Kamar Shah Ariffin

Ammoniacal nitrogen and COD removal from semi-aerobic landfill leachate using a composite adsorbent: Fixed bed column adsorption performance

The performance of a carbon-mineral composite adsorbent used in a fixed bed column for the removal of ammoniacal nitrogen and aggregate organic pollutant (COD), which are commonly found in landfill leachate, was evaluated. The breakthrough capacities for ammoniacal nitrogen and COD adsorption were 4.46 and 3.23 mg/g, respectively. Additionally, the optimum empty bed contact time (EBCT) was 75 min. The column efficiency for ammoniacal nitrogen and COD adsorption using fresh adsorbent was 86.4% and 92.6%, respectively, and these values increased to 90.0% and 93.7%, respectively, after the regeneration process.

Removal of ammoniacal nitrogen and COD from semi-aerobic landfill leachate using low-cost activated carbon?zeolite composite adsorbent

A carbon-zeolite composite adsorbent has been studied for COD and ammoniacal nitrogen removal in semi-aerobic landfill leachate. The optimum conditions for adsorption in the batch study occurred at pH 7, shaking speed of 200 rpm, and contact time of 105 min. The Langmuir isotherms corresponded slightly better than Freundlich isotherm for both ammoniacal nitrogen and COD removals. The Langmuir adsorption capacities for ammonia and COD were 27.47 mg/g and 22.99 mg/g, while the Freundlich adsorption capacities were 0.4227 mg/g and 0.0642 mg/g, respectively. The overall rate of the ammonia and COD adsorption processes appears to be dominated by chemisorption process.

Characteristics of Treated Palm Oil Fuel Ash and its Effects on Properties of High Strength Concrete

Palm oil fuel ash obtained from palm oil mill was treated via screening, grinding and heating to improve its pozzolanic reactivity. The characteristics of the palm oil fuel ash before and after treatment were monitored to assess the changes in the properties of the palm oil fuel ash. The resulting ultrafine palm oil fuel ash was then utilized to produce high strength concrete by replacing the ordinary Portland cement at 0, 20, 40 and 60% on mass-for-mass basis. The results show that the treatment process undertaken reduces the particle size, diminishes the unburned carbon content, while at the same time increases the glassy phases. The utilization of the ultrafine palm oil fuel ash in high strength concrete was observed to improve workability especially at higher ultrafine palm oil fuel ash content. In addition, the long-term compressive strength of the high strength concrete was significantly increased with the ultrafine palm oil fuel ash inclusion. Further, the long-term rapid chloride permeability was significant reduced especially at higher ultrafine palm oil fuel ash content of 60%, which could be translated into superior durability performance.

A novel rapid mist spray technique for synthesis of single phase precipitated calcium carbonate using solid-liquid-gas process

Various techniques and approaches have been designed to synthesize precipitated calcium carbonate. We used a continuous sprayed-mist technique that induced spontaneous precipitation reaction of the droplets with the higher surface area when in contact with the gas. The effects of optimum reactant concentration, gas flow rate, and reactant feeding rate including reaction conditions were investigated. The effectiveness of the techniques was scrutinized by analyzing the resultant PCC characteristics, especially the particle phase morphology and size distribution using XRD, FTIR, and SEM. The variation of initial concentration of milk of lime with different gas flow rate was studied. Experimental results, as well as XRD and FTIR, indicated that all the products produced were favorable for the formation of calcite. SEM revealed that the morphologies of PCC were all rhombohedral and tended to adhere to each other (twinning). It was found that production of PCC by using spray-mist method is suitable for lower initial concentration of Ca(OH)2 and higher gas flow rate only.

The Preparation of Iron-Free TiCl4 from Reduced and Nitrided Ilmenite by Polyethylene Terephthalate

In this study, titanium tetrachloride (TiCl4) solution was successfully synthesized from titanium oxycarbonitride (TiOxCyNz) by means of chlorination process at low temperatures. Iron-free TiOxCyNz was prepared by carbothermal reduction and nitridation of Ilmenite (FeTiO3) with coal-75 wt. % PETas a reductant in a H2/N2 gas mixture. Aeration leaching via the Becher process for iron removal with NH4Cl solution was the preferred method for iron removal. The effect of reduction temperature on the synthesis of titanium oxycarbonitride (TiO0.02C0.13N0.85) powder suitable for iron removal has been investigated in the temperature range of 1150–1250°C. The reduced-nitrided ilmenite samples were characterized by XRD and SEM/EDX in terms of phases and morphology. The results showed that iron was formed in spherical and separated particles from TiOCN. Furthermore, the effects of temperature between 350–450°C and soaking time from 1 to 3 hours on the chlorination of iron-free titanium oxycarbonitride have been evaluated. The evaluation was based on design of experiment (DOE) to identify the significant variables on the extent of titanium extraction. DOE analysis based on weight loss validated by ICP tests, indicated a good extraction of titanium and synthesis of TiCl4 at 450°C.

