Browse publications by year: 2016

  1. Ong SQ
    Sains Malaysiana, 2016;45:777-785.
    Dengue is a major issue in Malaysia as the dramatic emerge of infection. Yet an effective vaccine or medicine is not
    yet available, although many attempts are undergoing. Dengue vector control is still considered the most effective way
    for controlling and preventing the transmission of dengue virus. Nonetheless, as the conventional approaches are less
    successful in managing the dengue transmission, it is time to review the current applied and other available approaches.
    Current dengue vector relied greatly on the chemical approach as space treatment either thermal or ULV fogging, however,
    the approach seem like under the expectation. Beside space treatment, new control methods for example biological
    control (bacterium Bacillus thuringiensis, predatory mosquito Toxorhynchites) and attractive trap were carried out
    at certain location of Malaysia. Moreover, new emerged approaches such as mass release of genetic modification or
    artificially Wolbachia infected male dengue vector for the objective of generating sterile offspring when mate with
    wild population is urge to be tested in Malaysia, although concerns have to be taken before the actual mass release. In
    conclusion, control of dengue vector shall not consist exclusively for a single approach, neither genetic modification
    of artificially Wolbachia infected technique, nor the conventional insecticidal treatment. It should, however, comprise
    of the environment management as the fundamental approach, a well-planned integrated control program and a good
    cooperation among the organization.
    MeSH terms: Animals; Bacillus thuringiensis; Dengue; Dengue Virus; Disease Vectors; Insecticides; Malaysia; Male; Culicidae; Vaccines; Wolbachia
  2. Lai L, Mohd Nahar Azmi Mohamed, Mohamed Razif Mohamed Ali, Khong Tk, Ashril Yusof
    Sains Malaysiana, 2016;45:769-775.
    The objective of the present preliminary study was to investigate the effect of platelet-rich plasma (PRP) treatment
    alongside rehabilitation programme compared with rehabilitation programme alone on antioxidant enzymes’ (superoxide
    dismutase, SOD; catalase, CAT) activity and time to return to play (RTP) following hamstring injury among Malaysian
    athletes. Participants diagnosed with grade-2 acute hamstring injury (n=10) were randomised into 2 groups of PRP
    treatment and rehabilitation programme (PRP-T) and rehabilitation programme alone (CON). Blood samples were collected
    at baseline and 2 fortnightly (week-2, W2; week-4, W4) for the biochemical assessments. Participants were certified to
    have recovered upon fulfilling RTP criteria. PRP-T group showed a significantly lower CAT activity compared to CON group
    (47.55% lower at W2, 37% lower at W4, p<0.05), while there was no significant difference in SOD activity between the
    groups. Although PRP-T group benefited from an earlier (~15 days) time to RTP compared to the CON group, no statistically
    significant difference was noted; however, the effect size was large (Cohen’s d=0.9). These findings suggested that PRP
    treatment alongside rehabilitation potentially reduces the degree of secondary tissue damage and facilitates muscle
    recovery through regulation of antioxidant enzymes, which subsequently hastens time to RTP. Athletes and coaches could
    consider PRP as viable treatment for hamstring injury.
  3. Norhayati Ibrahim, Rafidah Aini Pakri Mohamed, Sharlene Teo, Normah Che In, Abdul Halim Abdul Gafor, Rozmi Ismail, et al.
    Sains Malaysiana, 2016;45(5):753-759.
    The prevalence of chronic kidney disease (CKD) have increased and become one of the major public health concerns
    worldwide including Malaysia. Previous studies on CKD generally focused on patients who were already undergoing
    dialysis treatment; however, studies investigating the stresses experienced by pre-dialysis CKD patients were limited. This
    study aimed to examine the prevalence of psychological distress and their association with the Health Related Quality
    of Life (HRQoL) during the different stages of CKD. This cross-sectional study involved 200 pre-dialysis patients from
    stages 3 to 5, who were recruited from the Nephrology Clinic at the National University of Malaysia Medical Centre
    (UKMMC). The instruments used in this study were the Short Form 36 (measuring HRQoL) and Hospital Anxiety and
    Depression Scale (HADS) to measure the psychological distress. The results showed that the prevalence of depression
    and anxiety increased proportionally with the CKD stages. The HRQoL sub-component scores declined as the CKD stages
    increased except for social functioning. An impaired HRQoL was associated with depression and anxiety in the CKD
    patients. The results suggested that it is very important to manage kidney disease at an early stage and that a healthier
    lifestyle is adopted.
