Metal-Impregnated Petroleum Coke-Derived Activated Carbon for the Adsorption of Arsenic in Acidic Waters.

The efficacy of metal-impregnated petroleum coke (PC) activated carbon for the adsorption of arsenite and arsenate in acidic waters is investigated in this study. Unmodified PC activated carbon, FeCl-loaded activated carbon, KMnO-loaded activated carbon, and a mixed FeCl-KMnO-loaded activated carbon were used for evaluation. The surface characteristics of the activated carbons before and after arsenic adsorption were analyzed by X-ray photoelectron spectroscopy (XPS).

Adsorption of Chromium (VI) Using an Activated Carbon Derived from Petroleum Coke Feedstock.

This study aims to determine the main adsorption mechanism by which chromium (VI) is adsorbed onto the surface of a petroleum-coke sourced activated carbon, a feedstock not prevalent in current literature. The study also aims to produce an activated carbon adsorbent that is both cost-effective and efficient for the removal of chromium (VI) in neutral waters. The efficacy of thermally-treated petroleum coke-activated carbon and nitrogenated petroleum coke-activated carbon using ammonium chloride is compared to the efficacy of commercially available activated carbon.

A randomized trial of the traditional sitting position versus the hamstring stretch position for labor epidural needle placement.

Background: Anecdotal and experimental evidence suggest that a sitting position with maximum knee extension, hip adduction, and forward lean (hamstring stretch position) may produce better reversal of the lumbar lordosis than a traditional sitting position.

Methods: In a randomized trial during initiation of epidural labor analgesia, we compared the traditional versus hamstring stretch positions. The primary outcome was the number of needle-bone contacts.