Microstructural Study of Leached Nitrided Malaysian Ilmenite with Coal-Polystyrene Reductant

Titanium oxycarbonitride (TiOxCyNz) produced from Malaysian ilmenite consists of impurities such as iron that adversely affect the efficiency of chlorination process. In this paper, the dissolution of iron present in TiOxCyNz was performed using ammonium chloride (NH4Cl) solution at 70 °C from 4-6 hrs. Effects of acid concentration, catalyst amount and leaching time on the rate of iron dissolution were also investigated. Microstructural and/or morphological studies of the raw materials, and products were carried out by X-ray diffraction (XRD), X-ray Fluorescence (XRF), scanning electron microscopy (SEM), and Energy Dispersive X-ray analysis. The results obtained from SEM/EDX analysis for the reduced samples HR15 (15% Polystyrene (PS) + 85% coal (C)), HR25 (25% PS + 75% C) and HR35 (35% PS + 65% C) showed that most of the Titanium oxycarbonitrides were found in the circular shape with increase grain coarsening. Iron dissolution was accelerated with acid concentrations and it increased with increasing leaching time from 4 to 6 hrs. The results also showed that the percentage of Fe removed from titanium oxycarbonitride was ~ 76.85% at 70 °C for 6 hrs with the PS/C ratio of 0.18 and 1 wt. % of glucose as catalyst.

Effects of Site Classification on Empirical Correlation between Shear Wave Velocity and Standard Penetration Resistance for Soils

In seismic engineering, the dynamic property of the soil is one of the most important aspects in ground response analysis. Dynamic property is significantly affected by local soil deposits. Shear wave velocity (Vs) of soil is one of the main parameters in determining the amplification factor on ground surface. It is not economically feasible to measure Vs for all sites. Therefore, a reliable empirical correlation between Vs and standard penetration resistance (Nspt) will be useful since Nspt data are easily obtainable in construction industry. This study aims to develop an empirical correlation between Vs and Nspt for all soils by considering the effect of site classification according to the Uniform Building Code. New empirical correlations for all soils are presented in this study and well compared with the previous study to evaluate prediction capability. Results show that site classification has a significant impact on the Vs estimation, and that the proposed correlations are the most appropriate for estimating the Vs profile in the studied area compared with existing correlations.

The Effects of Experimental Variables on Iron Removal from Nitrided Malaysian Ilmenite by Becher Process

Iron-free titanium oxycarbonitride (TiOxCyNz) is a promising feedstock for production of titanium tetrachloride (TiCl4) at low temperatures. In this study, the effects of leaching variables such as temperature, time, particle size of staring material and concentration of the leaching solutions were evaluated on iron removal from nitrided Malaysian ilmenite by Becher process. The nitrided ilmenite was prepared by isothermal reduction with graphite at 1200 °C for 3 h in H2-N2 atmosphere. The aerated leaching experiments were conducted at 50–90 °C with addition of 0.3–2.0 wt% of NH4Cl catalyst. The highest extent of iron removal (XFe) was obtained at about 96.2% for the sample leached at 90 °C for 7 h with 2.0 wt% NH4Cl. The iron concentrate and titanium oxycarbonitride product were characterized by ICP-OES, XRD, XRF and SEM-EDX analyses. The results indicated that the aeration leaching process was a successful route to prepare low-iron titanium oxycarbonitride.

Effects of Coal Bottom Ash on the Compressive Strength of Portland Cement Mortar

The possibility of utilizing treated coal bottom ash as a partial replacement of Portland cement was examined through compressive strength test on mortar samples. A total of 16 batches of mortar mixtures with cement:sand ratio of 1:2.5 and 1:2.75 were prepared using two types of treated coal bottom ash. The chemical compositions including the unburned carbon of coal bottom ash were also analyzed. In order to remove the excess unburned carbon which will affect the potential pozzolanic properties, the coal bottom ash was heated at 550 ± 50oC and 700 ± 50°C for 60 min in an electrical furnace.The results showed that compressive strength of mortar mixtures with cement:sand ratio of 1:2.5 and 1:2.75 containing treated coal bottom ash which was heated at 550oC results in an increase in compressive strength. At 10% and 20% of treated coal bottom ash replacement levels to Portland cement, the compressive strength of the mortar mixture was significantly improved at the age of 28 days. The compressive strength of the mortar mixtures at early ages gives lower strength as compared to the plain Portland cement mortar. However, the effect of treated coal bottom ash that was heated at 700°C is to reduce the compressive strength of the mortar mixtures except for mixture with cement:sand ratio of 1:2.5 containing 10% coal bottom ash at 56 days.

The Mineralogy of the Copper – Gold Ore Deposits at the Phu Kham, Mine, Laos

The Phu Kham Cu-Au deposit Porphyry-related skarn-type mineralization, Lao PDR is hosted by complexly deformed, schistose, quartz-sericite-pyrite altered Permo-Carboniferous volcanic, volcaniclastic and intrusive rocks. These rocks occupy the immediate hanging wall of a large NE-dipping thrust fault. Unmineralized, variably deformed red beds of the Mesozoic Khorat basin occur in the foot wall to the thrust. At Phu Kham the well defined foot wall and hanging wall sequences are separated by poorly-stratified quartz-rich conglomerate, breccia and lesser sandstone of uncertain affinities. In previous studies, the conglomerate package has both been included in the Khorat basin succession and interpreted tostratigraphically underlie the Permo-Carboniferous volcanics. Structural studies and additional U-P zircon geochronology were undertaken in 2009 to help clarify geological relations at Phu Kham. Improved constraints on thrust geometry and kinematics were also sought, enabling the deformation history at Phu Kham to be more confidently placed into a regional context. Results indicate the thrust was emplaced from the NE, and thus has greater affinity with deformation patterns in the NW-trending Truong Son fold belt.The conglomerate package is reinterpreted as a syn-orogenic molasse deposited ahead of the Advancing allochthon, but eventually overridden during the final stages of thrustemplacement. Unfortunately, definitive geochronological data supporting this conlusion were not obtained.