    MeSH terms: Anxiety; Anxiety Disorders; Cross-Sectional Studies; Depression; Depressive Disorder; Renal Dialysis; Humans; Life Style; Malaysia; Nephrology; Public Health; Stress, Psychological; Prevalence; Renal Insufficiency, Chronic
  4. Ashraf El-goniemy, Esraa Ali, Ismail Elshahawy
    Sains Malaysiana, 2016;45:745-751.
    The aim of the present study was to estimate the epidemic situation of mites, in rabbit dermatologic disease in and around
    Qena province, in the southern region of Egypt. Two hundred cases of dermatologic disease from the formentioned province
    were investigated by conducting deep skin scraping between May 2011 and October 2012. The overall prevalence was
    25%. Sarcoptic scabiei uniculi (22.5%) was the most frequent mite, followed by Notoedres cati cuniculi (2.5%). To the
    best of our knowledge this is the first report of Notoedres cati cuniculi among studied rabbits in the study region. Study
    on different breeds, English represents highest prevalence of mites 30%. Moreover, there was no significant difference
    in the prevalence of mange mite infection between male and female rabbits (p > 0.05). Similarly, the prevalence was not
    significant among the age groups and rabbit breeds (p > 0.05). In conclusion, the present prevalence of mange mites
    was still high enough to cause significant economic losses in the study area. Therefore, strengthening the control effort
    was suggested.
    MeSH terms: Animals; Egypt; Female; Male; Mite Infestations; Mites; Rabbits; Prevalence; Sarcoptidae; Cuniculidae
  5. See M, Marsham S, Chang CW, Chong VC, Sasekumar A, Dhillon SK, et al.
    Sains Malaysiana, 2016;45:735-743.
    Sagittal otolith morphometric measurements from Malaysian Mugilidae species were selected to investigate their possible
    role in species identification, due to the Mugilidae species’ morphological similarities, and age determination. Fish
    standard length (cm), otolith length (μm), width (μm) and mass (g) measurements were taken from eight species: Chelon
    macrolepis, C. melinopterus, C. subviridis, Ellochelon vaigiensis, Moolgarda cunnesius, M. seheli, Mugil cephalus and
    Valamugil engeli. Otolith aspect ratio, OAS (otolith length divided by width), was calculated and compared between
    species. The four homogenous groups based on their OAS were C. melinopterus (mean=1.65) and V. engeli (1.66) and M.
    cunnesius (1.89) and E. vaigiensis (1.89); M. seheli (2.08), C. macrolepis (2.14) and M. cephalus (2.17); and the latter
    two with C. subviridis (2.43). The relationships between fish standard length and otolith length/mass showed positive
    correlations for both, with otolith length providing the stronger correlation (rs
    = 0.897, P < 0.001) than otolith mass (rs
    = 0.795, P < 0.001). It is concluded that the more morphologically similar species have similar otolith aspect ratios,
    related to head shape; however, otolith shape is also affected by a variety of other environmental factors that have to
    be taken account of
  6. Mukai Y, Tan NH, Muhammad Khairulanwar Rosli, Liau CF
    Sains Malaysiana, 2016;45:729-733.
