Phytoremediation: The future of pollution management
Phytoremediation is a process of bioremediation which employs various types of plants to mine, transfer, stabilize, wipe out contaminants in the soil and further below the soil zone as well. The money to be earned by entrepreneurs in this area is still underestimated.
The world phytoremediation industry consists of about five dozen companies under numerous different categories. Most perceptible are the dedicated companies, with principal phytoremediation as the remediation technology. The next active division in the marketplace includes a handful of the large to midsize consulting firms that have developed a client friendly adeptness in phytoremediation.
The main tactics of the companies is to track to protect their market position by developing proprietary, protected technology, for example new plant varieties, genetically engineered plants, or proprietary soil amendments. On the other hand, to expand such technology is time-consuming and costly, and past knowledge has shed grim doubt on the capability of the ecological market and its small proceeds margins to prop up complicated research, predominantly biological research. Notwithstanding of such impediments, it is envisaged that transgenic plant life will play an imperative role in marketable phytoremediation in the coming years
The main processes involved in the technology are as follows
Phyto-stabilization : The procedure where, chemical compounds produced by the plant immobilize contaminants
Phyto-accretion : (also called phyto-mining). In this process, plant roots soak up the contaminants along with other nutrients and water. The contaminant accumulation is not removed but ends up in the plant shoots and leaves. This technique is used first and foremost for wastes containing metals. The metals are stored in the plant’s above ground shoots, which are harvested or are disposed of as a perilous waste. As a universal rule, bioavailable metals for plant uptake are cadmium, nickel, zinc, arsenic, selenium, and copper but not limited to that as there is a considerable amount of research to find new ones and their mechanism of uptake. Reasonably bioavailable metals are cobalt, manganese, and iron. Lead, chromium, and uranium are not very bioavailable. Lead is made much more bioavailable by the adding chelating amendments to soils. The availability of radioactive metals like uranium and cesium is enhanced using citric acid and ammonium nitrate.
Hydraulic Control: this process essentially involves, trees which indirectly remediate by controlling groundwater movement. Trees perform as natural pumps while their roots reach down towards the water table and institute a dense root bunch that take up huge quantities of water.
Root zone biodegradation: Here, the plants release biochemical substances by way of its roots, supplying nutrients to microorganisms in the soil.
Phyto-degradation: In this case, plants actually metabolize and destroy contaminants within plant tissues.
Root zone filtration: This is similar to phyto-accumulation, but here plants used for cleanup are raised in controlled atmosphere chambers with their roots in contact with water. The process involves pumping of ground water to the surface to irrigate these plants. Characteristically hydroponic systems make use of a non-natural soil medium, the best example is sand mixed with perlite or vermiculite. As the roots become inundated with contaminants, they are harvested and disposed.
Phyto-volatilization : This is a process by which plants take up water containing organic contaminants and release the contaminants into the air through their leaves.
