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. |
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| 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 |
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EnviroBlend® Chemistry (% by weight) |
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| +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.