    In general, demand feeding devices are equipped with a mechanical trigger switch. Such a switch is not suitable for
    juvenile fish with a small body size, because the body weight is insufficient to trigger the feeder. An infrared light
    sensor that does not require the fish to push a feeder switch is more suitable for small fish. The brown-marbled grouper
    Epinephelus fuscoguttatus is an important fish species in Southeast Asia. The purpose of this study was to compare the
    growth rates (GRs) of brown-marbled grouper juveniles reared using customised demand feeding devices with an infrared
    light sensor (the infrared light demand feeder (IRDF) group) and automatic feeding devices (the automatic feeder (AF)
    group). The results indicated that GRs of standard lengths and body weights showed no significant differences using
    one-way analysis of variance; however, the standard length of the IRDF group showed a tendency of a higher GR than
    the AF group. Although the feed conversion ratio (FCR) also showed no significant difference, the FCR of the IRDF group
    was more efficient, indicating that the IRDF group yielded a more desirable FCR. These results indicate that IRDF can be
    used in the culture of brown-marbled grouper juveniles. In view of the working schedule of the fish farm staff, IRDF are
    superior to other feeding devices, because they are less labour-intensive than usual tasks. We conclude that IRDF is a
    useful feeding system for aquaculture.
    MeSH terms: Analysis of Variance; Animals; Asia, Southeastern; Bass; Body Weight; Fisheries; Aquaculture; Body Size
  7. Seyedi SS, Tan SG, Namasivayam P, Yong CSY
    Sains Malaysiana, 2016;45:717-727.
    The Hibiscus sabdariffa var. UMKL (Roselle) investigated here may potentially be used as an alternative fibre source. To
    the best of our knowledge, there was no study focusing on the genetics underlying the cellulose biosynthesis machinery
    in Roselle thus far. This paper presents the results of the first isolation of the cellulose synthase gene, HsCesA1 from this
    plant, which is fundamental for working towards understanding the functions of CesA genes in the cellulose biosynthesis
    of Roselle. A full-length HsCesA1 cDNA of 3528 bp in length (accession no: KJ608192) encoding a polypeptide of 974
    amino acid was isolated. The full-length HsCesA1 gene of 5489 bp length (accession no: KJ661223) with 11-introns
    and a promoter region of 737 bp was further isolated. Important and conserved characteristics of a CesA protein were
    identified in the HsCesA1 deduced amino acid sequence, which strengthened the prediction that the isolated gene being
    a cellulose synthase belonging to the processive class of the 2-glycosyltransferase family 2A. Relative gene expression
    analysis by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) on young leaf and stem tissues
    found that HsCesA1 had similar levels of gene expression in both tissues. Phylogenetic and Blast analyses also supported
    the prediction that the isolated HsCesA1 may play roles in the cell wall depositions in both leaf and stem tissues.
    MeSH terms: Amino Acid Sequence; Amino Acids; Cell Wall; Cellulose; Glucosyltransferases; Introns; Peptides; Phylogeny; Promoter Regions, Genetic; DNA, Complementary; Plant Stems; Reverse Transcriptase Polymerase Chain Reaction; Hibiscus; Reverse Transcription
  8. Biswash MR, Sharmin M, Rahman NMF, Farhat T, Siddique MA
    Sains Malaysiana, 2016;45:706-716.
    A field experiment was conducted from June to December, 2013 to study the genetic diversity of 15 modern T. Aman rice
    varieties of Bangladesh (Oryza sativa L.) with a view to assess the superior genotype in future hybridization program
    for developing new rice varieties that is suitable for the target environment. Analysis of variance for each trait showed
    significant differences among the varieties. High heritability associated with high genetic advance in percent of mean
    was observed for plant height and thousand seed weight which indicated that selection for these characters would be
    effective. Hence, thrust has to be given for these characters in future breeding program to improve the yield trait in rice.
    Multivariate analysis based on 10 agronomic characters indicated that the 15 varieties were grouped into four distant
    clusters. The inter cluster distance was maximum between cluster II and cluster IV. The highest intra-cluster distance was
    found in cluster IV. Based on positive value of vector 1 and vector 2, plant height and 1000-seed weight had maximum
    contribution towards genetic divergence. From the results, it can be concluded that the varieties BRRI dhan40, BRRI
    dhan44, BRRI dhan46, BRRI dhan49 and BINA dhan7 may be selected for future hybridization program.
