Displaying publications 161 - 180 of 205 in total

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  1. Hussein Aliu Sule, Ahmad Ismail, Mohammad Noor Azmai Amal, Syaizwan Zahmir Zulkifli, Mohd Fauzul Aidil Mohd Roseli, Shamarina Shohaimi
    Sains Malaysiana, 2018;47:2589-2600.
    Tropical peat swamp forest (PSF) is one of the most endangered ecosystems in the world. However, the impacts of
    anthropogenic activities in PSF and its conversion area towards fish biodiversity are less understood. This study
    investigates the influences of water physico-chemical parameters on fish occurrences in peat swamp, paddy field and
    oil palm plantation in the North Selangor peat swamp forest (NSPSF), Selangor, Malaysia. Fish and water samples were
    collected from four sites located in the peat swamps, while two sites were located in the paddy field and oil palm plantation
    areas. Multivariate analyses were used to determine the associations between water qualities and fish occurrences in
    the three habitats. A total of 1,382 individual fish, belonging to 10 families, 15 genera and 20 species were collected.
    The family Cyprinidae had the highest representatives, followed by Bagridae and Osphronemidae. The most abundant
    species was Barbonymus schwanefeldii (Bleeker 1854), while the least abundant was Wallago leerii Bleeker, 1851. The
    paddy field and oil palm plantation area recorded significantly higher fish diversity and richness relative to peat swamp
    (p<0.05). The water physico-chemical parameters, such as pH, DO, NH3
    -N, PO4, SO4
    , and Cl2 showed no significant
    difference between paddy field and oil palm plantation (p>0.05), but was significantly different from the peat swamp
    (p<0.05). However, no water quality parameter was consistently observed to be associated with fish occurrences in all
    of the three habitats, but water temperature, NH3
    -N, Cl2, SO4
    , and EC were at least associated with fish occurrences in
    two habitats studied. This study confirmed that each habitat possess different water quality parameters associated with
    fish occurrences. Understanding all these ecological aspects could help future management and conservation of NSPSF.
    Matched MeSH terms: Water Quality
  2. 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
  3. Zin, Thant, SabaiAung, Tin, Sahipudin Saupin, Myint, Than, KhinSN, Daw, Aung, Meiji Soe, et al.
    MyJurnal
    The lower percentage of water, sanitation and hygiene are the root causes of diarrhoea and cholera. Cholera is a sudden onset of acute watery diarrhoea which can progress to severe dehydration and death if untreated. The current pandemic, Vibrio Cholera O1 started in 1961. This study explores water, sanitation, hygiene and cholera and diarrhoea in three affected villages of Beluran District, Sabah Malaysia to support effective and timely public health intervention. This cross sectional study uses purposive sampling. All (114) households were interviewed and household water samples collected. The study reported lower coverage improved sanitation facilities (35.3% to 52.3%), no latrine at home (37% to 63%), improved water supply (52% to 60%), and prevalence of hand washing after toilet (57% - 74%). For water quality, Ecoli was present in household water (32% to 37%) but Vibrio cholerae was not isolated in any of the water samples tested. Statistically significant associations were found for; 1) occupation−nonagriculture and unimproved sanitation facility and 2) house ownership and correct knowledge of ORS preparation. Predictors for household water quality were: latrine at home, and improved household toilet. Aggressive strategies to improve water supply, sanitation and hygiene−hand washing after toilet−were recommended for future prevention of cholera and diarrhoea in the affected area.
    Matched MeSH terms: Water Quality
  4. Shamsudin L, Shazili NA
    Environ Monit Assess, 1991 Oct;19(1-3):287-94.
    PMID: 24233946 DOI: 10.1007/BF00401318
