Displaying publications 1 - 20 of 204 in total

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  1. Mohammadpour R, Shaharuddin S, Chang CK, Zakaria NA, Ab Ghani A
    Water Sci Technol, 2014 10 18;70(7):1161-7.
    PMID: 25325539 DOI: 10.2166/wst.2014.343
    Free-surface constructed wetlands are known as a low-energy green technique to highly decrease a wide range of pollutants in wastewater and stormwater before discharge into natural water. In this study, two spatial analyses, principal factor analysis and hierarchical cluster analysis (HACA), were employed to interpret the effect of wetland on the water quality variables (WQVs) and to classify the wetland into groups with similar characteristics. Eleven WQVs were collected at the 17 sampling stations twice a month for 13 months. All sampling stations were classified by HACA into three clusters, with high, moderate, and low pollution areas. To improve the water quality, the performance of Cluster-III (micropool) is more significant than Cluster-I and Cluster-II. Implications of this study include potential savings of time and cost for long-term data monitoring purposes in the free-constructed wetland.
    Matched MeSH terms: Water Quality
  2. Al-Baldawi IA, Sheikh Abdullah SR, Anuar N, Suja F, Idris M
    Water Sci Technol, 2013;68(10):2271-8.
    PMID: 24292478 DOI: 10.2166/wst.2013.484
    One of the appropriate development technology options for the treatment of wastewater contaminated with diesel is constructed wetlands (CWs). Throughout 72 days of exposure, sampling was carried out for monitoring of physical parameters, plant growth and the efficiency of total petroleum hydrocarbon (TPH) removal, as an indication for diesel contamination, to assess the pilot-scale performance. Four pilot CWs with a horizontal sub-surface flow system were applied using the bulrush of Scirpus grossus. The CWs were loaded with different diesel concentrations of 0, 0.1, 0.2 and 0.25% (Vdiesel/Vwater). The TPH removal efficiencies were 82, 71, and 67% at the end of 72 days for diesel concentrations of 0.1, 0.2, and 0.25% respectively. In addition, the high removal efficiency of total suspended solids and chemical oxygen demand (COD) were 100 and 75.4% respectively, for a diesel concentration of 0.1%. It was concluded that S. grossus is a potential plant that can be used in a well-operated CW for restoring 0.1% diesel-contaminated water.
    Matched MeSH terms: Water Quality
  3. George DS, Anthony KK, Santhirasegaram V, Saruan NM, Kaur H, Razali Z, et al.
    Water Sci Technol, 2017 May;75(10):2465-2474.
    PMID: 28541954 DOI: 10.2166/wst.2017.080
    The effect of two different water sources (treated waste water and lake water) used for irrigation on the soil geochemical properties and the fruit quality parameters of the Lohan guava were studied. The fruits' physical attributes, physicochemical attributes, nutritional attributes, mineral content as well as consumers' acceptance were evaluated. The properties of the different water sources and their effect, on both the soil and the quality of the fruits, were evaluated. Analysis of the irrigation water revealed that treated waste water was of acceptable quality with reference to irrigation water quality guidelines, while the lake water used for irrigation fell short in several aspects. The different water sources used for irrigation in the farms affected the soil geochemical properties significantly. The quality of guavas harvested from the farms that were irrigated with different water sources was significantly different. Irrigation water qualities were observed to have positive effects on the quality of the fruits and consumers' acceptance as observed from the results of quality analysis and the consumers' acceptance test.
    Matched MeSH terms: Water Quality
  4. Jani J, Toor GS
    Water Res, 2018 06 15;137:344-354.
    PMID: 29571112 DOI: 10.1016/j.watres.2018.02.042
    Nitrogen (N) transport from land to water is a dominant contributor of N in estuarine waters leading to eutrophication, harmful algal blooms, and hypoxia. Our objectives were to (1) investigate the composition of inorganic and organic N forms, (2) distinguish the sources and biogeochemical mechanisms of nitrate-N (NO3-N) transport using stable isotopes of NO3- and Bayesian mixing model, and (3) determine the dissolved organic N (DON) bioavailability using bioassays in a longitudinal gradient from freshwater to estuarine ecosystem located in the Tampa Bay, Florida, United States. We found that DON was the most dominant N form (mean: 64%, range: 46-83%) followed by particulate organic N (PON, mean: 22%, range: 14-37%), whereas inorganic N forms (NOx-N: 7%, NH4-N: 7%) were 14% of total N in freshwater and estuarine waters. Stable isotope data of NO3- revealed that nitrification was the main contributor (36.4%), followed by soil and organic N sources (25.5%), NO3- fertilizers (22.4%), and NH4+ fertilizers (15.7%). Bioassays showed that 14 to 65% of DON concentrations decreased after 5-days of incubation indicating utilization of DON by microbes in freshwater and estuarine waters. These results suggest that despite low proportion of inorganic N forms, the higher concentrations and bioavailability of DON can be a potential source of N for algae and bacteria leading to water quality degradation in the estuarine waters.