    MeSH terms: Amantadine; Bangladesh; Breeding; Genotype; Oryza; Seeds; Genetic Variation; Multivariate Analysis
  9. Thabayneh Khalil M
    Sains Malaysiana, 2016;45:699-707.
    The radon concentration, the exhalation rates and the radiation exposure from samples of soil collected from different
    sites at Hebron province in Palestine were measured using the sealed-can technique based on the CR-39 detectors.
    The total average values of radon concentrations for 0, 20, 40 and 60 cm depths were 294, 357, 433 and 512 Bqm−3,
    respectively. As expected, our data showed an increase of radon concentration levels with depth. The average values of
    surface exhalation rates, the effective dose equivalent (Ep
    ), the annual effective dose (HE), the dissolved in soft tissues
    (Dsoft, tissue) and the dose rate due to alpha-radiation in lung (Dlung) were calculated. The values were found to be within
    the safe limits as recommended by ICRP and WHO. The results showed that these areas are safe from the health hazard
    site of view as far as the radon is concerned.
  10. Zhou H, Wang X, Li Y, Han F, Hu D
    Sains Malaysiana, 2016;45:689-697.
    The soil temperature near four external walls with different orientations was investigated in spring and summer. In both
    seasons, the soil temperature was higher in the positions closest to the buildings, suggesting that the buildings were a
    heat source for the soil surrounding them. Therefore, it could be confirmed that there was lateral heat transfer between
    the soil and the buildings. Based on this, a soil heat flux plate was set between the soil and the buildings to investigate the
    horizontal heat flux. The data showed diurnal variations of the horizontal heat flux in both spring and summer. In order
    to determine the factors that influenced the horizontal heat flux and to provide a basis to understand its mechanism, the
    correlations between the data of several meteorological factors and the horizontal heat flux were analysed. The results
    showed that solar radiation was significantly correlated with the horizontal heat flux (p<0.0001) in any single season and
    in the two seasons that were studied. Additionally, other meteorological factors (net radiation, air temperature, relative
    humidity and soil temperature and moisture) showed strong correlations with the horizontal heat flux on a diurnal scale
    only. On a seasonal time scale, the correlation might be significant (p<0.0001) as well, but the correlation coefficients
    decreased too significantly, such as those for soil temperature, air temperature and relative humidity. Alternatively, the
    correlation might not be significant (p>0.05), such as that for soil moisture. The stepwise regression results indicated
    that the relative importance of these meteorological factors was 48.63, 21.94, 14.44, 8.12 and 6.87% for solar radiation,
    soil temperature, air temperature, relative humidity and soil moisture, respectively, on a diurnal scale.
    MeSH terms: Circadian Rhythm; Hot Temperature; Humidity; Meteorological Concepts; Seasons; Soil; Solar Energy; Temperature
  11. Kashif Sarfraz Abbasi, Tariq Masud, Abdul Qayyum, Sami Ullah Khan, Shabbar Abbas, Jenks M
    Sains Malaysiana, 2016;45:677-688.
    Potatoes are usually stored under low temperatures for sprout prevention and to ensure their continuous supply. Low
    temperature sweetening in potato is the major temperature related disorder being faced by the growers and is also
    known to be associated with variety specific storage temperature. The present study aimed at identifying the appropriate
    storage temperature for the premium potato variety Lady Rosetta with special reference to the changes in its quality
    attributes, that is weight loss, total sugars, starch, ascorbic acids, total phenolic contents, radical scavenging activity,
    enzymatic activities and potato chip color. The selected potato variety was stored under different temperature (5, 15 and
    25o
    C) regimes to identify appropriate storage temperature. Our results showed significant variations in the tested quality
    attributes in response to different storage temperatures. Storage at 5o
    C maintained tuber dormancy up to 126 days,
    however, found associated with increased sugar accumulation (2.32 g/100 g), rapid starch depletion (13.25 g/100 g) and
    poor post processing performance (L-value, 52.00). In contrast, potato storage at 15o
    C retained lower sugar contents
    (1.33 g/100g) and superior chip color (L-value, 59.33) till the end of storage. However, they were found associated with
    the increased polyphenol oxidase (38.47 U/g f.w) and peroxidase (15.25 U/100 g f.w) activities as compare to those
    potatoes stored at 5o
    C during the same storage period. Storage life of potato tubers at 25o
    C was significantly reduced
    due to dormancy break on 84th day and subsequent starch degradation (15.29 g/100 g) increased sugar accumulation
    (1.32 g/100 g) and increased polyphenol oxidase (79.89 U/g f.w) and peroxidase activities (40.69 U/100 g f.w). Our
    results showed that potato variety Lady
    MeSH terms: Ascorbic Acid; Carbohydrates; Cold Temperature; Catechol Oxidase; Peroxidase; Peroxidases; Solanum tuberosum; Starch; Sweetening Agents; Temperature; Weight Loss; Plant Tubers
  12. Simon N, Che Aziz Ali, Kamal Roslan Mohamed, Kamilia Sharir
    Sains Malaysiana, 2016;45:659-667.
