, 13. 
The influent water is preferably at ambient temperature and is preferably 
neither heated nor chilled during the process. Sometimes the influent 
water may be above or below ambient, such as hot influent water received 
from a cooling tower. 
The traditional ion exchange unit has two parts, the cation unit and the 
anion unit. In most installations the water first goes into a cation unit, 
where the cations including Ca.sup.2+ and Mg.sup.2+ sorb to the resin, 
releasing H.sup.+. The water then goes to the anion unit, where the anions 
(sulfate SO.sub.4.sup.2-, nitrate NO.sub.3.sup.-, phosphate 
PO.sub.4.sup.3-, chloride Cl.sup.-, silicate SiO.sub.4.sup.4-, etc.) sorb 
onto the resin, releasing OH.sup.-. Then the H.sup.+ and OH.sup.- 
combine to yield ion-free, or deionized, water. 
In the present invention only the second of these two units, the anion 
unit, is used. The anion unit basically takes the naturally occurring 
anions (sulfate, nitrate, chloride, etc.) out of the water and produces a 
caustic, alkaline solution high in OH.sup.-. This alkaline, high pH 
solution is then used in the treatment equipment as a source of OH.sup.- 
and thus eliminating the need for either Ca(OH).sub.2 or NaOH. 
Anion-exchange system 22 is shown having an anion-exchange unit 38 which in 
this embodiment is counter-current continuous anion-exchange resin train 
38 (comprising first stage tank 40, second stage tank 41 and third stage 
tank 42), and a counter-current continuous resin regeneration unit 39 
having first stage tank 50, second stage tank 51, third stage tank 52, 
fourth stage tank 53 and fifth stage tank 54. Anion-exchange unit 38 and 
regeneration unit 39 are operated as fluidized beds. Anion-exchange unit 
or resin train 38 is shown having three conebottom tanks 40-42; it may 
optionally have 2-6 or more preferably 3-5 tanks. Each such tank is filled 
preferably to 20% to 40% of capacity with anion-exchange resin, preferably 
in bead form as is known in the art. There is a sufficient number of tanks 
in the train 38 and each tank is of sufficient size so that the total 
contact time of the water with the resin beads is preferably 10-30, more 
preferably 15-25, minutes, so as to permit effective anion exchange on the 
resin. Thus if the flow rate through the resin train 38 is 100 gallons per 
minute and there are three tanks each 40% filled with resin beads, each 
tank may preferably be 1667 gallons. Influent water travels through the 
tanks 40-42 through line 30, then line 30a, then line 30b, then exiting 
through line 24. 
Typically there are 5-7 tanks in regeneration unit 39, each typically about 
half the size of the tanks in train 38. Regeneration unit 39 is run so 
that the resin beads are regenerated at about the same rate or speed as 
they are used up in train 38. The resin beads go through the resin train 
38 via the pathway of line 45, then line 45a, then line 45b. To be 
regenerated, the resin beads follow the pathway of line 56 then lines 57, 
58, 59, 60, and 61 to storage tank 62. The rinse water (preferably from 
tank 42) goes through lines 63, 64 and 65 to tank 52. Regenerant solution 
(preferably 50% NaOH) goes through line 66 into tank 52 where it joins the 
rinse water to form a typical 4% NaOH brine, then through lines 67, 68 and 
69 to spent regenerant tank 70. Spent regenerant is preferably collected 
into a separate clarifier where calcium sulfate, calcium carbonate, 
magnesium hydroxide and other precipitants and suspended solids that are 
flushed from the regenerating resin are collected. 
The preferred counter-current design does not require the installation of a 
pre-filter as the counter-current principal continuously flushes the resin 
and suspended solids are washed away. In addition, the counter-current 
design does not require a backwash step prior to the regeneration of the 
anion resin. This method also uses far less resin and has a lower resin 
capitol cost. Compared with the batch system, the resin is also less 
stressed with less cracking and breakage and regeneration rates are far 
higher yielding better regenerant usage and lower regenerant cost. The 
continuous counter-current design also uses water from the process (such 
as from tank 42) as resin rinse water and regenerant dilution water. The 
spent regenerant from the counter-current process will be a high solids 
salt solution such as NaCl, Na.sub.2 SO.sub.4, NaNO.sub.3, Na.sub.3 
PO.sub.4, Na.sub.2 HPO.sub.4, etc. that is suitable for other uses. The 
concentration of this spent stream can be in the range of 4 to 7% 
depending on process design. 
