What to Look for When You Choose a Bleach Filter System

Value Versus Price

The presence of heavy metals and suspended solids that occur as an inherent part of any bleach production process adversely affects the quality of the bleach and significantly shortens its shelf life.

The obvious response to the market demands for high quality bleach is to filter your bleach. There are several technologies available to filter bleach - from bag and cartridge filters, to vacuum filters, to pressure filters. There are low end and high end options, widely varying performance standards, and significant differences in pricing. The key is to select the system that offers the best combination of benefit and cost.

The Powell Bleach Filter System is superior to any other system available in terms of design, performance, ease of operation, maintenance, and expected length of service life. While the system costs more up front in comparison to other filtering techniques, it is usually far more cost efficient in the long run. An objective evaluation of your filtering options coupled with an analysis of cost versus value will demonstrate clearly that the Powell Bleach Filter System is your best filtering investment.

System Design

The design of the bleach filter system is a key factor and ultimately impacts all other considerations. Some of the items to consider include the following:

Designed for Use with Bleach

A filter is not always a bleach filter. Filter systems are designed for a variety of liquids such as water, oils, chemicals, and many other fluids, and are not typically interchangeable. The bleach filter system you select should be designed specifically to filter bleach.

Incorporates an Enclosed Process

Sodium Hypochlorite can cause respiratory irritation if inhaled; likewise, contact with eyes or skin can cause severe irratation. To eliminate the potential for worker exposure to bleach or bleach fumes - and accompanying issues with OSHA, EPA, etc. - an appropriately designed bleach filter system should accommodate a totally enclosed pre-coat cycle, filtering cycle, and backwash cycle.

Accommodates Ventilation and Dust Control Operations

Typically, the filter aid is a dust that can become airborne when handled during the filtering process. The optimal filter process will accommodate major components of a ventilation system designed for appropriate dust removal or collection and disposal.

Materials of Construction

Materials that come in contact with sodium hypochlorite must be able to withstand its strong corrosive and oxidizing tendencies on a long-term basis. To ensure you receive the maximum value from your filter investment, consider only equipment with high-level materials of construction that can stand up to the long-term demands of sodium hypochlorite service.

Titanium Pumps

For long-term service life, only titanium pumps are able to stand up to the abrasive tendencies of the filter aid, as well as the demanding service requirements of sodium hypochlorite. Pumps should allow for high throughput rates with high differential pressures and long cycle times. High quality titanium pumps will also have low rpm and high quality seals for extended service life.

Titanium Pressure Vessels

In order to maintain useful service life for 30 years or longer, the pressure vessel should be of titanium and ASME coded. Other materials of construction may seem appropriate for use with sodium hypochlorite. However, only titanium vessels will stand up over time to the demands required of sodium hypochlorite production and filtration process equipment.


Prior to filtration, sodium hypochlorite produced in any production facility can typically have metal contamination in the range of 1 ppm iron, 400 ppb nickel, and 60 ppb copper. Also, significant amounts of suspended solids will be in the solution. The manufacturer of any system you consider should be able to guarantee the bleach can pass the Suspended Solids Test - which is often included in industrial and municipal specifications - in 3 minutes or less. The filter system should also be able to achieve a specified level of performance in terms of heavy metals elimination. Typically these levels should be less than 0.2 to 0.3 ppm iron, less than 10 ppb nickel, and less than 10 ppb copper.

Repeatable Results

Good performance on an intermittent basis is not good enough. The filter system's performance should be consistent, repeatable, and verifiable by any reputable laboratory in the US.

Can be Used with Any Quality of Caustic to Yield a High Quality Bleach

Superior filtration capabilities means it's possible to use a lower quality, less expensive grade of caustic to produce bleach of an equivalent or higher quality than bleach made with expensive membrane grade caustic. This ability can significantly impact the economics of bleach filter selection.


Over the service lifetime of a bleach filter system, control systems and components will become technologically obsolete. If the system cannot accommodate key upgrades, the entire system will have to be replaced. The longer the anticipated service life of the equipment, the more critical the ability to keep pace with current technology becomes.

Ability to Automate Filtration Process

Automated processes offer more than just convenience. The automated process produces a more consistent and reliable product, runs faster than a manual processs, requires less personnel to run, and is - because of these factors - more cost-efficient.

Disposal of Filter Aid and Backwash Material

Wastes are difficult and costly to dispose of safely and legally, making disposal a significant and expensive issue. The solution is a bleach filtration system that can minimize - or virtually eliminate - disposal issues.

Zero Discharge of Process Liquids

To avoid disposal expenses, consider a bleach filter system that offers the ability to reclaim backwash water. When the wastewater, including the backwash water with spent filter aid is processed further, the spent filter aid is separated from the backwash water, and the resulting liquids can be used in sodium hypochlorite production, eliminating liquid disposal costs entirely.

Non-Hazardous Waste

The filter aid is discharged from the process equipment as a dry cake. The dry cake must be analyzed for hazardous waste and can be disposed of accordingly.


The cost-benefit relationship is frequently overlooked in the equipment selection process. A more expensive piece of equipment, offering superior performance, minimal maintenance cost, and 5 to 10 times the useful service life is usually a much better investment than a shorter term, less expensive piece of equipment. In the case of a bleach filter system, it's a situation when more really is more.

It's the Same Old Story - You Get What You Pay For

The Powell Bleach Filter System can outperform any other system available in terms of design, performance, ease of operation and maintenance, and expected length of service life. However, as is always the case when it comes to quality, superior performance costs more up front but is usually far more cost efficient in the long run.

An objective evaluation of your filtering options against the above criteria, coupled with an analysis of cost versus value, will demonstrate clearly that the Powell Bleach Filter System is your best filtering investment.

Put a Powell Bleach Filter System on Your Site with Minimal Financial Impact

Many accountants maintain that flexible payment terms can do more to improve your cash flow situation than a bargain-basement price. Depending on circumstances and your situational preferences, Powell can offer financing in the form of a capital lease or an operating lease. Typically, capital or operating leases can be structured so you are not required to disburse cash until the equipment is delivered or - even more advantageous - the equipment is operating and generating cash flow. If you would like more information on leasing options, contact us at 989.681.2158 or by using our Contact Form.

More Information:

This article is available as a PDF. Click here to download it. For more information about filtering sodium hypochlorite (bleach), visit the Technical Information section.