- School of Distance Education, Universiti Sains Malaysia, Penang, Malaysia
The expansions of communities and cities over the last two decades have led to the increase of the number of health care facilities, and thus, clinical wastes are generated in significant amounts. Clinical wastes are a potential source... more
The expansions of communities and cities over the last two decades have led to the
increase of the number of health care facilities, and thus, clinical wastes are generated in
significant amounts. Clinical wastes are a potential source for many pathogens such as viruses,
parasites, fungi and bacteria. Therefore, clinical wastes should be treated before disposal into
the environment. The incineration is the most common technology applied for the treatment
process. However, the negative effects of incineration on humans and the environment have
led scientists to define alternative technologies for the safe disposal of clinical waste.
Numerous treatment technologies have been investigated as an alternative for incineration,
such as autoclave and microwave. These technologies generally depend on temperature while
the recent direction is to use a non-thermal sterilization processes. SC-CO2 is one of the nonthermal
sterilization technologies, which depends on pressure and low temperature. Currently,
SC-CO2 has been extensively used for the inactivation of microorganisms in food and
pharmaceutical industries. However, the application of SC-CO2 in treating clinical wastes
has been on a rise. Studies conducted on the inactivation of fungi in food, normal saline and
growth media indicate that SC-CO2 has the ability to inactivate these organisms. In clinical
wastes, SC-CO2 has been found to be effective in the inactivation of pathogenic bacteria.
Therefore, this review paper focuses on the potential of using SC-CO2 as alternative technology
for inactivating fungi in clinical wastes.
increase of the number of health care facilities, and thus, clinical wastes are generated in
significant amounts. Clinical wastes are a potential source for many pathogens such as viruses,
parasites, fungi and bacteria. Therefore, clinical wastes should be treated before disposal into
the environment. The incineration is the most common technology applied for the treatment
process. However, the negative effects of incineration on humans and the environment have
led scientists to define alternative technologies for the safe disposal of clinical waste.
Numerous treatment technologies have been investigated as an alternative for incineration,
such as autoclave and microwave. These technologies generally depend on temperature while
the recent direction is to use a non-thermal sterilization processes. SC-CO2 is one of the nonthermal
sterilization technologies, which depends on pressure and low temperature. Currently,
SC-CO2 has been extensively used for the inactivation of microorganisms in food and
pharmaceutical industries. However, the application of SC-CO2 in treating clinical wastes
has been on a rise. Studies conducted on the inactivation of fungi in food, normal saline and
growth media indicate that SC-CO2 has the ability to inactivate these organisms. In clinical
wastes, SC-CO2 has been found to be effective in the inactivation of pathogenic bacteria.
Therefore, this review paper focuses on the potential of using SC-CO2 as alternative technology
for inactivating fungi in clinical wastes.
Research Interests:
... 123456789/9935. Title: Citrus grandis osbeck: Influence of mevalonic acid and linalool on limonene accumulation in callus tissues. Authors: Zarina, Zakaria, Dr. Nik Nurulaini, Nik Ab. Rahman Mohd Omar, Abd Kadir. Keywords ...
... [3] Ramachandran S, Singh SK, Larroche C, Soccol CR, Pandey A. Oil cakes and their biotechnological applications – A review. Bioresource Technology 2007; 98: 2000–2009. ... Journal of the American Oil Chemists' Society 2006;... more
... [3] Ramachandran S, Singh SK, Larroche C, Soccol CR, Pandey A. Oil cakes and their biotechnological applications – A review. Bioresource Technology 2007; 98: 2000–2009. ... Journal of the American Oil Chemists' Society 2006; 83: 10. [5] Nik Norulaini NA, Md Zaidul IS ...
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ABSTRACT In the present study, steam autoclaving and supercritical carbon dioxide (SC-CO2) were utilized to inactivate Enterococcus faecalis, Escherichia coli, and Bacillus sphaericus in clinical solid waste. The success of steam-based... more
ABSTRACT In the present study, steam autoclaving and supercritical carbon dioxide (SC-CO2) were utilized to inactivate Enterococcus faecalis, Escherichia coli, and Bacillus sphaericus in clinical solid waste. The success of steam-based bacterial sterilization depends on temperature, treatment time, and the bacterial species present. Autoclave sterilization was found to be most effective at 121°C for 60 min and 131°C for 30 min. Complete inactivation of bacteria in clinical solid waste subjected to SC-CO2 sterilization was obtained after 30-120 min at a treatment range of 10-40 MPa and 35-80°C. The bacterial inactivation curves, which were generated using a modified Gompertz model to describe the relationship between survival rate and treatment time, was divided into three distinct phases. Scanning electron microscopy, bacterial protein, and enzymatic activity analyses showed that steam autoclaving physically inactivated bacteria by denaturing cellular enzymes, thereby inhibiting their activities. In contrast, SC-CO2 inactivated bacteria both physically and chemically. The reduction of proteins and enzymatic activity in SC-CO2-treated bacterial cells suggested that these cellular components were destroyed by the SC-CO2. The absence of re-growth after SC-CO2 sterilization and its promising bacterial inactivation efficiency suggested that it was an effective method for the treatment of infectious clinical solid waste. Therefore, SC-CO2 sterilization could be utilized in clinical solid waste management to eliminate infectious exposure and to improve the hygienic recycling and reuse of clinical solid waste materials.
