62 research outputs found

    Moringa oleifera seeds as natural coagulant for water treatment

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    Developing countries and third world countries are facing potable water supply problems because of inadequate financial resources. The cost of water treatment is increasing and the quality of river water is not stable due to suspended and colloidal particle load caused by land development and high storm runoff during the rainy seasons especially in a country like Malaysia. During the rainy seasons the turbidity level increases and the need for water treatment chemicals increase as well, which leads to high cost of treatment which the water treatment cannot sustain. As a result, the drinking water that reaches the consumer is not properly treated. Therefore, it is of great importance to find a natural alternative for water coagulant to treat the turbidity. It has been found that Moringa oleifera is the best natural coagulant discovered yet, that can replace aluminium sulphate (Alum) which is used widely all around the world. The study is focusing in Moringa oleifera seeds to find the active constituents which are responsible about the coagulation mechanism and improving the coagulation property. This will help in producing this alternative locally as Moringa oleifera is grown in Malaysia and other tropical countries and can be of great benefit for water treatment

    Optimization of Water Treatment Parameters using Processed Moringa oleifera As a Natural Coagulant for Low Turbidity Water

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    Moringa oleifera is a natural coagulant which can be used for water treatment in tropical developing countries. This study presents the results of production of natural coagulant from processed Moringa oleifera with simple technique (oil extraction, salt extraction, and microfiltration with 0.2 μm). The optimization study on physical factors was carried out for coagulation-flocculation process. Low initial turbidity water samples (synthetic and river water) were used with turbidity less than 50 Nephelometric Turbidity Units (NTU). The response surface methodology (RSM) was used, and the analysis of variance (ANOVA) was performed to validate the developed regression model. The residual turbidity obtained was 4.514 NTU for synthetic water and 1.598 NTU for river water by applying the optimum conditions of 40 rpm (low speed), mixing time of 41 minutes, and Moringa oleifera dosage of 0.75 mg/L

    Recombinant bromelain production in Escherichia coli: process optimization in shake flask culture by response surface methodology

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    Bromelain, a cysteine protease with various therapeutic and industrial applications, was expressed in Escherichia coli, BL21-AI clone, under different cultivation conditions (post-induction temperature, L-arabinose concentration and post-induction period). The optimized conditions by response surface methodology using face centered central composite design were 0.2% (w/v) L-arabinose, 8 hr and 25°C. The analysis of variance coupled with larger value of R2 (0.989) showed that the quadratic model used for the prediction was highly significant (p < 0.05). Under the optimized conditions, the model produced bromelain activity of 9.2 U/mg while validation experiments gave bromelain activity of 9.6 ± 0.02 U/mg at 0.15% (w/v) L-arabinose, 8 hr and 27°C. This study had innovatively developed cultivation conditions for better production of recombinant bromelain in shake flask culture

    Heterologous expression of Bromelain in Escherichia coli

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    In spite of the fact that commercial bromelain supplements are available in the market, to date, none of them are produced and formulated from recombinant forms. They are extracted and purified (often partially) from the stem and fruit of pineapple. This makes the production of bromelain very difficult, less reliable, often contaminated and expensive. In this study, a recombinant bromelain from BL21 A clone was expressed as soluble and insoluble active enzyme. Maximum activity was observed at 4-hour post induction with 0.2% L-arabinose and over 60% of the enzyme was found to be expressed in soluble form. The enzyme fractions were purified using Nickel-NTA spin column. Purification fold and % yield of the purified lysate were found to be 35 and 75% respectively. SDS-PAGE results showed that the purified bromelain exhibited a single band with molecular weight of about 45kDa

    Gender Disparity in School Participation and Achievement: The Case in Malaysia

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    AbstractGender differences with regard to academic performance remain one of the more challenging issues in educational research. Gender disparity in education has traditionally focus on the under participation of girls and still is in some parts of the world. In a number of countries, including Malaysia, gender disparity in basic and higher education are in favor of girls both in terms of participation and performance. The dual purpose of this paper is to address and to understand the nature of the issue by analyzing the trends of student participation and performance; and secondly, to seek whether student engagement and burnout are possible factors contributing to school dropout and low achievement. There are evidence in the literature to show student engagement and student burnout accounted for gender differences in school performance. The results of the analysis of secondary data reflected a trend that shows girls outperformed boys in national examinations across school levels and types. These trends are confirmed by results of a survey of the level of student engagement and student burnout on a sample of students aged 12, 14 and 16 which seems to suggest that boys are less engaged than girls, and experience more burnout. The findings are discussed in the context of developing support for students, particularly boys, to be more engaged, and less burnout in school and in learning

