BLOGNon-Backwashing Upflow Systems Found Ineffective

Non-Backwashing Upflow Systems Found Ineffective

02 November, 2012
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There are very good reasons for the way we engineer our filtration appliances. Since the beginning, we have followed the science and gone above and beyond was just “minimum” requirements. Why bother making something just to meet bare minimum requirements when you could make something valuable for people?

Backwashing (no, not the gross thing your cousin does to your drink) is one of those “science-y” things that has huge benefits, and is actually a necessity. We have considered producing a non-backwashing system before, but we could not do it in good conscience. The only exception is whole home cartridge systems, which are filter cartridges inside large housings (about 20″ tall) that get replaced every year.

We have seen a lot of non-backwashing and upflow filtration systems come and go in the marketplace, and we have never seen a company last longer than 18 months to 5 years. One of the problems could have been the fact that these devices, as we have long known, do not filter effectively and require more frequent replacements than is normal for a whole home filtration system.

Here are the down and dirty straight facts about backwashing, why the pros outweigh the cons, and how to make a wise decision for yourself.

What is Backwashing?

Backwashing is also known as regeneration. It is a process by which a filtration system cleans the filtration media inside the tank. This uses a good amount of pressure and varying amounts of water, depending on the length of the backwash cycle, the home’s flow rate and pressure, and the efficiency of the valve head.

Pros to Backwashing

1. Backwashing prevents packing or channeling, and creates a healthy environment for the carbon filtration to filter at maximum effectiveness without dangerous bacteria growth (without the use of silver nitrate – a toxic pesticide – or metal resins).

2. Backwashing requirements are set forth in granular activated carbon Material Safety Data Sheets. Complying with them is a wise idea.

3. Backwashing ensures a long lifespan for the filtration media, which simply saves the owner replacement costs and time spent replacing the media. The high quality of carbon and the use of automatic backwashing allows EWS whole home filtration appliances to need a filtration replacement only every 10 years (this lifespan is general, and can be longer or shorter depending on your water quality and water usage).

4. Not all backwash water is safe (this depends on the system and the filtration media used), but EWS backwash water is safe and filtered. EWS backwash water can be used in many ways: drained into the pool to help top off water levels, used to irrigate the garden or lawn, as drinking water for outdoor animals (most customers with ranches and farms use it to water their horses and livestock), or stored for later use and emergencies (we discovered our “prepper” customers love this option).

Cons to Backwashing

1. A backwashing EWS system uses about 60 gallons of water, once every 6 days. To some, this seems like a lot, while others see no objection. It is easy to think of it in terms like this: it is equivalent to having an extra person in the house that day. The water is not wasted if you use it in the above fashion. Otherwise, it can be put down the drain and reused and recycled by the water treatment facilities.

2. It can be noisy and sounds like rushing water. EWS uses a 20-minute process that uses a good amount of pressure and water volume to lift 85+ pounds of granular activated carbon (GAC) filtration media. This can be loud if you have thin walls. The best solution is to set the easy-to-use, advanced valve head to automatically backwash at a time you prefer. Many customers choose to have the system backwash during the day while they are at work, so there is no chance of being disrupted by a backwashing system.

The Big Kicker

The biggest problem we have with non-backwashing and upflow-type systems is that they simply do not remove contaminants well, if at all. For us, this is a huge ethical problem, and we find it highly irresponsible. Many people rely on water filtration to remove harmful endocrine-disrupting and carcinogenic contaminants from our water (i.e. atrazine, chlorine, chloramine, ammonia, fuels, pharmaceuticals, etc.), and it is a serious responsibility of water filtration manufacturers to provide that valuable service efficiently and effectively without hassle.

In 2005, a major collaborative study was done to see if there was a difference between regenerated (backwashed) and non-regenerated (non-backwashed) granular activated carbon (GAC).

The study discovered the following:

“In full-scale applications, the impact of regeneration [backwashing] was observed as activated carbon filters that received regular regeneration had minimal breakthrough of organic contaminants, while non-regenerated filters displayed no removal of target compounds.”

That is a BIG problem.

The study concluded with this statement:

“In two full-scale GAC applications evaluated, vastly different results were observed. At a drinking water facility with on-site and regular regeneration [backwashing], removal of trace organics occurring in source water was efficiently improved.

In contrast, a facility with relatively high levels of TOC [trace organic compounds] using GAC without regular replacement/regeneration provided very little removal. These data collectively show that activated carbon in both powdered and granular forms has great potential for the removal of trace organic contaminants; however…GAC regeneration/replacement will be critical for excellent removal.

And this is just one of the reasons why our EWS and CWL whole home filtration systems utilize backwashing, and will do so until technological advancements improve the process further or present us with another truly effective option.

The table on the left represents the backwashing system. The table on the right represents the non-backwashing upflow system.

Source: Role of membranes and activated carbon in the removal of endocrine disruptors and pharmaceuticals. Shane A. Snyder, Samer Adham, et al. July/Dec 2005.

 

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