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Laurence%201998 Laurence DAl... 4 Posts
11/04/2010

WTO Board / Fundamentals of Sand Filter Design

We have an application for sand pressure filters as pretreatment for Activated Carbon Adsorption system. Flow 517 GPM. Adsorbing Petroleum Hydrocarbons. Service flow rate 12 gpm/sq.ft. We are going to use 3 84" diameter sand filters. Would the following be acceptable for the layers of sand and gravel?:
Bottom Layer: combination of 1/2" x 1/4" and 1/4" x 1/8" Gravel
Third Layer: #8-12 Garnet
Second Layer: #30-40 Garnet
Top Layer: Filter Sand 0.45-0.55
Question 2: We can supply treated backwash water from two of the 84" diameter sand filters while the third is backwashed. What backwash flowrate and % bed expansion do we need for a sand filter for this type of duty?
 
Icon_missing_medium Ray McConnell 0 Posts
11/03/2010

WTO Board / Filox system barely functioning

Nick, I would agree with Dave that it is time to rebed the system and completely clean if not REBUILD the valve. Air injection filter systems require backwashing on a daily basis. This is necessary to prevent the buildup of oxidized iron within the media tank. If the air injection valve is on the inlet line to the system than this would explain the buildup of oxidized iron in the inlet side of the system. If so check for iron buildup in the line coming into the system. This is an extreme amount of iron for this application.
Also check the pressure from your jet pump. Even though you may be getting sufficient flow (10gpm) it takes a considerable amount of pressure (30+ psi consistently) to effectively backwash this type filter system. Quite often "Jet Pumps" (above ground well pumps) DO NOT build up sufficient "HEAD Pressure" to properly backwash the media and problems such as this happen in a very short time. I would also agree that Garnet would be better as the underbedding material.
Good Luck, Ray
 
Icon_missing_medium Rex Johnson 6 Posts
11/03/2010

WTO Board / Serratia marcescens

Citric acid will help keep resin cleaner but, of course, is not a disinfectant.
I have occasionally added a little bleach (not too much) to brine wells under very limited circumstances. However, if you have a chlorination system in place and working this should be a moot point unless you suspect fouling arising from previous sources and not yet addressed.
A whole house disinfection can never hurt. And with a carbon filter, most likely should be performed at least annualy.
The bottom line is: If there are Serratia marcescens present, and you are certain this is the cause of the pink slime then I go with Gary on this one:
"A chlorine disinfectant tablet in the water closet of the toliler will help for the toilet but not if it spread to the shower or sinks in the bathroom"
One final thought here - I have found galvanic activity to also produce similiar looking stuff but it's very different.
It's like our company - We treat every one the same - Different.
Cordially
Rex Johnson
American Star Water Treatment LLC
americanstarwater.com
 
Icon_missing_medium scottharper 0 Posts
11/03/2010

WTO Board / Serratia marcescens

Thank you for the response. I had figured this but wanted to ask others with more experience in water treatment than myself.
I guess my next step would be to get a sample to a lab and have it confirmed.
 
Icon_missing_medium Gary Schreib... 0 Posts
11/02/2010

WTO Board / Serratia marcescens

Nothing else you can do. That is an airborne contaminant. The following is quoted from a Wikipedia posting on Google:

"Due to its ubiquitous presence in the environment, and its preference for damp conditions, S. marcescens is commonly found growing in bathrooms (especially on tile grout, shower corners, toilet water line, and basin), where it manifests as a pink discoloration and slimy film feeding off phosphorus-containing materials or fatty substances such as soap and shampoo residue. Once established, complete eradication of the organism is often difficult, but can be accomplished by application of a bleach-based disinfectant. Rinsing and drying surfaces after use can also prevent the establishment of the bacteria by removing its food source and making the environment less hospitable."

A chlorine disinfectant tablet in the water closet of the toliler will help for the toilet but not if it spread to the shower or sinks in the bathroom.
 
Icon_missing_medium scottharper 0 Posts
11/02/2010

WTO Board / Serratia marcescens

My customer uses chlorination/dechlorination and softener for her well treatment. I recently began to service it monthly. She has recently told me that for a few years she has had a pinkish slime in her toilets. It cleans easily but returns in a few days. I suspect from reading(but have not confirmed yet) Serratia marcescens. I recently added citric acid to brine to clean the softener.This did not seem to help. Is there anything that can be done through pretreatment to eliminate this from her toilets.
Thank you for any ideas.
 
Icon_missing_medium christwemlow 0 Posts
11/02/2010

WTO Board / Backflow preventor for point of use water systems

I would suggest purchasing the AWWA-PNWS Cross Connection Control Manual. This will answer all your questions, and provide you with an excellent reference manual.
 
