Recycling of WTW "Alum" Sludge products to land... 2

[MarkL]

I am looking into the potential of re-cycling Aluminium contaminated sludges from water treatment works to land for provision of crop nutrients and soil conditioning properties. However the Aluminium is a cause for concern, potentially leading to soil acidification and the associated problems with nutrient immobilisation.

Are any of you able to shed some light on the following?

- At what level of addition does Aluminium become an issue?

- Would toxicity be greatly reduced on Alkaline soils?

- Can addition of Phosphates in some form lock up the Aluminium, and render the sludge less problematic?

Any answers to the above most gratefully received.

Regards, Mark Ley.

 

[JTGrubbs]

Look at DrinkInfo Tip from KY Drinking Water Branch on October 1, Home Page address:

http://water.nr.state.ky.us/dw/default.htm

Both Land Application and Beneficial Reuse are done under the Special Waste regulations, 401 KAR Chapter 45 (scroll down to Chapter 45 after accessing link to Title 401 KAR). The information provided by the Kentucky Legislative Web Server is unofficial and is intended for informational purposes only.
In Kentucky, Waste Management does have water treatment plants (WTPs) doing land application. Waste Management has also regulated some WTPs using residuals as fill material under beneficial reuse. Most that Waste Management has dealt with involve alum or iron salts; some have lime softening residuals, which makes an excellent agricultural soil amendment.
Alum sludge should have concentrations below 25 percent for land application. Before being applied to the land, the waste must, also, be analyzed for Cd, Cu, Pb, Ni and Zn. Use of copper sulfate can be problematic. Waste Management prefers Type B limits to be met (Cu @ 450 mg/kg) for land application or Beneficial Reuse, but will allow somewhat higher under variance provisions in deference to federal regulation that says Cu @ 1,500 is "clean." WTP residuals have some micronutrient value and can improve soil tilth. However, both alum and iron can bind with phosphorus, making it unavailable to plants.
There really isn't a maximum limit Waste Management imposes on the amount that can be applied, because nitrogen and Cd, which drive the limits set by regulation, are found in insignificant quantities in WTP residuals. The key is extractable P monitoring in the soil, and yes, monitoring the waste is required, as well as, the land to which the residue is applied. While concern grows for P being a potential pollutant, this may emerge as an important management tool for soils with excessive P since WTP residuals can treat that problem. Too high P can be a problem at wastewater sludge land application sites, so Waste Management encourages municipalities to add WTP residuals to their landfarm permits. Of course, free aluminum is a phytotoxin, but that is why agriculture soil is limed, and since Al is 7 percent of soil naturally, the contribution from WTP residuals is insignificant. Its just a matter of soil pH monitoring, which is required by regulation.
Some WTPs fill lagoons and then close as residual or special waste landfills. Many municipal systems discharge residuals into the sewers. With iron coagulant residuals, this is sometimes done as a method to control H2S and acid etching in sewer systems. Waste Management permitted a couple of composting operations to include residuals - as a bulking agent - obviously it doesn't "compost" by itself. Waste Management is not aware of any beneficial reuse involving WTP residuals as an ingredient in manufacturing, though alum residuals can be used to make bricks.
Waste Management does not require public notice for Type B land application or beneficial reuse and is not aware these practices have ever caused concern among the general public. Also, they are not aware of any research into human health/animal health effects. Waste Management assumes, as do other states, that the heavy metal concentrations that are safe for wastewater sludge are also safe in WTP residuals.
During the 1970's and 1980's, the Drinking Water Branch allowed the use of copper sulfate in the water source, particularly reservoirs, to control taste and odor problems from algae blooms. However, this approach caused fish (aquatic life) kills because dosage rates were not properly applied. Copper sulfate was only effective if source water was treated before the algae blooms occurred (timing of application). The use of copper sulfate has fallen out of favor because of aquatic life kills, timing, and the possibility of increased copper levels in finished water (lead and copper rule).
Drinking water treatment systems in Kentucky use, more favorably, potassium permanganate (KMnO4), and the Drinking Water Branch encourages this approach. KMnO4 at the water intake oxidizes the constituents from algae that cause the taste and odor problems.
Taste and odor problems arise after the algae is killed, which releases the smell (taste and odor) compounds into the water. Afterwards, activated carbon (granulated or powdered activated carbon) is used to pretreat the water to adsorb most of the algae compounds and reduce odor.
Resolving drinking water problems from algae is a complicated and dynamic problem. Each drinking water system must analyze the situation individually. Because of complications, there is no real quick solution to algae problems; however, we discourage the use of copper sulfate to resolve this problem.
If the consumer objects to taste and odor problems in summer months, or whenever algae becomes a problem, a teaspoon of lemon in the drinkable water can help resolve the taste and odor problem.  
Remember, this is an aesthetic problem, NOT a contaminant problem. The consumer should always remember that the water is still safe to drink when algae becomes a problem. Unless otherwise notified by the drinking water system, the homeowner's tap water meets all contaminant requirements of the Safe Drinking Water Act.
Alum is frequently used by drinking water treatment systems in Kentucky as a coagulant. There is a residual in sludge, but land application and beneficial reuse must meet the requirements as stated above for special waste under Waste Management's (special waste) regulations, 401 KAR Chapter 45 (scroll down to Chapter 45 after accessing link to Title 401 KAR). The information provided by the Kentucky Legislative Web Server is unofficial and is intended for informational purposes only. 
Jar tests are performed to adjust the dosage rates which helps reduce excess alum residue. See DrinkInfo tips from

