Mohamad Ali Fulazzaky

Application of Proteus mirabilis and Proteus vulgaris mixture to design self-healing concrete

AbstractThis study investigated two indigenous micro-organisms that can be isolated from soil. The isolated micro-organisms could precipitate calcium carbonate. These micro-organisms were applied to design self-healing concretes. Concrete is one of the most important materials which is used to build structures. Strength and durability of concrete is very important. Hence, a lot of research in this field is being conducted. Although a few reports can be found on the use of different micro-organism to design self-healing concretes, no research has been carried out to isolate suitable indigenous micro-organisms in Malaysia. In this study two strains of microorganisms were isolated from soil. Broken concrete was treated by a medium culture (MC) containing micro-organisms. Results of this study showed that, cracked concrete could be filled by calcium carbonate after treating by a MC containing micro-organisms. However, this treatment is not very effective on the strength of concrete. Results of this study can ...

Removal of oil and grease contamination from stream water using the granular activated carbon block filter

Most sources of oil and grease (O&G) are insoluble in water. Because the specific gravity of O&G is lower than water, it floats on the top surface. The presence of O&G may have adverse impact on water resources management. Activated carbon can remove O&G from water by adsorption process. Still the use of physical models to adsorb O&G from stream water needs to be verified. This study proposes the mathematical models for adsorption of O&G from stream water using the granular activated carbon block filter (GACBF). The parameters in equations are all physically meaningful, and the experimental data validation shows that the equations are sufficiently accurate. The proposed models to calculate the accumulation rate, lifetime, and adsorption capacity for the adsorption of O&G onto GACBF from Ulu Pontian River water are presented to contribute to clean technology and environmental contamination investigation and assessment.

Biofiltration process as an ideal approach to remove pollutants from polluted air

AbstractMost developing and developed countries are facing the problems and challenges of air pollution. Many governments have enacted laws and policies to enforce industrial activities to reduce air contaminating emissions and are mainly carried out by installation of air pollution control systems. Therefore, the use of suitable technique such as biofiltration processes to control air pollutants is necessary. Although many studies have been published on the designing and operations of polluted air treatment using biofiltration processes but a comprehensive review on it is still lacking. Till now due to conceptual designing and operational knowledge, several cases of failure or sub-optimum designing has been reported about the use of biofiltration process to treat polluted air. This paper presents a comprehensive review of biofiltration processes and technology for the control of organic and inorganic pollutants as an ideal approach to remove pollutants from polluted air. It also covers classification, fu...

Analysis of global and sequential mass transfers for the adsorption of atrazine and simazine onto granular activated carbons from a hydrodynamic column

The presence of micropollutants, particularly herbicides, in drinking water is undesired and therefore removal is required. Granular activated carbon (GAC) is used extensively to remove organic micropollutants during the treatment of potable waters. The performance of an adsorption-based separation depends on the existence of a force field at the surface of a solid. To date, the resistance of mass transfer for the adsorption of micropollutants from aqueous solution onto GAC still needs to be verified. This paper uses the developed mathematical models to analyse the global and sequential mass transfers for the adsorption of atrazine and simazine onto different GACs from a hydrodynamic column. The resistance of mass transfer is dependent on the porous diffusion before a 5% outflow occurred and both on the porous diffusion and film mass transfer after passing that percentage of outflow. The properties of adsorbate and adsorbent affecting the global, external and internal mass transfer are analysed to contribute to the investigation of adsorption mechanisms. The mechanisms of adsorption of atrazine and simazine onto GACs from the hydrodynamic column are verified.

Laboratory simulation of microbial enhanced oil recovery using Geobacillus toebii R-32639 isolated from the Handil reservoir

Microbial enhanced oil recovery (MEOR) is a biological based technology to enhance crude oil (CO) recovery at old oil wells by manipulating function or structure or both of the microbial environments existing in oil reservoirs. Even if many biosurfactant-producing microbes can be found in different environments, the ability of Geobacillus toebii R-32639 to enhance CO recovery needs to be verified. In this study, artificial cores (ACs) are used to simulate the application of MEOR by three scenarios of injecting nutrients, microbial culture and bioproducts. The use of Geobacillus toebii R-32639 as biosurfactant producer enables a lowering by 25.3% of interfacial tension and by 14.1% of CO viscosity and also enables the degrading of a 7.4–28.8% fraction of (C12–C34) hydrocarbons after 7 days of incubation. The injection of microbial culture into a laboratory-scale CO reservoir of the AC for the desirable purpose of enhanced oil recovery could feasibly achieve an average recovery factor of 14.27% but lower by 5.50% the AC porosity and by 91.0% the AC permeability; this is the best-case scenario of the microbial core flooding (MCF) experiments. The simulation of MEOR by using bacterial strains of Geobacillus toebii R-32639 provides valuable insight into the use of MCF experiments to obtain greater oil production from existing reservoirs.

