Effective treatment of petroleum oil-contaminated wastewater using activated sludge modified with magnetite/silicon nanocomposite

The study aimed to optimize the treatment of oil refinery-contaminated wastewater through modification of the well-established activated sludge process with new nanocomposite (NC) materials to produce high-quality treated effluents for potential reuse. Refinery wastewater samples were collected from one of the major oil refineries, Alexandria, Egypt, where the operation, performance, and efficiency of the current activated sludge (AS) unit were evaluated for 6 consecutive months. Two AS bench scale PVC basins were constructed. Magnetite nanoparticles (Fe3O4 NPs) and magnetite silica (Fe3O4/silica) nanocomposite (NC) were prepared and characterized. Bioremediation trials were carried out in a sequential batch mode using Fe3O4/silica NC-modified AS and control (unmodified AS). The proposed treatment produced high-quality effluents in a very short time (2 h) despite the very high initial pollutant concentration accompanied with a reduction in the produced sludge. The highest removal of TSS, TDS, BOD, COD, and OG from raw industrial wastewater recorded 78.33, 3.6, 87.65, 85.17, and 92.92% compared to 55.3, 12.6, 50.0, 40.22, and 56.84%, respectively, achieved by the unmodified AS unit. The results confirmed that integration of the AS treatment with nanomaterial composite is highly effective, promising, and economic for the treatment of highly toxic and complicated industrial wastewater such as petroleum refinery effluents.

Bioremediation potential of hydrocarbon degrading bacteria: isolation, characterization, and assessment

Oil contamination is a worldwide concern now. However, oil contaminated environment is enriched with microorganisms that can utilize petroleum oil and use hydrocarbon for their growth, nutrition and metabolic activities. In the present study, bacteria present in the oil contaminated soil were isolated by enrichment culture technique using Minimal Salt (MS) media supplemented with diesel oil and burned engine oil as a sole carbon source. The isolated bacteria were characterized by morphological and biochemical tests and identified by molecular tool through cycle sequencing method. Three isolates were morphologically characterized as gram-negative, cocci shaped and 16S rRNA sequence analysis revealed that the isolates are closely related to Pseudomonas sp., Acinetobacter sp., and Enterobacter sp. respectively. Growth condition was optimized at pH 7.0 and temperature 37 °C. All the isolates were susceptible to several antibiotics and they have no antagonistic effect with soil beneficial bacteria. Three isolates were grown in two different concentrations of diesel oil and burned engine oil (4% v/v and 8%, v/v) respectively. Study revealed that with increasing the concentration of diesel oil in the media the growth rate of all the isolates were decreased. In contrast, the growth rates of all the three isolates were increased, with increasing concentration of burned engine oil. In our study, all the isolates showed their degradation efficacy in 4% v/v diesel oil and in 8% v/v burned engine oil. So, our research clearly shows that the isolates could be potentially used for bioremediation purposes for cleaning up petroleum polluted area.

Assessment of the chemical hazard awareness of petrol tanker driver: A case study

Understanding the tanker driver hazard awareness on chemical exposure is important to ensure that they are fortified with the appropriate information regarding the risk of their occupation. This present study was conducted to determine the awareness of the petrol tanker driver on the chemical exposure during transportation petroleum product. The assessment on hazardous awareness of the petrol tank driver was conducted through questionnaire survey. Wherein, the questionnaire was designed with considering the variables of age of the driver, working experience, working hours in a day and knowledge on chemical hazard presence in the petroleum oil. A reliability test of Cronbach's Alpha was performed to validate the questionnaire and the Chi-Square test was conducted to determine the correlation among the studied variables. The findings of the present study revealed that the drivers who are frequently come into direct contact with petrol cannot identify the spillage had occurred during working. The study identified that there is an urgency to conduct training on safe handling of petroleum oil in order to eliminate the risk of chemical hazards exposure to the tanker driver.

A review on the application of chemical surfactant and surfactant foam for remediation of petroleum oil contaminated soil

Soil, exposed to petroleum oil contaminants (in the form of petrol, diesel, gasoline, crude oil, used motor oil), may cause potential damage to the environment, animal and human health. In this review article, mechanisms of the petroleum oil contaminant removal from soil by chemical surfactant systems such as surfactant solution, surfactant foam and nanoparticle stabilized surfactant foams are explained. Laboratory based research works, reported within the last decade on the application of similar systems towards the removal of petroleum oil contaminant from the soil, have been discussed. It is an important fact that the commercial implementation of the chemical surfactant based technology depends on the environmental properties (biodegradability and toxicity) of the surfactants. In recent times, surfactant foam and nanoparticle stabilized surfactant foam are becoming more popular and considered advantageous over the use of surfactant solution alone. However, more research works have to be conducted on nanoparticle stabilized foam. The impact of physicochemical properties of the nanoparticles on soil remediation has to be explored in depth.

The influence of petroleum oil films on the feather structure of tropical and temperate seabird species

Feather fouling is a primary cause of seabird mortality during marine hydrocarbon oil spills. Understanding how oils interact with feathers is an important step in mitigating this threat. Seabird feathers from 12 taxa, representing most seabird families from the tropics and southern latitudes, were exposed to crude and condensate oil films under laboratory settings. Feathers were measured for changes in mass proportional to feather size, and for barbule clumping. Seabird feathers from six distinct families exposed to very thin oil sheens (<0.3 μm) showed no significant change in proportional mass relative to control treatments, and 10 of the 12 species exposed to these films revealed no significant difference in barbule clumping. By contrast, exposure to both crude and condensate oil films ≥3 μm resulted in significant increases in feather mass and clumping. Our findings highlight the importance of considering the influence of oil on feather structure when compiling threat assessments involving seabirds.