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Chee-ming Chan - One of the best experts on this subject based on the ideXlab platform.
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Solidification behavior of fine-grained dredged Marine Soils: strength improvement
2020Co-Authors: Amira Azhar, Chee-ming Chan, Ahmad Tarmizi Abd. KarimAbstract:Solidification is a method that aims in improving the engineering properties of Soil such as Soil strength. Chemical stabilization involves mixing of Soil with cement. This will result on the hardening of the mixture by hydration of the cement. This study aims to determine the stabilization or hydration effect of the binders to dredged Marine Soil. Three types of binders are used in these studies that are ordinary Portland cement, fly ash and bottom ash. Mixture of binders varying from 5% to 25% was added to stabilize the dredged Marine Soil. Cone penetration test and laboratory vane shear test were conducted on these samples. The samples were air cured at room temperature (25 ± 5°C) for 3 days. The results also showed that strength increase with increasing amount of cement, fly ash and bottom ash. The shear strength of the samples also increase with increasing of curing period The hydration process of Soil-cement mixture occurs immediately after mixing process. For the mixture of fly ash-Soil and bottom ash-Soil, the pozzolanic reaction occurs but only in small reaction.
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Using bottom ash as filler material in fine-grained dredged Marine Soil solidification: determination of optimal dosage
2020Co-Authors: Chee-ming Chan, Amira AzharAbstract:Dredged Marine Soils (DMS) are the sediments and debris removed during the dredging processes. In Malaysia, DMS are considered a waste and currently not being recycled or reused. This is due to the poor engineering properties of the material, i.e. low strength and high compressibility. Therefore some form of pre-treatment measures, such as solidification of DMS needs to be taken before DMS can be reused. Soil solidification involves the use of solidification agents or binders admixed with the Soil to improve its load-bearing performance. This paper describes a lab-based attempt to determine the optimal binder-filler dosage for solidifying 2 DMS samples from Malaysian waters. The DMS were collected from dredge sites in Melaka and Kelantan, while the binder used was ordinary Portland cement (C) and the filler bottom ash (BA) retrieved from a local coal power plant. The standard unconfined compression test was conducted to gauge the material’s improved strength admixed with a range of cement and bottom ash blends. The optimal dosage of BA or filler for effective solidification of the DMS was found to be 25 %. With higher BA dosages strength of the treated DMS would increase till it peaked at the optimal dosage. After exceeding the optimal BA dosage, the strength was observed to decrease rather dramatically. In conclusion, BA can be effectively used as a filler material at an optimal dosage to reduce the amount of cement required for solidification of DMS.
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Induced cementation of dredged Marine Soils for civil engineering reuse
2020Co-Authors: Chee-ming ChanAbstract:Ports and harbour facilities require regular dredging to maintain trafficability and safety of the vessels. The material removed from the seabed, i.e. dredged Marine Soils, is generally considered a waste material for disposal, either in designated offshore locations or inland containment facilities. Either measure incurs costs, time and labour, not to mention the obvious lack of sustainable values. Besides, there is always the risk of transferring undesirable contaminants in the dredged materials to the disposal sites, as well as along the transportation routes. It is however, possible to reuse this otherwise waste, with suitable and adequate pre-treatment. Considering that the material is essentially Soil-based, primarily consisting sand, silt and clay with some larger Marine debris, it is perhaps most apt to harness its inherent properties as a ‘Soil’ and reuse it as a geomaterial. In civil engineering and construction terms, this would mean reusing the Soils as a backfill material, for creating new land bases or restoring eroded ones in near-shore areas. However the inherent poor physico-mechanical properties of dredged Soils, such as high saturation with water, low strength and high compressibility, make the material unsuitable to be reused as it is. An expedient approach is induced cementation, where additives are mixed with the Soil to improve the necessary properties prior to reuse. This paper examines the induced cementation of some dredged Marine Soil samples from the Malaysian waters with cement and/or other binders. The common factors, such as binder dosage, curing period and water/binder ratios, were monitored to ascertain the mechanisms involved to enhance the material’s performance.
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Pseudo-solidification of Dredged Marine Soils with Cement - Fly Ash for Reuse in Coastal Development
2020Co-Authors: Chee-ming ChanAbstract:The dislodged and removed sediments from the seabed, termed dredged Marine Soils, are generally classified as a waste material requiring special disposal procedures. This is due to the potential contamination risks of transporting and disposing the dredged Soils, and the fact that the material is of poor engineering quality, unsuitable for usage as a conventional good Soil in construction. Also, taking into account the incurred costs and risk exposure in transferring the material to the dump site, whether on land or offshore, it is intuitive to examine the possibilities of reusing the dredged Soils, especially in coastal development where the transportation route would be of shorter distance between the dredged site and the construction location. Pseudo-solidification of Soils is not a novel idea though, where hydraulic binders are injected and mixed with Soils to improve the inherent engineering properties for better load bearing capacity. It is commonly used on land in areas with vast and deep deposits of soft, weak Soils. However, to implement the technique on the displaced then replaced dredged Soil would require careful study, as the material is far more poorly than their land counterparts, and that the deployment of equipment and workforce in a coastal environment is understandably more challenging. The paper illustrates the laboratory investigation of the improved engineering performance of dredged Marine Soil sample with cement and fly ash blend. Some key findings include optimum dosage of cement and fly ash mix to produce up to 30 times of small strain stiffness improvement, pre-yield settlement reduction of the treated Soil unaffected by prolonged curing period, and damage of the cementitious bonds formed by the rather small dosage of admixtures in the Soil post-yield. In short, the test results show a promising reuse potential of the otherwise discarded dredged Marine Soils.
