M.A.Z. Mohd Remy Rozainy

Removal of Iron and Total Chromium Contaminations in Landfill Leachate by Using Electrocoagulation Process

This research work involves the study removal of Iron and Total Chromium by electrocoagulation process. This project focused on leachate landfill from Pulau Burung, Nibong Tebal, Penang as an electrolyte solution. These heavy metals are the main factor contributing to pollution in leachate landfill. Types of electrodes used in this study were Aluminium (grade 5052) and Stainless Steel (grade 316). The ranges of initial pH applied were pH (3, 4, 5, 6 and 7) and voltages applied were 1.5V, 2.0V and 2.5V. These three parameters were evaluated and the operation time was 60 minutes. At the end of electrocoagulation process, the solutions were stored and analysed using AAS to determine the final concentration of electrolyte solution.

Strength and Density of Geopolymer Mortar Cured at Ambient Temperature for Use as Repair Material

Geopolymers produced by synthesizing aluminosilicate source materials with an alkaline activator solution promised an excellent properties akin to the existing construction material. This study focused on the effect of various binder to sand ratio on geopolymer mortar properties. Mix design of geopolymer mortar was produced using NaOH concentration of 12 molars, ratio of fly ash/alkaline activator and ratio Na2SiO3/NaOH of 2.0 and 2.5 respectively. Samples subsequently ware cured at ambient temperature. The properties of geopolymer mortar were analysed in term of compressive strength and density at different period which are on the 3rd and 7th day of curing. Experimental results revealed that the addition of sand slightly increase the compressive strength of geopolymer. The optimum compressive strength obtained was up to 31.39 MPa on the 7th day. The density of geopolymer mortar was in the range between 2.0 g/cm3 to 2.23 g/cm3. Based on this findings, the special properties promoted by geopolymer mortar display high potential to be implemented in the field of concrete patch repair.

Potential of Geopolymer Mortar as Concrete Repairing Materials

Geopolymer mortars which produced by the reaction of fly ash with an alkaline activator and added with sand is going to be developed for use as concrete repair material. Thus, the typical and standard requirement as repair material is reviewed. This paper also discusses the efficiency of geopolymer mortar which is mainly dependent on the excellent bond between the sand and geopolymer binder. Based on the determined formulation of geopolymer mortar, the standard for testing is determined making it potentially becoming as an excellent repair materials.

Model Study for Upgrading of Sungai Belibis Pump Sump

Experimental study of hydraulic physical model investigates the flow characteristics in the pump sump. The model features four pumps (7.91 L/s for pump 1 and 2, and 4.74 L/s for pump 3 and 4) with a total of 9 cases of study. Different values of water depth (180mm, 200mm, and 300mm) and pump flow rate (15L/s, 20L/s, and 25L/s) were conducted. Velocity measurements at the dividing cross section were obtained by an Acoustic Doppler Velocimeter (ADV), pump flow rate by flow meter (Dyna Handheld Transit Time Ultrasonic Flow Meters) and swirl angle in the suction intakes were measured by a vortimeter/rotometer. No vortices were occurred near the suction intake at the high and medium water level conditions. In the low water level condition with high flow rate (25L/s), vortex Type 4 or 5 were observed near the suction intake and this condition is unacceptable. Since this condition indicate the presence of vortices more than Types 2 and an uneven flow through the suction intake, this can be categorized as the worst case and not recommended for pump sump operation.

Removal of Cadmium and Zinc Contaminations in Landfill Leachate by Using Electrocoagulation Process

The research works involve the study of removal of cadmium and zinc contaminations in landfill leachate by electrocoagulation process. This project focused on leachate landfill from Pulau Burung, Nibong Tebal, Penang as an electrolyte solution. Heavy metals are the main factor contributing to pollution in leachate landfill. Types of electrodes used in this study were aluminium (grade 5052) and Stainless Steel (grade 316). The ranges of initial pH applied were pH (3, 4, 5, 6 and 7) and voltages applied were 1.5V, 2.0V and 2.5V. At the end of electrocoagulation process, the solutions were stored and analysed usingatomic absorption spectroscopy (AAS) to determine the final concentration of electrolyte solution. It was found difference electrodes have difference effectiveness in removing heavy metals, relies on the types of electrodes (aluminium or stainless steel) and also types of heavy metals that were being treated. The initial pH also gives the significant effect to removal of heavy metal and the maximum voltages give higher removal of heavy metal. Removal of cadmium and zinc by stainless steel electrode was more effective than aluminium electrodes at voltage of 2.5V. The removal using stainless steel was 22.45% and 97.54% respectively. For removal using aluminium electrodes 18.37% and 92.12% respectively. It was found that the maximum voltages give higher removal of heavy metal for all removal of cadmium and zinc. The removal maximum when the applied voltage was 2.5V and minimum at 1.5V.

Oxygen Uptake by Biological Processes inside Oxidation Ditch

Abstract. In order to provide a better understanding of the Orbal Biological System (OBS), as one type of a modified oxidation ditch, the research aims to develop a preliminary process model to visualize the oxygen uptake by biological processes inside the oxidation ditch. Fundamentally, the model can be used as initial study to get a clearer picture of the oxygen utilization rate inside the ditch. Based on the results, the outer channel takes the highest portion of the overall oxygen consumption which is 66 % compare to the middle channel with only 14 % and followed by the inner channel with 20 %. However, simplifying assumptions made for the preliminary process model development (e.g. constant values of HRT throughout each channel) may affect the accuracy of describing the real conditions of the system.