[PENDING] SOMYA VASHISHTHA - CORE

If exposed to the environment, they can be dangerous to the environment and to life forms. In this study, we investigated the ability of microorganisms present in soil to degrade these hydrocarbons so that contaminated soil can be treated using a microbial consortium. Crude oil spreads very quickly on the sea surface and after a short time the thickness of the oil film can be as much as 1 mm.

The consequences of oil spills are therefore widespread and can be visible for a long time. Many mechanical and chemical recovery methods can be used for cleanup, depending on the type of oil spill, the temperature of the water, the type of coastline, etc. Soil bioremediation requires the identification of microbes present in the soil itself so that a large leakage, these can be further stimulated to clean the area.

My goal is therefore to isolate a strain of such oil-degrading microorganisms so that it can be grown under optimal conditions and used as a remediation tool.

LITERATURE REVIEW

Literature Review

Microbial Degradation of petroleum Hydrocarbons
Mechanism of Petroleum Hydrocarbon Degradation
Factors affecting Biodegradation of Petroleum Hydrocarbons
Literature cited for Soil Methodology

They increase the oil's surface area, thereby increasing its exposure to air, sunlight and underlying water. Evaporation: Evaporation is the preferred transfer of light and medium weight components of the oil from the liquid phase to the vapor phase. It is relatively insignificant in the overall weathering process in terms of volume reduction because many of the same components that would dissolve would typically evaporate first.

It reduces the volume at the smooth surface, but does not change the physico-chemical properties of the oil. The majority of the weathering processes can be slowed down once a stable emulsion is formed, and it also increases the volume significantly. It begins during the first day of the spill and may continue to occur throughout the first year.

It is affected by the proximity of the spill to the affected shoreline, the intensity of current and wave action on the affected shoreline, and persistence of the spilled product. It peaks within the first month of release, but may ultimately be limited by the availability of nutrients in the environment for their growth. Air injection or soil aeration can be used to extract pollutants from the soil as well as groundwater-saturated soil by mobilizing the volatile component.

The temperature of the steam must be higher than the boiling points of volatile components. It can remove some toxic components from a spill site faster than evaporation alone. The fastest and most complete degradation of most organic pollutants occurs under aerobic conditions[3].

The diesel from each flask was taken out, centrifuged and analyzed by gas chromatography. It has been shown that the addition of inoculum to soil can promote bioremediation of TPH. Results showed that the concentration of diesel fuel in the treated soil was reduced to <15% of the initial concentration within 35 days in both laboratory and pilot experiments.

Improvement of microbial activity in hydrocarbon-contaminated soil was assumed to be achieved by a combination of stepwise soil inoculation and nutrient addition.

Figure 1: Summary of all the weathering processes [1]

MATERIALS AND METHODS

Materials and Methods

Isolation of microorganism
Optimization of Process Parameters
Degradation Study

Then 1 ml of this contaminated water is taken from the white zone and a serial dilution of the order of 10-6 is carried out because the concentration in the contaminated water is too high. The rest of the parameters need to be optimized so that maximum fungal growth is observed. The concentration of the broth for one flask or 50 ml of solution is as follows.

The flasks and broth are properly sterilized at 15 psi, and the pH of the broth is measured before inoculation with approx. 1 ml of the liquid culture of the isolated fungi. The concentration of the broth was the same as in nitrogen source optimization, but the carbon source used was n-octane. The flasks are then sealed and placed in a shaker at 120 rpm and left for 4 to 5 days, depending on the growth of the fungus.

The concentration of the broth and the carbon source is the same as with temperature optimization. The different pH values are adjusted by the addition of NaCl or HCl solution, a standard 1N solution of the two is prepared to adjust the pH. The culture is prepared in 5 different flasks, so that each flask has a different magnesium concentration.

The concentration of the broth and carbon source are the same, except that the concentration of nitrogen source is the one obtained after optimization. The concentration of the broth and carbon source are the same, except that the concentrations of nitrogen source and magnesium are those obtained after optimization. The weight difference of the filter paper gives the amount of biomass grown.

