alum Archives – Bishop Water Technologies

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Slash sludge disposal costs with ClariPhos™

DATE POSTED: September 22, 2021

ClariPhos™ rare earth coagulant reduces sludge by as much as 50%

Is sludge disposal hauling away too much of your operating budget?

A 2016 report* prepared for the Vermont legislature, relying on national level EPA cost analysis, “estimated that approximately 40% of a wastewater treatment plant’s total annual operating cost is spent on solids management.” That report also predicted a future increase in solids production due to the increased need to reduce the nitrogen and phosphorus contribution from sewage into the surface water basins. This is particularly true for phosphorus (P).

Why do lower phosphorus limits increase sludge?

Unlike nitrogen, which can be effectively removed biologically, phosphorus removal is typically achieved with chemical precipitation. Traditionally, this has been done using iron- or aluminum-based coagulants. But these coagulants can produce significant amounts of sludge especially when phosphorus limits in effluent are extremely low. In some cases, phosphorus precipitation with alum or ferric coagulants can produce 12 to 16 mg/L of sludge for every mg of P removed.

They operate on an adsorption mechanism, typically requiring between a 2.5-to-1 molar ratio and a 4-to-1 molar ratio of iron or aluminum to P. They also create a fluffy floc with high amounts of bound water that is difficult to separate through settling and dewatering processes. The phosphorus, a solids-dispersing agent, suspends these solids, making them more difficult to settle. The result is a sludge that remains high in water content and much more costly to transport and dispose of.

Rare earth elements (REEs) can reduce sludge by as much as 50% compared with iron or aluminum

Cerium, a rare earth element, reacts at a 1-to-1 molar ratio with P to form the mineral rhabdophane. This precipitate has a specific gravity of 4, compared with the specific gravity of iron or aluminum precipitates of between 2.4 to 3.4. Higher density solids settle better, binding less water in the process. To gain a thorough knowledge of how this works, see our white paper.

ClariPhos forms a strong, stable bond with phosphorus at a molar ration of 1:1. Fe or Al coagulants typically require at least a 5:2 molar ratio, but can go as high as 8:1 when greater P reduction is needed.

**Bottom line – ClariPhos helps achieve significant sludge reduction and cost savings**

One 770,000 GPD facility discharging to a tributary to Lake Erie switched to REE precipitation primarily to meet a stringent aluminum limit by removing aluminum-based coagulants. The change provided immediate compliance with the aluminum limit, but the benefits didn’t stop there. Prior to switching to REE precipitation, the plant operated a belt filter press 8 hrs/day, 5 days/week, with an average solid content of 15%. That required hauling 75, 20-yard sludge containers to a landfill annually.

After switching to REEs, the belt filter press run time was reduced to one 8-hr shift per week, at a solids content of 21%. The number of 20-yard sludge containers landfilled annually dropped from 75 to 31, resulting in a savings of $70,000 per year in sludge hauling costs alone.

Savings achieved after switching from alum to ClariPhos coagulant

	Al	RE
Belt filter press operation	40 hrs/wk	8 hrs/wk
% solids	15	21
20-yard sludge containers landfilled/yr	75	31
Sludge hauling cost savings/yr	–	$70,000

Are you ready to slash your sludge disposal costs?

Learn more about the advantages of ClariPhos rare earth coagulant for achieving ultra-low phosphorus limits and reducing sludge production at your treatment plant.

* A Report to the Legislature on Wastewater Treatment Sludge and Septic Management in Vermont, July 16, 2016, Agency of Natural Resources, Department of Environmental Conservation.

Are you ready for a better coagulant for phosphorus removal?

DATE POSTED: December 22, 2020

3 simple steps to test rare-earth coagulant at your plant

New ClariPhos™ rare-earth coagulant is a proven solution to hit phosphorus levels as low as 0.07 mg/L in treated effluent and reduce sludge production by as much as 50% in the process.