    Increased primary plankton productivity was observed in a brackish water lagoon of Terengganu during the study period between January 1988 to December 1988. The lagoon is also the site for the fish cage culture activities of sea bass during the study period. An examination of water quality at the sampling stations during the study period indicated that both the organic and inorganic nutrients were high during the pre-monsoon period. The source of the nutrient in the lagoon was believed to be derived from the agro-based industrial effluents, fertilisers from paddy fields as well as untreated human and animal wastes. This coincided with the peak production of plankton in the surface waters of the brackish water lagoon. During this period both cultured and indigenous fish species were seen to suffer from oxygen asphyxiation (suffocation due to lack of oxygen). The primary productivity values ranged from 9 to 22 μg/L/h during the peak period while the microplankton species were composed of diatom, flagellates and dinoflagellates. Reduction in the primary productivity values were obtained with reduction in sallinity, specially during the peak monsoon months (November to March) corresponding to the Northeast monsoon period.
    Matched MeSH terms: Water Quality
  5. Rahman S, Khan MT, Akib S, Din NB, Biswas SK, Shirazi SM
    ScientificWorldJournal, 2014;2014:721357.
    PMID: 24701186 DOI: 10.1155/2014/721357
    Water is considered an everlasting free source that can be acquired naturally. Demand for processed supply water is growing higher due to an increasing population. Sustainable use of water could maintain a balance between its demand and supply. Rainwater harvesting (RWH) is the most traditional and sustainable method, which could be easily used for potable and nonpotable purposes both in residential and commercial buildings. This could reduce the pressure on processed supply water which enhances the green living. This paper ensures the sustainability of this system through assessing several water-quality parameters of collected rainwater with respect to allowable limits. A number of parameters were included in the analysis: pH, fecal coliform, total coliform, total dissolved solids, turbidity, NH3-N, lead, BOD5, and so forth. The study reveals that the overall quality of water is quite satisfactory as per Bangladesh standards. RWH system offers sufficient amount of water and energy savings through lower consumption. Moreover, considering the cost for installation and maintenance expenses, the system is effective and economical.
    Matched MeSH terms: Water Quality*
  6. Shufang Fan
    Sains Malaysiana, 2017;46:2179-2186.
    In this paper, with debris flow in Zhouqu as the research object, combined with experiments such as cation exchange capacity (CEC), mineral chemical composition and water quality analysis, relation between water and salt in solid source forming debris flow was studied via soil column leaching test and soluble salt analysis, and internal characteristics of debris flow was accordingly showed. It was found that, the soil was loose, and the content of gravel and sand was high, and the content of fine particle was low. The soluble contents at the slope of the accumulation body were described as, collapsed accumulation body > landslide accumulation body, slope toe > slope top, gentle slope > steep slope, also related to length of the slope. The results indicated that accumulations released a large number of base ion after intense weathering, which migrated with water, concentrated and enriched at the slope toe. Saline soil with high salt content collapsed when encountering water and then formed mudflow, thus becoming the internal power to trigger and initiate debris flow to some extent.
    Matched MeSH terms: Water Quality
  7. Ahmad A, Abd. Aziz Z, Shuhaimi-Othman M
    Sains Malaysiana, 2014;43:1657-1663.
    A study on the chironomids (Diptera:Chironomidae) diversity at pristine ecosystem was carried out at upstream of Sungai Langat, Selangor. The study determines chironomids distribution and composition at 7 streams and river within the upstream site of Langat Catchment. Chironomid was sampled using Surber net and water quality was measured based on Malaysia WQI. The result indicated that Chironomidae was represented by three subfamilies namely Chironominae, Orthocladiinae and Tanypodinae, which comprises of 2502 individuals. Chironominae was the most dominant subfamily (1619 individuals) followed by Orthocladinae (629 individuals) and Tanypodinae (254 individuals). Polypedilum (subfamily: Chironominae) is the most dominant genus found followed by Rheocricotopus (subfamily: Orthocladiinae), Microtendipes and Cryptochironomus. Polypedilum was abundant in all stations except Sg. Langat 3 which was dominated by Rheocricotopus. Sungai Langat 3 has the highest number of individual (1113) which is (44.5%) from total chironomid individual and followed by Sg. Lolo with 468 individuals that were dominated by Polypedilum.
