In this study, the microcrystalline cellulose/metal-organic framework 199 hybrid (MCC/MOF-199) was applied as sorbent for the dispersive micro-solid phase-extraction (D-μSPE) of chlorophenols. The D-μSPE method combined with high-performance liquid chromatography- ultraviolet detection (HPLC-UV) was employed to determine of four chlorophenols including 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,3-dichlorophenol (2,3-DCP), and 2,5-dichlorophenol (2,5-DCP) in aqueous. The main parameters of the D-μSPE process that influence the extraction (i.e. the amount of sorbent, elution condition, extraction time, and pH) were investigated and optimized. Based on the outputs, the presence of MCC on the surface of MOF-199 leads to improve the properties of MOF-199 and the MCC/MOF-199 has the highest sorption capacity, durability, and porosity in comparison with MCC and MOF-199. According to the validation study at the optimized conditions, the linearity for the analytes was achieved in the range from 0.1 to 200 ng mL-1 for 2-CP and 4-CP and 0.15 to 200 ng mL-1 for 2,3-DCP and 2,5-DCP with correlation coefficients between 0.9928 and 0.9965. The limits of detection calculated at S/N=3 were in the range of 0.03-0.05 ng mL-1. Besides, the relative standard deviations (RSDs) for three spiking levels (0.2, 10,100 ng mL-1) do not exceed 6.8% and extraction recoveries are between 81.0% and 88.3%. Finally, the D-μSPE-HPLC-UV method was successfully applied to the analysis of CPs in real water samples (mineral, river and wastewater samples) with good recoveries (95.8 to 99.5%) and satisfactory precisions (RSD < 6.8%).
Source-separating sanitation systems offer the possibility of recycling nutrients present in wastewater as crop fertilisers. Thereby, they can reduce agriculture's impacts on global sources, sinks, and cycles for nitrogen and phosphorous, as well as their associated environmental costs. However, it has been broadly assumed that people would be reluctant to perform the new sanitation behaviours that are necessary for implementing such systems in practice. Yet, few studies have tried to systematically gather evidence in support of this assumption. To address this gap, we surveyed 3763 people at 20 universities in 16 countries using a standardised questionnaire. We identified and systematically assessed cross-cultural and country-level explanatory factors that were strongly associated with people's willingness to consume food grown using human urine as fertiliser. Overall, 68% of the respondents favoured recycling human urine, 59% stated a willingness to eat urine-fertilised food, and only 11% believed that urine posed health risks that could not be mitigated by treatment. Most people did not expect to pay less for urine-fertilised food, but only 15% were willing to pay a price premium. Consumer perceptions were found to differ greatly by country and the strongest predictive factors for acceptance overall were cognitive factors (perceptions of risks and benefits) and social norms. Increasing awareness and building trust among consumers about the effectiveness of new sanitation systems via cognitive and normative messaging can help increase acceptance. Based on our findings, we believe that in many countries, acceptance by food consumers will not be the major social barrier to closing the loop on human urine. That a potential market exists for urine-fertilised food, however, needs to be communicated to other stakeholders in the sanitation service chain.
Heavy metals with high chemical activity from sludge and waste release, agriculture, and
mining activity are a major concern. They should be carefully managed before reaching the
main water bodies. Excessive exposure to heavy metal may cause toxic effect to any types of
organism from the biomolecular to the physiological level, and ultimately cause death. Monitoring is the best technique to ensure the safety of our environment before a rehabilitation is
needed. Nowadays, enzyme-based biosensors are utilised in biomonitoring programmes as
this technique allows for a real-time detection and rapid result. It is also inexpensive and easy
to handle. Enzyme-based biosensors are an alternative for the preliminary screening of
contamination before a secondary screening is performed using high-performance technology.
This review highlights the current knowledge on enzyme-based biosensors, focusing on
cholinesterase for toxic metal detection in the environment.
