The manganese dioxide coated surface of GreensandPlus acts as a catalyst in the oxidation reduction reaction of iron and manganese. The silica sand core of GreensandPlus allows it to withstand waters that are low in silica, TDS and hardness without breakdown. GreensandPlus is effective at higher operating temperatures and higher differential pressures than standard manganese greensand. Tolerance to higher differential pressure can provide for longer run times between backwashes and a greater margin of safety. Systems may be designed using either vertical or horizontal pressure filters, as well as gravity filters. GreensandPlus is a proven technology for iron, manganese, hydrogen sulfide, arsenic and radium removal. Unlike other media, there is no need for extensive preconditioning of filter media or lengthy startup periods during which required water quality may not be met. GreensandPlus is an exact replacement for manganese greensand. It can be used in CO or IR applications and requires no changes in backwash rate or times or chemical feeds. GreensandPlus has the WQA Gold Seal Certification for compliance with NSF/ANSI 61. Packaging is available in 1/2 cubic foot bags or 1 metric ton (2,205 lbs) bulk sacks.
Physical Form: Black, nodular granules shipped in a dry form
Apparent Density: 88 pounds per cubic foot net
Shipping Weight: 90 pounds per cubic foot gross
Specific Gravity: Approximately 2.4
Porosity: Approximately 0.45
Screen Grading (dry): 18 X 60 mesh
Effective Size: 0.30 to 0.35 mm
Uniformity Coefficient: Less than 1.60
pH Range: 6.2-8.5 (see General Notes)
Maximum Temperature: No limit
Backwash Rate: Minimum 12 gpm/sq. ft. at 55ºF (see expansion chart)
Service Flow Rate: 2 – 12 gpm/sq. ft.
Minimum Bed Depth: 15 inches of each media for dual media beds or 30 inches of GreensandPlus alone.
Suggested Operating Conditions:
Dual media: anthracite 15-18 in. and
GreensandPlus 15-24 in.
700-1200 grains of oxidized iron and
manganese/sq.ft. of bed area based on
oxidant demand and operation to iron break
through or dp limitations.
Sufficient rate using treated water to produce
40% bed expansion for 8 minutes or until
waste water is clear.
Optional using 0.8-2.0 cfm/sq. ft. with a
simultaneous treated water backwash
at 4.0-4.5 gpm/sq. ft.
Raw Water Rinse
At normal service flow rate for 3 minutes or
until effluent is acceptable.
Recommended flow rates with CO operation
are 2-12 gpm/sq. ft. Extremely high
concentrations of iron and manganese
usually require lower flow rates for equivalent
run lengths. Higher flow rates can be
considered with very low concentrations of
iron and manganese. For optimizing design
parameters, pilot plant testing is
recommended.The run length between
backwashes can be estimated as follows:
What is the run length for a water containing
1.7 mg/L iron and 0.3 mg/L manganese at a
4 gpm/sq. ft. service rate:
= (1 x mg/L Fe) + (2 x mg/L Mn)
= (1 x 1.7) + (2 x 0.3)
= (2.3 mg/L or 2.3/17.1 = 0.13 grains/gal. (gpg)
At 1,200 grains / sq. ft. loading ÷ 0.13 gpg = 9,230 gal./sq. ft.
At 4 gpm / sq. ft. service rate 9,230/4 = 2,307 min.
The backwash frequency is approximately every 32-38 hours of actual operation.