Over 50 treatment plants in the US are already using it to comply with tough phosphorus discharge regulations, avoid the need to add tertiary filtration and reduce operating costs.

Testing ClariPhos performance for your plant can be done easily, just by switching your current liquid ferric or alum coagulant to our rare-earth coagulant.

The results will be visible almost immediately since ClariPhos binds more tightly to phosphorus. This produces a denser, heavier precipitate that settles about two times faster what you’re currently using. Your clarifier will perform better, you’ll achieve higher phosphorus reduction and produce significantly less sludge as an added benefit.

Here’s how we’d do it:

1) Jar testing

Simple jar tests with ClariPhos and a small sample of wastewater can quickly demonstrate the effectiveness and anticipated performance of the coagulant at your plant. The results are also used to calculate the dose rate and verify that your current equipment is up to the task. We find that the dosage rates can be significantly lower for ClariPhos as compared to conventional coagulants, so a smaller, more precise feed pump may be needed. If your treatment plant does not currently have a phosphorus removal step, we can also help design and install the process and equipment.

2) Plant assessment

A quick look at the plant’s treatment processes, configuration and performance will enable our wastewater specialist to verify process equipment and select the best feed point for ClariPhos to ensure optimum mixing and retention time.

3) Installation

Replace your existing coagulant with ClariPhos and let the test begin. The duration depends on your plant and the conditions it faces. We recommend that the test go long enough to experience typical variations in flow and loading to collect a good data set.

Download the ClariPhos brochure.

Learn more about ClariPhos rare-earth coagulant for phosphorus reduction and the operational benefits it can bring to your plant.

Achieve phosphorus limits as low as 0.07 mg/L with ClariPhos rare earth coagulant

DATE POSTED: October 6, 2020

ClariPhos produces up to 50% less sludge than conventional alternatives

Hitting an ultra-low phosphorus limit for treated wastewater effluent can be difficult using ferric- or aluminum-based coagulants alone. Often, large amounts of these conventional coagulants must be used, yet treatment plants may still be unable to meet low phosphorus targets without the addition of costly tertiary filtration equipment.

But ClariPhos rare earth coagulant is enabling treatment plants to achieve phosphorus levels as low as 0.07 mg/L without filtration and without the need to use large amounts of coagulant. The rare earth elements in ClariPhos™, cerium and lanthanum, bind tightly to phosphorus and form a dense precipitate that readily settles out of solution within minutes.

Easily switch to ClariPhos
In most cases, plant operators can simply replace conventional coagulants with ClariPhos to easily and cost-effectively improve the chemical precipitation and settling of phosphorus. ClariPhos requires no special chemical feed equipment and will often work with existing feed pumps. This simple switch can not only enable a plant to achieve regulatory compliance for phosphorus discharge, but it can also help communities to avoid spending millions for costly filtration equipment and ongoing operating costs.

Dozens of treatment plants are already using ClariPhos rare earth coagulant to meet stringent phosphorus targets and lower operating costs from reduced sludge production improved sludge dewatering and decreased sludge hauling and disposal costs.

Case Study:
In just one example, a 3.4 MGD municipal wastewater treatment plant tested Neo rare earth coagulant for its ability to meet a new final water quality effluent limit on phosphorus of 0.075 mg/L. The trial showed that the coagulant alone could consistently reduce phosphorus in the treated effluent to 0.036 mg/L.

This result was far superior to what the plant was able to achieve with its conventional coagulant, ferrous chloride, which could only reduce phosphorus to an average of 0.5 mg/L. After switching to Neo rare earth coagulant, the plant was also able to avoid installing new nutrient removal equipment, at an estimated cost of $2.8 million, and reduce solids production by about 35%.

Read the full case study.

Learn more about ClariPhos rare earth coagulants for phosphorus reduction.