    Matched MeSH terms: Water Quality
  5. Jia Y, Zheng F, Maier HR, Ostfeld A, Creaco E, Savic D, et al.
    Water Res, 2021 Sep 01;202:117419.
    PMID: 34274902 DOI: 10.1016/j.watres.2021.117419
    Urban sewer networks (SNs) are increasingly facing water quality issues as a result of many challenges, such as population growth, urbanization and climate change. A promising way to addressing these issues is by developing and using water quality models. Many of these models have been developed in recent years to facilitate the management of SNs. Given the proliferation of different water quality models and the promise they have shown, it is timely to assess the state-of-the-art in this field, to identify potential challenges and suggest future research directions. In this review, model types, modeled quality parameters, modeling purpose, data availability, type of case studies and model performance evaluation are critically analyzed and discussed based on a review of 110 papers published between 2010 and 2019. The review identified that applications of empirical and kinetic models dominate those of data-driven models for addressing water quality issues. The majority of models are developed for prediction and process understanding using experimental or field sampled data. While many models have been applied to real problems, the corresponding prediction accuracies are overall moderate or, in some cases, low, especially when dealing with larger SNs. The review also identified the most common issues associated with water quality modeling of SNs and based on these proposed several future research directions. These include the identification of appropriate data resolutions for the development of different SN models, the need and opportunity to develop hybrid SN models and the improvement of SN model transferability.
    Matched MeSH terms: Water Quality*
  6. Gazzaz NM, Yusoff MK, Juahir H, Ramli MF, Aris AZ
    Water Environ Res, 2013 Aug;85(8):751-66.
    PMID: 24003601
    This study investigated relationships of a water quality index (WQI) with multiple water quality variables (WQVs), explored variability in water quality over time and space, and established linear and non-linear models predictive of WQI from raw WQVs. Data were processed using Spearman's rank correlation analysis, multiple linear regression, and artificial neural network modeling. Correlation analysis indicated that from a temporal perspective, the WQI, temperature, and zinc, arsenic, chemical oxygen demand, sodium, and dissolved oxygen concentrations increased, whereas turbidity and suspended solids, total solids, nitrate nitrogen (NO3-N), and biochemical oxygen demand concentrations decreased with year. From a spatial perspective, an increase with distance of the sampling station from the headwater was exhibited by 10 WQVs: magnesium, calcium, dissolved solids, electrical conductivity, temperature, NO3-N, arsenic, chloride, potassium, and sodium. At the same time, the WQI; Escherichia coli bacteria counts; and suspended solids, total solids, and dissolved oxygen concentrations decreased with distance from the headwater. Lastly, regression and artificial neural network models with high prediction powers (81.2% and 91.4%, respectively) were developed and are discussed.
    Matched MeSH terms: Water Quality*
  7. Jami MS, Rosli NS, Amosa MK
    Water Environ Res, 2016 Jun;88(6):566-76.
    PMID: 26556067 DOI: 10.2175/106143015X14362865227157
    Availability of quality-certified water is pertinent to the production of food and pharmaceutical products. Adverse effects of manganese content of water on the corrosion of vessels and reactors necessitate that process water is scrutinized for allowable concentration levels before being applied in the production processes. In this research, optimization of the adsorption process conditions germane to the removal of manganese from biotreated palm oil mill effluent (BPOME) using zeolite 3A subsequent to a comparative adsorption with clinoptilolite was studied. A face-centered central composite design (FCCCD) of the response surface methodology (RSM) was adopted for the study. Analysis of variance (ANOVA) for response surface quadratic model revealed that the model was significant with dosage and agitation speed connoting the main significant process factors for the optimization. R(2) of 0.9478 yielded by the model was in agreement with predicted R(2). Langmuir and pseudo-second-order suggest the adsorption mechanism involved monolayer adsorption and cation exchanging.
