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Drinking Water

 

THEORY OF ZEOLITE FILTER MEDIA

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

  • The high internal and external surface area (@25m2/g) exceeds that of quartz
    by more than 10 times.
  • pore space permeability for water transmission through the grains or fragments
    is 100% compared to non-permeable quartz grains.
  • will tend to make slightly acidic (e.g. pH - 5.5-6.0) water more near neutral.
  • The amount, or layer thickness  in the filtration systems can be much thinner
    (smaller volume) than quartz sand systems - because of the high “surface area and
    pore space”
  • fragments tend to be discoid shaped, rather than round, thus presenting a large
    surface area (per unit of mass) (see diagram below).
  • The density of 2-4 mm granules 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 is twice that of
    quartz sand.

PRODUCT DESCRIPTION

  • Mineral:              Natural Zeolite primarily clinoptilolite (see spec sheet)
  • 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
  • Hydrophilic:
  • NSF:                   Zeolite based drinking water treatment product ANSI/NSF Standard 61
  • Hardness:      Low clay, hard, abrasion resistant  

COMPARISON OF ZEOLITE FILTER PERFORMANCE VS CONVENTIONAL MEDIA:
Pressure Vessels

FILTER
MEDIA

BED
COMPOSITION

FILTRATION
RATING (nominal)

SOLIDS LOADING
CAPACITY

Sand
(6-12 gpm/ft2)

20 x 40 mesh

~20µ

1X

Sand/Anthracite
(6-12 gpm/ft2)

#1 anthracite (66%)
20 x 40 mesh sand
(34%)

~15µ

1.4X

Multimedia
(10-12 gpm/ft2)

#1 anthracite (66%)
20 x 40 mesh sand
(30%)
# 50 garnet (15%)
# 16 garnet (10%)

~12µ

1.6X

Zeolite*
(10-20 gpm/ft2)

14 x 40 mesh (100%)

~5µ

2.8X

COMPARISON OF ZEOLITE FILTER PERFORMANCE VS CONVENTIONAL MEDIA:
Gravity Flow Beds


FILTER
MEDIA

BED
COMPOSITION

FILTRATION
RATING (nominal)

SOLIDS LOADING
CAPACITY

Sand
(2 gpm/ft2)

20 x 40 mesh

~20µ

1X

Sand/Anthracite
(2 gpm/ft2)

#1 anthracite (66%)
20 x 40 mesh sand
(34%)

~15µ

1.4X

Zeolite*
(4 gpm/ft2  design)

14 x 40 mesh

~5µ

2.6 - 2.8X

 

BENEFITS

  • BETTER FILTRATE CLARITY. Typical sand/anthracite filter beds have a 12 to 15 micron nominal filter rating. typically would have a nominal filer rating of less than 5 microns. This property greatly reduces the effluent turbidity, generally measured in national turbidity units (NTUs).
     
  • INCREASED FLOW RATES IN GRAVITY SYSTEMS. In a sand/anthracite filter media system the flow rate is typically 1.2 to 2.0 gpm per square foot. In a filter media system, the flow rate is typically in the 4.0 gpm per square foot range.
     
  • INCREASED FLOW RATES IN PRESSURE VESSEL SYSTEMS.  In a sand/anthracite pressure vessel filter system the flow rates are typically 6 to 7 gpm per square foot.
    In a pressure vessel filter system the flow rates are typically in the 12 to 15 (and sometimes 20) gpm per square foot range.
     
  • LOWER CAPITAL REQUIREMENT TO INCREASE FILTRATION CAPACITY. Generally,the capacity of a filter plant can be doubled with no increase in the plant by switching the filter media to zeolite.
     
  • FEWER BACKWASH CYCLES.  requires only one half of the backwash cycles that are required by sand/anthracite.
     
  • LESS BACKWASH WATER. The fewer backwash cycles generally cut the amount of backwash water by one third to one half. This means treating less backwash water and greater plant capacity.
     
  • GREATER LOADING DUE TO GREATER SURFACE AREA. Zeolite generally has 6 to 7 times the surface area as sand. This makes BRZ a much better filter media with greater holding capacity.
     
  • REMOVAL OF HEAVY METAL CATIONS, NITROGEN, CHLORAMINES, CERTAIN ORGANIC HYDROCARBONS, AND MANY OTHER CONTAMINANTS.
     
  • LONG FILTER BED LIFE. The anticipated filter bed life is 10 years.
     
  • LAND APPLICATION OF SPENT ZEOLITE FILTER BED. Under most conditions,
    filter bed can be applied to lawns and gardens as soil amendments.
     
  • SIMPLER HANDLING Zeolite, monomedia, beds simplify materials handling, shipments and bed loading.
     
  • BETTER CLEANING Active, dynamic, bed tumbling and mixing during backwash
    efficiently cleans bed granules.