185 research outputs found
Thermal Performance Evaluation of a Small-Scale Drying Machine for Palm Oil Mill Sludge
Malaysia is one of the major contributors of palm oil production globally with large amount of palm oil production. This has significantly contributed to large amount of palm oil mill effluent that eventually affect the environment. A small-scale drying machine for palm oil mill is evaluated on its thermal performance to assess the suitability of the machine to produce organic fertilizer from the palm oil mill sludge. Evaluation was performed with computational fluid dynamics simulation and experiment on design configuration options of the drying machine. The effect of air flow to the thermal performance was also studied in conjunction with the design configurations of the drying machine. The results showed promising potential of a design configuration over another in term of thermal performance and functionality
Thermal Performance Evaluation of a Small-Scale Drying Machine for Palm Oil Mill Sludge
Malaysia is one of the major contributors of palm oil production globally with large amount of palm oil production. This has significantly contributed to large amount of palm oil mill effluent that eventually affect the environment. A small-scale drying machine for palm oil mill is evaluated on its thermal performance to assess the suitability of the machine to produce organic fertilizer from the palm oil mill sludge. Evaluation was performed with computational fluid dynamics simulation and experiment on design configuration options of the drying machine. The effect of air flow to the thermal performance was also studied in conjunction with the design configurations of the drying machine. The results showed promising potential of a design configuration over another in term of thermal performance and functionality
Purification and characterization of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. G1
A cyclodextrin glucanotransferase (CGTase) was successively purified by ammonium sulphate precipitation, and affinity chromatography on a-CD (epoxy)-Sepharose 6B column. The specific activity of the CGTase was increased approximately 2200-fold, from 8.43 U/mg protein to 18,866 U/mg protein. SDS-PAGE showed that the purified CGTase was homogeneous and the molecular weight of the purified CGTase was about 75 kDa. The molecular weight of the enzyme that was estimated by gel filtration under native condition was 79 kDa. This has indicated that Bacillus sp. G1 CGTase is a monomeric protein. The isoelectric point (pI) of the enzyme was about 8.8. Characterization of the enzyme exhibited optimum pH and temperature of 6.0 and 60 8C, respectively. The enzyme was stable from pH 7.0 to 9.0 and retained its high activity up to 60 8C. However, in the presence of 20 mM Ca2+, the purified CGTase is able to prolong its thermal stability up to 70 8C. CGTase was strongly inhibited by ZnSO4, CuSO4, CoCl2, FeSO4, FeCl3 and EDTA. Km and Vmax for the purified enzyme were 0.15 mg/ml and 60.39 mg bcyclodextrin/( ml min), respectively, with soluble starch as substrate. In cyclodextrin production, tapioca starch was found to be the best substrate used to produce CDs. The enzyme produced g- and b-CD in the ratio of 0.11:0.89 after 24 h incubation at 60 8C, without the presence of any selective agents
Near-real-time Biomonitoring of Heavy Metals Using the Xenoassay® System
Heavy metals have widespread industrial uses and have been found in increasing quantities as contaminants in all components of the biosphere. Water and sediment of rivers near industrial areas such as the Juru River in Penang and Langat River in Selangor are polluted with heavy metals. Thus, rapid and fast methods to detect the presence of heavy metals in the environment are necessary. Existing instrumental methods such as atomic absorption and emission spectrometry are very sensitive but the sole use of these instruments for heavy metal detection is extremely expensive, needs a skillful person to operate and is not amenable to near-real-time analysis. The best scenario for routine biomonitoring of heavy metals is the marriage between instrument- and bioassays. Currently, the USEPA has recognized whole cell-based bioassays such as as PolytoxTM and Microtox® for the detection of heavy metals. Unfortunately these cell-based assays cannot be used as real-time or near real-time assays in the field as they require bulky incubators. Near-real-time monitoring of heavy metals giving results in less than one hour is very useful in environmental CSI (Criminal Scene Investigation) or ECSI where temporal and spatial concentrations of heavy metals in running waters are a challenge to environmentalists to pinpoint heavy metals POS (point of source) for legal purposes. Enzyme-based inhibitive assays are simple, rapid and fast and could be developed for near real-time assays. We have developed an inhibitive assay system –Xenoassay® based on proteases for the assay of heavy metals. The system could detect the heavy metals mercury, cadmium, lead, copper, zinc and silver at the sub parts per million level. Field trial near-real-time assay capability shows promising results
Carbonized rice husk and cocopeat as alternative media bed for aquaponic system