Less preferably counter-current continuous resin train 38 and/or 
counter-current continuous resin regeneration unit 39 can be a batch or 
single-tank process or system or setup using comparably or appropriately 
sized tanks as known in the art. Batch regeneration has the resin 
collected in a batch tank and then regenerated with regenerant solution. 
The regenerated resin is fed to a storage tank to supply regenerated resin 
to the head of the process train. Spent regenerant is allowed to settle in 
a storage tank where solids are separated off. 
The anion-exchange resin is preferably a crosslinked polystyrene matrix, 
strongly basic anion-exchange resin, gel type (Type II), in bead form, 
preferably DIAION SA 20A from Mitsubishi Chemical, which are 0.4-0.6 mm 
diameter beads having a total capacity (Meq/ml) (Min.) of 1.3. Other 
DIAION anion-exchange resin beads from Mitsubishi Chemical can be used, 
including DIAION PA 408 and PA 418, which are porous type (Type II) having 
total capacity (Meq/ml)(Min.) of 0.9-1.3. Less preferred anion-exchange 
resin beads include Rohm and Haas Amberlite IRA-410, a strongly basic, 
Type II, quaternary ammonium anion-exchange resin, and weakly basic 
anion-exchange resins made of crosslinked polymethacrylate and crosslinked 
polyacrylate, and Type I anion-exchange resins. Useful anion-exchange 
resin beads may also be obtained from Dow Chemical, Purolite, Mobay, and 
other sources as known in the art. 
In the anion-exchange unit 38 anions such as Cl.sup.-, SO.sub.4.sup.2-, 
NO.sub.3.sup.- and other anions (phosphate, silicate, etc.) are removed 
and are replaced by OH.sup.- ions, thus raising the pH and becoming a 
caustic solution. The treated water leaving the anion-exchange unit 38 via 
line 24 has a pH of preferably 9.5-13.3 as described above, more 
preferably 12-12.8, more preferably about 12.3-12.5. The water from line 
24 combines with untreated water from line 32 and goes into mixing tank 
20. 
Mixing tank 20 is sized as a function of the flow rate to provide 
preferably 10-30, more preferably about 15, minutes of contact time. Thus 
a flow rate of 10 gallons per minute with 15 minutes contact time would 
require a 150 gallon tank. In tank 20 OH.sup.- combines with Mg.sup.2+ 
to yield Mg(OH).sub.2 precipitate. (Silicate is co-precipitated in this 
process). The OH.sup.- also combines with naturally occurring 
HCO.sub.3.sup.- to yield CO.sub.3.sup.2-, which combines with Ca.sup.2+ 
to form CaCO.sub.3 precipitate. In tank 20 there is precipitated primarily 
Mg(OH).sub.2 and as much CaCO.sub.3 as the natural HCO.sub.3.sup.- 
alkalinity will permit. If there is sufficient natural HCO.sub.3.sup.- 
carbonate alkalinity, then mixing tank 21 is not needed. 
Optional mixing tank 21 is the same size as tank 20. If natural bicarbonate 
alkalinity is low or insufficient, carbon dioxide can be fed or injected 
via line 26 into mixing tank 21 to force the precipitation of calcium as 
calcium carbonate. (CO.sub.2 +2OH.sup.- .fwdarw.H.sub.2 O+CO.sub.3.sup.2- 
; CO.sub.3.sup.2- +Ca.sup.2+ .fwdarw.CaCO.sub.3). This can be controlled 
by a calcium hardness analyzer or a pH controller (not shown) sensing tank 
21, where the pH is preferably 9.5-11.5, more preferably 10-11, more 
preferably 10.3-10.7. As has been described and as is shown in FIGS. 1 and 
2, the water softening equipment is operated on the stream of water to 
remove via precipitation reactions hardness ions from the water to yield 
or provide a stream of water having reduced hardness and reduced anion 
content. 
The effluent from tank 20 (or tank 21 if it is used) goes to clarifier 33 
for flocculation, settling and clarification as known in the art. 
Clarifier 33 is sized as a function of flow rate and rise rate, as known 
in the art. Sludge is pumped via line 28 to a filter press or some similar 
dewatering device. Treated effluent water passes via line 29 to a process 
use or other end use or reuse as effectively softened water; it may 
optionally be neutralized to a lower controlled pH by addition of carbon 
dioxide via pH controller 34. Less preferably mineral acid can be used to 
lower the pH. If sent to a sewer or as process water, the pH is preferably 
6-9; if sent for cooling water, the pH is typically 6 or 7 to 8.5. 