Evaluation of gas retention time effects on the bio-trickling filter reactor performance for treating air contaminated with formaldehyde

The effect of different gas retention times (GRTs) on the efficiency of formaldehyde (FA) removal has been studied using a bio-trickling filter reactor (BTFR) for obtaining the optimal operating conditions. Mathematical models to determine the optimum process conditions of the BTFR system for FA removal from contaminated air are developed. Approximately 66% of the FA introduced into the BTFR treatment process dissolved in the nutrient solution, and about 34% of the residual FA was still present in the air. The predominant bacteria on the surface of supporting materials are identified as the five bacterial colonies Salmonella bongori, Salmonella choleraesuis subsp. arizonae, Salmonella typhimurium, Serratia entomophila and Serratia ficaria, and they have the ability to metabolise FA from two-phases (gas and liquid), as a source of carbon and energy. The optimum removal efficiencies of 450 mg FA L−1 of contaminated air ranged from 95 to 99% are verified for GRTs ranging from 100 to 150 s. Exponential models are proposed as a new approach for determining the optimal operating conditions of the BTFR system and can make significant contributions to improving the air quality.

Assessing the suitability of stream water for five different uses and its aquatic environment.

Surface water is one of the essential resources for supporting sustainable development. The suitability of such water for a given use depends both on the available quantity and tolerable quality. Temporary status for a surface water quality has been identified extensively. Still the suitability of the water for different purposes needs to be verified. This study proposes a water quality evaluation system to assess the aptitude of the Selangor River water for aquatic biota, drinking water production, leisure and aquatic sport, irrigation use, livestock watering, and aquaculture use. Aptitude of the water has been classified in many parts of the river segment as unsuitable for aquatic biota, drinking water production, leisure and aquatic sport as well as aquaculture use. The water quality aptitude classes of the stream water for nine locations along the river are evaluated to contribute to decision support system. The suitability of the water for five different uses and its aquatic ecosystem are verified.

Removal of formaldehyde from polluted air in a biotrickling filter reactor

AbstractOptimization of biotrickling filter reactor (BTFR) for the removal of formaldehyde contained in synthetic contaminated air was investigated. The importance of formaldehyde from contaminated air is necessary mainly because it is toxic, carcinogen, and mutagen for humans. Although several studies have been conducted on formaldehyde removal by using BTFR from contaminated air, but optimum conditions for formaldehyde removal is not being studied using a trustable method. The determination of optimum condition to remove formaldehyde was carried out with Taguchi experimental design method. The influence of different factors (pH, nitrogen, phosphorus, formaldehyde concentration) on formaldehyde removal efficiency in BTFR was determined, and the optimum condition for maximizing this response was obtained. The result shows that pH has a greater effect on BTFR efficiency for formaldehyde removal. By operating BTFR in optimum condition, the removal rate increased up to 98%. Thus, the operation of BTFR at opt...

Characterization of pyrene biodegradation by white‐rot fungus Polyporus sp. S133

A white‐rot fungus of Polyporus sp. S133 was isolated from an oil‐polluted soil. The metabolism of pyrene by this fungus was investigated in liquid medium with 5 mg of the compound. Depletion of pyrene was evident during the 30‐day growth period and was 21% and 90%, respectively, in cometabolism and metabolism of pyrene alone. Pyrene was absorbed to fungal cells or biodegraded to form simpler structural compounds. Seventy‐one percent of eliminated pyrene was transformed by Polyporus sp. S133 into other compounds, whereas only 18% was absorbed in the fungal cell. The effects of pH and temperature on biomass production of Polyporus sp. S133 for pyrene were examined; the properties of laccase and 1,2‐dioxygenase produced by Polyporus sp. S133 during pyrene degradation were investigated. The optimal values of pH were 3, 5, and 4 for laccase, 1,2‐dioxygenase, and biomass production, respectively, whereas the optimal values of temperature were 25 °C for laccase and 50 °C for 1,2‐dioxygenase and biomass production. Under optimal conditions, pyrene was mainly metabolized to 1‐hydroxypyrene and gentisic acid. The structure of 1‐hydroxypyrene and gentisic acid was determined by gas chromatography–mass spectrometry after identification using thin‐layer chromatography.

The influence of rain intensity on raindrop diameter and the kinetics of tropical rainfall: case study of Skudai, Malaysia

ABSTRACT The modelling of soil loss and investigation of urban hydrology and wet weather pollution in Malaysia requires the definition of rainfall parameters for the region. In this study, an inexpensive method was applied to establish the influence of raindrop diameter on kinetics and rain intensity in Skudai, Peninsular Malaysia, as a prelude to wider regional research. Raindrop sizes vary from less than 1.2 mm to as big as 7.0 mm, with median raindrop diameters of 2.51 mm and a mean diameter of 2.56 mm. The median raindrop diameter–intensity relationship correlates strongly using power and exponential equations, with coefficients of determination of 0.75 and 0.73, respectively. The kinetic energy–intensity relationship fits an exponential function and also a linear equation with R2 values of 0.49 and 0.34, respectively. An average rain kinetic energy of 30 J m-2 mm-1 was recorded. This research leads to an objective reclassification of rainfall intensities in the region. Editor Z.W. Kundzewicz; Associate editor not assigned