    Matched MeSH terms: Water Quality
  8. Gazzaz NM, Yusoff MK, Ramli MF, Juahir H, Aris AZ
    Water Environ Res, 2015 Feb;87(2):99-112.
    PMID: 25790513
    This paper describes the design of an artificial neural network (ANN) model to predict the water quality index (WQI) using land use areas as predictors. Ten-year records of land use statistics and water quality data for Kinta River (Malaysia) were employed in the modeling process. The most accurate WQI predictions were obtained with the network architecture 7-23-1; the back propagation training algorithm; and a learning rate of 0.02. The WQI forecasts of this model had significant (p < 0.01), positive, very high correlation (ρs = 0.882) with the measured WQI values. Sensitivity analysis revealed that the relative importance of the land use classes to WQI predictions followed the order: mining > rubber > forest > logging > urban areas > agriculture > oil palm. These findings show that the ANNs are highly reliable means of relating water quality to land use, thus integrating land use development with river water quality management.
    Matched MeSH terms: Water Quality/standards*
  9. Rasul MG, Islam MS, Yunus RBM, Mokhtar MB, Alam L, Yahaya FM
    Water Environ Res, 2017 Dec 01;89(12):2088-2102.
    PMID: 28087920 DOI: 10.2175/106143017X14839994522740
      The spatio-temporal variability of water quality associated with anthropogenic activities was studied for the Bertam River and its main tributaries within the Bertam Catchment, Cameron Highlands, Malaysia. A number of physico-chemical parameters of collected samples were analyzed to evaluate their spatio-temporal variability. Nonparametric statistical analysis showed significant temporal and spatial differences (p < 0.05) in most of the parameters across the catchment. Parameters except dissolved oxygen and chemical oxygen demand displayed higher values in rainy season. The higher concentration of total suspended solids was caused by massive soil erosion and sedimentation. Seasonal variations in contaminant concentrations are largely affected by precipitation and anthropogenic influences. Untreated domestic wastewater discharge as well as agricultural runoff significantly influenced the water quality. Poor agricultural practices and development activities at slope areas also affected the water quality within the catchment. The analytical results provided a basis for protection of river environments and ecological restoration in mountainous Bertam Catchment.
    Matched MeSH terms: Water Quality*
  10. Zin T, Mudin KD, Myint T, Naing DKS, Sein T, Shamsul BS
    WHO South East Asia J Public Health, 2013 Jan-Mar;2(1):6-11.
    PMID: 28612817 DOI: 10.4103/2224-3151.115828
    BACKGROUND AND OBJECTIVES: Water and sanitation are major public health issues exacerbated by rapid population growth, limited resources, disasters and environmental depletion. This study was undertaken to study the influencing factors for household water quality improvement for reducing diarrhoea in resource-limited areas.

    MATERIALS AND METHODS: Data were collected from articles and reviews from relevant randomized controlled trials, new articles, systematic reviews and meta-analyses from PubMed, World Health Organization (WHO), United Nations Children's Fund (UNICEF) and WELL Resource Centre For Water, Sanitation And Environmental Health.

    DISCUSSION: Water quality on diarrhoea prevention could be affected by contamination during storage, collection and even at point-of-use. Point-of-use water treatment (household-based) is the most cost-effective method for prevention of diarrhoea. Chemical disinfection, filtration, thermal disinfection, solar disinfection and flocculation and disinfection are five most promising household water treatment methodologies for resource-limited areas.

    CONCLUSION: Promoting household water treatment is most essential for preventing diarrhoeal disease. In addition, the water should be of acceptable taste, appropriate for emergency and non-emergency use.
