Biodegradation of Polycyclic Aromatic Hydrocarbons by Exopolymers Synthesized by Moderately Halophilic Bacteria: Chemical Composition and Functional Properties

Three strains of halophilic bioemulsifier-producing bacteria; Bacillus sp. 2BSG-PDA-16, Bacillus sp. DV2-37 and Bacillus licheniformis ABRII6 were isolated from crude oil polluted water samples. Characteristics of exopolymers produced by these strains in media supplemented with various hydrocarbons instead of glucose were studied. Yield production, chemical composition, emulsifying, rheological and flocculating properties of exopolymers varied according to the strain and the carbon source. The highest amount of exopolymers synthesized by Bacillus sp. 2BSG-PDA-16, Bacillus sp. DV2-37 and B. licheniformis ABRII6 was 11, 18.5 and 12.4 g/l, respectively from media amended with glucose, while the most active emulsifiers were those obtained from media added with crude oil. Furthermore, all exopolymers produced were capable of emulsifying crude oil more efficiently than the three chemical surfactants tested as control (Tween 20, Tween 80 and Triton X-100). Respect to chemical composition, exopolymers produced on hydrocarbons always have lower content of carbohydrates and proteins than exopolymers produced in medium amended with glucose, however they showed higher amounts of uronic acids, sulfates and acetyl residues. The rheological study suggested that the exopolymers have characteristics of the pseudoplastic fluids. Efficiency of bacterial strains to remove PAH seems to agree with their potential applicability in oil bioremediation technology.     

Photocatalytic degradation of pharmaceutical micro-pollutants using ZnO

Environmental Science and Pollution Research - This research paper presents the results of an experimental investigation of the degradation of three different contaminants including progesterone...     

Photocatalytic demulsification of oil/water emulsions containing nonionic surfactant

Environmental Science and Pollution Research - Separation of oil-water (OW) emulsions is investigated using a photocatalytic demulsification approach. Experiments were conducted using two types of...     

The Representation of Biofuels in Political Cartoons: Ironies,Contradictions and Moral Dilemmas

Biofuels are an important component in the suite of renewable energy alternatives but their development trajectory has been fraught with controversy. This study investigated the representation of biofuels in political cartoons on the Internet. Political cartoons have relied on informative, persuasive, and performative attributes to engender critical reflection and mobilize action. We analyzed a corpus of 130 relevant cartoons obtained through Google Images which were then thematically categorized. The problems highlighted in these cartoons focused on the social injustices arising from the diversion of food sources to fuel, the environmental destruction arising from deforestation, the unfulfilled expectations for climate change mitigation, and the policy contradictions that emerged. We suggest that political cartoons’ discursive dimensions allow us to make immediate connections between the image and our cultural stores of meaning, while at the same time further elucidate the dilemmas and contradictions embedded in the public's interface with biofuels as an environmental issue.     

Bioremoval of PVP-coated silver nanoparticles using Aspergillus niger: the role of exopolysaccharides

Environmental Science and Pollution Research - Extensive use of engineered nanoparticles has led to their eventual release in the environment. The present work aims to study the removal of...     

Adaptation planning for sea level rise: a study of US coastal cities

Sea level rise (SLR) is expected, even without greenhouse gas emissions. As SLR is inevitable, adapting to its impacts has received increasing attention, and local governments are the key actors in this emerging agenda. This study indicates that adaptation planning for SLR should be integrated into two local major planning mechanisms in the United States: the local comprehensive plans and hazard mitigation plans. By evaluating 36 plans from 15 US coastal cities that are considered at high risk and vulnerable to rising sea levels, the results demonstrate that SLR is widely identified, but the overall quality of the plans to address it requires significant improvement. A detailed table of selected plans' characteristics is also provided as a lens on how localities tackle this challenging issue. The paper concludes with planning suggestions for coastal communities to better adapt to SLR.