Oil Spill Cleanup with “sorbents,” both absorbents or adsorbents, is an essential everyday task. This article is for safety managers and those who need to be more knowledgeable about the technical options available for cleanup. The key factors to understand are whether the oil is “absorbed” or “adsorbed” and whether the cleanup medium soaks up water too, or just the oil. There is the right product for every job and every phase of large oil spills.
NEOSafe™ is a new Huron Industries oil “absorption”, anti-slip solution that is also hydrophobic, meaning it repels water. This product has a unique niche in the oil spill cleanup market because of these characteristics, which make it the best product technically for many situations.
Sorbent is a general term that includes both the mechanism of absorption and adsorption.
- Absorption is when one product soaks up another product and becomes one. There can be physical absorption via a capillary action, which we are discussing with oil spill cleanup or chemical in the case of many biological processes. An oil spill absorbent can swell up to 70% larger than its original size when it absorbs oil.
- Adsorption is when oil molecules are attached to the surface of the adsorbent material. This is more like when the dust is attracted to a dust buster and can be removed physically. Oil is “adsorbed” on the material’s surface, and significantly less swelling of the original product normally occurs.
Oil spills are a significant problem in many industrial facilities
Oil and lubricant handling companies are highly aware of oil spills’ safety and environmental hazards. The consequences of a spill not being cleaned up promptly and thoroughly can be enormous, and the costs are very high. Sorbents are the solution; the only question is, “which one”?
Before we dig a little deeper into the sorbents available and which one is best in which circumstance, there is one more important physical property that is critical. That’s whether the sorbent will attract (or absorb) water or repel it as it cleans up the oil. Since many spills are on or under water, in wet areas, or have water mixed with oil in the spill, the answer is critical to success. The more technical terms for this are:
- Oleophilic: when the sorbent will ATTRACT water
- Hydrophobic: when the sorbent will REPEL water
Common adsorbent oil spill cleanup includes:
- Natural products like sawdust, peat moss, feathers, and cellulose. These are great at adsorbing both water and oil.
- Minerals like the common vermiculite, ash, sand, and more. These are sold in bulk for all sizes of oil spill cleanup but more commonly for larger spills.
- Polymers are synthetic adsorbents and absorbents and may adsorb a considerable amount of material, up to 60 times their weight. Huron’s NEOSafe is in this category of products.
Some significant factors in deciding the best oil sorbent for a particular job might include these common things. But, of course, these need to be considered before a spill occurs and be on hand in adequate amounts, or all the theoretical discussions are not helpful.
- Size of the spill
- Environmental or safety consequences if not cleaned up promptly and fully
- Whether water is involved, a spill in water or mixed with water
- Cost of the sorbent. Natural sorbents, like clay and peat moss, are less expensive than synthetics, but they can be much harder to clean up and dispose of once the spill is over. Using more costly but more effective sorbents in the final stages of a spill cleanup will almost always save money.
- The best form for the sorbent to be stored in:
- Bulk, usually five gal or 55 gal containers. Usually very cost-effective
- Socks or booms. Easy to deploy and easy to pick up for disposal
- Mats, pads, or rolls. 19″ by 17″ rectangular pads are perfect for small spills or preventive deployment
- Pom Poms, sorbent in strands, are usually used to pull through the water to absorb oil. In addition, the sorbent is typically designed to repel water.
- Absorption or adsorption rate of the material. If the spill is from lighter oils like diesel fuel, the rate will be faster, and more products will work satisfactorily. For heavier oils, pom-poms, with their many fibers and synthetic materials like NEOSafe, may work much better.
- Weight can be a consideration depending on how far the material must be transported to the spill site. For example, polymer-type absorbents can be much lighter than clay and similar materials.
- Capacity and retention are essential factors to determine how much sorbent material you need to clean a given volume of oil. You will need a lot less, with synthetic materials picking up significantly more oil by weight. Retention is how well the oil stays in the sorbent until you can dispose of it. Good retention is vital in preventing oil spill cleanup from getting out of control with messy drips after cleaning up oily surfaces.
- Sorbent booms and pom-poms can be better choices for spills on water. However, choosing one hydrophobic (repels water) will mean more oil absorbed per foot of an expensive boom.
- Ease of use based on the spill size is always important. The time to clean up a spill and restore normal industrial operations is a hidden cost that should be considered. Absorbent pads may be more expensive, but they are quickly deployed and disposed of instead of cleaning up a 5-gallon bucket of loose clay.
- Disposal of the oil and the sorbent must be considered. NEOSafe has a strong advantage in this area because it can be disposed of per the disposal instructions of the oil it has absorbed. However, other sorbents may carry a disposal expense.
- Environmental Hazard of the material itself. Crystalline Silica, for example, is a severe environmental hazard in industrial settings and is found in most conventional mineral absorbents. In addition, it has been proven to cause lung cancer and chronic bronchitis.
- Crystalline silica can be released into the air from cutting, grinding, drilling, crushing, sanding, or breaking apart many different materials. Silica is a well-known occupational hazard and has also been recently examined for its environmental concentrations near silica sand mines and transport terminals.
With the vast range of sorbents on the market, it’s vital that company safety managers understand their most likely oil spill scenario and plan for cleanup using the most effective sorbents possible. That is not always one lowest-cost product. It will most likely be a combination of products based on the operations and risks involved.
Absorbents have the advantages of:
- More oil absorbed per unit weight of the sorbent
- Easier to disposal typically because the oil is “locked” inside the sorbent
- Combined with booms, socks, and other enclosures, they can be very efficient and easy to handle
Adsorbents have the advantage of:
- The lower cost typically because they are common industrial and organic materials
A significantly more effective product like NEOSafe, a polymer-based solution, may provide the lowest overall cost. Best for:
- The final part of oil spill cleanup
- Drawing out oil from concrete or other floor surfaces
- Oily and greasy parts cleanup
- Complex spill cleanups involving oil and water mixtures