    Matched MeSH terms: Water Quality
  11. Raveena, K., Arularasu, M., Ganesan, S.S. K., Amelia, T.S.M., Ong, M.C., Bhubalan, K., et al.
    MyJurnal
    Mangrove located near urban area is exposed to various industrial discharge including heavy metals. Mangrove soil is capable of accumulating and storing these heavy metals. Heavy metals are toxic and non-biodegradable, so their accumulations affect water quality, while bioaccumulation and bio-assimilation of heavy metals in mangrove organisms negatively impact the food chain. Bacteria-derived biosurfactants are compounds capable of removing heavy metals from soil and sediment. Furthermore, environmentally friendly properties, such as biodegradability and low toxicity, exhibited by biosurfactants make them a suitable replacement for chemical surfactants for remediation efforts. This study was conducted to investigate the lead- (Pb) and zinc- (Zn) removing capability of rhamnolipid (RL), a type of biosurfactant produced by marine bacterium, Pseudomonas aeruginosa UMTKB-5. Rhamnolipid solutions of three different concentrations (25 mg/L, 50 mg/L and 75 mg/L) were added to mangrove soil and incubated for 7 days. The removal of Pb from soils was up to 18.3% using 25 mg/L RL solution, while 50 mg/L RL solution removed 48.3%, and 75 mg/L RL solution removed 75.9% Pb over time. Meanwhile, zinc removal of 25 mg/L RL solution was up to 24.9%, while 50 mg/L removed 16.5%, and 75 mg/L RL removed 30.5% of Zn. The results showed that RL from P. aeruginosa UMTKB-5 could be a potential biomaterial to be used to remediate heavy metals in sediment.
    Matched MeSH terms: Water Quality
  12. Minhat FI, Yahya K, Talib A, Ahmad O
    Trop Life Sci Res, 2013 Aug;24(1):35-43.
    PMID: 24575240 MyJurnal
    The distribution of benthic Foraminifera throughout the coastal waters of Taman Negara Pulau Pinang (Penang National Park), Malaysia was studied to assess the impact of various anthropogenic activities, such as fishing, ecotourism and floating cage culture. Samples were obtained at 200 m intervals within the subtidal zone, extending up to 1200 m offshore at Teluk Bahang, Teluk Aling, Teluk Ketapang and Pantai Acheh. The depth within coastal waters ranged between 1.5 m and 10.0 m, with predominantly muddy substrate at most stations. Water quality analysis showed little variation in micronutrient (nitrite, NO2; nitrate, NO3; ammonia, NH4 and orthophosphate, PO4) concentrations between sampling stations. Temperature (29.6±0.48°C), salinity (29.4±0.28 ppt), dissolved oxygen content (5.4±0.95 mg/l) and pH (8.5± 0.13) also showed little fluctuation between stations. A total of nine genera of foraminifera were identified in the study (i.e., Ammonia, Elphidium, Ammobaculites, Bigenerina, Quinqueloculina, Reopax, Globigerina, Textularia and Nonion). The distribution of benthic foraminifera was dominated by opportunistic groups that have a high tolerance to anthropogenic stressors. Ammonia had the highest frequency of occurrence (84.7%), followed by Bigenerina (50%), Ammobaculites (44.2%) and Elphidium (38.9%). The Ammonia-Elphidium Index (AEI) was used to describe the hypoxic condition of benthic communities at all sites. Teluk Bahang had the highest AEI value. The foraminiferal assemblages and distribution in Teluk Bahang, Teluk Aling, Teluk Ketapang and Pantai Acheh showed no correlation with physical or chemical environmental parameters.
    Matched MeSH terms: Water Quality
  13. Peck Yen T, Rohasliney H
    Trop Life Sci Res, 2013 Aug;24(1):19-34.
    PMID: 24575239 MyJurnal
    This paper aimed to describe the effects of sand mining on the Kelantan River with respect to physical and chemical parameter analyses. Three replicates of water samples were collected from five stations along the Kelantan River (November 2010 until February 2011). The physical parameters included water temperature, water conductivity, dissolved oxygen (DO), pH, total dissolved solids (TDS), total suspended solids (TSS) and turbidity, whereas the chemical parameters included the concentration of nitrogen nutrients such as ammonia, nitrate and nitrite. The Kelantan River case study revealed that TSS, turbidity and nitrate contents exceed the Malaysian Interim National Water Quality Standard (INWQS) range and are significantly different between Station 1 (KK) and Station 3 (TM). Station 1 has the largest variation of TDS, TSS, turbidity and nitrogen nutrients because of sand mining and upstream logging activities. The extremely high content of TSS and the turbidity have caused poor and stressful conditions for the aquatic life in the Kelantan River.
    Matched MeSH terms: Water Quality
  14. Chu KB, Abdulah A, Abdullah SZ, Bakar RA
    Trop Life Sci Res, 2013 Dec;24(2):77-84.
    PMID: 24575250 MyJurnal
    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.
    Matched MeSH terms: Water Quality
  15. Fatema K, Wan Maznah WO, Isa MM
    Trop Life Sci Res, 2014 Dec;25(2):1-19.
