Search

The electrochemical treatment of canal water was investigated in a batch-wise system in the presence of stainless steel 316-grade electrodes. Three effective process parameters, including current density, reaction time, and electrode spacing, were evaluated in the range of 0.25–2.5 mA/cm2, 1–10 min, and 0.5–2.5 cm, respectively. Operational variables of electrochemical disinfection are optimized in response surface methodology (RSM) using Box–Behnken design. Before electrochemical disinfection, a pretreatment process of coagulants mixing for turbidity removal was conducted. Results revealed that a 10 ppm dosage of Ferric chloride (FeCl3.6H2O) and alum (Al2(SO4)3·16H2O) at neutral pH is appropriate. Furthermore, the RSM analysis shows that interelectrode spacing is the most prominent factor affecting the disinfection performance, and increasing electrode spacing inversely affects the disinfection efficiency. Results revealed that 1.52 mA/cm2 current density, 6.35 min reaction time, and 1.13 cm of electrode spacing are the optimum conditions, resulting in a statistically 98.08% disinfection of the total coliform. The energy required for electrochemically disinfection of water at optimum conditions was 0.256 kWh/m3. [ABSTRACT FROM AUTHOR]

In this research, Zinc Oxide-Ethylene @ glycol distilled water based nanofluid was synthesized using the sonochemical method. The convective heat transfer properties of as synthesized nanofluid were observed for a closed single circular tube pipe in turbulent flow regimes. The prepared nanofluids were characterized by ultra violet spectroscopy (UV–VIS), UV–VIS absorbance, X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and stability analysis. Five calibrated k-type thermocouples were mounted on the surface of the test section. Analytical data related to heat transfer properties of the synthesized nanofluid for the heat exchanger, incorporated with the closed circular tube test section were collected. The addition of ZnO solid nanoparticles in the EG@DW mixture enhanced the value of thermal conductivity and other thermophysical characteristics of the nanofluids. Maximum thermal conductivity was observed at 45 °C for using 0.1 wt.% of ZnO nanoparticles EG@DW nanofluid. Increasing the wt.% of ZnO solid nanoparticles in the EG@DW mixture had increased the thermal conductivity subsequently with change in temperature from 20 to 45 °C. Furthermore, Nusselt numbers of ZnO-EG@DW-based nanofluid was estimated for the various concentration of ZnO present in EG@DW-based fluid. The presence of ZnO solid nanoparticles into the EG@DW base fluid escalate the Nusselt (Nu) number by 49.5%, 40.79%, 37% and 23.06% for 0.1, 0.075, 0.05 and 0.025 wt.% concentrations, respectively, at room temperature. Varying wt.% of ZnO (0.1, 0.075, 0.05 and 0.025) nanoparticles had shown improved heat transfer (h) properties compared to the base fluid alone. The absolute average heat transfer of ZnO-EG@DW nanofluid using the highest concentration of 0.1 wt.% was improved compared to the EG@DW mixture. The magnitude of absolute average heat transfer was increased from 600 W/m2k for the EG@DW mixture to 1200 W/m2k for ZnO-EG@DW nanofluid. Similarly, the heat transfer improvement for the other three wt.% (0.075, 0.05 and 0.025) was noticed as 600–1160, 600–950 and 600–900 W/m2k, respectively, which is greater than base fluid. [ABSTRACT FROM AUTHOR]