    Band ratio combination has been proven to be one of the most useful image processing methods for lithological
    discrimination, as discussed by many researchers in the past. In this study, bands from Landsat 5 TM were used to generate
    different ratio combinations to discriminate the different lithologies of two islands located at the southern end of the
    Langkawi archipelago, specifically the Dayang Bunting and Tuba Islands. Both islands comprise similar lithological
    units – namely, limestone/marble (Permian & Silurian-Ordovician), granite and alluvium. There are two rock formations
    that are limestone/marble dominated. The first is known as the Chuping Formation, which consists of limestone/marble
    and the other is the Setul Formation, which consists of not only limestone/marble but also of two detrital intervals.
    Different ratio combinations obtained from past researchers and that was produced from this study were tested on the
    image of the Dayang Bunting and Tuba Islands to identify the best ratio combinations that were able to discriminate the
    different lithologies for both islands. A total of 28 combinations were performed to examine which combinations are the
    most effective. From the 28 combinations, three were identified as the most suitable; 4/3 5/2 3/1, 5/3 4/3 4/1 and 4/2 5/3
    4/3 in the RGB sequence. These combinations enhanced the spectral differences of each lithology unit so that it can be
    distinguished easily. Apart from the difference in the spectral response, the texture of the lithologies was also enhanced
    to assist in discriminating the different units.
  13. Tan KT, Norhamidi Muhamad, Muchtar A, Abu Bakar Sulong, Neo MC
    Sains Malaysiana, 2016;45:653-658.
    Metallic foams are a new class of materials that have a great potential to be used in various functional and structural applications. Due to their competitive price compared to aluminium, metallic foams are anticipated to become an alternative material for light-weight structures. In this study, stainless steel foams are fabricated using a powder space holder method. The materials used include stainless steel powder, a novel space holder glycine and binders consisting of palm stearin and of polyethylene (PE). The stainless steel foams are sintered at 1100o C, 1200o C and 1300o C with sintering times of 1, 2 and 3 h, respectively, to investigate the effects of the sintering parameters on the compressive yield strength of the stainless steel foams. The results showed that all of the stainless steel foams produced exhibit the general behaviours of metal foams. The sintering time is the most significant parameter that influences the compressive yield strength of stainless steel foams. Increasing the sintering temperature and sintering time will increase the compressive yield strength. The interaction between the sintering temperature and sintering time is found to be not statistically significant.
    MeSH terms: Aluminum; Glycine; Stainless Steel; Temperature; Triglycerides; Compressive Strength; Polyethylene
  14. Halim S, Bagiah H, Chen S, Lim K, Awang Kechi M
    Sains Malaysiana, 2016;45:643-651.