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Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious... more
Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO2) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO2 sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20MPa, 60°C, and 60min. The SC-CO2-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO2 exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.
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ABSTRACT Palm oil is one of the many vegetable oils widely consumed around the world. The production of palm oil requires voluminous amount of water with the concurrent generation of large amount of wastewater known as palm oil mill... more
ABSTRACT Palm oil is one of the many vegetable oils widely consumed around the world. The production of palm oil requires voluminous amount of water with the concurrent generation of large amount of wastewater known as palm oil mill effluent (POME). POME is a mixture of water, oil, and natural sediments (solid particles and fibres).There is a dearth of information on the physical properties of these POME sediments. This study intends to distinguish the physical properties of oily and non-oily POME sediments which include sediment size, particle size distribution (PSD), sediment shape, sediment surface morphology, and sediment density. These characterizations are important for future researches because these properties have significant effects on the settling process that occurs either under natural gravity or by coagulations. It was found that the oily and non-oily POME sediments have different sizes with nonspherical irregular shapes, and because of that, the aspect ratio (AR) and circularity shape factors were adopted to describe the shapes of these sediments. The results also indicate that the density of oily POME sediment decreases as the sediment size increases.
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Il'astewaterfrom a semiconductor manufaclurer generally contains a strong dark color due to the presence of refractory photoresist solvents. A study has been conducted to compare the treatment eficlencies of various natural... more
Il'astewaterfrom a semiconductor manufaclurer generally contains a strong dark color due to the presence of refractory photoresist solvents. A study has been conducted to compare the treatment eficlencies of various natural coagulants (rice, corn and sago flour) on semiconductor wastewater. A three level.factorial design has been chosen as an experimental design to study lhe interaction between two influencingfactors; i.e. retention time and dosage of the coagulant to analyze the results. The parameters studied are chemical orygen demand (COD) and turbidity. Results indicate the dosage of the coagulant has a higher injluence in COD and turbidity reduclion. The regressions for COD and turbidity reduction by corn flour are 57.7894 and 77.86%, by sago Jlour are 84.48% and 78.74%, by rice /lour are 73.44% and 83.22%, respectirely.
Research Interests:
Research Interests:
... Tengku Norsalwani Tuan Lah1, Nik Norulaini Nik Ab. ... ng the co-cult defatted PKC hand, 2.562 106 spores/m pared to the co-culture w se activity lo was 1.424 FPU % for raw P multaneously o the possib o breakdown ading enzym ed by [9]... more
... Tengku Norsalwani Tuan Lah1, Nik Norulaini Nik Ab. ... ng the co-cult defatted PKC hand, 2.562 106 spores/m pared to the co-culture w se activity lo was 1.424 FPU % for raw P multaneously o the possib o breakdown ading enzym ed by [9] wh lulase comp sulting mor itory effects ...
Research Interests:
Research Interests:
Supercritical carbon dioxide (SC CO(2)) was used for the extraction of oil and squalene from Amaranthus grain. Very small amounts of oil could be extracted by SC CO(2) from undisrupted grains, although SC CO(2) possesses higher... more
Supercritical carbon dioxide (SC CO(2)) was used for the extraction of oil and squalene from Amaranthus grain. Very small amounts of oil could be extracted by SC CO(2) from undisrupted grains, although SC CO(2) possesses higher diffusivity. Grinding increased the extraction rate and oil yield, and smaller particle size gave higher extraction rate. The oil yield and initial extraction rate increased linearly with the increasing SC CO(2) flow rate from 1 to 2 L/min. Increasing the flow rate of SC CO(2) above 2 L/min resulted in only a slight increase of oil yield and extraction rate. In the pressure range of 150-250 bar, extraction decreased with increasing temperature at a constant pressure, whereas at a pressure of 300 bar, the extraction yield increased with increasing temperature. Possible reasons for this are discussed. Effects of temperature and pressure on squalene yield were different from those on oil yield. A good oil yield (4.77 g of oil/100 g of grain) was obtained at 40 degrees C and 250 bar. The highest squalene yield (0.31 g of squalene/100 g of grain) and concentration (15.3% in extract) were obtained at 50 degrees C and 200 bar, although the oil yield under this condition was low (2.07 g of oil/100 g of grain). The moisture content within 0-10% had little influence on yields of oil and squalene at 40 degrees C and 250 bar. Finally, the oil yield and the squalene concentration in the extracts by SC CO(2) were compared to those by solvent extraction.
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Research Interests:
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... Nik Abdul Rahman, Nik Norulaini and Zakaria, Zarina and Abdul Kadir, Mohd Omar (2003) Influence Of Elicitor Availability On Limonene And Linalool Accumulation From Citrus Grandis Cell Cultures. ... Deposited By: Mr Erwan Roslan.... more
... Nik Abdul Rahman, Nik Norulaini and Zakaria, Zarina and Abdul Kadir, Mohd Omar (2003) Influence Of Elicitor Availability On Limonene And Linalool Accumulation From Citrus Grandis Cell Cultures. ... Deposited By: Mr Erwan Roslan. Deposited On: 23 Jul 2009 14:23. ...