Water purification system

Abstract

The present invention relates to a water purification system useful for arsenic removal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a cross-sectional view of a cartridge constructed according to the teachings of the present invention. In this illustration the media is horizontally packed into the cartridge.

FIG. 1 b is a cross-sectional view of an alternate design for the cartridge constructed according to the teachings of the present invention. FIG. 1b illustrates how the media may also be vertically packed within the cartridge.

FIG. 1 c is a cross-sectional view of one alternative for packing of the three layers of media.

FIG. 2 is a view of a water purification assembly according to the teachings of the present invention.

DETAILS

REFERENCE NUMERALS

• 1 filter 1
• 2 untreated limestone
• 3 filter 2
• 4 iron imbibed activated carbon
• 5 iron activated limestone
• 6 cartridge
• 7 inlet end
• 8 outlet end
• 9 media
• 10 pleated filter
• 20 untreated limestone packing
• 21 iron imbibed activated carbon packing
• 22 iron activated limestone packing
• 30 first feed container
• 31 first end of the inlet tube
• 32 inlet tube
• 33 second end of the inlet tube
• 34 cartridge (full outer view)
• 35 outlet end of cartridge
• 36 outlet tube
• 37 second end of the outlet tube
• 38 second container
• 39 spigot
• 40 flow control valve
• 41 inlet end of cartridge
• 42 first end of the outlet tube

DETAILED DESCRIPTION OF THE DRAWINGS

Cartridge

A cartridge design for residential use is shown in FIG. 1a. Although FIG. 1a depicts one design of a cartridge, the figure is not intended to be limiting. One of ordinary skill in the art would recognize that this design is not limited to residential use but may be expanded and/or modified for commercial use. As depicted in FIG. 1, for residential use, the cartridge (6) can be fabricated from typical polymeric materials, for example, polyvinyl chloride, polypropylene, polyethylene, polyethylenterephtalate, ceramic, metal or natural materials. The internal volume can be varied to suit the particular media (9) loading need for the targeted liquid composition which can vary. A typical height of the column for household use ranges from 0.20-0.50 meters. Typical internal volume is the range of 0.1 to 10 liters, preferably 2 to 3 liters. Typical internal volume for municipal systems could be up to 10000 liters, or with up to 100 cartridges arranged in a parallel flow pattern. The cartridge is free standing on a base and contains inlet (7) and outlet (8) ends, optionally nozzles properly sized to fit any given tubing.

The cartridge is filled with the media (9) described in Table 1. These ingredients ensure arsenic and heavy metal removal from water, as well as water that is colorless and odorless

TABLE 1
Contents of column
Filter 1 (1)
untreated limestone (2)
Filter 2 (3)
iron imbibed activated carbon (4)
iron activated limestone (5)

The range in %-volume of the different media can be defined to be 1-70% for the limestone untreated material 0-70% for the iron imbibed activated carbon, and 30%-99% for the iron coated limestone. The preferable range in % volume: for the media is 25-30% untreated limestone, 18-22% iron-activated carbon and 48-54% iron coated limestone.

An alternative cartridge design concept is shown in FIG. 1b. This design uses pleated filter (10) media to guide the water through a more plug flow pattern to prevent channeling and more efficiently uses the media.

FIG. 1 c shows a cross-sectional view of each of the three layers of packing. The first illustration (20) depicts the untreated limestone packed into the cartridge. The second illustration (21) depicts the iron imbibed activated carbon packed into the cartridge. The third illustration (22) depicts the iron activated limestone packed in a pleated formation into the cartridge.

Water Purifying Assembly

One design for an entire water purifying assembly for residential use is shown in FIG. 2. The system, as depicted in, FIG. 2, is designed to require minimal assembly. The figure is not meant to limit the invention to the representation presented. It is conceivable that one of ordinary skill in the art may modify and or expand this representation so that it is practical for commercial and other uses. However, with regard to the figure depicted, a potential user will fill the first feed container (30) with an untreated solution. In the case of a gravity operated system, the height differential between the feed container (30) and the cartridge (34) provides sufficient head pressure for water to flow by gravity through the first end (31) of the inlet tube (32), through to the second end (33) of the inlet tube to the inlet end of the cartridge (41). Optionally, a flow control valve (40) may be incorporated onto the inlet tube to control the flow rate of the fluid. Ideally, the flow control valve (40) is set to a specific location so that the starting flow rate is between 50 and 500 ml/min, preferably between 100-200 ml/min. Water flow through the column is from bottom to top which allows for the use of a minimal amount of media during flow and relatively steady flow rate during the life of the cartridge (34). Treated water will pass from the outlet of the cartridge (35) through the first end of the outlet tube (42), through the outlet tube (36), through the second end of the outlet tube (37) and into the second container (38) for storage which is optionally equipped with a spigot for dispensing the water (39).

EXAMPLES

Example 1

The system was set up as shown in FIG. 2. A 50 liter carboy of deionized water was spiked with 150 ppb As(III) and 150 ppb As(V), 2 ppm Fe(II). The solution measured at pH 6.5. The cartridge column was packed with 1.0 liters of iron activated limestone 0.2-0.5 mm, 0.5 liters of untreated limestone, and 0.5 liters of iron activated carbon, (See FIG. 1). ⅜″ tubing was connected from a first source container to column; air was bled out of line; and the flow control valve was set for initial flow rate of 180 ml/minute. Water flowing out of the column was collected in a 50 liter second container and analyzed periodically during the run.

Tests have been conducted that demonstrate the treatment of 20- and 50-liter batches of arsenic-containing water at an average flow rate of 160 ml/min. One cartridge has been shown to treat more than 4,000 liters of water by running multiple batches per day over several weeks. Arsenic III and V have been reduced from 300 ppb (150 ppb each III and V) to less than 10 ppb over this several week period. Furthermore other benefits were realized such as the reduction of other ions, pH control and improvement in water color and clarity.

Table 2 below illustrates this proposition

TABLE 2
Arsenic Concentration vs Total Water Flowed Through System
Accumulated Liters As III and V (ppb)
0                  0
100                0
200                0
300                0
400                0
500                0
600                0
700                0
800                0
900                0
1000               0
1100               0
1200               0
1300               0
1400               0
1500               0
1600               0
1700               0
1800               0
1900               0
2000               0
2100               0
2200               0
2300               0
2400               1
2500               1
2600               1
2700               1
2800               1
2900               1
3000               1
3100               2
3200               2
3300               2
3400               2
3500               3
3600               3
3700               3
3800               3
3900               5
4000               5
The influent water, prior to running through the system contained 300 ppb As, 2 ppm Fe(II) and had a pH of 6.5. Arsenic was measured by ICP-MS.

Claims

1. A device for purifying solutions comprising: i. a first containerii. an inlet tube comprising two ends wherein the first end of the inlet tube extends into the first container;iii. a cartridge having two ends comprising media wherein the second end of the inlet tube attaches to the cartridgeiv. an outlet tube comprising two ends wherein the first end of the outlet tube extends from the cartridge; andv. a second container wherein the second end of the outlet tube extends into the second container

2. The device of claim 1 wherein the device comprises a pump.

3. The device of claim 1 wherein the two ends of the cartridge comprise an upper end and a lower end wherein the upper end is in the upper third of the cartridge and the lower end is in the lower third of the cartridge.

4. The device of claim 3 wherein the second end of the inlet tube attaches to the lower end of the cartridge.

5. The device of claim 3 wherein the first end of the outlet tube extends out of the upper end of the cartridge.

6. The device of claim 4 wherein the first end of the outlet tube extends out of the upper end of the cartridge.