This manuscript describes the reuse of biowaste for the biosynthesis of silver nanoparticles (AgNPs) and their applications. In particular, we hypothesized that the phytochemicals in the onion peels could act as reductant for silver nanoparticles syntheses. AgNO3 solution (1 mmol) was added dropwise to an aqueous solution of onion peel extract in 3:7 ratio. The reaction mixture was subjected to heating at 90 °C for about 30 min. During the synthesis of the AgNPs, the change of the colour of solution was observed. The AgNPs solution was centrifuged to obtain the two layers, which consists of clear solution and solid layers at 12000 rpm for 30 min. The precipitate was filtered and was re-dispersed in deionised water (25 mL). The solution was centrifuged again to obtain the purified AgNPs. Subsequently, this solution was freeze dried for 48 h to afford the powdered AgNPs. In this work, the structure of the AgNPs were synthesized in spherical shape, with an average size of 12.5 nm observed in the Transmission electron microscopy (TEM) analysis. For catalytic application, the synthesized AgNPs could be applied as green catalyst to promote Knoevenagel and Hantzsch reactions. In most cases, the desired products were obtained in satisfactory yields. In addition, the AgNPs were found to be recyclable for the subsequent reactions. After five successive runs, the average isolated yields for both transformations were recorded to be 91% (Knoevenagel condensation) and 94% (Hantzsch reaction), which indicated that the existing AgNPs could apply as green catalyst in the field of organic synthesis. Furthermore, the AgNPs also showed satisfactory result in antioxidant activity. The current results indicate that the AgNPs can act as alternative antioxidant agent and green catalyst in mediating organic transformations.
Oil and grease remain the dominant contaminants in the palm oil mill effluent (POME) despite the conventional treatment of POME. The removal of residual oil from palm oil-water mixture (POME model) using the progressive freezing process was investigated. An optimization technique called response surface methodology (RSM) with the design of rotatable central composite design was applied to figure out the optimum experimental variables generated by Design-Expert software (version 6.0.4. Stat-Ease, trial version). Besides, RSM also helps to investigate the interactive effects among the independent variables compared to one factor at a time. The variables involved are coolant temperature, XA (4-12 °C), freezing time, XB (20-60 min), and circulation flow, XC (200-600 rpm). The statistical analysis showed that a two-factor interaction model was developed using the obtained experimental data with a coefficient of determination (R2) value of 0.9582. From the RSM-generated model, the optimum conditions for extraction of oil from the POME model were a coolant temperature of 6 °C in 50 min freezing time with a circulation flowrate of 500 rpm. The validation of the model showed that the predicted oil yield and experimental oil yield were 92.56 and 93.20%, respectively.
Biopolymer interaction in oil-in-water (o/w) emulsions has been demonstrated to positively modify the emulsion physicochemical properties which lead to desirable stability. The present work focused on the effect of pea protein isolate (PPI), pectin, carboxymethyl cellulose (CMC) and their interaction on physicochemical properties and oxidative stability of o/w emulsions using a mixture design approach. The emulsions were prepared with 40 % sunflower oil stabilized with 1 % of PPI, pectin and CMC, respectively, as well as their mixtures according to a simplex-centroid design (10 points). ThepH values for all emulsions were within acidic condition (3.22 to 4.66) and increased significantly (p
Of late, dyeing fabrics with natural dyes have become an attraction because of its eco-friendly and less threatening disposition towards humankind. In the textile colouration industry, natural dyes play an important role because of the need for replacement synthetic dyes which have a great deal of tension with the environmental issues. This study focuses on the colour shade, colour coordinates, and fastness properties of dyed silk fabric from tagetes erecta (Mexican Marigold flower) using the water boiling extraction method. The dyeing was carried out using lemon juice as a natural mordant through the simultaneous mordanting method, using two different dyeing methods: infrared (IR) dyeing and exhaustion dyeing. The shades produced for exhaustion dyed fabric is light-yellow compared to the IR dyed fabric, which is medium-light yellow. These shades were confirmed with the CIELAB colour coordinates, L*a*b* values. The colourfastness to washing, perspiration, rubbing, and light of the fabrics were conducted to investigate the performance of the dye and mordant on the dyed silk fabrics. The colourfastness properties of the dyed silk fabric using infrared (IR) dyeing technique have better performance than using exhaustion dyeing technique.