Optionally a second clarifier can be provided between first stage mixing 
tank 20 and second stage mixing tank 21. In this configuration, high rates 
of magnesium and silica removal are achieved. The sludge from this 
intermediate clarifier will have commercial value for its magnesium 
hydroxide content (if the influent is not highly contaminated). The 
effluent from this intermediate clarifier is then passed into the second 
stage mixing tank where optional carbon dioxide is added and calcium 
carbonate is precipitated. This two-stage process has very high magnesium 
and calcium removal rates. The magnesium can be dropped to under 1 ppm 
with calcium reduced to under 10 ppm while sulfate can be reduce to under 
50 ppm. Chloride reduction becomes a function of the counter-current 
stages used in the design or the recycle rate through the unit. 
Similarly to FIG. 1, the invention can less preferably be practiced in a 
situation where the mixing tanks and clarifier are replaced by a lined or 
encased pond (such as a wastewater pond or environmental pond) or similar 
tankage. In such situations the ponds or tankage would have reactor and 
clarifier sections. 
Alternatively, tank 20 can receive (a) effluent water from two or more 
separate or independent anion-exchange units and (b) untreated water (ie, 
water which has not gone through an anion-exchange unit) from one or two 
or more sources separate or independent of or in substitution for influent 
line 23 and/or line 32, such as a series of wells or a series of process 
lines to be softened for reuse. For example, line 30 could be from a first 
well and line 32 could be from a separate, second well. 
FIG. 2 illustrates a less preferred water treatment system according to the 
invention. It is in most ways the same as FIG. 1. In FIG. 2 the thick line 
shows the principal flow of water. Line 1 carries alkaline solution (high 
in OH.sup.-) as anion unit effluent (pH preferably 11-13.1, more 
preferably 12.3-12.7) from the anion-exchange unit 10 to the first stage 
mixing tank or reaction zone 2. Mixing tank 2 also receives untreated 
influent water via line 13. The water then flows through optional second 
stage mixing tank or reaction zone 3, clarifier 5, and into line 7 via 
pump 6. A portion (typically less than half) of the water from line 7 
(having pH of preferably 9.5-13.1, more preferably 10.3-10.7) is carried 
or supplied or sidestreamed via line 8 through deep media filter 9 to 
anion-exchange unit 10, where the process is repeated as described above. 
The portion to be diverted is controlled by pH controller 14 sensing tank 
2 and controlling valve 15, using the same principles used in FIG. 1. The 
other portion of the water from line 7 is carried via line 11 to exit the 
system as end use or reuse or service water. Carbon dioxide can be added 
via line 12 as described above for FIG. 1 using pH controller 16 to 
control valve 17 to lower the pH as desired or needed. Filter 9 removes 
particulate or fines (down to about 1 micron particles) missed by or 
carried over from the clarifier. Any filter can be used; a backwash style 
is preferred. 
A strong anion resin unit 10 (conventional bottle style) is installed 
consisting of its associated equipment including a caustic storage tank 
(either sodium, potassium or ammonium hydroxide). The size of anion unit 
10 depends on the water quality, flow rate, contact time desired and how 
filled it is with anion-exchange resin beads (preferably 20-40%). Carbon 
dioxide can be provided via line 4 to the optional mixing tank 3 in the 
event there is insufficient bicarbonate alkalinity in the water. 
As can be seen, the unit of FIG. 2 is constructed and operated in most 
respects the same as or comparable to the unit of FIG. 1. The mixing tanks 
2, 3 and clarifier 5 are the same as in FIG. 1; the operating pHs and 
conditions and controls are the same or comparable. When the filter 9 and 
anion-exchange unit 10 are filled with particulate, they are backwashed as 
shown via backwash supply lines 18, 19 with the backwash being added to 
tank 2. As an option there can be a second filter 9 and/or a second anion 
unit 10; the system can be switched to the backups while the first units 
are being backwashed and regenerated. After anion unit 10 is backwashed, 
it is regenerated by brining it with typically 4% NaOH, then slow rinsing, 
then fast rinsing, all as known in the art. The slow and rapid rinse 
waters may be piped to a storage tank, where they may be slowly pumped to 
tank 2; this is an optional step to reduce reject fluid loading. 
Optionally, anion unit 10 and filter 9 can be replaced by a 
counter-current anion-exchange unit and counter-current regeneration unit 
as in FIG. 1. 
