Using Biosorbents to Remove Oil From Water

Remove Oil From Water. Dumping of insufficiently treated household and industrial wastewater contaminates water, poisons water bodies and destroys ecosystems. Among the substances contaminating oceans, seas, lakes and rivers of the planet, various oil products hold a leading position.

The amount of oil products dumped into the ocean, but different accounts, varies from 5 to 10 million tons annually. The main sources of such contamination are crude oil extraction sites, oil transportation, terminals and storage facilities, railroads etc. The most toxic oil products are naphthalene, methylnaphthalene, phenanthrene and trimethylbenzene. Besides, there is direct economic damage from oil products getting into the water, in the order of several billion dollars each year.

That is why the search for new methods, materials and technologies to purify water and minimize the amount of oil and oil products in the hydrosphere.

There are mechanical, chemical and biological methods of removing oil from wastewater. Adsorption is widely used for deep purification of contaminated water. In this respect, the above methods have several disadvantages.

Chemical methods involve mixing of chemical reagents with the water. The reactions occurring in the treatment process may result in formation of materials more toxic than before.

Mechanical methods remove only the oil and oil slime from the surface. Emulsified and solved oil cannot be removed, making this method inefficient.

Biological oxidation can be efficient in case of low oil concentration, in the surface layers of water in a certain pH and temperature range.

Adsorption is one of the most promising directions in water treatment. The advantage of the method is its low cost, general availability, enough raw materials, non-toxicity, high efficiency and the capability to treat wastewater with many contaminants.

Adsorbents can be inorganic, synthetic, natural organic and organomineral. All are similar in their adsorption and other characteristics. They are used as Natural materials of vegetable or mineral origin are used(cotton, peat, peat moss, sawdust, wood chips, wood powder, hemp, hay, clay, perlite etc), as well as artificial synthetic materials based on rayon, hydrocellulose, synthetic fibers, thermoplastic materials, foam polyurethane etc.

The analysis of sorption methods to remove oil and its products from water indicates the prospect of using natural adsorbents. These are peat (absorbs 3.5 to 9.8 kg of crude oil), wool (8-10 kg of oil absorbed by one kilogram), sawdust, moss, seed peels, activated charcoal, etc. Sapropel and lignin are also quite promising as adsorbents.

обновлено: January 6, 2017 автором: dannik