The impact of rare earth biosolids as a soil amendment

DATE POSTED: February 27, 2020

The precipitate from chemical phosphorus removal systems typically becomes a component of the total biosolids produced by a wastewater facility. Biosolids containing ferric and alum sludge are often used as a soil amendment to add phosphorus as well as other nutrients.

But if your plant is considering switching to rare earth coagulant to achieve an ultra-low phosphorus target or other operational benefits, how effective will the biosolids be as a soil amendment and how will the rare earth metals impact the plants that will grow in that soil?

To find out, a study was conducted in Wisconsin to compare the availability of phosphorus to corn crops from rare earth biosolids, ferric biosolids and commercial fertilizer. Small plot studies were conducted at four different locations in the state and each one included plots with an untreated control and those that were treated with a commercial P fertilizer, ferric biosolids and rare earth biosolids.

The results showed that the commercial fertilizer increased phosphorus in the soil the most, followed by rare earth biosolids, then ferric biosolids, suggesting that rare earth biosolids provide more available phosphorus than ferric biosolids.

Measurements of corn whole-plant dry matter showed that the yield either increased or was unaffected by the rare earth biosolids. This indicates that soil amendment with rare earth biosolids is not expected to negatively impact the growth and yield of corn.

Since rare earth metals were also found in plants from the untreated control plots, researchers concluded that the application of rare earth biosolids is not adding foreign metals to the soil. The study also suggests that since rare earth concentration in the plant material is not significantly higher than the control, the rare earths are not bioavailable. As a result, the application of rare earth biosolids is not expected to increase the concentration of rare earths in corn beyond what would be found naturally.

Read the full research study.

Learn more about ClariPhos™ rare earth coagulant for phosphorus removal.

Here’s a New Year resolution you can stick to – achieving lower phosphorus limits

DATE POSTED: January 29, 2020

The New Year has come and gone, which means we all should be making good progress on achieving—or abandoning—our commitments for personal improvement in 2020. Maybe your treatment plant is also in need of improving some of its processes—such as phosphorus removal. This might be necessary to ensure consistent regulatory compliance, reduce chemical or sludge handling costs, or to hit a new, more stringent phosphorus limit.

Regardless of the reason, new, rare earth coagulant offers a fast, simple and cost-effective way to dramatically reduce phosphorus discharge that’s much easier to achieve than going to the gym four times per week or getting more sleep.

With ClariPhos™ rare earth coagulant, treatment plants can reduce phosphorus levels as low as 0.07 mg/L, using far less chemical and without the need to spend millions for a tertiary filtration system. That’s because the rare earth elements in ClariPhos, cerium and lanthanum, bind tightly to phosphorus to form a dense precipitate that settles up to two times faster than alternatives. This helps clarifiers operate more efficiently, lower chemical consumption, reduce sludge production by 30-50% and improve solids dewatering by 30% or more.

ClariPhos forms a dense precipitate that settles up to two times faster than ferric- or alum-based coagulants

Easily switch to ClariPhos by simply replacing current coagulant

In most cases, plant operators can simply replace conventional alum or ferric coagulants with ClariPhos to easily and cost-effectively improve the chemical precipitation and settling of phosphorus. ClariPhos requires no special chemical feed equipment and will often work with existing feed pumps.

Dozens of treatment plants have already switched to ClariPhos to meet tough phosphorus limits and gain many other operational benefits.

In one example, a 3.4 MGD municipal wastewater treatment plant tested Neo rare earth coagulant for its ability to meet a new final water quality effluent limit on phosphorus of 0.075 mg/L.

The trial showed that the coagulant alone could consistently reduce phosphorus in the treated effluent to 0.036 mg/L. This result was far superior to what the plant was able to achieve with its conventional coagulant, ferrous chloride, which could only reduce phosphorus to an average of 0.5 mg/L. After switching to Neo rare earth coagulant, the plant was also able to avoid installing new nutrient removal equipment, at an estimated cost of $2.8 million, and reduce solids production by about 35%.