The effect of alginite on the decomposition of the herbicide propisochlor

Biodegradation of two persistent aromatic compounds by using oil shale

Low-cost oil shale was investigated as a biodegradation promoter material, in order to exploit its potential for more widespread and efficient usage in the elimination of pollution. Degradation of two model pollutants, 4-nitrophenol and phenol, was examined in the presence of oil shale in a batch system. In order to investigate the role of the natural microflora of the oil shale in degradation, sodium azide was added to inhibit microbial growth. The effect of metal ions was also investigated. In the sodium azide-free solutions the model pollutants were completely degraded up to 2000 µmol/L concentration in a dose-dependent way, while the addition of sodium azide delayed greatly but did not stop the degradation. Manganese(II) ions increased the rate of the degradation of 4-nitrophenol, and given quantities of iron(II), manganese(II) or zinc(II) ions were also effective in degradation of phenol. Our results suggest that oil shale is not only an adsorbent but has an active role in the degradation of pollutants by its natural microflora. Utilizing these features of oil shale, it is a suitable candidate as an ameliorating agent, which can also be used in industrial size.

Enantioselective and Synergetic Toxicity of Axial Chiral Herbicide Propisochlor to SP2/0 Myeloma Cells

The axial chiral herbicide propisochlor is used to control weeds. Different enantiomers of a compound usually have different biological activities. It is unclear how the toxicities of the propisochlor enantiomers differ. Propisochlor enantiomers, separated by high-performance liquid chromatography, were tested on SP2/0 myeloma cells. Cytotoxicity and apoptosis were measured, and interactions between the enantiomers were evaluated. The rac-propisochlor, pure R-(+) isomer, and pure S-(-) isomer inhibited cell proliferation and induced apoptosis. The rac-propisochlor, R-(+) isomer, and S-(-) isomer half maximal effective concentration values after 24 h of incubation were 111 ± 0.15, 68 ± 0.09, and 99 ± 0.21 μM, respectively. R-(+) isomer induced the most apoptosis. R-(+) isomer was ∼1.63 times more cytotoxic than rac-propisochlor and ∼1.46 times more cytotoxic than S-(-) isomer. Antagonistic cytotoxic interactions were found between R-(+) and S-(-) isomers. This is the first time the toxicities of these enantiomers and antagonism between the enantiomers have been reported. The antagonism indicates that the ecotoxicological effects of the enantiomers should be investigated.