Filter Operation Information

[Hypatia]

We are looking for a filter system to bring our restricted access reuse water to public access reuse levels. After running several pilots, we have narrowed our selection down to three filters. If any of you have had experience with one of the following, please let me know how the filter performed and what maintence issues should we know about:

AquaDisk, DynaSand, HydroClear

Aquadisk is a cloth media, while the other two are sand filters. Dynasand has continuous backwashing. Hydroclear backwashes with pulses throughout the day.

 

[bimr]

I assume that you are talking about reuse of treated municipal wastewater?

For that application, you will need a good filter as well as disinfection to get low.

A good regulation to follow for disinfected recycled water is the State of California's Title 22 Regulations. This regulation is available on the web.

Two of the filters (AquaDisk, DynaSand) that you have mentioned may not meet the standards in that regulation. You need a better water quality than those filters are capable of providing. Those filters (AquaDisk, DynaSand) are normally used for wastewater applications, not water or water recycling.

There are two aspects to be concerned with. The filtering ability and the disinfection ability. If you can produce a better water quality out of the filter, then your disinfection requirements as reflected in the MPN are reduced.

 

[Hypatia]

Yes, I am talking about reuse of treated municipal wastewater. Here is some additional information regarding our setup:

We are located in Florida. Currently approx 17 to 27 MGD of the municipal water is treated to levels covered in Chapter 62-610 FAC, Part II: restricted public access reuse water. This water is sent to a farm that grows cattle feed.

A local development wants a small quantity of reuse water for irrigation of golf course and schools (appx 3 MGD). The water to be sent to them has to meet Part III: public access area reuse. The regulations only require us to lower our TSS levels. We desire to lower TSS and turbidity as well. We have piloted the filters to check performance. We are now interested in operational issues associated with the three filters.

 

[oxilume]

I realize that you are aware of Florida's Water Reuse Guidelines found at:

http://www.dep.state.fl.us/water/reuse/docs/valued_resource_Final Report.pdf

Please see page 15, "Our Vision of Water Reuse in 2020."
It addresses that membrane treatment will be used for "controlling" contaminants and pathogens. The next bullet states,
"UV disinfection will be the norm for water reuse & domestic wastewater facilities."

Do Not set yourself up for a potential lawsuit by not disinfecting the wastewater to drinking water standards. See Safe Water Drinking Act.

The CDC has recently identfied a bacteria that is resistant to chlorine. It is called mycobacteria. The health issues are fairly severe. Lifeguards and frequent swimmers at indoor swimming pools & spas have been diagnosed with nontuberculous mycobacteria (NTM). Likewise, the problem is being addressed with machinists at very large industrial machine shops due to mycobacteria growing in metal working fluids.

If you need more information goto:

http://www.oxilume.com/page12.htm

click on the links on that page.
Todd Foret
toddforet@usa.net

 

[bimr]

Not sure why you are bothering to pilot test these units. This is relatively proven technology, it has just been to expensive to use. You are probably not going to find many installations where these products are actually being used to reclaim water. There are not that many installations out there.

If you want to get more information, you will probably have to resort to telephoning the manufacturer's installation lists. All of the equipment suppliers try to keep track of their best installations.

DynaSand and HydroClear have been around for years and there are no equipment maintenance issues associated with them. The AquaDisk unit is a relatively new product so that there will not be an extensive track record.

I see from the website:

http://www.dhs.cahwnet.gov/ps/ddwem/publications/

waterrecycling/treatmenttechnology.pdf
that all of these products have been approved, at least in California.