1. Introduction
1.1 Background of the Study
At present age there is a rapid increase of contaminants in the environment, but one of the major global concerns is the heavy metal concentrations in the environment as a result of man’s activities and since the biosphere is a closed system this heavy metals remains on earth and continuously increase as the human population increase. The acute and chronic effects of these heavy metals especially lead have been a worldwide concern. In fact in April 2000 the use of leaded gasoline was phased out in Metro Manila, such movement was partly due to the implementation of Clean Air Act of 1999 as well as the environmental concern of previous president Fidel V. Ramos [2].
Add an intro here about the presence and sources of lead and correlate it with the possibility of contaminating waters.
Conventional methods for metal removal in water include chemical precipitation, lime coagulation, ion exchange, reverse osmosis and solvent extraction [3]. Although this methods for the removal of heavy metals from wastewaters, however, are often cost prohibitive having inadequate efficiencies at low metal concentrations, particularly in the range of 1 to 100 mg/L. Some of these methods, furthermore, generate toxic sludge, the disposal of which is a burden on the techno-economic feasibility of treatment procedures [3].
The search for new technologies involving the removal of toxic metals from wastewaters has directed attention to biosorption, based on metal binding capacities of various biological materials. Biosorption can be defined as the ability of biological materials to accumulate heavy metals from wastewater through metabolically mediated or physico-chemical pathways of uptake [4]. Biosorption for the removal of heavy metal ions may provide an attractive
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