The concentration of the broth is the same as in previous cases, but the temperature, nitrogen concentration, pH, magnesium and trace element concentration are the. Since the initial weight of the hexane solvent is measured before use, we can subtract the final weight of the hexane from the initial weight of the hexane to get the oil weight.

RESULTS AND DISCUSSION

Results and Discussion 1 Optimization Results

It is clear that peptone is the most favorable nitrogen source as it gives the highest amount of biomass, but peptone as a source for a number of experiments is not economically favorable.

Temperature Biomass(mg)

But after 300 you could see that the fungus had started to degenerate and at 400 there was no growth at all. It can therefore be inferred that at temperatures as high as 400°C this particular fungus does not grow favorably.

Degradation Study

No Sample Name Initial Oil (g)

Even with increasing concentration of the oil, the fungus is able to degrade it, as is evident in the shape (Figure 15). When the initial amount of added oil is increased to 5 g, significant degradation is still seen after 15, 30 and 45 days; it is almost uniform. The amount of biomass produced during this period is also increasing and at the same time the dissolved oxygen is decreasing due to the simple fact that since no external oxygen is supplied, the biomass uses the dissolved oxygen for its growth.

It can be argued that the highest amount of oxygen used is for the bottle placed for 45 days, and yet this does not give the highest percentage of degradation, which is caused by the bottle left for 20 days; This can be explained by the fact that the greater the number of days, the greater the amount of oxygen required for survival. After 20 days, the fungus produces less biomass and thus uses less oxygen, but since the amount of oil added was only 1 gram, it could easily break it down with so much activity; whereas when the fungus is placed for 45 days, firstly the fungus survives longer and thus consumes more oxygen, secondly the initial amount of oil added is also 4 grams greater and thus a greater amount of activity is required for its decomposition, hence the percentage of degradation is relatively less. From this result it can be deduced that high oil concentration is toxic to the fungus and it starts.

Heavy crude oil contains components with more than 23 carbon atoms and are therefore very bulky molecules that do not evaporate or dissolve. The overall degradation efficiency of the fungus decreases compared to light crude oil, as the maximum degradation achieved for heavy crude oil is 56.4%. The general trends of degradation observed in light crude oil are also visible here; with increasing amount of added oil the degradation is observed, but at very high concentrations it is virtually non-existent.

The maximum degradation is observed in the flask placed for 45 days with the initial addition of 5 g of oil; therefore, we can emphasize that the fungus has the ability to break down even heavy oil, but it requires a longer period of time. It can be argued that the maximum biomass is produced in a flask placed for 30 days with 5 g of initial oil added, but it does not cause the maximum degradation; as the number of days increases, the biomass produced decreases, which tells us that the denaturation of the fungus has begun. After 30 days, the biomass produced is more, but maybe it breaks down less oil due to the competition for survival or that the fungus enters the death phase in the decomposition process, because at 45 days the percentage of decomposition is the highest.

The reason for this is the same as for light crude oil. The solution after decomposition or even during the process is clear; the oil is trapped in the mycelium of the fungus, and the solution remains clear.

Figure 16: Initial Amount vs Final Amount(light Crude Oil)

CONCLUSION

Conclusion

Bury et al., “Identification and biodegradation potential of tropical aerobic hydrocarbon-degrading microorganisms,” Research in Microbiology. Da¸browski; 'The seasonal variability of yeasts and yeast-like organisms in water and bottom sediment of the Szczecin Lagoon,'. Rehman; “Laboratory Bioremediation of Diesel Hydrocarbon in Soil by an Indigenous Bacterial Consortium”; Indian Journal of Experimental Biology.

Bhattacharya; ―Degradation of polyaromatic hydrocarbons by mixed culture isolated from oil-contaminated soil – A bioprocess engineering study.‖; Indian Journal of Biotechnology. Hasanain; ―Bioremediation of soils contaminated with crude oil: a black art or an engineering challenge?‖; Process Safety and Environmental Protection; 83 (B.