Showing papers by "Hamidi Abdul Aziz published in 2011"

Effects of municipal wastewater on accumulation of heavy metals in soil and wheat (Triticum aestivum L.) with two irrigation methods.

Abstract: A study was carried out to investigate the effects of municipal wastewater on accumulation of heavy metals in soil and wheat (Triticum aestivum L.) with two irrigation methods. Soil samplings of 0 to 20 cm depth were taken from Fereydoonshahr area in Isfahan province in the center of Iran. Wheat was transplanted in these soils. The experiment consisted of four treatments including soil irrigation with water by FI (Flooding Irrigation) (T1) and DI system (Drip Irrigation) (T2), soil irrigation with wastewater by FI (T3) and DI system (T4). Soil characteristics such as soil reaction (pH), electrical conductivity (EC), organic matter (OM), extractable Fe, manganese, nickel and cadmium were measured before and after the test. After 40 days, samples were taken for testing. The evidences provided by this experiment indicated that urban wastewater caused increase of heavy metals in wheat with both irrigation methods. Accumulation of heavy metals in roots was more than in shoots in FI and DI system. These results showed that the accumulation of heavy metals in wheat in FI system was more important than in DI system.

Optimum Process Parameters for the Treatment of Landfill Leachate Using Powdered Activated Carbon Augmented Sequencing Batch Reactor (SBR) Technology

Abstract: The sequencing batch reactor (SBR) process was used for the treatment of raw landfill leachate. Optimum preliminary parameters of leachate/activated sludge ratio, powdered activated carbon (PAC) dosage, and settling time were studied. Optimum obtained parameters (mixing ratio of 10%, PAC dosage of 10 g/L, and settling time of 1.5 h) were applied on two types of SBRs, namely, non-powdered and powdered activated carbon (NPAC and PAC, respectively). Consequently, the effect of factors, the aeration rate and contact time, on both NPAC and PAC reactors were studied. Response surface methodology was used for the design, analysis, and optimization of the experiments. Removal efficiencies of ammonia (NH3-N), color, chemical oxygen demand (COD), total dissolved salts (TDS), and sludge volume index (SVI) were measured for 13 experiments. Based on the obtained results, the optimum aeration rate and contact time for both NPAC and PAC reactors were 2 and 1 L/min and 5.56 and 5.5 h, respectively. Better performance (in...

The use of Polyaluminum Chloride for the treatment of Landfill Leachate via Coagulation and Flocculation processes

Abstract: Leachate is a highly complex and polluted wastewater that is produced by the interaction of percolating water through the body of a landfill. Treatment of landfill leachate is essential as it could threaten the surrounding ecosystem. The aim of this research was to determine the efficiency of polyaluminum chloride (PACl) in removing chemical oxygen demand (COD), ammoniacal nitrogen (NH 3-N) and color from two different landfill sites in Malaysia. The optimum dosage in removal of these parameters was determined and found to be lower for Kulim Landfill Site (KLS) than Ampang Jajar Landfill Site (AJLS). At optimum dosage of PACl as coagulant, the COD removal for KLS was higher than that obtained for AJLS. The removal of color for both sites was almost similar. The removal NH 3-N was rather moderate for both the landfill sites with KLS exhibiting relatively higher removal rates.

Grid Computing for Disaster Mitigation

Abstract: The infamous 2004 Andaman tsunami has highlighted the need to be prepared and to be resilient to such disasters. Further, recent episodes of infectious disease epidemics worldwide underline the urgency to control and manage infectious diseases. Universiti Sains Malaysia (USM) has recently formed the Disaster Research Nexus (DRN) within the School of Civil Engineering to spearhead research and development in natural disaster mitigation programs to mitigate the adverse effects of natural disasters. This paper presents a brief exposition on the aspirations of DRN towards achieving resilience in communities affected by these natural disasters. A brief review of the simulations of the 2004 Andaman tsunami, with grid application is presented. Finally, the application of grid technology in large scale simulations of disease transmission dynamics is discussed.

Malaysian rice husk ash – improving the durability and corrosion resistance of concrete: pre-review

Abstract: The objective of this paper is to presents and study a pre-review of Malaysian rice ash ask as a partial cement replacement in different percentage, grinding time and performance corrosion of RHA blended concrete The increasing demand for producing durable construction materials is the outcome of the fast polluting environment Supplementary cementitious materials prove to be effective to meet most of the requirements of durable concrete Rice husk ash is found to be greater to other supplementary materials like silica fume and fly ash Due to its high pozzolanic activity, both strength and durability of concrete are enriched Addition of rice husk ash to Portland cement not only improves the early strength of concrete, but also forms a calcium silicate hydrate gel around the cement particles which is highly dense and less porous This may increase the strength of concrete against cracking Previously, investigation on the corrosion performance of rice husk ash blended concrete is very limited Further researches are ongoing or have started recently by the authors to study the performance of RHA and corrosion of concrete mixes Various tests were carried out to evaluate durability of concrete made with 10, 20, 30 and 40% replacements of RHA by weight of cement Nevertheless, the results of compressive strength, absorption test and chloride penetration from previous investigation were presents in this study

Optimization of NaOH thermo-chemical pre-treatment for enhancing solubilisation of rice straw by Response Surface Methodology

Abstract: A municipal solid waste produced in urban and rural communities is a serious pollution source of water resource in developing country. One of the main problem in treatment of organic solid waste is its non-readily biodegradability due to the complexity of organic material especially hemicellolluse. This study reports Sodium Hydroxide (NaOH) thermochemical pretreatment of rice straw as a indicators of cellulosic compound to enhance its biodegradability. Laboratory-scale experiments were carried out in completely mixed reactors, 500 ml capacity. In order to optimization of hydrolysis of rice straw, Response Surface Method (RSM) based on three factors and one response design was performed to optimize experimental conditions. The effects of reaction parameters including sodium hydroxide concentration (0-30 g/l), reaction time (10-180 min) and temperature (30-200 oC) were evaluated. The optimum conditions resulted by RSM were: NaOH concentration 29.9 g/l, reaction time 133.1 min. and temperature 157.6 oC. The actual experimental soluble chemical oxygen demand (SCOD) of rice straw soluble was 41200 mg/l under optimum condition, which compared well to the maximum predicted value of 41211 mg/l.