In both FIGS. 1 and 2, the spent regenerant from the anion resin is 
collected in a storage tank 70 or 46 for off or on-site recovery; the 
sludge from the reactor/clarifier is also collected for off or on-site 
recovery. With respect to regenerant recovery processes, ammonium 
hydroxide can be used for anion regeneration and the spent regenerant can 
be mixed with the produced sludge to create a nitrogen-rich fertilizer. 
This fertilizer can be further augmented with phosphorus compounds. 
Optionally, potassium hydroxide can be used as the anion regenerant. The 
spent potassium hydroxide regenerant can be a valuable product for use in 
wastewater plants (activated waste plant). The potassium would provide a 
valuable nutrient to the process. Where sodium hydroxide is used as the 
regenerant, the spent regenerant can be used as a reagent for aluminum 
processing, or a feed stock to caustic, soda ash or soda bicarbonate 
manufacture. If the water being treated contains high chlorides the spent 
regenerant can be used to manufacture sodium hypochlorite. 
The sludge (sometimes referred to as lime sludge) produced can be 
(depending on the metals contained in the influent water) dried, 
pelletized and used in steel-making. Alternatively, the sludge (if derived 
from water free of heavy metals) can be used in a utility power station 
flue gas desulfurization unit. If lime is used as the regenerant, gypsum 
or calcium chloride can be obtained as useful by-products. The use of lime 
as a regenerant is desirable in waters with a high sulfate content or 
where there is a use for a gypsum slurry. If sodium or potassium hydroxide 
is used as the regenerant to treat high chloride waters the spent 
regenerant can be used as a feed stock to a diaphragm or membrane caustic 
plant to make the alkali and chlorine. For waters containing high sulfate 
where sodium or potassium hydroxide is used as regenerant, the spent 
regenerant is suitable as a feed stock to a LeBlanc Process (or 
comparable) soda ash, sodium bicarbonate or caustic manufacturing plant. 
Additional benefits of the invented system are as follows. Organics such as 
oily materials that could normally foul an anion resin unit can be removed 
in the flocculation process or by continuous counter-current flow. Some 
portion of dissolved organic materials (primarily acids or anions) that 
would pass from a conventional lime softener are captured in the invented 
process. The amount of reduction is a function of the percent of flow 
through the anion circuit. Unlike Reverse Osmosis or evaporation 
technology, capital and operating costs are rather low. Maintenance is 
minimal and operating control is fairly simple. The unit can handle a wide 
variety of influent waters and can automatically adjust to changes in 
influent quality. 
As can be seen, the anion-exchange units in FIGS. 1 and 2 are used 
independently of any cation-exchange unit; there is no cation-exchange 
unit (removing cations and adding H.sup.+) prior to the water going 
through the clarifier. It is noted that a small cation-exchange unit can 
be added at the effluent end to polish the effluent water, such as to 
enhance the removal of sodium and/or lower the pH (Na.sup.+ being 
replaced by H.sup.+ ; H.sup.+ combining with OH.sup.- to yield H.sub.2 
O), prior to the effluent being sent out for use or service, but this is 
completely optional. This procedure is particularly useful in waters with 
low magnesium and calcium but high chloride content. Less preferably, 
where high sodium wastewaters are being treated a magnesium cycle 
cation-exchange unit may be placed in front of the anion train. (A 
magnesium cycle cation-exchange unit removes cations such as Na.sup.+ 
from the water and replaces them with magnesium ions.) In this 
configuration sodium is removed and is replaced by magnesium and the 
magnesium is then dropped out in its normal fashion in the invented 
process. 
The following Examples further illustrate various aspects of the invention. 
EXAMPLE 1 
A pilot plant was set up basically as shown in FIG. 1. Tanks 40-42 were 
each 30-gallon conebottom tanks; tank 20 was 30 gallons (pH about 
11.3-11.6) and line 32 was controlled via pH controller 25. Tank 21 (30 
gallons) was used and utilized CO.sub.2 sparging via line 26 via a pH 
controller sensing tank 21 and maintaining pH at about 10.3-10.6. 
Clarifier 33 was a 70 gallon conebottom tank with overflow weir. The total 
flow rate was 6 gallons/min. with 2 gal/min. through line 30 to unit 38 
and 4 gal/min. through line 32 directly to tank 20. Each of tanks 40-42 
was filled with about one cubic foot (about 40% of capacity) of Mitsubishi 
DIAION SA 20A anion-exchange resin beads which had been prepared by 
soaking in 4% NaOH and rinsing in DI water. Total bead contact time was 
thus about 18 minutes. 
