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Problem statement: Steel making slag from Electric Arc Furnace (EAF) is an abundant byproduct in Malaysia steel making industry. It has potential to be used for heavy metal removal from contaminated water or waste water. Approach: The aim of this study was to investigate the characteristic and behavior of manganese removal by using EAF slag for efficient metal removal. The removal characteristics of manganese were investigated in term of sorption kinetics and isotherm. The batch adsorption kinetics and isotherm studies were carried out at 28[degrees]C and ten grams of EAF slag was added into 1 L manganese solution of various concentrations of 10, 25, 50, 75, 100 and 120 mg [L.sup.-1]. All these different mixtures were stirred and sampled at various desired times and centrifuged. The supernatant solutions were then collected for chemical analysis. Results: It was found that the EAF slag adsorption kinetics can be described well by the pseudo-2nd order kinetic model with fairly high correlation coefficients. The adsorption process obeyed the Langmuir isotherm model and the maximum uptake of the manganese from the solution is 2.31 mg [L.sup.-1][g.sup.-1] of EAF slag used. Conclusion: From the study, it was concluded that the EAF slag can be an efficient adsorbent to remove manganese from both the solution and waste water. Key words: Electric are furnace slag, manganese, sorption kinetics and isotherm, efficient adsorbent, INTRODUCTION Human activities in achieving development have caused environmental pollution over the past few decades. One of the major concern of pollutant is heavy metals as they are non-degradable and [...]

The adsorption of two reactive dyes, Reactive Black 5 and Reactive Red E, onto palm kernel shell-activated carbon (PKSAC) was studied. The effect of the presence of more than one dye in solution on the equilibrium and kinetics of adsorption was investigated. Equilibrium isotherm models were applied to describe the adsorption capacities of single and binary systems. Adsorption of reactive dyes for single system can be represented by the Freundlich and the Redlich-Peterson models. For binary system, the equilibrium was described successfully by the modified extended Freundlich model. Experimental data showed that competitive adsorption for active sites on the carbon surface resulted in a reduction in the overall uptake capacity of the reactive dyes. The rates of adsorption in single system were found to agree well with the pseudosecond-order kinetic model. Finally, the chemical oxygen demand (COD) of the treated reactive dye solutions from single and binary systems showed that a minimum of 4 g/L dosage of PKSAC was needed to reduce the COD to an acceptable level according to the Water Quality Guidelines and the Pollutant Fact Sheets Guidelines. DOI: 10.1061/(ASCE)EE.1943-7870.0000091 CE Database subject headings: Adsorption; Dyes; Chemical oxygen demand; Equilibrium; Activated carbon.

Problem statement: Earlier work on ohmic heating technique focused on viscous food and foods containing solid particles. In this study, the use of ohmic heating on sterilization of guava juice is carried out. Computational fluid dynamics is used to model and simulate the system. Approach: Investigate the buoyancy effect on the CFD simulation of continuous ohmic heating systems of fluid foods. A two-dimensional model describing the flow, temperature and electric field distribution of non-Newtonian power law guava juice fluid in a cylindrical continuous ohmic heating cell was developed. The electrical conductivity, thermo physical and rheological properties of the fluid was temperature dependent. The numerical simulation was carried out using FLUENT 6.1 software package. A user defined functions available in FLUENT 6.1 was employed for the electric field equation. The heating cell used consisted of a cylindrical tube of diameter 0.05 m, height 0.50 m and having three collinear electrodes of 0.02 m width separated by a distance of 0.22 m. The sample was subjected to zero voltage at the top and bottom of electrodes while electrical potential of 90 volts (AC 50-60 Hz) was set at the middle electrode. The inlet velocity is 0.003 m [sec.sup.1] and the temperature is in the range of 30-90[degrees]C. Results: The simulation was carried with and without buoyancy driven force effect. The ohmic heating was successfully simulated using CFD and the results shows that the buoyancy has a strong effect in temperature profiles and flow pattern of the collinear electrodes configuration ohmic heating. A more uniform velocity and temperature profiles were obtained with the buoyancy effect included. Conclusion: For accurate results, the inclusion of buoyancy effect into the CFD simulation is important. Key word: CFD numerical modeling, 2D ohmic heating, Natural convection, guava juice, INTRODUCTION Ohmic heating is a developing technology with considerable potential for the food industry. The main advantages of ohmic processing are the rapid and relatively uniform heating achieved, together with [...]

Significant quantities of steel slag are generated as waste material or byproduct every day from steel industries. Slag is produced from different types of furnaces with different operating conditions. Slag contains Ferrous Oxide, Calcium Oxide, Silica etc. Physical and chemical properties of slag are affected by different methods of slag solidification such as air cooled, steam, and injection of additives. Several material characterization methods, such as X-ray Diffraction (XRD), Scanned Electron Microscopy (SEM) and Inductive Coupled Plasma (ICP-OES) are used to determine elemental composition in the steel slag. Therefore, slags can become one of the promising materials in various applications such as in transportation industry, construction, cement production, waste water and water treatment. The various applications of steel slag indicate that it can be reused and utilized rather than being disposed to the landfill. This paper presents a review of its applications and utilization.

Globally, considerable effort and resources are being channeled toward controlling the rising threat from pollution and other related impacts from man-made activities, which have detrimental effects on human health and the environment. The presence of some associated gases such as nitrogen oxides and sulfur oxides in the flue gas interfering with the carbon capture processes are responsible for acid rain and ground-layer ozone formation. The wet flue gas desulfurization and the selective catalytic reduction technologies are associated with high investment, production of secondary pollution, poor catalyst durability, and high temperature requirements. In response to these limitations, the development of a hybrid environmental catalyst, especially using activated carbon, carbon-coated monolith, and metal oxides, is desirable. For a catalyst to be competitive, it must be cost-effective with enhanced sorption capacity, regenerability, and be safe for disposal. Some of the recent methods for dispersing the metal oxides on the supports and the simultaneous removal of sulfur oxides and nitrogen oxides were enumerated in this review and the possible ways for improvement have been presented. [ABSTRACT FROM AUTHOR]