    The effect of rare earth nanoparticles, M=Sm2 O3 , Nd2 O3 and Ho2 O3 added to (Bi1.6Pb0.4Sr2 Ca2 Cu3 O10+δ)1-x(M)x , where x = 0.00 - 0.05, superconductor were studied by X-ray diffraction technique (XRD), resistivity (R), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). The volume fraction of high-Tc phase, Bi-2223, decreased from 84% for pure sample to 48, 30 and 23% at x = 0.05 for Sm2 O3 , Ho2 O3 and Nd2 O3 additions, respectively. The critical temperature Tc(R=0) that is 102 K for the pure sample decreased to 78, 73 and 69 K at x = 0.05 for samples with Sm2 O3 , Nd2 O3 and Ho2 O3 nanoparticles additions, respectively. The additions of rare earth nanoparticles decreased the grain size and increased the random orientation of the grains. The results showed that the phases’ formations, variations of lattice parameters and electrical properties are sensitive to the size of nanoparticles and magnetic properties of its ions.
  15. Jau CL, Wan Aizan Wan Abdul Rahman, Avérous L, Teck HL
    Sains Malaysiana, 2016;45:633-641.
    This paper reports the post-processing ageing phenomena of thermoplastic sago starch (TPS) and plasticised sago pith waste (SPW), which were processed using twin-screw extrusion and compression moulding techniques. Wide angle X-ray diffraction (XRD) analyses showed that after processing, starch molecules rearranged into VH-type (which was formed rapidly right post processing and concluded within 4 days) and B-type (which was formed slowly over a period of months) crystallites. Evidence from Fourier transform infrared spectroscopy (FTIR) analyses corroborated the 2-stage crystallisation process, which observed changes in peak styles and peak intensities (at 1043 and 1026 cm-1) and bandnarrowing. Thermogravimetric analysis (TGA) studies showed that the thermal stability of plasticised SPW declined continuously for 90 days before gradual increments ensued. For all formulations tested, post-processing ageing led to drastic changes in the tensile strength (increased) and elongation at break (decreased). Glycerol and fibres restrained the retrogradation of starch molecules in TPS and SPW.
    MeSH terms: Aging; Bone Screws; Crystallization; Glycerol; Plasticizers; Starch; Tensile Strength; Thermogravimetry; X-Ray Diffraction; Spectroscopy, Fourier Transform Infrared; Laxatives
  16. Goh SL, Lim FP, Ibrahim Mohamed, Noorizam Daud
    Sains Malaysiana, 2016;45:499-506.
    This paper discussed methods for outlier detection in standard 2 × 2 crossover studies. Two outlier detection procedures were carried out based on residuals. Under a simplified model of 2 × 2 crossover design, we present the classical calculation of studentized residual (SR1) and propose a new studentized residual using median absolute deviation (SR2) to identify possible outlying subjects. The performances of both procedures in detecting subject outliers were compared. We show via simulation that a proposed procedure using SR2 is more powerful than that using SR1 for outlier detection. As an illustration, these procedures were applied to two real data sets from studies of bioavailability and kinesiology, respectively.
  17. Syaliza Abdul Hammid, Zaini Assim, Fasihuddin Ahmad
    Sains Malaysiana, 2016;45:627-632.
    Cinnamomum species (Lauraceae) are well known for their fragrance and medicinal value. The essential oils of three Cinnamomum species (C. macrophyllum, C. crassinervium and C. griffithii) collected in Sarawak were obtained by hydrodistillation and analyzed by gas chromatograpy mass spectrometry (GC-MS). The analysis of the oils showed that most of the essential oils were mainly phenylpropanoids and monoterpenes with a small amount of sesquiterpenes present. Both C. griffithii and C. crassinervium contained similar major chemical composition such as β-linalool, methyl cinnamate and eugenol methyl ether. No presence of methyl cinnamate and β-linalool were found in the oil of C. macrophyllum. m-Eugenol was prominent in the leaf oil of C. macrophyllum, while cinnamaldehyde was found mainly in the bark oil of C. macrophyllum. High percentage of camphor was identified in the bark and root oil of C. macrophyllum, compared to small amount of camphor found in the both root oil of C. griffithii and C. crassinervium.
  18. Yusrabbil Amiyati Yusof, Azhar Ariffin
    Sains Malaysiana, 2016;45:621-625.