Resin beads were moved periodically from tank 42 to tank 41 to tank 40, 
particularly when the pH dropped in tank 20. Tanks 50-54 were 15 gallons 
each; the rinse water in tank 54 came from tank 42 (pH 12.3-12.5). The 
regenerant solution into tank 52 was 50% NaOH. The spent regenerant 
solution from tank 50 (containing NaCl, Na.sub.2 SO.sub.4, etc.) went to a 
recycling operation. 
About 300 gallons each of five different source waters were run through the 
pilot plant. The results shown in Table 1 are the averages of three 
readings. Calcium is expressed as CaCO.sub.3 ; magnesium is expressed as 
CaCO.sub.3 ; chloride is expressed as NaCl; sulfate is expressed as 
SO.sub.4 ; sodium is expressed as Na. 
TABLE 1 
______________________________________ 
Influent Effluent 
Percent 
Source Water (ppm) (ppm) Reduction 
______________________________________ 
1. wastewater 1 
Calcium 1703 33 98.08% 
Magnesium 671 0.2 99.97% 
Chloride 6800 2500 63.24% 
Sulfate 2160 417 80.69% 
Sodium 2860 2250 21.33% 
2. wastewater 2 
Calcium 1195 59 95.04% 
Magnesium 266 0.21 99.92% 
Chloride 5000 3850 23.00% 
Sulfate 2175 1236 43.17% 
Sodium 2700 2360 12.59% 
3. Cooling Tower water 
Calcium 745 51 93.15% 
Magnesium 1072 0.21 99.98% 
Chloride 4700 3000 36.17% 
Sulfate 7710 5220 32.30% 
Sodium 3690 3210 13.01% 
4. well water 1 
Calcium 723 17 97.64% 
Magnesium 290 6 97.99% 
Chloride 500 390 22.00% 
Sulfate 582 49 91.55% 
Sodium 332 268 19.28% 
5. well water 2 
Calcium 112 10 91.41% 
Magnesium 1065 0.21 99.98% 
Chloride 150 50 66.67% 
Sulfate 68 0.3 99.56% 
Sodium 97 67 30.93% 
______________________________________ 
The results, particularly the percent reductions, were surprising and 
unexpected. 
EXAMPLE 2 
Table 2 shows, for selected components, test results of water sample Nos. 
6, 7 and 8 which were run through a static lab test configured or 
patterned basically according to the design or configuration of FIG. 2, 
and run as per FIG. 2 described above. The resin beads were Mitsubishi 
Chemical DIAION SA 20A. The numbers are parts per million. 
TABLE 2 
______________________________________ 
Influent 
Effluent 
Influent 
Effluent 
Influent 
Effluent 
Water Water Water Water Water Water 
Component 
No. 6 No. 6 No. 7 No. 7 No. 8 No. 8 
______________________________________ 
Calcium 462 28.9 26 25 30 24 
(as Ca) 
Magnesium 
240 0.147 6 0.145 5.4 0.14 
(as Mg) 
Chloride 2600 1700 715 600 1450 730 
Sulfate 15000 100 425 25 860 33 
Silica 3.4 1.25 5 &lt;1.0 7.6 &lt;1.0 
Sodium 2900 1740 
Potassium 
81.8 48.2 
Strontium 
7.18 1.35 
Lead 0.127 &lt;0.01 
______________________________________ 
These test results show that, to an extent that was surprising and 
unexpected, the process of the invention was effective in softening the 
water and reducing the content of selected components. The invention also 
surprisingly lowered the sodium and potassium concentrations, as shown in 
water sample No. 6. 
In addition to softening the influent water, the invention also effectively 
reduces the concentration of undesirable anions (particularly chloride, 
sulfate, phosphate, nitrate and silicate) and reduces the concentration of 
undesirable amphoteric components and non-hardness cations. It is 
believed, and testing thus far has indicated, that the percent reductions 
shown in Table 3 can be achieved by the practice of the present invention; 
that is, the invention can be used to treat influent water having 
components (principally ionic material) in the following concentration 
ranges (ppm) so as to achieve the percent reductions in concentration 
listed. For ppm concentration calculations, Ca and Mg are expressed as 
CaCO.sub.3 ; Cl is expressed as NaCl; sulfate is expressed as SO.sub.4 ; 
phosphate is expressed as P; nitrate is expressed as NO.sub.3 ; nitrite is 
expressed as NO.sub.2 ; and silica is expressed as SiO.sub.2. If there are 
two streams of water, the aggregate concentration of a component in the 
two streams is the concentration which would exist if the two streams were 
combined and mixed. 