Icon_missing_medium richardrizzo 0 Posts
11/01/2010

WTO Board / Backflow preventor for point of use water systems

http://www.treeo.ufl.edu/backflow/ has a lot of useful info and links regarding backflow prevention.
 
Icon_missing_medium georgesaliba 0 Posts
11/01/2010

WTO Board / Backflow preventor for point of use water systems

Testable backflow preventers have full sized ball valves at entry and exit ends of the device. There are also test cocks on the side or top of the devices to allow testers to hook up their test gauges. Each test cock only test the section of the device that they are directly relative to.

The smallest testable backflow preventer is 1/2"

To qualify as a backflow preventer the device must be able to be tested.
A single check, check valve is not considered to be a backflow preventer.

There are three types of approved devices.
Double check valve
Reduced Pressure Zone
Pressure Type Vacuum Breaker
Each device has a hazard level that dictates which device is used where.

Then there is natures backflow preventer called an Air Gap.

George

 
Icon_missing_medium craigboesdorfer 0 Posts
11/01/2010

WTO Board / Filox system barely functioning

What we have noticed about Filox systems is that there has to be enough dissolved oxygen for them to work properly. To that end we add a chlorinator feed pump to every Filox system and have had great results. The other thing I noticed in your challenge was the build up of "rusty,goopy,sludge". To me this sounds like bacterial iron which the introduction of chlorine will also help
 
Icon_missing_medium darrinfeltner 0 Posts
11/01/2010

WTO Board / Backflow preventor for point of use water systems

Does anyone have information on backflow preventors for point of use water systems? Many cities and states are now requiring them on all point of use systems as an additional revenue source. I know there are different requirements depending on the local codes but would like to find answers to the following questions.

What is the difference between a testable and a non-testable backflow preventor?

Is there a backflow preventor designed for 1/4" line?

Does a check valve or double check valve qualify as a backflow preventor?

Any assistance would be greatly appreciated.
 
Icon_missing_medium davehedger 0 Posts
11/01/2010

WTO Board / Filox system barely functioning

Nick, dealing with that much iron is going to ba an ongoing hassle. Rebedding at some frequency is probably simply going to be a periodic cost to the homeowner. I would suggest a couple additional things beyond what Jim suggested. You should completely strip the control head of the piston, seals and spacers, as well as the flat cap, and soak in muriatic acid. There are some ports inside that need to be cleaned. Also, make sure the mounting base is not plugged. If you do rebed, I recommend using garnet for underbedding rather than gravel. And of coarse clean or replace the distributor stack. Hope that helps.
 
Icon_missing_medium Jim Wark 8 Posts
11/01/2010

WTO Board / Filox system barely functioning

Sorry again for the poor typing ( Too much champagne at my wedding) , the backwash is important to be sized properly and at a higher flow than the service flow. With that much iron and H2S, You might consider a larger unit to handle this high demand.
 
Icon_missing_medium Jim Wark 8 Posts
11/01/2010

WTO Board / Filox system barely functioning

Nick,
Filox systems of this type have had reviews running the spectrum from great to frustrating. Many of the things you just detailed have me looking towards needing a rebed of the media. I would open the valve from the tank and check the media to see if it might be fouled by just working so hard to take care of all that iron and H2S. My personal experience has been to oversize the tank slightlyto make sure I get a very good backwash of the media every time. The backwash flow as a general rule, should be about checked, as it should be usually much higher than the service flow for these heavier medias.
Another good idea is to get a new updated water analysis since well water can change quite a bit even seasonally in some areas. There could als beother chnges such as inthe PH, DO or other contaminants that are changing the needs or sizing of your media.
Good Luck, I am sure many others will have good ideas to consider also.
 
Icon_missing_medium nickchristopher 0 Posts
10/31/2010

WTO Board / Filox system barely functioning

I purchased a Filox system with a Fleck 2510sxt 10"x54" tank and 1.0 cubic feet of media. System ran ok for over a year and now its hardly working even after multiple backwashes.
I have high iron (16ppm) and H2S smell prior to treatment. No H2S smell makes it out of the tap but iron is prevalent now. I used to backwash every three days and now am trying every day since it got bad.
When running a backwash cycle, the first 13 minutes (which I guess is for the actual backwashing) the volume coming out of the drain is pretty strong (its a very short run from the valve drain to the sink - about 4 feet of plactic hose). However, the second stage when it runs for ~40 minutes (I guess this is where it adds oxygen to the filter media?), I'm barely getting a trickle. It used to come out a lot heavier. So..
..I pulled the backplate off and opened the piston. Spacers were a bit mucked up and the back two were so bad I had to pull them out with a pliers. I then pulled the head and there was a fair amount of build up on the inlet side (rusty, goopy, sludge). I tried to clean them up as much as possible and put everything back together. Initial Backwash still runs strong and I got a slight improvement on the second stage drain, but not much.
My shalow well is powered by an above ground jet pump that seems real strong (I opened up the bypass valve when I had piston out to flush it and I get a huge torrent of water coming out).
Has the media failed? Something else? What's my next step?
Note I have a pre-treatment tank that I use for soda ash to bring the PH up. Should I add chlorine to that? I recently shocked the well with chlorine when the problem first started.
Thanks guys...Nick
 