    Matched MeSH terms: Water Quality
  8. Brindha K, Paul R, Walter J, Tan ML, Singh MK
    Environ Geochem Health, 2020 Nov;42(11):3819-3839.
    PMID: 32601907 DOI: 10.1007/s10653-020-00637-9
    Monitoring the groundwater chemical composition and identifying the presence of pollutants is an integral part of any comprehensive groundwater management strategy. The present study was conducted in a part of West Tripura, northeast India, to investigate the presence and sources of trace metals in groundwater and the risk to human health due to direct ingestion of groundwater. Samples were collected from 68 locations twice a year from 2016 to 2018. Mixed Ca-Mg-HCO3, Ca-Cl and Ca-Mg-Cl were the main groundwater types. Hydrogeochemical methods showed groundwater mineralization due to (1) carbonate dissolution, (2) silicate weathering, (3) cation exchange processes and (4) anthropogenic sources. Occurrence of faecal coliforms increased in groundwater after monsoons. Nitrate and microbial contamination from wastewater infiltration were apparent. Iron, manganese, lead, cadmium and arsenic were above the drinking water limits prescribed by the Bureau of Indian Standards. Water quality index indicated 1.5% had poor, 8.7% had marginal, 16.2% had fair, 66.2% had good and 7.4% had excellent water quality. Correlation and principal component analysis reiterated the sources of major ions and trace metals identified from hydrogeochemical methods. Human exposure assessment suggests health risk due to high iron in groundwater. The presence of unsafe levels of trace metals in groundwater requires proper treatment measures before domestic use.
    Matched MeSH terms: Water Quality*
  9. Pak HY, Chuah CJ, Yong EL, Snyder SA
    Sci Total Environ, 2021 Aug 01;780:146661.
    PMID: 34030308 DOI: 10.1016/j.scitotenv.2021.146661
    Land use plays a significant role in determining the spatial patterns of water quality in the Johor River Basin (JRB), Malaysia. In the recent years, there have been several occurrences of pollution in these rivers, which has generated concerns over the long-term sustainability of the water resources in the JRB. Specifically, this water resource is a shared commodity between two states, namely, Johor state of Malaysia and Singapore, a neighbouring country adjacent to Malaysia. Prior to this study, few research on the influence of land use configuration on water quality have been conducted in Johor. In addition, it is also unclear how water quality varies under different seasonality in the presence of point sources. In this study, we investigated the influence of land use and point sources from wastewater treatment plants (WWTPs) on the water quality in the JRB. Two statistical techniques - Multivariate Linear Regression (MLR) and Redundancy Analysis (RA) were undertaken to analyse the relationships between river water quality and land use configuration, as well as point sources from WWTPs under different seasonality. Water samples were collected from 49 sites within the JRB from March to December in 2019. Results showed that influence from WWTPs on water quality was greater during the dry season and less significant during the wet season. In particular, point source was highly positively correlated with ammoniacal‑nitrogen (NH3-N). On the other hand, land use influence was greater than point source influence during the wet season. Residential and urban land use were important predictors for nutrients and organic matter (chemical oxygen demand); and forest land use were important sinks for heavy metals but a significant source of manganese.
    Matched MeSH terms: Water Quality
  10. 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
  11. Khoo KS, Lim AL, Sukiman Sarmani
    Sains Malaysiana, 2007;36:45-52.