http://water.nr.state.ky.us/dw/Tips/2000Tips/Oct2000Tip.htm

and

http://water.nr.state.ky.us/dw/Tips/2000Tips/Sep2000Tip.htm

.
For more information on land application and beneficial reuse of waste, contact Division of Waste Management at (502) 564-6716. For information regarding safe drinking water, contact Vicki Ray and staff in the Drinking Water Branch at (502) 564-3410, or through e-mail from the employees staff list.

 

[22854]

We have a problem with the organic acids present in the water after killing algae with sodium hypoclorite. Do you think that a coagulation then a sand-anthracite filter followed by a filter with granular activated carbon will be able to remove both chlorine and organic acids ?

Will the activated carbon adsob the remaining oxidized components ?
After this treatment the water goes to a demin water plant to produce BFW.

 

[JuanCarlos]

Please write me. I am working on a thesis topic somewhat related to your subject and want to see what findings you have.
Write to juancarlos.adame@recreation.bombardier.com
Thank you

 

[JuanCarlos]

Please write me. I am working on a thesis topic somewhat related to your subject and want to see what findings you have.
Write to juancarlos.adame@recreation.bombardier.com
Thank you

 

[JuanCarlos]

Please write me. I am working on a thesis topic somewhat related to your subject and want to see what findings you have.
Write to juancarlos.adame@recreation.bombardier.com
Thank you

 

[rooharn]

Hi Mark,
I have an interest in the processing of Alum sludge for manufactured products, possibly for use in water treatment facilities.
I would like to know how you have found issues of supply and handling of alum?
Sources of information?
Kind regards.RH

 

Looking for beneficial re-use options of lime sludge from drinking water treatment.

 

[goodsludge]

Mark:

As long as the water treatment residual (WTR) is formed at a near neutral pH, Al toxicity concerns are minimized - Al is the most abundant metal in soil to begin with!

WTR is great for controlling excessive soil phosphorus, which helps minimize impact of P pollution in waterways. As part of a buffer strip along a stream, it works very well to trap soluble P.

More info? Give me a call US 814-867-1477 or jdewolfe@mcguirinc.com.

 

[kwse]

I am trying to plan for handling of dewatered alum sludge frmo a water reclamation plant. Can anyone tell of current methods of storing and unloading the alum sludge from a silo/hopper? It has been suggested that a conical silo with vibratory feeder would work. I have no experience with this and am not sure how thixotropic dewatered alum sludge might be.