Effect of Fe loading quantity on reduction reactivity of nano zero-valent iron supported on chelating resin

In this study, nanoscale zero-valent iron （NZVI） were immobilized within a chelating resin （DOW 3N）. To investigate the effect of Fe loading on NZVI reactivity, three NZVI-resin composites with different Fe loading were obtained by preparing Fe（III） solution in 0, 30 and 70% （v/v） ethanol aqueous, respectively; the bromate was used as a model contami- nant. TEM reveals that increasing the Fe loading resulted in much larger size and poor dispersion of nanoscale iron particles. The results indicated that the removal efficiency of bromate and the rate constant （Kobs） were decreased with increasing the Fe loading. For the NZVI-resin composite with lower Fe loading, the removal efficiency ofbromate declined more significantly with the increase of DO concentrations. Under acidic conditions, decreasing the pH value had the most significant influence on NZVI- R3 with highest Fe loading for bromate removal; however, under alkaline conditions, the most significant influence of pH was on NZVI-R1 with lowest Fe loading. The effects of co-existing anions NO3, PO43- and HCO3- were also investigated. All of the co-existing anions showed the inhibition to bromate reduction.

Development of All-Weather and Real-Time Bottom-Mounted Monitor of Bed Load Quantity

Quantity of bed load is an important physical parameter in sediment transport research. Aiming at the difficulties in the bed load measurement, this paper develops a bottom-mounted monitor to measure the bed load transport rate by adopting the sedimentation pit method and resolving such key problems as weighing and desilting, which can achieve long-time, all-weather and real-time telemeasurement of the bed load transport rate of plain rivers, estuaries and coasts. Both laboratory and field tests show that this monitor is reasonable in design, stable in properties and convenient in measurement, and it can be used to monitor the bed load transport rate in practical projects.

Why do platinum catalysts show diverse electrocatalytic performance?

As one of the best electrocatalysts for the hydrogen evolution reaction,platinum catalysts are a benchmark for the performance evaluation of new catalysts.However,platinum catalysts reported in the literature show diverse electrocatalytic performances,resulting in the lack of a common reference standard.In this study,we investigated several factors that affect the performance of platinum catalysts by performing experimental measurements and data processing.These factors included the solution resistance,electrolyte temperature,loading quantity,catalyst microstructure,and normalization method of the current density.Finally,we recommended criteria for the performance evaluation of electrocatalysts.