Before purchasing a filter, you should ask the manufacturer to describe the conditions under which the filter will perform satisfactorily.  You should provide data to the manufacturer on your water quality and required effluent water quality, and discuss whether their filter will yield the desired results.

In many cases, several steps of treatment are required to achieve desired water quality.  So a manufacturer’s filter may be a necessary component of the treatment process, but not sufficient by itself, to produce the results you want.

Here are some tips for getting the best performance from your filter.

Tip #1 – Do not exceed the design flow of the filter.  If you need to expand the flow to be filtered, consult the manufacturer to see what options are available.

Tip #2 – If water quality changes, consult the manufacturer of the filter to determine whether modifications in treatment are needed.

Tip #3 – If performance of the filter has degraded over time,

1. Analyze the water prior to filtration and compare current concentrations with previous ones.  If concentrations of suspended solids and/or other substances or particles sizes have changed significantly, you may need to modify the filter to accommodate those changes.
2. If the filter is cleaned via backwashing, check to determine how frequently backwashing is taking place and the duration of the cycle.   Also, check to make sure there is a sufficient volume of water available for thorough backwashing.
3. Check pressure at the inlet of the filter to make sure it is sufficient for the type of filter you have.
4. If you are adding coagulants, check to make sure dosing is at the correct level.  Over or under dosing can adversely affect filter performance.
5. Check to see whether required periodic servicing is being performed as recommended.

Tip #4 – Maintain the manufacturer’s recommend maintenance procedures.  If you find that these have been neglected, consult the manufacture for corrective actions that can put filter performance back on track.  Simply resuming periodic maintenance may not be adequate to correct problems that have arisen.

For any questions or to discuss any problems you’re experiencing with filter performance, contact an Everfilt Applications Engineer at: (951) 360-8380.

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For these reasons, many end users are choosing to filter their backwash water so it can be sent back to the head of the process or re-used for a variety of purposes.  In order to treat the water to make it reusable, the following steps need to be followed:

1. Provide a cone-bottom tank to hold backwash water and provide opportunities for the heavier particles to settle to the bottom of the tank.

1. Install a pump to transfer clarified water from the holding tank to a bag or cartridge filter with elements rated for removal of 95% or more of the particles that have not settled.  (You can guess at the appropriate micron rating- not recommended – or you can send a sample of the clarified water to a laboratory for a particle size distribution analysis.)

1. Filtered water from the bag or cartridge filter can be used for a variety of purposes such as:
   1. Process water
   2. Water for future backwash cycles
   3. Cooling tower or boiler make-up
   4. Firefighting water
   5. Landscape irrigation and
   6. Wash down

Maximizing water re-use makes sense both in terms of the environment and the company bottom line.  For more information or a treatment proposal, contact an Everfilt engineer at everfilt@everfilt.com .

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• the water contains iron or
• that pipes and/or boilers are corroded

Differentiating between these two causes is important, because it affects the type of treatment that will be most effective in resolving the problems.

The first step is to take a sample of water before it enters the facility and another sample at a point where discoloration and/or rust-colored flakes are apparent.  The water should be analyzed by a licensed laboratory for the presence of dissolved iron, total iron and total suspended solids (TSS).

If iron is present in water as it comes into your facility, an iron removal filter (or Greensand filter) will be needed.   Most of the iron in the raw water will be present in dissolved form (as ferrous iron).  Removing the iron is most frequently accomplished via oxidation, which transforms it from ferrous iron to ferric iron.  The small particles of ferric iron can then be removed via mechanical filtration.   Oxidation is accomplished typically through aeration and/or the injection of an oxidizing chemical such as sodium hypochlorite or potassium permanganate.

The type of mechanical filter often used is a Greensand filter.  Greensand is a granular filter media coated with manganese dioxide.  It continues the process of oxidation started by either aeration or chemical injection and traps the iron particles within the media bed.

If iron is not present in water as it comes into your facility, the discoloration and rust-colored flakes are most likely caused by corrosion in pipes and boilers.   Correcting the underlying causes can be expensive and many facilities cannot undertake all corrective actions immediately.   In the interim, the water can be treated for the removal of the flakes and color.   This may require installation of filters at multiple locations, depending upon where the problems are most severe and/or where they are believed to originate.