The aim of this study was to propose a groundwater quality index (GWQI) that presents water quality data as a single number and represents the water quality level. The development of the GWQI in agricultural areas is vital as the groundwater considered as an alternative water source for domestic purposes. The insufficiency of the groundwater quality standard in Malaysia revealed the importance of the GWQI development in determining the quality of groundwater. Groundwater samples were collected from thirteen groundwater wells in the Northern Kuala Langat and the Southern Kuala Langat regions from February 2018 to January 2019. Thirty-four parameters that embodied physicochemical characteristics, aggregate indicator, major ions, and trace elements were considered in the development of the GWQI. Multivariate analysis has been used to finalize the important parameters by using principal component analysis (PCA). Notably, seven parameters-electrical conductivity, chemical oxygen demand (COD), magnesium, calcium, potassium, sodium, and chloride were chosen to evaluate the quality of groundwater. The GWQI was then verified by comparing the groundwater quality in Kota Bharu, Kelantan. A sensitivity analysis was performed on this index to verify its reliability. The sensitivity GWQI has been analyzed and showed high sensitivity to any changes of the pollutant parameters. The development of GWQI should be beneficial to the public, practitioners, and industries. From another angle, this index can help to detect any form of pollution which ultimately could be minimized by controlling the sources of pollutants.
The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for the risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium- and low-risk categories under current and predicted climate conditions. The 1730 screenings undertaken encompassed wide geographical areas (regions, political entities, parts thereof, water bodies, river basins, lake drainage basins, and marine regions), which permitted thresholds to be identified for almost all aquatic organismal groups screened as well as for tropical, temperate and continental climate classes, and for tropical and temperate marine ecoregions. In total, 33 species were identified as posing a 'very high risk' of being or becoming invasive, and the scores of several of these species under current climate increased under future climate conditions, primarily due to their wide thermal tolerances. The risk thresholds determined for taxonomic groups and climate zones provide a basis against which area-specific or climate-based calibrated thresholds may be interpreted. In turn, the risk rankings help decision-makers identify which species require an immediate 'rapid' management action (e.g. eradication, control) to avoid or mitigate adverse impacts, which require a full risk assessment, and which are to be restricted or banned with regard to importation and/or sale as ornamental or aquarium/fishery enhancement.
A livelihood is a means of making a living, securing necessities of life such as water, shelter medicine and clothing. For communities dependent on forest resources for livelihoods, sustainability of forests are important. In Kampung Tambirat this study aims to find the income generated from forest resources particularly Nypah palm forests, the measures of conservation, challenges and type of assistance required so that the villagers engagement in the activities will flourish in the future and benefit the younger generations. It is found that there are no conservation measures for Nypah forests and seasonal floods further increases the difficulty for the villagers to sustain their livelihood activities.
Ga₂O₃/ITO/glass photoelectrodes prepared by the CVD method has rarely been tested in the electrochemical cell for water splitting. In this study, we investigate the photoelectrolytic performance of Ga₂O₃/ITO-glass photocatalysts produced by the high-temperature CVD route. The changing of N₂ carrier gas flow rate from 0 to 1800 seem induces change in the materials properties. XRD signal strength of the produced bi-phase Ga₂O₃ is observed to deteriorate, while diffraction line width broadens with increasing N₂ supply. Films show a combination of nanoclumps and nanostrips morphology. Ga/O ratio decreases, while the optical bandgap gradually increases from 4.37 to 4.42 eV with increasing O content and crystallite size. Photoluminescence measurements show UV, blue, green and red emissions, respectively. Linear sweep voltammetry of the electrodes in 0.1 M KOH electrolyte shows improvement in photocurrent density from 160 to 257 μA/cm² versus Ag/AgCl at 1 V bias, and a maximum photon-to-current conversion efficiency 0.06%.
Faecal sterols detection is a promising method for identifying sources of faecal pollution. In this study, faecal contamination in water samples from point source (sewage treatment plants, chicken farms, quail farms and horse stables) was extracted using the solid phase extraction (SPE) technique. Faecal sterols (coprostanol, cholesterol, stigmasterol, beta-sitosterol and stigmastanol) were selected as parameters to differentiate the source of faecal pollution. The results indicated that coprostanol, cholesterol and beta-sitosterol were the most significant parameters that can be used as source tracers for faecal contamination. Chemometric techniques, such as cluster analysis, principal component analysis and discriminant analysis were applied to the data set on faecal contamination in water from various pollution sources in order to validate the faecal sterols' profiles. Cluster analysis generated three clusters: coprostanol was in cluster 1, cholesterol and beta-sitosterol formed cluster 2, while cluster 3 contained stigmasterol and stigmastanol. Discriminant analysis suggested that coprostanol, cholesterol and beta-sitosterol were the most significant parameters to discriminate between the faecal pollution source. The use of chemometric techniques provides useful and promising indicators in tracing the source of faecal contamination.
