There are many lessons one can learn from the Exxon Valdez oil spill in 1989 and the recent disaster in Gulf of Mexico. To summarize, effects on the ecosystem mainly concerned the intertidal zone with seabird and marine mammal populations. One of the frequently asked questions concerning is: "How many animals were killed?" No one is able to answer this question.
Eight weeks after BP's well ruptured, the impact on marine life became increasingly visible with images of dead or dying hermit crabs and brown pelicans trapped and weighed down in dark syrupy oil while spawning Atlantic bluefin tuna are threatened in the Gulf of Mexico – only one of the two places in the world where they can reproduce themselves. Fresh rows broke out after it became public that endangered sea turtles and other marine creatures were corralled into 500 square-mile "burn fields" and burnt alive in operations intended to contain the oil.
Concerns regarding public health risks and long-term impacts on the food chain in the Gulf of Mexico where one-third of the water, or 78,264 square miles, have been closed to fishing, are growing.
The technologies usually applied for remediation and containment of oil spills present several critical points and are not effective at all for many situation. Below are listed the main technologies used and we add some technical motivation why these methods are not sufficient and in most cases can causes damages to the population and the ecosystem with a long term impact.
 |
Building sand barrier berms Building a barrier berm to protect the mainland wetlands from oil is not a new strategy and depends on the suitability of the construction. Protecting areas where vulnerable species live and focusing on them is the best strategy to adopt in order to increase the speed of recovery. The planned berms are intended to protect the islands and inland areas from oil, yet they rapidly erode through natural processes. |
 |
Oil containment booms Booms are long, floating, tube-shaped barriers fitted with rigid or flexible underwater skirts. They are used as floating fences to surround, contain and detect spreading oil slicks. Some booms have a limited skimming capacity. The drawback is that they require a lot of time and labor to deploy, oil can wash over or slip under booms, and different booms must be available for various conditions. However, this is a containment solution for the problem but cannot solve it. |
 |
Oil skimmers There are at least 20 different categories of oil skimmers. Often they are used in combination with containment booms and pumps to collect the surface oil-water mixture, convey the mixture to storage tanks and separate the oil from water. Yet, skimmers do not work well in heavy seas, have a relatively low recovery rate and tend to clog and break down. However the oil skimmers are applied, huge quantities of contaminated water will still remain after the recovery operation. |
 |
Use of Dispersants The use of chemical dispersants reduce the effect of oil spills by changing the chemical and physical properties of the oil. By enhancing the amount of oil that physically mixes into the water, dispersants can reduce the potential that a surface slick will contaminate shoreline habitats. Although called for in the Oil Pollution Act of 1990 as a tool for minimizing the impact of oil spills, the use of chemical dispersants has long been controversial. We cannot forget that when dispersants are used the oil remains in the water and can sink into bottom sediments exposing marine species to oil that can accumulate in tissues. Dispersants contain a mixture of solvents, surfactants and additives and they have their own toxicity levels and are being used at significantly higher volumes where little is known about their environmental impact. |
 |
Bioremediation and natural degradation Some naturally occurring marine bacteria eat oil. When fertilizer is added, bacteria multiply, increasing the consumption and breakdown of oil. This method for removing oil presents many problems. In particular, one must acknowledge that bacteria have difficulty consuming weathered, hardened oil. Furthermore, it is well known that fertilizers may dramatically increase plat growth which then reduces water oxygen levels needed by fish and shellfish. Long-term effects of artificial fertilizers are unknown. |
 |
Controlled burning of surface oil Initial efforts to reduce the spread of an oil spill often begin with controlled burning which tends to have less toxic effects than dispersant methods. During burning operations, volatile organic compounds (VOCs) are released from the crude oil into the air. In addition to VOCs, crude oil contains toxic metals such as mercury and lead and other combustion products at low levels such as aldehydes and acid gases. Combustion releases sooty smoke containing toxic gases that may cause nausea, headaches and breathing problems. Only relatively fresh oil readily ignites and it must be at least a millimeter thick. Burning can leave hard residues on land surfaces. |
Download the article of ENT Magazine #3 June - July 2010
APPLICATION OF RECAM® TO SOLVE THE EMERGENCY OF OIL SPILLS
RECAM® can be used both like a barrier system and for oil removal from sea water. In the case of a barrier, it is sufficient to spread the material on the water surface for it to start to form a uniform and homogeneous barrier which does not let hydrocarbons go through. On the contrary, it starts to attract the oil towards the barrier. In a second phase, it is possible to spread RECAM® on the water surface and start to recover the oil with a process that it is not a simple sorption process, but an action of capturing the oil inside the nanostructured material.
Once RECAM® detains the oil, there are no risks for the oil to be released in the water or in the environment because RECAM® does not only absorb oil but it entraps hydrocarbons inside its nanostructure. Once the oil is trapped there is no way for it to be released. This phenomenon is possible thanks to the affinity of RECAM® towards non polar compounds and its hydrophobic behavior.
In order to recover oil which is not floating on the sea surface but in depth, it is possible to inject RECAM® material from the deep water. Indeed, it starts to attract the oil and encloses it, then slowly rises to the surface of the water, with the trapped hydrocarbons, where they can easily be recovered. It is possible to recover RECAM® with an easy and fast way, just by using nets.
RECAM® material can be burnt with the oil recovered. During the combustion process, no toxic gases are released because RECAM® is completely inert and it is not infflammable. Hydrocarbons are burnt providing an energy production and RECAM® can then be used again to recover oil.RECAM® is unique both in terms of efficiency in hydrocarbon removal and in terms of being eco-friendly, particularly when compared to other products It does not produce waste and is regenerable. RECAM® may be re-utilized and the crude oil is recovered without any traces of water. It is also important to emphasize that RECAM® is more effective for heavy oils and crude oil than for light hydrocarbons. This is an important difference if compared with other products available on the market.
In the table below RECAM® is compared to other products available for oil spill remediation.
|
PRODUCT |
SUPPLIER |
COMPOSITION |
EFFICIENCY (kg of oil recovered/kg of product) |
WASTE PRODUCTION |
REGENERABLE |
POSSIBLE TO RECOVER THE OIL |
|
RECAM® |
SA Envitech a.s. |
Carbon |
92 |
NO |
YES |
YES (90%) |
|
Fibertec® |
First Line Technology |
Cotton |
15 |
YES |
NO |
NO |
|
MPU® |
Mobus Technology |
Polyurethane, PP, PE |
4 |
YES |
NO |
LOW (4%) |
|
Pom-Poms® |
- |
PP |
2 |
YES |
NO |
NO |