Removing the flakes requires a media filter – probably one containing two layers of filter media (a dual-media filter).  This should be the first step in the treatment process.  The second step will remove color by means of granular activated carbon.

Remember that each situation can present special considerations not mentioned above.  For a full analysis of your particular circumstances and recommendations regarding corrective steps, contact an Everfilt applications engineer.

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produce the desired water quality.  In other instances, the customer may pay far more for the system than is necessary because a micron removal level has been specified when the water to be filtered doesn’t even contain particles that small.  It’s always surprising when a customer prefers to guess at the type of filter(s) needed or the characteristics of the water rather than pay a small amount of money for laboratory analyses which will allow a very precise selection of treatment units.

The three most common types of tests that aid in selection of filter types and sizes are:

1. Total Suspended Solids (TSS)
2. Particle Size Distribution (PSD)
3. Concentrations of substances to be removed

Total Suspended Solids (TSS):  Every type of filter or treatment unit has a capacity within which it produces desired results most efficiently.  If the amount of suspended solids exceeds the capacity of a filter, the unit will not perform satisfactorily.  As an example, a media filter (such as a sand filter) performs best when TSS = < 100 mg/l (ppm).   Water containing suspended solids > 100 mg/l requires pre-treatment.  The amount of TSS determines which type of pre-treatment filter will be most effective.  Wastewater that appears cloudy will typically contain 1,000 mg/l or more of suspended solids, and the size of the solids is usually 5 micron or smaller.  Under these conditions, coagulation followed by a clarifier (or settling tank) is needed.  This first step, by itself, may be adequate to reach the desired micron removal.  If it is not, a second step of filtration will be effective and can be specified with greater precision.

Particle Size Distribution:  Some water laboratories do not have the equipment needed to perform this test.  If they do not, contact Everfilt and we will assist in sending a water sample to an appropriate laboratory.  The advantage of a particle size distribution is that it indicates the type of filter required to remove the target particle size.  For example, water being fed to a reverse osmosis unit typically requires removal of particles 5 micron and larger.  If the water to be treated contains only particles 40 micron and larger, a sand filter will be effective.  If the water contains particles only as small as 20 micron, a dual media filter will be effective.  The sand filter is less expensive than a dual media filter, so knowing which type of filter is most suitable will produces the best results and possibly at lower cost.

Concentrations of Specific Substances:  The amount of target substances often determines the required size and sometimes even the type of treatment unit.  For example, if a substance to be removed is a dissolved organic and activated carbon is the treatment of choice, the amount of contact time will be determined, in part, by the concentration of the substance.  Another example is water hardness.  If the level of hardness is extremely high, reverse osmosis is the most cost-effective approach.  An ion exchange water softener would not be recommended.  These and many other decisions can be made accurately only by performing a water analysis.

There are many instances when a water analysis is not required.  But if it is, the customer always benefits by having one performed.  If you are considering treatment of your water or wastewater, contact an Everfilt engineer for recommendations regarding treatment and the advisability of a laboratory analysis.

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Tip #1

Activated carbon is made from a variety of raw materials including coal, bone, wood, coconut shell, walnut shell and lignite.  When the raw material is charred, many pores are created, thus vastly expanding the amount of surface area available for adsorption of unwanted substances.

The number and size of the pores depends on the raw material used and the specific process used to prepare it.  Each type of carbon contains pores of different sizes, but the distribution of pore sizes varies with the raw material.

One way to increase the performance of carbon is to select a carbon type that has pore sizes most closely matched to the size of the molecules to be removed.  For example, color molecules are relatively large, so a carbon product with a high percentage of large pores will be more effective.

Tip # 2

Water to be treated with activated carbon typically contains suspended solids.  Activated carbon will trap those particles, but in so doing, the particles block surfaces on the carbon granules and reduce the amount of surface area available for absorption.   Before treating water or wastewater with carbon alone, test for suspended solids.  If TSS (Total Suspended Solids) is greater than 1 mg/l, a multi-media filter should be placed ahead of the carbon unit.  This will extend the life of the carbon and reduce the frequency and expense of carbon change-outs.

