1.1 Background of study
Heavy metal contamination has been on the rise in proportion to the pace of worldwide industrialization, leading to significant health problems and toxic effects on plant and microbial biodiversity. Global industrialization produces considerable amounts of toxic waste that pollute the biosphere. Heavy metal contamination has significantly increased due to mining, smelting, manufacturing, gas exhaust, energy and fuel production, fertilizer sewage and pesticide application and municipal waste generation.
Heavy metals are elements with metallic properties and specific weights higher than 5g/cm3.[Gorhe and Paszkowski., 2006]
Excessive accumulation of heavy metals in plants can be toxic because these metals can modify essential protein structure or replace an essential element causing chlorosis, growth impairment, browning or roots, and inactivation of photo systems among others. Furthermore indigestion of contaminated food or drinking water can expose humans and animals to toxic levels of the heavy metal.
Methods for heavy metal removal excavation and land fill thermal treatment. However, because of the high cost, low efficiency, and large destruction of soil structure and fertility, these methods are ineffective. [Jing YD, et al., 2007]
In order to eliminate or control hazardous chemicals, biological processes are employed. One effective and promising process is phytoremediation, which is the use of plants to extract, sequester, and detoxify pollutants through physical, chemical, and biological processes.[Jing YD, et al., 2007].
The advantages of phytoremediation include low cost, speed of deployment, preservation of natural soil properties, and reliance on solar energy.[Zhuang Xl 2007]. The success of phytoremediation depends on the extent of soil contamination, bioavailability of the metal, and the ability of the plant to absorb and accumulate metals in shoots. However, plants with exceptionally high metal accumulating capacity after have a slow growth rate and produce limited amounts of biomass when the concentration of metals in the contamination soil is very high and toxic.
1.2 SIGNIFICANCE OF THE STUDY
The study is significant in the view of cases of diseases associated with the contamination of heavy metals pollutions. It is aimed at appreciating bioremediation in the reduction of heavy metal pollutants in water, food and air using phytoremediation and bioremediation.
1.3 OBJECTIVE OF THE STUDY
The negligence of heavy metals contamination has led to some health issues. Therefore, efforts are being made to ensure the proper reduction of heavy metals pollution in our society.
The objective of the project work was to verify if heavy metals contaminant
can be reduced through the process of phytoremediation and bioremediation.
1.4 SCOPE OF WORK
The scope of the study involved the reduction of heavy metals in samples of soil from the bank of the campus sewage pond, University of Nigeria, Nsukka and the removal using Bryophyllum pinatum, Bacillus cereus and Aspergillus fumigatus.[email protected][email protected]