Oscillatory flow reactors for synthetic chemistry applications

Oscillatory flow reactors (OFRs) superimpose an oscillatory flow to the net movement through a flow reactor. OFRs have been engineered to enable improved mixing, excellent heat- and mass transfer and good plug flow character under a broad range of operating conditions. Such features render these reactors appealing, since they are suitable for reactions that require long residence times, improved mass transfer (such as in biphasic liquid-liquid systems) or to homogeneously suspend solid particles. Various OFR configurations, offering specific features, have been developed over the past two decades, with significant progress still being made. This review outlines the principles and recent advances in OFR technology and overviews the synthetic applications of OFRs for liquid-liquid and solid-liquid biphasic systems.

Estimating Just Suspension Speed for Stirred Reactors Using Power Measurement

A simplified mathematical model was developed to predict the just suspended speed, NJS in a solid-liquid system by analyzing the net impeller power consumption to suspend solid particles. A fully baffled tank with an internal diameter of 400mm equipped with a standard Rushton turbine with a diameter of D=T/3 (133mm) was used in this work. Glass beads were used as the solid phase and distilled water was used as the liquid phase. Solid loadings were varied within the range of 0-27 wt%. Power consumption was measured using the shaft torque method. The predicted NJS values were in a good approximation to the experimental values using the Zwietering’s criterion with a deviation of 2 – 10%. The deviation was lower for higher solid concentrations.

K-Means Method for Clustering Water Quality Status on The Rivers of Banjarmasin

The surface river water quality in Banjarmasin city tends to decline constantly as the result of direct and indirect waste disposal from various human activities along the river body. This study aimed to determine the vulnerability points against pollution in the rivers of Banjarmasin using clustering techniques with K-means algorithm. The parameters observed include Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspend Solid (TSS) and Dissolved Oxygen (DO). The data were collected at eight water monitoring stations on various rivers in Banjarmasin city. With the K-means method, four water quality status were clustered. The result showed that 6 stations observed during the period April to October 2016 were categorized into the heavy polluted cluster with major pollution point of sources came from the domestic and industrial activities.

STAND-ALONE WATER TREATMENT: PERFORMANCE OF ELECTROSPUN NANOFIBERS

The aim of this study was to evaluate the use of nanofiber microfiltration membranes, spun by an innovative electrospinning technique, in water filtration applications. This study bridges between developments in electrospinning techniques for the production of flat sheet membranes and the application of these membranes in water filtration. The functionalized or non-functionalized for the removal of pathogens was investigated, in term of chemical oxygen demand, total suspend solid and ammonium in the waste water. Physical properties such as clean water permeability (CWP) and strength were also examined. The results showed a very good removal of TSS (range 94.83-97.34%), COD (89.32-95.27%) and NH3­-N (64.48-72.87%). These test showed that the electrospun membranes can be used for water filtration applications.