Tip #3

Activated carbon will reduce any dissolved organic substances in water or wastewater.  That includes substances you may not need to remove.  In cases where there are substantial concentrations of a variety of dissolved organic substances, a clay pre-filter can be effective in reducing the organic load, thereby extending the life of the carbon.  Like carbon, clay works by absorption and needs to be replaced periodically.  However, it is much less expensive than activated carbon, so the total cost of replacement (combining clay and carbon) is less than if carbon alone is used.

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In order to determine whether color is coming from suspended solids or from dissolved solids, have a water laboratory test for color units in a representative sample of water.  Then have the lab technician pour the water through 5-micron filter paper and test the filtered water again for color units.

If color is not detectable and the water appears clear, a multi-media filter is the most effective choice and activated carbon will not be necessary.  If most, but not enough of the color is removed, then a multi-media filter followed by activated carbon should produce the desired result.  If color is virtually unaffected by the filter paper, then use activated carbon.

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Many firms need very high quality water in order to manufacture a product that’s competitive in today’s demanding marketplace.  Waterprofessionals.com defines, “ultrapure” water as “water which meets stringent limits on several or all of the following: dissolved and suspended solids, organic carbon, dissolved gases and biological organisms (e.g., bacteria, viruses, pyrogens).”

Firms that typically require ultrapure water include food and beverage companies, pharmaceutical firms, and manufacturers of electronic components.   Each firm must design a water treatment process that will achieve the water quality needed for the product being produced.  That means the process will have to be designed in accordance with the characteristics of the raw water available to each firm.  As a result, not all ultrapure water treatment plants will be the same.

For example, raw water that is very hard will need to be softened.  Water with low hardness won’t require softening.  Water that has color will require an activated carbon filter to remove it.  Water that is clear will not require a carbon filter.  Some firms will need to demineralize their water, while others will not.  Because each treatment process is tailored to the specific requirements of each firm, a water analysis should be performed in order to guide the selection of treatment components.

So what are the disadvantages of not using high quality water? Poor water quality has an adverse impact on the finished product and its marketability.

For more information or to obtain a review of your existing water treatment process,  call to speak with one of our water treatment experts: (951) 360-8380.

Take the steps to upgrade your industrial process water.  In the end you will improve product quality and market share.

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A tap showing calcification left by the use of hard water

Softening water has a lot of benefits, some of them more common use than others. It’s not just residential either. Business and commercial industries are making the switch.  Schools, commercial laundries, and manufacturers all look to make improvements to their building and business with the benefits of soft water.   Let’s start with the basics, what is soft water, how it is different than hard water and what are the benefits.

Hard Water: According to a University of Idaho study they defined it as, “Hard water is found throughout the world and in about 85 percent of the United States, according to the U.S. Geological Survey. Hard water areas exist where water has access to rock that contains calcium, magnesium, or both.

The U.S. Department of the Interior classifies hardness based on the concentration of calcium and magnesium in grains per gallon (gpg). A typical aspirin contains about 5 grains of material. Were the aspirin to be dissolved in a gallon of water, it would add 5 gpg of material to the water.”

Soft Water: Elimination of such elements and materials to create softer water, easier to use and wash with.

Mineral inlays in a PVC rod

The benefits are numerous.  Washing clothes can become an expensive, daunting household chore as we may all know too well.  Hard water has a tougher time eliminating soaps, detergents and cleaning agents from clothes.  Sometimes it even gives clothing the appearance of residue still on the clothes. As a result multiple loads of laundry may have to be done, or clothes may need to be rewashed.  Laundry mats can’t afford to lose customers because the clothes aren’t coming out as clean as they can. A study conducted by the American Institute of Laundering determined that detergent and laundering costs are twice as high in hard water compared with soft water.  More financial burden points to the deterioration of clothing and fabric quicker with the use of hard water. A Purdue University study found that fabrics washed in hard water wear out up to 15 percent quicker than fabrics washed in soft water. When people stop going to a local laundry mat because clothes aren’t clean, residue is on them or they have to do multiple loads, they lose money.

In general everything that requires water operates more efficiently with soft water running through it.   Hard water leaves deposits in pipes and in industrial equipment such as pumps, heat exchangers, and boilers.  These deposits damage equipment and lead to frequent repairs or replacement.  Softened water results in more efficient equipment performance and lower operating costs.

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