Matched MeSH terms: Water Pollutants/analysis*; Water Pollutants/classification; Water Pollutants/isolation & purification
The Silver Reed Model LK150 knitting machine is a home knitting machine which is
extremely lightweight and compact, making it preferable by most home knitters.
There are various knitwears with interesting patterns can be made using this model. In
the field of garments manufacturing by using flatbed knitting machines, it is
important to understand the physical properties of fabric so that their impact on
dimensional changes can be predicted to produce the most suitable end use. The
samples were produced by using a blended bamboo/cotton yarn, with a composition
of 30% cotton and 70% bamboo. The main objectives of this study are to to evaluate
the physical properties of single jersey fabric knitted on home knitting machine by
using different stitch dials and to relate the physical properties with different stitch
lengths. Then, all tests were conducted to compare the physical properties of samples
between three different stitch dials and the effects of before and after washing. The
physical properties measured in this research were stitch length, stitch density, weight,
thickness, absorbency and shrinkage. The result indicated that the longer the stitch
length, the higher the percentage of the water impact penetration. Meanwhile, there
was a slight reduction on the density, thickness and fabric weight. In addition, the
result after three times washing showed that the samples only had slight changes in
density, thickness, weight and stitch length, but has significant changes on the water
impact penetration.
The mass mortality of cobia (Rachycentron canadum) within 2-3 days was reported by 3 private farms in Bukit Tambun, Pulau Pinang, in February and March 2007. Only cobia with body weights of 3-4 kg were affected. Most diseased cobia swam on the surface and displayed flashing behaviour. All samples were positive for viral nervous necrosis (VNN) with low to medium levels of infection. Infestations by leeches (Zeylanicobdella arugamensis), body monogeneans (Benedenia sp.) and copepods (Caligus sp.) were also found, but no pathogenic bacteria were isolated. All water quality parameters monitored were within optimal ranges for culturing cobia. The main causes of high mortality in cobia remain unclear during the study. However, we believe that the mass mortality of cobia could be probably due to VNN infection and that the rate of mortality will increase further when cobia are subjected to aquaculture-related stresses (e.g., limited space). Traditional cages with a size of 2 (length) × 2 (width) × 1 m (depth) should only be used for rearing cobia below 1 kg in weight given the species' natural behaviours. In addition, cobia fingerlings should be screened for VNN prior to stocking them in cages.
A total of 37 fish species from 14 families were observed during surveys conducted from January to March 2005 at 8 selected streams near the Gunung Jerai Forest Reserve. The list includes two species (Rasbora trilineata and Systomus partipentazona) that were visually identified at the lower part of the Sungai Teroi stream. Single specimens of Leiocassis micropogon, Clarias macrocephalus and Hampala macrolepidota were also obtained at certain sampling stations. Devario regina and Systomus binotatus were the most abundant species at all sampling stations. However, the list is still incomplete as the study was carried out over a short time period and there are large areas that have not yet been surveyed. The presence of exotic species (Carassius auratus) at Sungai Badak indicates anthropogenic influences. Therefore, a long-term monitoring program for Gunung Jerai Forest Reserve streams should be planned and carried out to assess the impacts of future development on fish biodiversity and water quality.
Rattans (subfamily Calamoideae) are an important component of the forests of the Old World. However, few studies have been conducted on the distribution of these abundant palms within different habitats, specifically in Peninsular Malaysia. This study was aimed at assessing rattan diversity, abundance and biomass change across two different habitat types, namely, dipterocarp forests and fresh-water swamps within the Segari Melintang Forest Reserve, Perak, within two years. All rattan stems within five 100 m × 100 m sized study plots (A-E) of the two habitat types were counted in 2011 and 2013, and Shannon-Wiener diversity indices (H') and Bray-Curtis dissimilarity indices were calculated. A total of 11 species from 5 genera (161 stems ha(-1)) were sampled. Rattan abundance was higher in all swamp plots; however, rattan diversity (H') was highest in the dipterocarp plot (D: H' (2011)1.79; H' (2013)1.84). Bray-Curtis indices of rattan abundance (highest similarity in swamp: plot BC(2011) 0.484, BC(2013) 0.262) and biomass were highest for study plots with the same vegetation types in both years. For rattan biomass, the most similar plot pairs changed during the years: dipterocarp plots A and D were most similar in 2011 (0.509), and swamp plots B and C were most similar in 2013 (0.282). This study helped contribute information regarding the distribution and dynamics of rattans in a primary rainforest of Peninsular Malaysia.
