Papers by Keyword: Metal Removal

Abstract: Metals removal from wastewater has become a major concern over the years due to the adverse effects of metals on organisms and environment. Adsorption is one of the safest, simplest, and most cost-effective methods for metals removal. The primary purpose of this study was to develop a magnetically separable activated carbon from pineapple crown leaf for zinc removal. Magnetic activated carbon (MAC) were characterized by SEM-EDX and FTIR. The ability of MAC to adsorb zinc ion was studied through variation of initial solution pH, concentration, and contact time. The optimum pH for zinc removal was four, while the equilibrium was reached after 180 min. In this condition, the percentage removal of zinc was 70.5%.

Abstract: Electrical Discharge Machining (EDM) is a machine for cutting workpieces with thermal energy derived from electrical spark from tool (cathode) to workpiece (anode). As EDM process requires a dielectric fluid in the cutting operation, the characteristics of the dielectric fluid play an essential role for obtaining excellent cutting. Jatropha curcas has been demonstrated for use as a dielectric fluid in EDM process. However, the drawback is that the Rate of Metal Removal (RMR) is lower than that of generally-used dielectric fluid in industry. We consider that the cause is a much higher viscousity of the jatropha curcas. This study was conducted to investigate the characteristics of a new dielectric fluid mixture of jatropha curcas and kerosene. Kerosene was used in the mixture to reduce the viscousity of the jatropha curcas since the kerosene has a much lower viscousity. The measurement of the viscousity of the fluid mixture was performed using an Ostwald viscousimeter. Evidently, when the jatropha curcas mixed with the kerosine the viscousity of the mixture is lower than that of the pure jatropha curcas. The effects of the viscousity of the fluid mixture were investigated by measuring the RMR and Tool Wear Rate (TWR). The RMR and TWR were determined by calculating the difference in the weight of the workpiece and the tool, respectively, before and after the cutting for a certain cutting interval. The measurements were carried out for eleven different concentration of the fluid mixture by varying the current of 15 and 21 Amp, with replication of 3 times. As the result, the energy released during the cutting process affects the values of TWR and RMR. It was also found that in contrast to the effect on TWR, the RMR was not influenced by the viscousity of the mixture.

Abstract: Carbon based materials are widely used as an absorbent to study the adsorption capacity of several metal ions (Fe, Mn, B) from industrial effluent water. In this project, three types of carbon materials were selected; (1) activated carbon (AC), (2) Carbon nanofibers supported on activated carbon (CNF-AC) and (3) commercial carbon nanofibers (CNF-C). CNF-AC is physically in the form of nanofibers which directly attached onto activated carbon surface, meanwhile CNF-C is un-attached/loose nanofibers. It was found that pH of effluent water and the type of adsorbent play important roles for adsorption of metal ions. The higher adsorption of iron ions was observed when the pH of effluent water adjusted to pH 6 with an adsorbent capacity order is CNF-AC>CNF-C>AC. Furthermore, the adsorption order for manganese ion represent as AC>CNF-AC>CNF-C. Different behavior was observed for boron ions which show higher adsorption at pH 4 with the affinities order is CNF-AC>CNF-C>AC. The results show that CNF-AC has a potential to be used as effective adsorbent for removal of metal ion from industrial effluent water for environment protection.

Abstract: Packed bed column studies were carried out to evaluate the performance of natural Ceiba pentandra (L). Gaertn. (kapok) for the heavy metal removal from Palm Oil Mill Effluent (POME) under varying flow rate (5-10 ml/min) and packing density (0.04-0.08 g/cm³). A multilevel factorial design based on Packing density and flow rate of the influent was developed. Maximum metal reductions for Fe, Mn and Zn were 2.06 ppm, 0.081 ppm, and 0.064 ppm respectively obtained at 0.08 g/cm³ packing density and 5 ml/min flow rate. The results suggest the suitability of raw kapok fiber for low-cost removal of heavy metals.

Abstract: Adsorption of Zn(II) and Pb(II) from aqueous solution were studied by using modified coir pith as an adsorbent. The extended adsorption conditions were investigated as a function of calcination temperature, contact time, adsorbent size, initial pH of solution and initial Zn(II) and Pb(II) concentrations. The adsorption capacity increased rapidly in first 5 minute and reached equilibrium in 120 minutes for Zn(II) and 10 minutes for Pb(II). In case of Zn(II); the results showed that the calcination temperature of modified coir pith above 600oC gave the higher adsorption capacity. The sizes of modified coir pith have no effect on the adsorption capacity. The adsorption capacity increased with increasing initial solution pH value. In case of Pb(II); the calcination temperature of modified coir pith showed no effect on the adsorption capacity. The sizes of modified coir pith showed a little effect on the adsorption capacity. The adsorption capacity increased with increasing of initial solution pH value up to pH of 3 and then stable. The results also corresponded with the Langmuir and Freundlich isotherms and pseudo second order kinetic adsorption models. The modified coir pith gave a higher Zn(II) and Pb(II) adsorption capacity of 29.33 mg Zn(II)/g adsorbent and 36.50 mg Pb(II)/g adsorbent, respectively.

Abstract: An investigation was undertaken regarding the removal chromium ions and turbidity from aqueous solutions by crosslinked starch-graft-polyacrylamide-co-Sodium xanthate (CSAX) containing acylamino、carboxyl and xanthogen groups, which were prepared by grafting copolymerization of crosslinked corn starch, acrylamide (AM), and sodium xanthate in aqueous solution. The performances of CSAX in wastewater treatment were evaluated by flocculation experiment. The effects of the pH of the wastewater were considered. The results show that the CSAX was successfully synthesized with the functions of removing both turbidity and chromium ions from aqueous solution. The highest removal Cr(Ⅵ) took place at pH 2, while the highest removal Cr(Ⅲ) at pH 5. The subsection flocculation process was beneficial to remove both Cr(Ⅵ) and Cr(Ⅲ) synchronously. Cr(Ⅲ) and turbidity have a cooperative removal effect with each other in the process of treating wastewater containing both chromium ions and turbidity.

Abstract: The examination of deburring and surface finishing (DSF) quality was held at the enterprises of Russia. Here are the results of the examination. It was held on the base of general conclusion from the Scientific Research Institute “V and T” investigation results. The practical use of DSF at the engineering plants was also taken into account.