Icon_missing_medium Jim Wark 8 Posts
10/31/2010

WTO Board / recovery of PEG

Peter,
I just came back from the Philippines and figure you ae probably talkin about a locator at the SLEX. If you want you can email me directly and I can get some info from you and point you in the right directions.
Jim
 
Icon_missing_medium Rex Johnson 6 Posts
10/30/2010

WTO Board / sediment in ice cubes

Rob - A few thoughts here.
As Gary correctly pointed out when the cubes freeze most of all of the sediment in the water is pushed to the center of the cube.
You mentioned that someone believed 'metal flakes' were incorporated into the water. This is easily tested for with a magnet you can buy at any auto parts store. Freeze the cubes - observe the sedimentation. Thaw the cubes in a bowl. Pass the magnet over the bottom of the bowl. If there is metal therein you will collect it.
Frankly, I doubt it's metal.
You mention that this is a new house. Many times water lines need to be adequately purged before use. Seldom does this actually happen.
You also state that the TDS is 491. In my book this is pretty high. I think the USEPA threshold is 500 - not positive - but of so that's pretty close to the max.
Solutions: Purge the water comprehensively from the lines - both hot and cold. Ensure your softener is working properly.
Then install a 5 stage RO at the kitchen sink and run it to your dedicated faucet and the ice maker. You will be pleased with the results.
Your wholesaler should have a 50 gpd RO for about $100.
Cordially
Rex Johnson
American Star Water
 
Icon_missing_medium robbyers 7 Posts
10/30/2010

WTO Board / sediment in ice cubes

Do you have any thoughts on how this can be addressed?
 
Icon_missing_medium Gary Schreib... 0 Posts
10/29/2010

WTO Board / sediment in ice cubes

As the ice cube freezes, all of the dissolved minerals get pushed to the center. Near the end of the freezing, there isn't much water left in the center of the cube, so these minerals become very concentrated, and they form the "white stuff". Precipitate.
 
Icon_missing_medium peterde dios 0 Posts
10/29/2010

WTO Board / recovery of PEG

i am in Laguna Philippines and i am looking at ways to recover polyethylene glycol from water rinses. i am considering UF and is looking for literatures or references.
 
Icon_missing_medium robbyers 7 Posts
10/29/2010

WTO Board / sediment in ice cubes

Hi Guys,
the service tech for the appliance division brought me a small sample of water to test. the complaint is that they think there is metal flakes in their ice cubes. There does appear to be a very fine white sediment in the aluminum ice cube tray. The water is pre softened, Ph is 8.82 and a TDS of 491 ppm. Sodium is at 350 ppm, no iron, nitrates or chlorine. This is a new house.
Thank you, Rob Byers
 
Laurence%201998 Laurence DAl... 4 Posts
10/28/2010

WTO Board / Dieldrin

Also another question: what are your concentration units um? Do you mean ug/L?
 
Laurence%201998 Laurence DAl... 4 Posts
10/28/2010

WTO Board / Dieldrin

Dieldrin sounds like a pesticide or herbicide. It is actually an insecticide. A chlorinated hydrocarbon. We don't have it in our database or organic compound isotherms. You are talking a large flow of 2288 GPM so a pilot study with a drum filter would be in order to see how effective your activated carbon is. For rough sizing you can use the 20% rule; 20 lbs organics adsorbed per 100 lbs carbon. Then double or triple the amount of carbon. Contact me privately to discuss.
 
Icon_missing_medium davepaulson 0 Posts
10/26/2010

WTO Board / Boron Headache

The Merlin uses a higher flux/lower rejection membrane as part of the design reason they have a higher flow rate. Most other RO membranes will do better. The low pressure will contribute to the problem. What recovery is the system run at?
 
Icon_missing_medium henryhidell 0 Posts
10/26/2010

WTO Board / Boron Headache

I am not entirely sure that it is the boron alone. If you constantly ozonate the water while it is in storage as you have indicated, it could also be a result of over-ozonated water. The upper limit of boron in water before it causes problems is generally around 20 mg per/L/ day which of course relates to the amount of water the customer actually consumes. So, I would look at ozone levels in the water as well and identify how the ozone is vented from the tank. I am sure that you have done this, but I would take a another look. It could be combination of issues, not just boron. Also, even lower values of boron interact with certain medications so if your customer is on a medicine, you should know what it is.