    Characterisation of the leaching behaviour of coal fly ash from Tenaga Nasional Berhad (TNB) by using tank leaching test method has been reported. The leachability of the constituents such as major elements and toxic metals in the coal fly ash was studied. Eight renewed leachant solutions after 6 hours, 1, 2, 5, 8, 21, 36 and 64 days were investigated after filtration. The parameters namely pH, cumulative release regarding the major elements and toxic metals to duration were presented. The results showed that the pH solutions increased from pH 4 to neutral and remained stable during the test. It might have resulted from the large buffering capacity of the coal fly ashes. Five major elements namely Al, Ca, K, Mg and Na were detected with Ca concentration in the leachant solutions was the highest for all samples. Toxic metals such as As, Ba, Co, Cr, Mn, Ni, Pb, Se and Zn were found and the test showed consistent results on the As, Ba, Mn, Se and Zn in leachant solutions. The findings also showed that some of the toxic metal concentrations namely As, Ba, Cr, Pb and Se exceeded the maximum allowance of the guideline of drinking water quality in Malaysia and WHO. Obviously, proper waste management has to be applied in this scenario.
    Matched MeSH terms: Water Quality
  12. Cao X, Yu ZX, Xie M, Pan K, Tan QG
    Environ Sci Technol, 2023 Jan 17;57(2):1060-1070.
    PMID: 36595456 DOI: 10.1021/acs.est.2c06447
    In coastal waters, particulate metals constitute a substantial fraction of the total metals; however, the prevalent water quality criteria are primarily based on dissolved metals, seemingly neglecting the contribution of particulate metals. Here we developed a method to quantify the toxicity risk of particulate metals, and proposed a way to calculate modifying factors (MFs) for setting site-specific criteria in turbid waters. Specifically, we used a side-by-side experimental design to study copper (Cu) bioaccumulation and toxicity in an estuarine clam, Potamocorbula laevis, under the exposure to "dissolved only" and "dissolved + particulate" 65Cu. A toxicokinetic-toxicodynamic model (TK-TD) was used to quantify the processes of Cu uptake, ingestion, assimilation, egestion, and elimination, and to relate mortality risk to tissue Cu. We find that particulate Cu contributes 40-67% of the Cu bioaccumulation when the suspended particulate matter (SPM) ranges from 12 to 229 mg L-1. The Cu-bearing SPM also increases the sensitivity of organisms to internalized Cu by decreasing the internal threshold concentration (CIT) from 141 to 76.8 μg g-1. MFs were derived based on the TK-TD model to consider the contribution of particulate Cu (in the studied SPM range) for increasing Cu bioaccumulation (MF = 1.3-2.2) and toxicity (MF = 2.3-3.9). Water quality criteria derived from dissolved metal exposure need to be lowered by dividing by an MF to provide adequate protection. Overall, the method we developed provides a scientifically sound framework to manage the risks of metals in turbid waters.
    Matched MeSH terms: Water Quality
  13. Lim, Leong Seng, Isabella Ebi, Liew, Kit Shing, Yap, Tzuen Kiat, Tan, Nai Han
    MyJurnal
    Tieshangang Bay in the Beibu Gulf, Guangxi of China, is a strategic location for pearl farming. Although water pollution has been reported in this bay but the general health of the pearl oyster, Pinctada fucata martensii, farmed there has never been assessed. The present study examined the condition of P. fucata martensii farmed in the Tieshangang Bay by analyzing its length-weight relationship (LWR) and relative condition factor (RCF). A total of 111 specimens were sampled for measuring their shell height and total weight for determining the LWR and RCF. The coefficient of correlation of the LWR was high (R2 = 0.93), significant at 0.01 level. Negative allometric growth (b = 2.7048) was observed. However, P. fucata martensii achieved the expected growth in terms of weight, as determined through the RCF (mean 1.13). Negative allometric growth is commonly reported on the wild Pinctada spp. collected from different regions. Apparently, the water pollution in the Tieshangang Bay did not compromise the general health of the pearl oyster cultured there. Nevertheless, further study on the farm’s surrounding water quality and plankton availability is necessary to investigate the interaction between the growth of the oyster and its culture environment. In conclusion, the P. fucata martensii farmed in the Tieshangang Bay was considered healthy and the bay is still suitable for pearl oyster farming.