This study analyses the sampling performance of three benthic sampling tools
commonly used to collect freshwater macroinvertebrates. Efficiency of qualitative D-frame
and square aquatic nets were compared to a quantitative Surber sampler in tropical
Malaysian streams. The abundance and diversity of macroinvertebrates collected using
each tool evaluated along with their relative variations (RVs). Each tool was used to
sample macroinvertebrates from three streams draining different areas: a vegetable farm,
a tea plantation and a forest reserve. High macroinvertebrate diversities were recorded using the square net and Surber sampler at the forested stream site; however, very low
species abundance was recorded by the Surber sampler. Relatively large variations in the
Surber sampler collections (RVs of 36% and 28%) were observed for the vegetable farm
and tea plantation streams, respectively. Of the three sampling methods, the square net
was the most efficient, collecting a greater diversity of macroinvertebrate taxa and a
greater number of specimens (i.e., abundance) overall, particularly from the vegetable
farm and the tea plantation streams (RV
Heavy metal accumulation and depuration may alter the effectiveness of Meretrix meretrix as a biomonitoring organism for water quality assessment. Therefore, this study was conducted to evaluate the effects of heavy metal accumulation and depuration on M. meretrix, by immersing it in Copper (Cu), Zinc (Zn), and Lead (Pb)
solutions under laboratory conditions. The results showed that M. meretrix is able to accumulate Cu, Zn, and Pb at the rate of 0.99, 21.80, and 0.57 μg/g per day, respectively, and depurates at the rate of 0.42, 23.55, and 1.01 μg/g per day, respectively. These results indicate that M. meretrix could be effectively used as a biomonitoring organism for Cu because the accumulation rate is significantly (p ≤ 0.05) higher than the depuration rate. However, this was not the case for Zn because the accumulation rate was almost similar to the depuration rate, while for Pb, accumulation or depuration did not occur in M. meretrix.
The distribution and abundance of zooplankton species of Harapan and Aman
Lakes were investigated in relation to physical parameters and chlorophyll-a content. Both
lakes were characterised by the occurrence of algal bloom problem. The composition of
zooplankton was collected at monthly intervals from November 2013 to February 2014.
The total number of taxa in Harapan and Aman Lakes were 23 and 27, respectively.
Rotifera was the highest abundance group represent 64% of the total species recorded
followed by Copepoda (29%) and Cladocera (7%). Three dominant zooplankton that been
recorded in both the lakes are Brachionus forficula, Brachionus nilsoni, and Trichocerca
sp. High abundance of these species indicates that the lakes are eutrophic water bodies.
Overall, zooplankton species distribution and abundance in the study sites are influenced
by various environmental factors such as water transparency and chlorophyll-a content.
Taxonomic study on the composition of epiphytic algae living on submerged leaf and root tissues of macrophyte Eichhornia crassipes (Mart.) Solms-Loubach, found at Laguna de Bay, Philippines was conducted. In total, 21 algal taxa were identified: seven Cyanophyceae, six Euglenophyceae, five Chlorophyceae, two Trebouxiophyceae and one Klebsormidiophyceae. Of these taxa, the occurrence of two rare cyanobacteria, Pseudanabaena minima (G.S. An) Anagnostidis and Synechococcus nidulans (Pringsheim) Komárek are reported for the first time in the Philippines. Two species are also reported here for the first time in the Philippines based on current taxonomic nomenclature and these are Pseudopediastrum boryanum (Turpin) E. Hegewald, Phormidium granulatum (Gardner) Anagnostidis which were based on the former names of Pediastrum boryanum (Turpin) Meneghini and Oscillatoria granulata Gardner, respectively. These taxonomic records are considered important basal information in enriching the knowledge about the diversity and habitat distribution of cyanobacteria and microalgae on macrophytes found in freshwater habitats in the Philippines.