استخدام فلتر الزيوليت الطبيعى والصناعى والنشط فى معالجة المياه

Zeolite filter media: Setting a new standard for water filtration

BY

TECHNOLAB EL-BAHAA GROUP

GENERAL.DR

BAHAA BADR

WATER TREATMENT ADVISOR

01229834104

High purity zeolite has the physical, mineral properties needed for efficient water filtration.

Over the past 50 years, advances in granular filter media water filtration have been achieved by using smaller mesh size sand combined with garnet or garnet/anthracite (multimedia) to achieve a nominal 12 to 15µ rating and to improve bed design and fluidics.

High purity zeolite media is now available that achieves a <5µ nominal rating.

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Structure and properties

Mineralogically, there are about 40 known types of natural zeolites (hydrated silicates) of which clinoptilolite is the most common.

Clinoptilolite is classified as a crystalline, aluminum, silicon, oxide mineral (Berkhout 2002; Rempel, 1996).

This report describes a high purity 14 x 40 mesh, approximately 55 lb/cu. ft. bulk weight, clinoptilolite (zeolite) from the western US that has a high porosity, high surface area, a micro-crystal structure, and is abrasion resistant.

This zeolite media is classified under 21CFR Part 182.2729 and under 40 CFR Part 180 as GRAS (Generally Recognized As Safe). It is also listed under NSF Standard 61.

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Performance and advantages

Since the mid-1970s, lab and field test data reports in the US have indicated that zeolite filtration media has consistently outperformed sand, sand/anthracite and multimedia in both pressure vessels and gravity filtration tests (e.g., Foreman:1985: Johnson & Petersen, 2001 Hansen, 1997:, Johnson et al, 1997; Fuger, 2003).

Generally, the zeolite filter beds have 1.7 to 1.9 times the solids loading capacity/ft3 and superior filtration performance versus multimedia.

Based on more than 100 lab and field tests (2/3 using pressure vessels and 1/3 using gravity beds) since the mid-1990s representing commercial, residential and industrial water filtration projects, it has been concluded that high purity zeolite media is superior to conventional granular media.

Our test results using pressure vessels indicate:

For solids loading capacity, high purity zeolite surpassed multimedia, sand/anthracite and sand;

Zeolite more effectively removes fine particles in the 0.5µ to 10µ range that escape conventional medaiI).

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Table I. Summary of performance test data for pressure vessels.

Filter media Filter rating (nominal) Solids loading capacity
Sand (20 x 40 mesh) ~20µ 1X
Sand/Anthracite (20 x 40 mesh & Anthracite) ~15µ ~1.4X
Multimedia ~12µ ~1.6X
Zeolite (14 x 40 mesh) <5µ ~2.6X
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Similar results were observed for gravity beds. Some representative examples of high purity zeolite filter performance are provided below.

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River water turbidity:

Zeolite versus multimedia media filtration tests were conducted for fine particle (turbidity) removal from river water. Pressure vessels (18" diameter) were operated with a service flow rate of 15 gpm/ft2 of bed area for six consecutive days and turbidity (NTU) was measured in the feed and filtrate water.

The zeolite filtrate (product water) average NTU was approximately 1/3 of the multimedia filtrate (see Figure 1), indicating superior fine particle removal by the zeolite.

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Prefilter for GAC:

Municipal water supplied to a restaurant contained elevated iron and other fine particles. Cartridge (5µ) filters rapidly loaded and caused reduced water flow to the GAC beds and chiller.

A backwashing zeolite filter (10" diameter vessel with a 24" bed depth) was installed and tested by an independent engineer and technical consultant.

The feedwater had 0.1µ to 10µ particles (average SDI or silt density index = 4.3).

The zeolite bed effectively removed the iron particles. The product water particles were in the 0.1µ to 2.3µ range, with an average SDI = 0.

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RO prefilter:

An electric utility installed a 1,500 gpm water treatment facility with two multimedia filters and RO equipment to produce boiler make-up water.

The RO units could not be operated due to filter vessel pressure loss problems and an elevated SDI in the filtrate.

The two multimedia beds were replaced with equivalent bed volumes of 14 x 40 mesh high purity zeolite media and the strict design specifications for the RO feed water have been consistently met for over two years.

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Bottled water plant:

A bottled water plant pumped groundwater to four 48"diameter pressure vessels that feed two RO units.

