Intrinsic Bioremediation

Conversion of environmental pollutants into the harmless forms through the innate capabilities of naturally occurring microbial population is called intrinsic bioremediation. However, there is increasing interest on intrinsic bioremediation for control of all or some of the contamination at waste sites. The intrinsic i.e inherent capacity of microorganism, to metabolize the contaminants should be tested at laboratory and field levels before use for intrinsic bioremediation. Through site monitoring programmes progress of intrinsic bioremediation should be recorded time to time. The conditions of site that favors intrinsic bioremediation are ground water flow throughout the year, carbonate minerals to buffer acidity produced during biodegradation supply of electron acceptors and nutrients for microbial growth and absence of toxic compounds. The other environmental factors such as pH concentration, temperature and nutrient availability determine whether or not biotransformation takes place. Bioremediation of waste mixtures containing metals such as Hg, Pb, As and cyanide at toxic concentration can create problem (Madsen, l99l).

The ability of surface bacteria to degrade a given mixture of pollutants in ground water is dependent on the type and concentration of compounds, electron acceptor and duration of bacteria exposed to contaminants. Therefore, ability of indigenous bacteria degrading contaminants can be determined in laboratory by plate count and macrocosm studies.