    Glycerol is a valuable co-product from oleochemical industry such as from fatty acid and biodiesel production. By having three hydroxyl groups in its molecule, glycerol can undergo chemical modifications that lead to many possible applications. This paper reports the tosylation process of glycerol with para-toluenesulfonyl chloride (p-TsCl). Reaction of glycerol with p-TsCl in the presence of a base produced mono-, di- and tri-tosylate of glycerol even though the reaction was carried out at the mole ratio of 1.2:1.0 of glycerol to p-TsCl. The compounds were successfully isolated and characterized. Mono-, di- and tri-tosylate of glycerol exhibited inhibitory activity against Staphylococcus aureus (gram positive bacteria) and Pseudomonas aeruginosa (gram negative bacteria).
    MeSH terms: Fatty Acids; Glycerol; Gram-Negative Bacteria; Gram-Positive Bacteria; Pseudomonas aeruginosa; Staphylococcal Infections; Staphylococcus aureus; Biofuels
  19. Chowdhury M, Vohra M
    Sains Malaysiana, 2016;45:477-487.
    The present study investigated the use of modified titanium dioxide (TiO2) based photocatalytic degradation (PCD) process for the removal of some critical charged aqueous phase pollutants. First of all, the use of Nafion TiO2 (Nf-TiO2) and silica TiO2 (Si-TiO2) for the removal of aqueous phase ammonia (NH4+/NH3) species employing near UV lamp as energy source was studied. The use of Nf-TiO2 enhanced NH4+/NH3 PCD with optimum removal noted for 1 mL of Nafion solution coating per g of TiO2 and respective overall NH4+/NH3 removal was about 1.7 times higher compared to plain TiO2 at 6 h reaction time. Similarly the 0.5 mL silica solution coating per g TiO2 sample, also enhanced NH4+/NH3 removal with optimum efficiency similar to Nf-TiO2. The results from effect of ammonia concentration on to its PCD using Nf-TiO2 indicated that overall mass based NH4+/NH3 removal was higher at greater NH4+/NH3 amounts indicating high efficiency of Nf-TiO2. Similar trends were noted for Si-TiO2 as well. Furthermore, the results from modified TiO2 and mixed NH4+/NH3 and cyanide (CN-) systems indicated successful removal of co-pollutant CN- along with simultaneous degradation of NH4+/NH3 species at rates that were still higher than plain TiO2. Nevertheless application of Nf-TiO2 for the treatment of cationic dye methylene blue (MB) indicated slower MB removal compared to plain TiO2 though significant MB degradation using Nf-TiO2 could still be achieved at pH3. Additionally the results from solar radiation energized PCD process indicated positive role of solar radiation for the removal of NH4+/NH3 species under a varying set of conditions.
    MeSH terms: Ammonia; Cyanides; Fluorocarbon Polymers; Methylene Blue; Reaction Time; Silicon Dioxide; Solar Energy; Titanium
  20. Hamouda RA, Yeheia DS, Hamzah HA, Hussein MH
    Sains Malaysiana, 2016;45:467-476.
    Algae have recently received a lot of attention as a new biomass source for the production of renewable energy and an important bioremediation agent. This study was carried out to evaluate the potential of green algae Scenedesmus obliquus grow in different concentrations of wastewater and the improvement of cultivation conditions to produce biomass rich in sugar to produce bioethanol by fermentation processes. The highest sugar content of S. obliquus biomass was recorded for algae cultivated with 40 and 85% wastewater after 9 days under aeration condition with dark and light duration (44.5%). It was found that the highest removal efficiency of BOD and COD were 18% for S. obliquus grown under aeration condition. The highest ethanol efficiency of S. obliquus biomass hydrolysate was 20.33% at 4th day. The best condition of S. obliquus to grow efficiently was under aeration with light and dark durations, where it has high efficiency to remove heavy metals from wastewater in this condition.
    MeSH terms: Ethanol; Attention; Biodegradation, Environmental; Carbohydrates; Fermentation; Biomass; Metals, Heavy; Scenedesmus; Renewable Energy; Waste Water
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