    Matched MeSH terms: Water Quality
  14. Bar AR, Mondal I, Das S, Biswas B, Samanta S, Jose F, et al.
    Environ Monit Assess, 2023 Jul 20;195(8):975.
    PMID: 37474709 DOI: 10.1007/s10661-023-11552-8
    The study explores the spatio-temporal variation of water quality parameters in the Hooghly estuary, which is considered an ecologically-stressed shallow estuary and a major distributary for the Ganges River. The estimated parameters are chlorophyll-a, total suspended matter (TSM), and chromophoric dissolved organic matter (CDOM). The Sentinel-3 OLCI remote sensing imageries were analyzed for the duration of October 2018 to February 2019. We observed that the water quality of the Hooghly estuaries is comparatively low-oxygenated, mesotrophic, and phosphate-limited. Ongoing channel dredging for maintaining shipping channel depth keeps the TSM in the estuary at an elevated level, with the highest amount of TSM observed during March of 2019 (41.59g m-3) at station A, upstream point. Since the pre-monsoon season, TSM data shows a decreasing trend towards the mouth of the estuary. Chl-a concentration is higher during pre-monsoon than monsoon and post-monsoon periods, with the highest value observed in April at 1.09 mg m-3 in station D during the pre-monsoon period. The CDOM concentration was high in the middle section (January-February) and gradually decreased towards the estuary's head and mouth. The highest CDOM was found in February at locations C and D during the pre-monsoon period. Every station shows a significant correlation among CDOM, TSM, and Chl-a measured parameters. Based on our satellite data analysis, it is recommended that SNAP C2RCC be regionally used for TSM, Chl-a, and CDOM for water quality product retrieval and in various algorithms for the Hooghly estuary monitoring.
    Matched MeSH terms: Water Quality*
  15. Behera MR, Chun C, Palani S, Tkalich P
    Mar Pollut Bull, 2013 Dec 15;77(1-2):380-95.
    PMID: 24139643 DOI: 10.1016/j.marpolbul.2013.09.043
    The study presents a baseline variability and climatology study of measured hydrodynamic, water properties and some water quality parameters of West Johor Strait, Singapore at hourly-to-seasonal scales to uncover their dependency and correlation to one or more drivers. The considered parameters include, but not limited by sea surface elevation, current magnitude and direction, solar radiation and air temperature, water temperature, salinity, chlorophyll-a and turbidity. FFT (Fast Fourier Transform) analysis is carried out for the parameters to delineate relative effect of tidal and weather drivers. The group and individual correlations between the parameters are obtained by principal component analysis (PCA) and cross-correlation (CC) technique, respectively. The CC technique also identifies the dependency and time lag between driving natural forces and dependent water property and water quality parameters. The temporal variability and climatology of the driving forces and the dependent parameters are established at the hourly, daily, fortnightly and seasonal scales.
    Matched MeSH terms: Water Quality/standards*
  16. Farahin AW, Natrah I, Nagao N, Yusoff FM, Shariff M, Banerjee S, et al.
    Front Bioeng Biotechnol, 2021;9:568776.
    PMID: 33585428 DOI: 10.3389/fbioe.2021.568776
    Microalgae can use either ammonium or nitrate for its growth and vitality. However, at a certain level of concentration, ammonium nitrogen exhibits toxicity which consequently can inhibit microalgae productivity. Therefore, this study is aimed to investigate the tolerance of Tetraselmis tetrathele to high ammonium nitrogen concentrations and its effects on growth rate, photosynthetic efficiency (F
    v
    /F
    m
    ), pigment contents (chlorophyll a, lutein, neoxanthin, and β-carotene), and fatty acids production. Experiments were performed at different ammonium nitrogen concentrations (0.31-0.87 gL-1) for 6 days under a light source with an intensity of 300 μmol photons m-2 s-1 and nitrate-nitrogen source as the experimental control. The findings indicated no apparent enhancement of photosynthetic efficiency (Fv/Fm) at high levels of ammonium nitrogen (


