Soil Pollution Research Paper

Introduction

Soil pollution or land pollution is major problem in the world. Soil pollution is results from buildup of contaminants, toxic compounds, radioactive materials, chemical compounds. The most common sources of soil pollution are hydrocarbons, heavy metals (Cd, Pb, Zn, Cu, Hg and As). herbicides, pesticides, tars and PCBs. Industry is to blame for the biggest pollution disaster in the whole world. Heavy metals like Fe, Zn, Cu, Pb, As etc. are come from industrialized plants which are very much harmful for land and human being. High level of radionuclide like nitrogen and phosphorus can be found surrounding farm centers containing high population densities of livestock. Pesticides also soak into the soil and leaving lasting effects.

By operational definition, bioremediation is the use of living organisms, to degrade the environmental contaminants into less toxic forms. It involves naturally occurring bacteria and fungi or plants to degrade or detoxify substances hazardous to human health. Contaminant compounds are transformed by living organisms through reactions that take place as a part of their metabolic processes. Biodegradation of a compound is a result of the actions of multiple organisms. When microorganisms are imported to a contaminated site to enhance degradation that process known as bioaugmentation. For bioremediation to be effective, microorganisms must enzymatically attack the pollutants and convert them to harmless products (Vidali 2001). As bioremediation can be effective only where environmental conditions permit microbial growth and activity. It involves the manipulation of environmental parameters to allow microbial growth and degradation to proceed at a faster rate. Bioremediation has some limitations. Some contaminants, such as chlorinated organic or high aromatic hydrocarbons, are resistant to microbial attack. They are degraded slowly; hence it is not easy to predict the rates of clean-up for a bioremediation exercise. Bioremediation techniques are typically more economical than traditional methods such as incineration.

In situ bioremediation 2. Ex situ bioremediation

Ex situ Bioremediation Ex situ bioremediation means there is no need to excavate or remove soils or water. It involves supplying oxygen and nutrients circulating aqueous solutions through contaminated soils to stimulate naturally occurring bacteria to degrade organic contaminants. This technique includes conditions such as the infiltration of water containing nutrients and oxygen or other electron acceptors for groundwater treatment (Vidali 2001). Most often, ex situ bioremediation is applied to the degradation of contaminants in saturated soils and groundwater. It is a superior method to cleaning contaminated environments since it is

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cheaper and uses harmless microbial organisms to degrade the chemicals. Chemotaxis is important to the study of in- situ bioremediation because microbial organisms with chemotactic abilities can move into an area containing contaminants. By enhancing the cell 's chemotactic abilities, in-situ bioremediation will become a safer method in degrading harmful