The study evaluates the suitability of carbonized rice husk and cocopeat substrates as alternative media bed in aquaponics unit for cultivation of red Nile tilapia and Gynura procumbens. Area occupied by the aquaponics unit is about 4.5 m2 and it was operated under equatorial climate conditions. Various substrates namely lightweight expanded clay aggregate (LECA), cocopeat, carbonized rice husk and a mixture of cocopeat-rice husk at ratio 1:1 were prepared using polybags for growing of the longevity spinach. The resultant effects from fish cultivation and plants growth on the water qualities and nitrification efficiency of the aquaponics unit were reported. The aquaponics unit were operated for twelve weeks and the values of pH, temperature, and dissolved oxygen level were measured to be within the range of 6.4-6.9, 27.7-29oC, and 5.5-7 mg·L-1, respectively. Survival rate for fish was 98% with specific growth rate (SGR) and food conversion ratio (FCR) of 6.9% per day and 1.13, respectively. Nutrient deficiency was not evident and plants showed healthy growth with harvest yield ranging between 3.6 and 3.9 kg·m-2. Results attained signified the suitability of utilizing carbonized rice husk and cocopeat as alternatives media bed compared to commercial media bed such as LECA
Stiffness modulus properties of hot mix asphalt containing waste engine oil
This study presents the effect of waste engine oil (WEO) on the mechanical properties of hot mix asphalt mixtures. It was added into mixture at 0%, 3%, 5%, 7%, 10% and 15% by weight of binder. The mechanical properties of the mixes were evaluated by conducting indirect tensile stiffness modulus (ITSM) at temperatures of 25C and 40C. The results indicated that modified mixes exhibited lower stiffness modulus with the increasing amount of WEO as well as testing temperature. The increasing amount of WEO was found to have a good linear correlation to the decreasing of stiffness modulus. The finding showed that the WEO has the significant role as a softening agent which affected the stiffness modulus even at low percentage
Adhesion Characterization of Palm Oil Mill Sludge Modified Asphalt Binder
The adhesion of mineral aggregates to asphalt binder is an essential point that attributes to the quality and performance of the asphalt mixture. Moreover, the considerable problem to the asphalt pavement could come from the lack of bonding between the materials. Generally, adhesion of mineral aggregates depends on the source or type of aggregate and asphalt binder. This study investigated the adherence coverage of palm oil mill sludge (POMS) modified binder with granite aggregate. Base asphalt binder of penetration grade 60/70 was blended with 1%,2%,3%,4% and 5% of POMS to produce the modified asphalt binders, respectively. Consequently, POMS modified binders were mixed with the granite aggregate to produce loose mix samples. In this current study, boiling test procedure was used to reduce the adhesive bonding of the loose mix sample. Then, Image J software was used to evaluate the stripping area of the samples. The results from image analysis revealed that different stripping areas due to different amounts of POMS incorporated in the modified asphalt binder. Up to 4% POMS modified asphalt showed an acceptable resistance toward moisture compared to un-modified asphalt. Image J helped to produce a clear stripping result compared to visual observation. In conclusion, POMS could be used as an asphalt modifier with satisfactory adhesion properties
Adhesion Characterization of Palm Oil Mill Sludge Modified Asphalt Binder
The adhesion of mineral aggregates to asphalt binder is an essential point that attributes to the quality and performance of the asphalt mixture. Moreover, the considerable problem to the asphalt pavement could come from the lack of bonding between the materials. Generally, adhesion of mineral aggregates depends on the source or type of aggregate and asphalt binder. This study investigated the adherence coverage of palm oil mill sludge (POMS) modified binder with granite aggregate. Base asphalt binder of penetration grade 60/70 was blended with 1%,2%,3%,4% and 5% of POMS to produce the modified asphalt binders, respectively. Consequently, POMS modified binders were mixed with the granite aggregate to produce loose mix samples. In this current study, boiling test procedure was used to reduce the adhesive bonding of the loose mix sample. Then, Image J software was used to evaluate the stripping area of the samples. The results from image analysis revealed that different stripping areas due to different amounts of POMS incorporated in the modified asphalt binder. Up to 4% POMS modified asphalt showed an acceptable resistance toward moisture compared to un-modified asphalt. Image J helped to produce a clear stripping result compared to visual observation. In conclusion, POMS could be used as an asphalt modifier with satisfactory adhesion properties
Axial Compression Behaviour of Full-Scale Prefabricated Wood-Wool Wall Panel
This study aims to investigate an axial compression behaviour of prefabricated wall constructed using wood-wool cement composite panel (WWCP). A total of three full scale wall specimens were fabricated at the laboratory with dimension of 2400 mm width, 2400 mm height and 147 mm thickness. The new fabrication technique namely as cross laminated technique was considered where the walls is fabricated using two layers of 600 mm x 2400 mm x 50 mm thickness of WWCP strips, where each layer consists of four panel strips that were arranged at cross wise panel orientation. The front and rear panel strips were bonded together using 15 mm thickness of mortar paste and as a finishing 16 mm thickness of mortar base plaster were applied on both surfaces. The prefabricated wall specimens were tested under axial compression load up to failure after 28 days of curing period. The axial load carrying capacity, vertical and lateral displacement and failure mode behaviour of walls were observed during and after test conducted. The results of experimental testing recorded that; the maximum axial compression load of prefabricated wood-wool wall specimens achieved the capacity of 1038.54 kN. This shows that the new prefabricated wall constructed using cross laminated wood-wool panel can be used as a load bearing wall system for low rise building
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