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The Effect of Binder and Waste Granular Materials (WGM) on the Shear Strength and Shear Resistance of Dredged Marine Soils (DMS)
MATEC Web of Conferences, 2017Co-Authors: Mohammad Zawawi Rosman, Chee-ming ChanAbstract:Dredged Marine Soil (DMS) is considered as weak and soft problematic Soil. It is possible to give this type of Soil a second life if only its geotechnical properties are improved. Infusing Soil with solidification agent is the common practice of Soil improvement. This study uses binder and waste granular material (WGM) such as cement, bottom ash (BA) and palm oil clinker (POC). The aforementioned materials are capable to fortify the poor features of the Soil. Series numbers of Soil bed samples were tested for its shear strength and shear resistance. Test results show that the mentioned Soil parameters were corresponded with each other. In short, geo-waste and biomass materials are possible to be reused instead of being discarded.
P. Priyadharsini - One of the best experts on this subject based on the ideXlab platform.
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Diversity of Silver Nanoparticle Synthesizing Actinobacteria Isolated from Marine Soil, Tamil Nadu, India
Arabian Journal for Science and Engineering, 2016Co-Authors: A. Ranjani, P. M. Gopinath, K. Rajesh, D. Dhanasekaran, P. PriyadharsiniAbstract:Marine actinobacteria have been considered as a potential source of bioactive compounds holding a prominent position as targets in screening programs due to their diversity and their proven ability to produce novel metabolites and other molecules of pharmaceutical importance. In this regard, an attempt was made to study the diversity of actinobacteria and its ability to synthesize silver nanoparticles in Ramanathapuram and Thoothukudi districts of Tamil Nadu. A total of 1143 actinobacteria were isolated, out of which 49 were morphologically distinct based on the spore color, mycelia formation and pigment production. Themorphologically distinct isolates were characterized and identified using light microscope as Streptomyces sp. (16), Nocardiopsis sp. (8), Kitasatosporia sp. (7), Actinopolyspora sp. (2), Thermoactinomyces sp. (5), Actinomadura sp. (4) Kibdelosporangium sp. (3), Saccharopolyspora sp. (3) and Thermomonospora sp. (1). The correlation coefficient analysis between the isolates and the physicochemical parameters of the Soil revealed positive correlation with nitrogen. Silver nanoparticles production by the green chemistry approach was investigated using the isolated Marine actinobacteria which showed that 25 isolates out of 49, synthesized silver nanoparticles.
Nor Hanisah Hamzah - One of the best experts on this subject based on the ideXlab platform.
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The Engineering Properties of Dredged Marine Soil Solidified with Activated Steel Slag
InCIEC 2014, 2015Co-Authors: Chee-ming Chan, Nor Hanisah HamzahAbstract:Dredging is the operation of removing material from one part of the water environment and relocating it to another. Generally, the purpose of dredging is to relocate underwater sediments and Soils for the offshore construction, maintenance of waterways and reclamation. Dredging produces a very large amount of dislodged materials known as dredged Soils, which are commonly considered a waste. Generally, dredged Soil is dumped into open sea and causes environmental problems. On the other hand, steel slag is an industrial waste resulting from the process of steelmaking. However, for the last 3 decades, almost 35 % of the steel slag produced was dumped in landfills. As such, this study is about the mixing of a dredged Marine Soil with activated steel slag, with the aim of determining the effectiveness of the slag in solidifying the Soil. The dredged Soil was collected from Marina Melaka and categorized as a high plasticity silt (MH). It has a natural moisture content of 130. 7 %, specific gravity 2.53, liquid limit 66 % and plastic limit 51.6 %. The steel slag was first ground to particles smaller than 2 mm for mixing with the Soil. It was activated with 4, 6, 8, 10 and 12 mol of natrium hydroxide (NaOH), with only the optimum molarity resulting in maximum improvement of the Soil being used throughout the study. 3 predetermined ratios of clay: activated steel slag were examined, i.e. 3:7, 5:5 and 7:3, and the Soil-slag specimens were left to cure for 3, 7, 14 and 28 days. The solidified specimens were subjected to the unconfined compressive strength (UCS) test, the vane shear test as well as the bender element test at the respective ages. It was found that greater strength and stiffness improvement were produced by higher steel slag content. Longer curing periods resulted in more significant improvement of the engineering properties too. The steel slag addition also helped reduce moisture in the originally wet Soil. Overall it can be concluded that activated steel slag from Malaysian steel-making industry can be potentially used to solidify the otherwise waste dredged Marine Soils for reuse as a sound geomaterial.
