User:Csmith3443/sandbox

Lead
Lead is commonly found in wastewaters as it is released from manufacturing facilities that utilize the metal or that recycle it. Lead as an environmental contaminant can cause many adverse health effects in animals and humans, and higher cases in young children in developing countries. Multiple species of bacteria have been shown to utilize different methods for removing lead from soils or ground water including biosorption, biofilm-mediated, and cell surface hydrophobicity. The removal of lead from water and soils has many difficulties such as an increased energy consumption, introduction of additional chemicals, and pollution from byproducts. The use of Microorganisms for bioremediation is an environmentally friendly process that can reach the goals of removing the contaminant from the environment. Pseudomonas aeruginosa in a previous study was shown to be able to adsorb 61.2% of lead from a water source in optimal conditions indicating that it could be useful for bioremediation of lead. This species of Pseudomonas was also shown to be able to remove soil bound lead showing more versatility than only that of water containing lead.

Chromium
Chromium is the second largest heavy metal in contaminated environmental systems like soil and water. It can be introduced into the environment from human activities and through natural processes. Chromium can exist in nature in two forms, Trivalent Chromium (Cr III) and Hexavalent Chromium (Cr VI) with Cr (VI) being the most toxic as it can denature proteins and has mutagenic effects. Many strategies have been used to remove Chromium from environmental systems. Many methods involve high prices, high energy requirements, and generation of dangerous byproducts. The eco-friendly way to remediate the system from the Chromium is a method known as bioadsorption as the heavy metal has an affinity for cell wall components. Two species of bacterial organisms with the highest adsorption are Psuedomonas and Aeromonas cavisiae. The bioremedation of chromium from contaminated systems can take two paths for the most effective route. At concentrations of 50 mg/ Cr (VI) or lower, biological reduction of Cr (Vi) to Cr (III), at concentrations above 50 mg, bioadsorption dominates. The adsorption method showed a reduction of 70% for concentrations of 5-500 mg/L with a maximum of 94% at 100 mg/L. The biological reduction pathway had a maximum reduction at 60 mg/L at initial concentrations of 250 mg/L.

Uranium
Hexavalent uranium contamination is a large global problem in areas such as, near uranium mines, and near weapon crafting facilities. The typical, very costly, method for removing uranium from ground water is to pump the water out, treat it above ground, then pump it back to its original location. Some ways that have been attempted to remediate the contaminates are biosorption and bioaccumulation, a third option has been shown to have a more stable outcome, which is reduction of uranium (VI) to uranium (IV) which is immobile in solution and settles to the bottom. A wide range of microorganisms have shown to be able to utilize uranium for this reaction including Pseudomonas sp., Pantoea sp., Enterobacter sp., several Geobacter species, and Thermus scotoductus . The difficulties with this method are determining what methods and conditions are optimal for this type of bioremediation, including pH, type of substrate (electron donor), and salt concentrations.