    PMID: 27073596 MyJurnal
    In this study, factor analysis (FA) was applied to extract the hidden factors responsible for water quality variations during both wet and dry seasons. Water samples were collected from six sampling stations (St. 1 Lalang River, St. 2 Semeling River, St. 3 Jagung River, St. 4 Teluk Wang River, St. 5 Gelam River and St. 6 Derhaka River) in the Merbok estuary, Malaysia from January to December 2011; the samples were further analysed in the laboratory. Correlation analysis of the data sets showed strong correlations between the parameters. Nutrients such as nitrate (NO3 (-)), nitrite (NO2 (-)), ammonia (NH3) and phosphate (PO4 (3-)) were determined to be critical indicators of water quality throughout the year. Influential water quality parameters during the wet season were conductivity, salinity, biochemical oxygen demand (BOD), dissolved oxygen (DO) and chlorophyll a (Chla), whereas total suspended solid (TSS) and pH were critical water quality indicators during the dry season. The Kruskal-Wallis H test showed that water quality parameters were significantly different among the sampling months and stations (p<0.05), and Mann-Whitney U tests further revealed that the significantly different parameters were temperature, pH, DO, TSS, NO2 (-) and BOD (p<0.01), whereas salinity, conductivity, NO3 (-), PO4 (3-), NH3 and Chla were not significantly different (p>0.05). Water quality parameters in the estuary varied on both temporal and spatial scales and these results may serve as baseline information for estuary management, specifically for the Merbok estuary.
    Matched MeSH terms: Water Quality
  16. Ishadi NA, Rawi CS, Ahmad AH, Abdul NH
    Trop Life Sci Res, 2014 Dec;25(2):61-79.
    PMID: 27073600 MyJurnal
    The hemipteran (Insecta) diversity in the upper part of the Kerian River Basin was low with only 8 families and 16 genera recorded at 4 study sites from 3 rivers. Water bug composition varied among sampling sites (Kruskal-Wallis χ (2) = 0.00, p<0.05) but was not affected by wet-dry seasons (Z = 0.00, p>0.05). All recorded water parameters were weakly associated with generic abundance but the biochemical oxygen demand (BOD), chemical oxygen demand (COD), Water Quality Index (WQI) and heavy metals (zinc and manganese) showed relatively strong positive or negative relations with hemipteran diversity and richness (H' and R2). Within the ranges of measured water parameters, the WQI was negatively associated with hemipteran diversity and richness, implying the tolerance of the water bugs to the level of pollution encountered in the river basin. Based on its highest abundance and occurrence (ISI), Rhagovelia was the most important genus and along with Rheumatogonus and Paraplea, these genera were common at all study sites. In conclusion, habitat availability and suitability together with some environmental parameters influenced the abundance and composition of hemipterans in this river basin.
    Matched MeSH terms: Water Quality
  17. Shah AS, Hashim ZH, Sah SA
    Trop Life Sci Res, 2009 Dec;20(2):59-70.
    PMID: 24575179 MyJurnal
    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.
    Matched MeSH terms: Water Quality
  18. Omar WM
    Trop Life Sci Res, 2010 Dec;21(2):51-67.
    PMID: 24575199
    Algal communities possess many attributes as biological indicators of spatial and temporal environmental changes. Algal parameters, especially the community structural and functional variables that have been used in biological monitoring programs, are highlighted in this document. Biological indicators like algae have only recently been included in water quality assessments in some areas of Malaysia. The use of algal parameters in identifying various types of water degradation is essential and complementary to other environmental indicators.
    Matched MeSH terms: Water Quality
  19. Wahi Abdul Rashid, Vun, Leong Wan, Mohd Harun Abdullah
    Trop Life Sci Res, 2009;20(1):-.
    MyJurnal
    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.
    Matched MeSH terms: Water Quality
  20. Wan Maznah Wan Omar
    Trop Life Sci Res, 2010;21(2):-.
    MyJurnal
    Algal communities possess many attributes as biological indicators of spatial and temporal environmental changes. Algal parameters, especially the community structural and functional variables that have been used in biological monitoring programs, are highlighted in this document. Biological indicators like algae have only recently been included in water quality assessments in some areas of Malaysia. The use of algal parameters in identifying various types of water degradation is essential and complementary to other environmental indicators.
    Matched MeSH terms: Water Quality
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