Abstract Graphene oxide (GO) prepared by modified hummers method was used as adsorbent for removal of heavy metal ions. The oxygenous functional groups on the surface of GO were primarily responsible for the sorption of metal ions. The effects of the parameters of pH value, contact time, Cu(II) concentration, and adsorbent dosage on adsorption were examined. The sorption process conformed to…
An ongoing reform in China mandates employers to contribute significant amounts to employee pension funds. The current study estimates the impact of this reform on the wage, employment, and performance of firms using data from over 140,000 medium and large manufacturers in China during 2004 and 2006. We find that the nominal wages of employees were rigid, but their real wages may have declined …
Transesterification of cottonseed oil with methanol to biodiesel was investigated in various Brønsted acidic ionic liquids with an alkane sulfonic acid group. The properties, structures, and acidities of the ionic liquids were experimentally characterized and theoretically analyzed. The Brønsted acidity-activity correlation for the ionic liquids was studied. Among all these ionic liquids, 1-…