Enviroblend Vs. Portland Cement
Although lime-based treatment technologies (i.e. Portland Cement, CKD) can occasionally pass an initial TCLP test, actual long term treatment is at risk. Once treated waste is exposed to the environment, a highly alkaline product such as Portland will continue to drive up the pH, often too quickly and irregularly. Because many metals will leach at low and high pHs (on a bell curve), a sudden increase in pH can cause metals to leach over time. Therefore, pH maintenance is imperative to long-term stability.
The table below shows the effectiveness of the EnviroBlend chemistry resulting in the very low leaching in both the TCLP (acid) and SPLP "Acid Rain" tests. Both the lime and Portland Cement treatments are able to sometimes beat the TCLP test at high dosages but they actually increase the amount of the lead leaching in the SPLP test.
|
|
EnviroBlend |
Lime/Portland Cement/CKD |
Chemical
Reaction and
pH Regulation |
|
EnviroBlend chemistries help to stabilize the pH
of the environment over
time. Since many metals
leach at both high and low pHs, pH
maintenance
is imperative to long-term stability. |
Lime-based treatment can often drive pH up too
quickly and irregularly.
It will often pass the TCLP
test, however, may not continue to stabilize
waste
over time if the pH increases after treatment. |
| Chemical Cost |
|
Due to the superiority in effectiveness of
EnviroBlend technologies, a typical dosage rate
is 1%-10%. This enables total chemical
expense,
as determined by cost of treatment per
ton, to be kept at a minimum. Up to 75% savings
over lime-based treatment is possible. |
Lime-based treatment typically
is effective at
dosage rates of 10%-100%, significantly higher
than
that required of EnviroBlend. Costs
associated with quantity of
material needed for
treatment can drive up expenses in removal,
transportation,
and production. |
| Bulking Factor |
|
Lower bulking factor decreases
material handling
expense, improves production and typically
shortens
project duration. |
Higher bulking factor increase
amount of
material handling, and therefore increases
production time. |
Transportation
and Disposal
Costs |
|
Total transportation and disposal
expense
decreases due to lower bulking; there is less
material to be transported and disposed |
Higher bulking factor drives
transportation and
disposal expense up due to higher volume of
material. |
DOSAGE RATES
The use of lime based technologies are sometimes able to beat the TCLP test (within a narrow dosage window), but it can be seen that they fall significantly short compared with the EnviroBlend chemistry. The table below shows the effectiveness of the EnviroBlend chemistry resulting in the very low leaching in both the TCLP (acid) and SPLP "Acid Rain" tests. Both the lime and Portland cement treatments are able to sometimes beat the TCLP test at high dosages but they actually increase the amount of the lead leaching in the SPLP test.
Treatment of Lead TCLP Hazardous Wastes Actual Test Results on a Sample of Smelter Slag
| |
TCLP (acid) Leach Test |
Hazardous
Waste Criteria
(mg/L) |
SPLP Acid Rain (Water) Test |
| |
Lead(mg/L) |
Final pH |
|
Lead(mg/L)
|
Final pH |
| Untreated |
600 |
6.0 |
5.0 |
<0.003 |
8.2 |
| Lime (Calcium Hydroxide) (% by weight) |
| +5% |
76 |
6.5 |
5.0 |
290 |
12.2 |
| +10% |
0.2 |
8.6 |
5.0 |
540 |
12.5 |
| +15% |
<0.2 |
10.4 |
5.0 |
11 |
11.9 |
| Portland Cement (% by weight) |
| +5% |
450 |
5.3 |
5.0 |
19 |
11.5 |
| +15% |
<0.2 |
10.4 |
5.0 |
11 |
11.9 |
| +25% |
1.2 |
11.6 |
5.0 |
12 |
11.9 |
| +50% |
10.0 |
12.0 |
5.0 |
3.0 |
12.1 |
| EnviroBlend® Chemistry (% by weight) |
| +4% |
2.4 |
5.8 |
5.0 |
<0.003 |
10.6 |
| +6% |
0.4 |
5.5 |
5.0 |
<0.003 |
10.3 |
| +8% |
<0.2 |
5.6 |
5.0 |
<0.003 |
8.5 |
Note: All samples crushed to pass a 9.5 mm sieve per Method 1311 Toxicity Characteristic Leaching Procedure, 40 CFR, Part 261, Appendix II.
Low Dosage Rates
Due to the superiority in effectiveness of EnviroBlend technologies, dosage rates for treatment are typically a fraction of what is required when using a lime-based treatment, sometimes by 50%-90%.
Costs associated with quantity of material needed for treatment can drive up expenses in removal, transportation, production time and disposal costs.
Click here for a Cost Comparison Evaluation.
Especially in today's regulatory environment — a facility can not risk
problems with ineffective and inconsistent treatment. EnviroBlend
understands this issue and assists facilities to determine the best
chemistry. Premier Chemicals offers many types of EnviroBlend and
clients are assured they are using the correct reagent and lowest-cost
solution.
Email enviroblendinfo@premiermagnesia.com for information regarding a complimentary side-by-side treatability study comparing EnviroBlend to your current reagent.