The multimedia reduced the well water SDI by an average 5 percent compared to 45 to 50 percent SDI reduction for the zeolite media.

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Cooling tower makeup water:

A major chemical plant facility in South Texas had turbidity problems with river make-up water being used for a cooling tower, The sand/garnet gravity filter inadequately removed turbid particles after rain events.

The sand/garnet was replaced with an equal volume (545.5 ft3) of 14 x 40 mesh zeolite. The zeolite, when operated at the same flow rate (2.5 gpm/ft2), removed greater than 98 percent of the turbidity versus approximately 20 percent for the sand/garnet.

The zeolite has provided superior filtration for two years.

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Produced water filtration:

A US oil company wanted to convert unusable oil production water into reusable irrigation water.

The production water was processed for oil/water separation: chemical flocculation; clarification; and ozone oxidation. It was then filtered using two pressure vessels (72"diameter) with high purity zeolite media operating at approximately 12 gpm/ft2.

The filtrate was used directly as feedwater for an RO unit and the product water was recycled as agricultural irrigation water.

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Flow rates, backwashing guidelines

For pressure vessels, a 36" bed depth is generally used with undergravel, plus approximately 50 percent freeboard, similar to multimedia beds.

The optimum service flow rate for pressure vessels ranges from 12 to greater than 20 gpm/ft2 of bed area, depending on the water filtration application.

For example, use 12 gpm/ft2 for RO and GAC pre-filtration; use 15 gpm/ft2 to achieve low turbidity well water, surface water and for industrial projects; and 18 to 20 gpm/ft2 rate to get high water volume for projects with lower filtration requirements.

Since virgin zeolite has "fines" from mine production, it is important to backwash it prior to placing in service.

The backwash rule-of-thumb is to achieve 35 percent bed expansion using a backwash rate of 20 gpm/ft2 until the water is clear for new zeolite, and for six minutes for routine operational backwash cycles.

Alternatively, air scour can be used with water to reduce backwash water usage.

ZEOlite filter

by

technolab el-bahaa group

general.dr

bahaa badr

01229834104
ZEOlite is a naturally occurring zeolite and a member of the aluminum silicate mineral family. Natural zeolites were crystallized millions of years ago by reaction of alkaline water and volcanic ash.

The uniform three dimensional honeycomb structure and rough surface gives ZEOlite a surface area thousand times grater than filter sand and making it highly effective for trapping fine particles down to 3 – 5 microns.

Zeolites three-dimensional honeycomb structure has an open and negatively charged framework.

The net negative charge hold the cations for the cation exchange capacity (CEC). Major exchangeable cations include: potassium, calcium, sodium, copper, zinc and nickel.

One pound of ZEOBEST replaces two pounds of sand because the bulk density is about half that of sand. Since ZEOBEST has a greater capacity for particles, the time between backwashes can be increased.

Not all zeolites were created equal. Unlike other filter media that may or may not be the same, zeolite filter media vary greatly from one zeolite filter media to another.

it excels in every attribute of a high quality zeolite filter media. Our large homogeneous deposit produces ZEOBEST that contains 90% (+/- 5%) clinoptilite, has a CEC rating if 1.2 to 1.8+ meg./gram, and a surface area of 1,357 square yards per ounce

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Advantages

Filters turbidity down to 3 – 5 microns for significant water clarity

Higher surface area allows for longer filter runs between backwashes

Cation exchange capacity adsorbs ammonia to reduce chloramines
Longer filter runs results in savings in backwash water and time out of service

Naturally occurring material

Half the weight of sand. 50 lbs of ZEOBEST compares to 100 lbs of sand

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Physical Characteristics

Color: pale green

Bulk Density: 50 lbs./cu. ft.

Specific Gravity: 1.5 – 1.7

Effective Size: .50 – 3.0 mm

Uniformity Coefficienty: 1.5

Mesh Size: #30 – 3/8 in.

Hardness: 5.1 (Mohs scale)

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Operational Specifications

Bed depth: 12 – 36 in.

Freeboard: 50% of bed depth (min.)

Service flow rate: 15 – 20 gpm/sq. ft.

Backwash flow rate: 15 – 20 gpm/sq. ft.

Backwash expansion rate: 35% of bed depth

موضوع: فلتر الزيوليت الأحد سبتمبر 30, 2012 4:41 am

Activated Zeolite

(1).remove peculiar smell of the water

(2).adsorptive exchange function

(3).breakage rate/less than 1.0%

Activated zeolite filter media

(1). Activated zeolite is produced by various special craft activation.

