Absorbents, wipers and rags are used every day to clean up leaks and spills and are generally non-hazardous.
Mats, socks, pillows, loose absorbents and wipers are made from many different types of materials such as polypropylene, cotton, corn cob and earthen minerals like vermiculite, cork and clay.
Absorbents take on the characteristics of the liquids they have absorbed, and should be handled with the same precautions as the liquid.
Selecting the correct absorbent for the job helps keep employees & facilities safer.
Information about chemicals can be obtained from Safety Data Sheets , suppliers, chemical indexes and many online resources to properly use, store, handle, recycle and dispose of it.
There are three main categories of products:
Universal Absorbents. Will absorb both oil and water based liquids.
Oil-Only Absorbents- Will only absorb oil based liquids. These will float on water.
Will absorb both oil and water based liquids. Yellow is more commonly used for aggressive chemicals.
In addition to the form in which the sorbent is presented and the ability of a particular material to selectively take up oil, other factors also affect a sorbent’s effectiveness.
Buoyancy - Remain afloat even when saturated with oil and water.
Absorption rate - Fast Absorption rate / capillary action means quicker cleaner of spills.
Saturation - Sorbents should have high saturation point / absorption capacity.
Oil retention - One of the key aspects of the overall performance of a sorbent is its ability to retain Absorbed Liquids.
Strength and durability - The durability of a sorbent is important in those situations where it may be left in-situ for an extended period of time before recovery.
Cost - The cost of sorbent products varies greatly and is primarily dependent upon the material used. Organic and inorganic materials are comparatively less expensive than synthetic products.
Availability, storage and transportation - The performance of synthetic sorbents makes their use attractive but they may not always be immediately available at the site of the spill.
100% polypropylene is naturally hydrophobic or repels water, while like materials adhere or are attracted to the surface area of the polypropylene fibers. And since polypropylene is a petroleum derivative, it will absorb any oil or oil-based liquids.
In addition to having a lower density than water, polypropylene's natural aversion to water made these "oil only" absorbents an excellent choice for environmental clean up. Both the oil and the absorbent floated on the top of the water.
Dyes are also added in to the manufacturing process to color-code sorbents - creating a very easy to use color system to identify which absorbent you need for the job.
As industrial and other indoor absorbent applications emerged, sorbents were needed to clean up more than just petroleum-based spills. Water-based liquids and chemicals leak, drip and spill in manufacturing and industrial facilities around the world. So by adding a surfactant into the manufacturing process, sorbents can absorb both oil and water-based liquids - making the product hydrophilic.
“Properly disposing of spent absorbents will help your facility avoid non-compliance fines and minimize your impact on the environment.”
In terms of waste management: it is more difficult to dispose of a mixture of oiled sorbents than pure pollutant.
The disposal methods of sorbents after use are varied and depend on:
Do not mix oiled sorbent with other types of waste, as it will complicate its disposal.
Temporary storage and transport of oiled material - Ideally, sorbents are compressed to minimize bulk and optimise transport logistics. Oil and water released as a result of compressing the sorbents must be recovered and kept in temporary storage .
Reuse - In theory, some types of sorbent can be reused if the oil can be extracted. This can be achieved either by compression using a mangle or wringer (as in rope mop skimmer systems), by centrifuge or by solvent extraction.
Incineration - Burning contaminated sorbent may be a viable option if the sorbent material is combustible and does not contain excessive quantities of water.
Landfill - Disposal of sorbent material as landfill is also usually strictly controlled by local or national regulations. Oiled sorbent material is treated as a hazardous waste & the use of designated hazardous material landfill sites may be required
Biodegradation - Organic sorbent materials generally have the advantage of being biodegradable. Depending on local waste disposal regulations and assuming a relatively low oil content, disposal of organic sorbents by land farming may be permitted.
