Highly efficient removal of ammonia nitrogen from wastewater by dielectrophoresis-enhanced adsorption

A new approach, based on dielectrophoresis (DEP), was developed in this work to enhance traditional adsorption for the removal of ammonia nitrogen (NH3-N) from wastewater. The factors that affected the removal efficiency were systematically investigated, which allowed us to determine optimal operation parameters. With this new method we found that the removal efficiency was significantly improved from 66.7% by adsorption only to 95% by adsorption-DEP using titanium metal mesh as electrodes of the DEP and zeolite as the absorbent material. In addition, the dosage of the absorbent/zeolite and the processing time needed for the removal were greatly reduced after the introduction of DEP into the process. In addition, a very low discharge concentration (C, 1.5 mg/L) of NH3-N was achieved by the new method, which well met the discharge criterion of C < 8 mg/L (the emission standard of pollutants for rare earth industry in China).

Discharge Criterion along the Surface of Solid Dielectric in SF6 under High Pressure

This article is devoted to the formation of a mechanism of discharge along the surface of a dielectric in sulphur hexafluoride electrode systems in different configurations. The article also addresses to the calculation of the electric field distribution and criteria for increase of discharge along the dielectric surface, depending on the field configuration, pressure and heights.

Impact of Daily versus Weekly Supply of Locally Produced Ready-to-Use Food on Growth of Moderately Wasted Children on Nias Island, Indonesia

This study reports the outcomes of daily (semi-urban areas) and weekly (remote rural regions) programs for moderately wasted children supplemented with locally produced ready-to-use foods in the form of fortified cereal/nut/legume-based biscuits on Nias Island, Indonesia (RUF-Nias biscuit). Thirty-four children in daily and twenty children in weekly programs aged ≥6 to <60 months with weight-for-height z-score (WHZ) ≥ −3 to < −2 SD were recruited (October 2007–June 2008) on Nias and admitted into existing nutrition centers in the Church World Service project area. Individual discharge criterion was WHZ ≥ −1.5 SD. Weight gain of the children in daily and weekly programs was 3.9±3.8 and 2.0±2.0 g/kg/day, respectively. A higher proportion of children in daily than weekly programs reached target WHZ (76% vs. 35%, P=0.004). Weight gain at program discharge/closure was highly predicted (R2=0.228, P<0.001) by compliance to RUF biscuits: high vs. low compliance resulted in a 1.33 (95% CI 0.16 to 1.53) g/kg/day higher weight gain. Compliance and admission in daily programs were significant factors in reducing the risk of not reaching the discharge criterion. However, mothers complained more frequently about time constraints in the daily relative to weekly programs.