TABLE 3 
______________________________________ 
Less 
Preferred 
Preferred 
Influent Influent Preferred 
Less Preferred 
Water Water Percent Percent 
Component 
ppm ppm Reduction 
Reduction 
______________________________________ 
Ca 700-2000 100-5000 at least 98% 
at least 80, 
90 or 95% 
Mg 200-1000 100-4000 at least 99.9% 
at least 85, 
90 or 95% 
C1 500-2000 100-7000 at least 95% 
at least 20, 
40, 60, 80 or 
90% 
Sulfate 500-2500 100-20,000 
at least 99% 
at least 25, 
40, 60, 80, 
90 or 95% 
Na or K 300-1000 100-4000 at least 25% 
at least 10, 
15 or 20% 
Cu, Pb, Fe, 
1-10 0.5-40 at least 99% 
at least 70, 
Ba, Mn or 80, 85, 90, 
Sr 95 or 98% 
Zn, Cr, As, 
1-10 0.5-40 at least 99% 
at least 50, 
Se, Ni, Ng, 70, 80, 90 or 
Cd or Al 95% 
Phosphate 
0.3-4 0.1-10 at least 99% 
at least 50, 
70, 80, 90 or 
95% 
Nitrate 1-20 0.5-100 at least 99% 
at least 50, 
70, 80, 90 or 
95% 
Nitrite or 
1-30 0.5-100 at least 99% 
at least 50, 
Mo 70, 80, 90 or 
95% 
F 1-10 0.3-50 at least 99% 
at least 20, 
40, 60, 80, 
90 or 95% 
Silica 1-30 0.5-150 at least 99% 
at least 50, 
70, 80, 90 or 
95% 
Cyanide 2-20 0.5-80 at least 95% 
at least 40, 
60, 70, 80 or 
90% 
______________________________________ 
It is believed that Na and K are removed by association with Mg(OH).sub.2, 
magnesium silicate and CaCO.sub.3 precipitates, such as by being entrained 
in the molecular structure or being tied up or adsorbed onto the surface, 
etc. Silica is removed by precipitation as magnesium silicate and/or anion 
exchange removal. The anions are removed in the anion exchange unit, by 
being entrained in the structure of other precipitates, by being adsorbed 
onto the surface of other precipitates, or in some cases by being removed 
as insoluble salt precipitates such as calcium phosphate or calcium 
sulfate or as complexes such as sodium ferrocyanide. With regard to the 
metal ions, some are amphoteric and are removed in the anion-exchange 
unit, others go through the anion exchange unit and precipitate out as 
their hydroxide or carbonate salt in the reactor/clarifier. The invented 
process and system will remove such ionic material as well or better than 
the traditional lime treatment system. The traditional lime treatment 
system produces considerable sludge; the present invention avoids this by 
minimizing sludge and waste production and eliminates many of the 
operational headaches of conventional lime treatment. 
The present invention can be used to produce drinking water in areas of 
poor quality and to convert seawater into drinking water; it can clean or 
polish wastewater to create usable process water; it can polish process 
water for extended use. In areas with brackish water or high chloride or 
sulfate content, the invention can produce a rinse or process water that 
improves product quality in a process such as soda ash or sodium 
bicarbonate refining. In coastal areas it makes the production of 
magnesium hydroxide and magnesium oxide from seawater more economical and 
environmentally friendly. Gypsum, magnesium hydroxide and calcium 
carbonate may be individually formed. The effluent water from such a 
process could be sent to a reverse osmosis (RO) process to produce 
drinking water at a faction of the cost of normal RO processed seawater. 
With this process RO reject can be reintroduced into the head of the 
process to be reprocessed or evaporated to produce a medium quality sodium 
chloride. 
Anion content in the final effluent is greatly reduced. These anions would 
include chloride, sulfate, nitrate, silicate, phosphate and organic acids. 
The elimination of the organic component has the added benefit of color 
reduction and lowering of Total Organic Carbon (TOC). When the invention 
is applied in a drinking water application, the lowering of TOC will 
result in a lower potential of making THMs (Tri-HaloMethanes). 
Although the preferred embodiments of the invention have been shown and 
described, it should be understood that various modifications and changes 
may be resorted to without departing from the scope of the invention as 
disclosed and claimed herein.