Emerging trends in photodegradation of petrochemical wastes: a review.

Various human activities like mining and extraction of mineral oils have been used for the modernization of society and well-beings. However, the by-products such as petrochemical wastes generated from such industries are carcinogenic and toxic, which had increased environmental pollution and risks to human health several folds. Various methods such as physical, chemical and biological methods have been used to degrade these pollutants from wastewater. Advance oxidation processes (AOPs) are evolving techniques for efficient sequestration of chemically stable and less biodegradable organic pollutants. In the present review, photocatalytic degradation of petrochemical wastes containing monoaromatic and poly-aromatic hydrocarbons has been studied using various heterogeneous photocatalysts (such as TiO2, ZnO and CdS. The present article seeks to offer a scientific and technical overview of the current trend in the use of the photocatalyst for remediation and degradation of petrochemical waste depending upon the recent advances in photodegradation of petrochemical research using bibliometric analysis. We further outlined the effect of various heterogeneous catalysts and their ecotoxicity, various degradation pathways of petrochemical wastes, the key regulatory parameters and the reactors used. A critical analysis of the available literature revealed that TiO2 is widely reported in the degradation processes along with other semiconductors/nanomaterials in visible and UV light irradiation. Further, various degradation studies have been carried out at laboratory scale in the presence of UV light. However, further elaborative research is needed for successful application of the laboratory scale techniques to pilot-scale operation and to develop environmental friendly catalysts which support the sustainable treatment technology with the "zero concept" of industrial wastewater. Nevertheless, there is a need to develop more effective methods which consume less energy and are more efficient in pilot scale for the demineralization of pollutant.

Association of mustard oil as cooking media with carcinoma of the gallbladder.

PURPOSE: Carcinoma of the gallbladder (CaGB) is a common health problem in Northern India. Exact causative factors are still obscure. Dietary habits are also known to be a major factor in the gallbladder carcinogenesis. Mustard oil is mostly used as cooking media, which is adulterated by sanguinarine, diethylnitrosamine and repeated frying. We tried to find out the association of mustard oil as cooking media with CaGB. METHODS: Twenty patients each of CaGB (group I) and cholelithiasis (group II) were included in the study. Sanguinarine and diethylnitrosamine (DEN) were extracted from the tissue and blood samples from both groups. Mean and standard error of mean of the concentration of the sanguinarine and DEN were calculated. Mann-Whitney U test was applied to test the level of significance between the two groups. RESULTS: The mean concentration of tissue sanguinarine in both groups (I and II) was 195.18 ng/mg and 24.05 ng/mg, respectively, and the difference was statistically highly significant (p < 0.001). The estimated concentration of blood sanguinarine was 230.96 ng/mL and 14.0 ng/mL in group I and II, respectively, and the difference was statistically highly significant (p < 0.001). The concentration of DEN in the tissue sample was 38.08 ng/mg in CaGB and 2.51 ng/mg in cholelithiasis patient, and these values were statistically highly significant (p < 0.001). Similarly, blood DEN concentration was 119.05 ng/mL and 4.22 ng/mL in group I and II, respectively, and the difference was statistically highly significant (p < 0.001). CONCLUSION: There is an increase in concentration of sanguinarine and diethylnitrosamine in CaGB blood and tissue in comparison to the cholelithiasis group suggesting an association with carcinoma of the gallbladder.