In-vivo interaction of some organophosphorus insecticides with different biochemical targets in white rats

A comparative study between five organophosphorus insecticides: Leptophos, EPN, Cyanofenphos, Chlorpyrifos and Diazinon, was carried out for acute oral toxicity to white rats and for their in vivo interaction at 1/10th of LD50 doses with the activity of six serum enzymes after 4 wks from oral administration. Leptophos, Chlorpyrifos and diazinon exerted significant inhibition particularly to glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), glutamyltransferase (GT) and lactate dehydrogenase (LDH). Adding ascorbic acid in the diet at 0.5% enhanced the acute oral toxicity of leptophos, chlorpyrifos and diazinon. For all the compounds, presence of ascorbic acid protected a number of the monitored serum enzymes from being inhibited except for leptophos. Ascorbic acid caused hypoglycemia with sublethal doses of leptophos, chlorpyrifos, and diazinon. The synergist piperonyl butoxide alone at 750 mg/kg dose inhibited the activity of the six serum enzymes. Presence of ascorbic acid in the diet intensified the inhibitory effect of piperonyl butoxide to all enzymes except for GOT.     

An Assessment of U(VI) removal from groundwater using biochar produced from hydrothermal carbonization

The ever-increasing growth of biorefineries is expected to produce huge amounts of lignocellulosic biochar as a byproduct. The hydrothermal carbonization (HTC) process to produce biochar from lignocellulosic biomass is getting more attention due to its inherent advantage of using wet biomass. In the present study, biochar was produced from switchgrass at 300 °C in subcritical water and characterized using X-ray diffraction, fourier transform infra-red spectroscopy, scanning electron micrcoscopy, and thermogravimetric analysis. The physiochemical properties indicated that biochar could serve as an excellent adsorbent to remove uranium from groundwater. A batch adsorption experiment at the natural pH (~3.9) of biochar indicated an H-type isotherm. The adsorption data was fitted using a Langmuir isotherm model and the sorption capacity was estimated to be ca. 2.12 mg of U g(-1) of biochar. The adsorption process was highly dependent on the pH of the system. An increase towards circumneutral pH resulted in the maximum adsorption of ca. 4 mg U g(-1) of biochar. The adsorption mechanism of U(VI) onto biochar was strongly related to its pH-dependent aqueous speciation. The results of the column study indicate that biochar could be used as an effective adsorbent for U(VI), as a reactive barrier medium. Overall, the biochar produced via HTC is environmentally benign, carbon neutral, and efficient in removing U(VI) from groundwater.