Krishnan Kannabiran - One of the best experts on this subject based on the ideXlab platform.
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Anti-MRSA activity of Actinomycetes isolated from Marine Soil sample of Ariyaman Beach, Tamil Nadu, India
Research Journal of Pharmacy and Technology, 2018Co-Authors: Krishnamoorthy Bhakyashree, Krishnan KannabiranAbstract:Drug resistance among pathogenic microorganisms has become the biggest threat to the treatment of human infective diseases worldwide, often making the treatment ineffective. Actinomycetes are capable of producing novel bioactive metabolites and new chemical entities. The objective of the present study was to screen actinomycetes showing anti-Methicillin resistant Staphylococcus aureus (MRSA) activity from aMarine Soil sample collected at Ariyaman beach of Tamil Nadu, India. The Marine Soil sample waspre-treated, and inoculated onto aspecific medium for isolation of actinomycetes. The isolates were screened for its antibacterial activity against MRSA and Vancomycin-resistant Enterococci (VRE)using cross streak method and well diffusion method. The potential isolate was identified by morphological and biochemical characterization. Among the isolates screened for anti-MRSA activity, VITADK3 showed significant activity against ATCC MRSA strains, 43300 and 700699 with 18mm and 16 mm zone of inhibition respectively. The isolate was confirmed as belonging to actinomycetes based on the results obtained from morphological and physiological characterization. The results of the study suggest that the isolate VITADK3 from Ariyaman beach is a good source for the production of anti-MRSA secondary metabolites.
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isolation and characterization of antagonistic actinomycetes from Marine Soil
Journal of Microbial & Biochemical Technology, 2010Co-Authors: Lakshmipathy Deepika, Krishnan KannabiranAbstract:Soil sample was collected from the coastal region of Tamil Nadu with the aim of isolating actinobacteria and screen them for antagonistic activity against common bacterial and fungal pathogens. Serial dilution of the Soil sample and subsequent screening of the isolates obtained, resulted in the identification of a potential strain VITDDK2 with significant activity against Klebsiella pneumoniae, Aspergillus flavus and Aspergillus niger. In addition, the strain VITDDK2 also possessed chitinolytic activity. Chemotaxonomic analysis showed that the isolate VITDDK2 belongs to cell wall Type I. 16 S rRNA partial gene sequence and phylogenetic analysis showed that the strain VITDDK2 shared 93% similarity with Streptomyces sp. strain 346. Also the secondary structure of the rRNA of VITDDK2 and the restriction sites were predicted using Genebee and NEBCutter softwares respectively.
Chan Chee-ming - One of the best experts on this subject based on the ideXlab platform.
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The fundamental compressibility characteristics of solidified dredged Marine Soil
2020Co-Authors: Jong Siaw-yi, Chan Chee-mingAbstract:Yearly large amount of dredged Soils is produced during construction of Marine structures in Malaysian waters. Dredged Soils are generally dumped or deposited in open water, upland or hydraulic fills. As dredged Soils consist mainly of clay, some sand and other minerals, they generally display high compressibility, low yield stresses and low permeability. In order to improve the material‟s properties for possible reuse as sound geo-materials, the addition of solidifying agents, such as ordinary Portland cement (OPC) and fly ash is necessary. This study was aimed to determine the one-dimensional compressibility the treated Soil, with relation to the solidifying agent dosage and curing period. Standard oedometer tests were carried out on the untreated and treated dredged Soils for comparison purposes. The dredged Soils were collected from Sungai Dinding, Lumut, Perak. The solidification was carried out with addition of 10 % solidifying agents by dry weight of the Soil, with OPC and fly ash mixed at different proportions. The untreated and mixed samples were lightly kneaded and pressed into individual consolidation rings, measuring 75 mm in diameter and 20 mm in height. The specimens were then cured in a dry condition for 3 and 7 days. The oedometer test results showed encouraging solidification effect of the originally soft, weak dredged Soil, where compressibility reduction exceeding 60 % was attained with the OPC-fly ash mixture. The enhanced stiffness also indicates decreased permeability of the treated material, an engineering property desirable in load-bearing geo-materials.
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The effect of sunlight exposure on the survival of Escherichia Coli in dredged Marine Soils
2020Co-Authors: Nurasiah Mira Anuar, Chan Chee-mingAbstract:A detailed knowledge on the survival of fecal indicator is essential before the dredged Marine Soil being reused. Microcosms studies have been carried out to find out the relative survival of Escherichia Coli (E. Coli) in dredged Marine Soils. Survivals of E.Coli were carried out using dredged Marine Soils collected at Semerak Lagoon, Tok Bali, Kelantan. The experiment was conducted in the flask filled with dredged Marine Soils and exposed to natural sunlight for 4 hours. Temperature was ranging between 28⁰C and 35⁰C. Experiment in the dark was conducted to isolate the effect of sunlight radiation from the other factors, also to determine the effect temperature on the survival of E. Coli. The variability of E.Coli survival due to the effect of natural sunlight was shown to depend on the variability of the temperature. It is noted that the natural sunlight radiation was found to be one of the factors affecting the survival of E. Coli in dredged Marine Soils.