Its adsorptive capacity is stronger than natural zeolite and ion exchange
ability is also much better.

(2). It is beneficial to remove various micro-pollutants yet the water-lixivium
is nonpoisonous, remove harmful substances to human body and the iron
and fluorine removal effect in the water is remarkable.

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استخدام فلتر الزيوليت الطبيعى والصناعى والنشط فى معالجة المياه 4a_zeo10

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استخدام فلتر الزيوليت الطبيعى والصناعى والنشط فى معالجة المياه Activa10

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THEORY OF ZEOLITE FILTER MEDIA

Using ZCA™ natural zeolite in physical filtration systems offers several advantages, including:

• The high internal and external surface area of ZCA™(@25m2/g) exceeds that of quartz by more than 10 times.

• ZCA™ pore space permeability for water transmission through the grains or fragments is 100% compared to nonpermeable quartz grains.

• ZCA™ will tend to make slightly acidic (e.g. pH - 5.5-6.0) water more near neutral.

• The amount, or layer thickness of ZCA™ in the filtration systems can be much thinner (smaller volume) than quartz

sand systems - because of the high “surface area and pore space” of ZCA.

• ZCA™ fragments tend to be discoid shaped, rather than round, thus presenting a large surface area (per unit of

mass)).

• The density of 2-4 mm granules of ZCA™ is about 55-60 lb/ft3, which is about half of that of quartz grains of similar
size.

Thus the volume of one ton of ZCA™ is twice that of quartz sand.
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PRODUCT DESCRIPTION

Mineral Natural Zeolite primarily clinoptilolite )

Size 14 x 40 mesh

Weight 55 pounds per cubic foot

Sieve analysis Uniformly coefficient 1.8

GRAS Classified “GRAS” generally regarded as safe under (21 CFR Part 182.2729; 40 CFR Part
180.1001)

Surface Area Surface area 24.9 square meters/gm

Porosity High porosity, irregular surface

Moisture Holds 55% of its weight in water

NSF Zeolite based drinking water treatment product ANSI/NSF Standard 61

Hardness Low clay, hard, abrasion resistant
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COMPARISON OF ZEOLITE FILTERS PERFORMANCE VS CONVENTIONAL MEDIA

Pressure Vessels

FILTER MEDIA BED COMPOSITION

FILTRATION RATING
(nominal)

SOLIDS LOADING

CAPACITY

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Gravity Flow Beds

FILTER MEDIA BED COMPOSITION

FILTRATION RATING
(nominal)

SOLIDS LOADING

CAPACITY

Water Treatment

Natural zeolite is one of the best natural materials available for water filtration.

Its high porosity and specific surface area combined with its natural cation exchange capacity make it far superior to sand and other minerals used for water filtration.

Natural zeolite removes particulate contamination down to 10µm and below, it adsorbs dissolved cations such as Fe, Mn, Cu, Zn, and heavy metals such as Pb and As, and it can remove odours and some organic contaminants.

Natural zeolite has a particular affinity for ammonium ions and is used successfully in many industrial water treatment plants to remove high levels of ammonium ions from waste water.

It is also employed to remove heavy metal contamination from industrial effluent.

Zeolites are used in the same way as sand and can replace sand in existing installations to give improved performance.

They can also be used in conjunction with sand and/or other filter media such as activated carbon to produce very pure water or to clean heavily contaminated water.

With the new regulations on water recycling, zeolites offer the potential to produce clean usable water from almost any source.

Natural zeolites granules have been described by some as the world's smallest filter.

They are used for water potabilization, swimming pool filtration and industrial water treatment.

Zeolites are also used in sewage treatment in many countries although they have yet to be fully exploited here in Spain.

Given the importance of water as a natural resource and the shortages we face on a regular basis, the use of zeolites could make an important contribution to the efficient use of water in this country.

Many studies have been carried out which demonstrate the effectiveness of natural zeolites in water treatment applications, and you can find a selection of these on the R+D page of this website.

Zeolite's affinity for ammonium ions makes it particularly useful for use in fish farms.

High ammonia levels are detrimental to the health of the fish, but natural zeolite is highly effective in removing ammonia.

It is also used in aquarium filters, pond filters, and in the transportation of live fish.