Initial consentretion

                                     What is initial concentration?

High initial concentration of spilled oil has a negative effect on the biotransformation process that causes a significant lag phase of about 2–4 weeks. Even after biostimulation, at least a week is needed for microorganisms to adapt and the entire bioremediation process may require months and even years to be completed (Atlas, 1995; Zahed et al., 2010a). The rates of uptake and mineralization of many organic compounds by a microbial population depend on the concentration of the compound (Olivera et al., 1997; Rahman et al., 2002).

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).