    NH


    4


    +


    -N) for T. tetrathele within 24 h. However, after 24 h, the photosynthetic efficiency of T. tetrathele increased significantly (p < 0.05) in high concentration of


    NH


    4


    +


    -N. Chlorophyll a content in T. tetrathele grown in all of the different


    NH


    4


    +


    -N levels increased significantly compared to nitrate-nitrogen (NO3-N) treatment (p < 0.05); which supported that this microalgal could grow even in high level of


    NH


    4


    +


    -N concentrations. The findings also indicated that T. tetrathele is highly resistant to high ammonium nitrogen which suggests T. tetrathele to be used in the aquaculture industry for bioremediation purpose to remove ammonium nitrogen, thus reducing the production cost while improving the water quality.
    Matched MeSH terms: Water Quality
  17. 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
  18. Jani J, Lusk MG, Yang YY, Toor GS
    PLoS One, 2020;15(4):e0230908.
    PMID: 32236119 DOI: 10.1371/journal.pone.0230908
    Stormwater runoff is recognized as a cause of water quality degradation because it may carry nitrogen (N) and other pollutants to aquatic ecosystems. Stormwater ponds are a stormwater control measure often used to manage stormwater runoff by holding a permanent pool of water, which reduces the peak flow, magnitude of runoff volume, and concentrations of nutrients and pollutants. We instrumented the outlet of a stormwater pond in an urban residential neighbourhood in Florida, United States to (1) investigate the concentration and composition of N forms during the summer rainy season (May to September 2016), and (2) determine the bioavailability of organic N in the stormwater pond with a bioassay experiment. A total of 144 outflow water samples over 13 storm events were collected at the outlet of the stormwater pond that collects runoff from the residential catchment. Samples were analysed for various inorganic N [ammonium (NH4-N), nitrate (NO3-N)], and organic N forms [dissolved organic nitrogen (DON), and particulate organic nitrogen (PON)]. Flow-weighted mean concentration of total N (TN) in pond outflow for all collected storm events was 1.3±1.42 mg L-1, with DON as the dominant form (78%), followed by PON and NO3-N (each at 8%), and NH4-N (6%). In the bioassay experiment, organic N (DON+PON) was significantly decreased by 25-28% after 5 days of incubation, suggesting that a portion of the DON carried from the pond outflow to receiving water bodies may be bioavailable. These results suggest that efforts to mitigate stormwater N outflows from urban ponds should incorporate both inorganic and organic N in management plans.
    Matched MeSH terms: Water Quality
  19. Shuhaimi-Othman M, Nadzifah Y, Nur-Amalina R, Umirah NS
    ScientificWorldJournal, 2012;2012:861576.
    PMID: 22919358 DOI: 10.1100/2012/861576
    Freshwater quality criteria for iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn) were developed with particular reference to aquatic biota in Malaysia, and based on USEPA's guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia which were Macrobrachium lanchesteri (prawn), two fish: Poecilia reticulata and Rasbora sumatrana, Melanoides tuberculata (snail), Stenocypris major (ostracod), Chironomus javanus (midge larvae), Nais elinguis (annelid), and Duttaphrynus melanostictus (tadpole) to determine 96 h LC(50) values for Fe, Pb, Ni, and Zn. The final acute value (FAV) for Fe, Pb, Ni, and Zn were 74.5, 17.0, 165, and 304.9 μg L(-1), respectively. Using an estimated acute-to-chronic ratio (ACR) of 8.3, the value for final chronic value (FCV) was derived. Based on FAV and FCV, a criterion maximum concentration (CMC) and a criterion continuous concentration (CCC) for Fe, Pb, Ni, and Zn that are 37.2, 8.5, 82.5, and 152.4 μg L(-1) and 9.0, 2.0, 19.9, and 36.7 μg L(-1), respectively, were derived. The results of this study provide useful data for deriving national or local water quality criteria for Fe, Pb, Ni, and Zn based on aquatic biota in Malaysia. Based on LC(50) values, this study indicated that N. elinguis, M. lanchesteri, N. elinguis, and R. sumatrana were the most sensitive to Fe, Pb, Ni, and Zn, respectively.
    Matched MeSH terms: Water Quality*
  20. Mohamed Ramli N, Giatsis C, Md Yusoff F, Verreth J, Verdegem M
    PLoS One, 2018;13(4):e0195862.
    PMID: 29659617 DOI: 10.1371/journal.pone.0195862
    The experimental set-up of this study mimicked recirculating aquaculture systems (RAS) where water quality parameters such as dissolved oxygen, pH, temperature, and turbidity were controlled and wastes produced by fish and feeding were converted to inorganic forms. A key process in the RAS was the conversion of ammonia to nitrite and nitrite to nitrate through nitrification. It was hypothesized that algae inclusion in RAS would improve the ammonia removal from the water; thereby improving RAS water quality and stability. To test this hypothesis, the stability of the microbiota community composition in a freshwater RAS with (RAS+A) or without algae (RAS-A) was challenged by introducing an acute pH drop (from pH 7 to 4 during three hours) to the system. Stigeoclonium nanum, a periphytic freshwater microalga was used in this study. No significant effect of the algae presence was found on the resistance to the acute pH drop on ammonia conversion to nitrite and nitrite conversion to nitrate. Also the resilience of the ammonia conversion to the pH drop disruption was not affected by the addition of algae. This could be due to the low biomass of algae achieved in the RAS. However, with regard to the conversion step of nitrite to nitrate, RAS+A was significantly more resilient than RAS-A. In terms of overall bacterial communities, the composition and predictive function of the bacterial communities was significantly different between RAS+A and RAS-A.
    Matched MeSH terms: Water Quality
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