    Development of Porous PCL Based Microcarrier

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    Polycaprolactone (PCL) has been used for cell cultivation due to its biocompatibility. PCL microcarrier featuring microporous structure were generated in the present study. PCL-based porous microcarrier was fabricated with different parameters by using emulsion evaporation method. From the study, size distribution of the microcarrier and the size of pore generated on microcarrier were affected by most of the parameters tested such as sterring speed, PVA concentration, camphene concentration, temperature and ratio between PCL and solvent.  Optimum pore size was generated at 20% camphene concentration with the average size of 11.74 µm which is conducive for cells to attached and populated well within the pores.  The surface properties of developed porous can be improved for potential application in cell culture research and development, as well as in tissue engineering

    Using computational fluid dynamics in the determination of solar collector orientation and stack height of a solar induced ventilation prototype

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    Stack ventilation in the hot and humid climate is inherently inefficient due to minimal air temperature differences between indoor and outdoor environment of a naturally ventilated building. Solar induced ventilation is a viable alternative in enhancing this stack ventilation. This paper aims to demonstrate investigations on the effective solar collector orientation and stack height for a solar induced ventilation prototype that utilizes roof solar collector and vertical stack. The orientation of the solar collector is significant as it determines the amount of solar radiation absorbed by the solar collector. Meanwhile, the height of the vertical stack influences the creation of the stack pressure in inducing air movement. Investigations were executed using a simulation modelling software called FloVENT. The validation of the simulation modelling against physical experiment indicated a good agreement between these two results. Analyses were executed on the air temperature increments inside the solar collector. A high increment of the air temperature resulted in the effective orientation. Meanwhile, the air temperature and mass flow rate of the various heights of the vertical stack were also analyzed. The findings concluded that the recommended orientation for the prototype’s solar collector is the west-facing orientation. It was also found that the higher the vertical stack, the lower the air temperature inside the stack would be, but with greater induced mass flow rate

    Production of natural coagulant from Moringa oleifera seed for drinking water treatment

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    Water treatment industry worldwide including South East Asia IS facing high demand for synthetic coagulants for water treatment process. Research is continuously being done to find the best treatment methods and lower cost alternatives. Moringa oleifera seed could be a suitable natural alternative to synthetic coagulants. This paper investigates processing Moringa oleifera seed in order to concentrate the bio-active constituents which have coagulation activity. The proposed method to isolate and purify the bio-active constituents is the cross flow filtration method, which produced the natural coagulant with very cost effective processing technique (oil extraction; salt extraction; and microfiltratlon through 0.20 ~Im). Coagulation activity was determined using conventional jar test procedures, and the major water quality control parameters monitored was the residual turbidity for river water with low initial turbidity. Results showed residual turbidity of less than 5 NTU which is recommended by the World Health Organization (WHO). The turbidity removal was 94.82% for river water of low initial turbidity of 44.2 NTU, without any chemicals added. The microfiitration method is considered to be a practical method which needs no chemicals added. The product is commercially valuable and can contribute to the economic development of South East Asian countries

    Esterification for butyl butyrate formation using Candida cylindracea lipase produced from palm oil mill effluent supplemented medium

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    The ability of Candida cylindracea lipase produced using palm oil mill effluent (POME) as a basal medium to catal yze the esterification reaction for butyl butyrate formation was investi-gated. Butyric acid and n-butanol were used as substrates at different molar ratios. Different con-version yields were observed according to the affinity of the produced lipase toward the substrates. The n -butanol to butyric acid molar ratio of 8 and lipase concentration of 75 U/mg gave the highest butyl butyrate formation of 63.33% based on the statistical optimization using face centered central composite design (FCCCD) after 12 h reaction. The esterification potential of the POME based lipase when compared with the commercial lipase from the same strain using the optimum levels was found to show a similar pattern. It can be concluded therefore that the produced lipase pos-sesses appropriate characteristics to be used as a biocatalyst in the esterification reactions for butyl butyrate formatio
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