The Experts below are selected from a list of 118989 Experts worldwide ranked by ideXlab platform
Howard C Bailey - One of the best experts on this subject based on the ideXlab platform.
-
chronic toxicity of chloride to Freshwater Species effects of hardness and implications for water quality guidelines
Environmental Toxicology and Chemistry, 2011Co-Authors: James R Elphick, Kelli D Bergh, Howard C BaileyAbstract:Toxicity tests using nine Freshwater Species (Ceriodaphnia dubia, Daphnia magna, Oncorhynchus mykiss, Pimephales promelas, Lumbriculus variegatus, Tubifex tubifex, Chironomus dilutus, Hyallela azteca, and Brachionus calyciflorus) were conducted to evaluate their sensitivity to chloride. Acute-to-chronic ratios (ACRs) from these tests indicate the ACR of 7.59 employed by the United States Environmental Protection Agency (U.S. EPA) in deriving its water quality guideline for chloride may be conservative; a revised ACR of 3.50 is presented here. The endpoints used to calculate the ACR included 24-h to 96-h median lethal concentrations (LC50s) for acute tests, and 48-h to 54-d inhibition concentration (ICx) values for growth or reproduction for chronic exposures. Data from the present chronic toxicity tests, and other investigators, were used to propose a water quality guideline for long-term exposure to chloride using a Species sensitivity distribution (SSD) approach. The 5th percentile from the SSD was calculated as 307 mg/L and proposed as the water quality guideline. Cladocerans were the most sensitive Species in the dataset. Ceriodaphnia dubia was used to evaluate the relationship between water hardness and sensitivity to chloride. A strong relationship was observed and was used to establish a hardness-related equation to modify the proposed water quality guideline on the basis of water hardness, resulting in values ranging from 64 mg/L chloride at 10 mg/L hardness to 388 mg/L chloride at 160 mg/L hardness (as CaCO3). These data suggest that current water quality guidelines for chloride may be overly conservative in water with moderate-to-high hardness, and may not be sufficiently protective under soft-water conditions. Environ. Toxicol. Chem. 2011;30:239–246. © 2010 SETAC
-
chronic toxicity of chloride to Freshwater Species effects of hardness and implications for water quality guidelines
Environmental Toxicology and Chemistry, 2011Co-Authors: James R Elphick, Kelli D Bergh, Howard C BaileyAbstract:Toxicity tests using nine Freshwater Species (Ceriodaphnia dubia, Daphnia magna, Oncorhynchus mykiss, Pimephales promelas, Lumbriculus variegatus, Tubifex tubifex, Chironomus dilutus, Hyallela azteca, and Brachionus calyciflorus) were conducted to evaluate their sensitivity to chloride. Acute-to-chronic ratios (ACRs) from these tests indicate the ACR of 7.59 employed by the United States Environmental Protection Agency (U.S. EPA) in deriving its water quality guideline for chloride may be conservative; a revised ACR of 3.50 is presented here. The endpoints used to calculate the ACR included 24-h to 96-h median lethal concentrations (LC50s) for acute tests, and 48-h to 54-d inhibition concentration (ICx) values for growth or reproduction for chronic exposures. Data from the present chronic toxicity tests, and other investigators, were used to propose a water quality guideline for long-term exposure to chloride using a Species sensitivity distribution (SSD) approach. The 5th percentile from the SSD was calculated as 307 mg/L and proposed as the water quality guideline. Cladocerans were the most sensitive Species in the dataset. Ceriodaphnia dubia was used to evaluate the relationship between water hardness and sensitivity to chloride. A strong relationship was observed and was used to establish a hardness-related equation to modify the proposed water quality guideline on the basis of water hardness, resulting in values ranging from 64 mg/L chloride at 10 mg/L hardness to 388 mg/L chloride at 160 mg/L hardness (as CaCO3). These data suggest that current water quality guidelines for chloride may be overly conservative in water with moderate-to-high hardness, and may not be sufficiently protective under soft-water conditions. Environ. Toxicol. Chem. 2011;30:239–246. © 2010 SETAC
Nicholas A Paul - One of the best experts on this subject based on the ideXlab platform.
-
comparing the potential production and value of high energy liquid fuels and protein from marine and Freshwater macroalgae
Gcb Bioenergy, 2015Co-Authors: Nicolas Neveux, Marie Magnusson, Thomas Maschmeyer, Rocky De Nys, Nicholas A PaulAbstract:The biomass production and biochemical properties of marine and Freshwater Species of green macroalgae (multicellular algae), cultivated in outdoor conditions, were evaluated to assess the potential conversion into high-energy liquid biofuels, specifically biocrude and biodiesel and the value of these products. Biomass productivities were typically two times higher for marine macroalgae (8.5–11.9 g m � 2 d � 1 , dry weight) than for Freshwater macroalgae (3.4–5.1 g m � 2 d � 1 , dry weight). The biochemical compositions of the Species were also distinct, with higher ash content (25.5–36.6%) in marine macroalgae and higher calorific value (15.8– 16.4 MJ kg � 1 ) in Freshwater macroalgae. Lipid content was highest for Freshwater Oedogonium and marine Derbesia. Lipids are a critical organic component for biocrude production by hydrothermal liquefaction (HTL) and the theoretical biocrude yield was therefore highest for Oedogonium (17.7%, dry weight) and Derbesia (16.2%, dry weight). Theoretical biocrude yields were also higher than biodiesel yields for all Species due to the conversion of the whole organic component of biomass, including the predominant carbohydrate fraction. However, all marine Species had higher biomass productivities and therefore had higher projected biocrude productivities than Freshwater Species, up to 7.1 t of biocrude ha � 1 yr � 1 for Derbesia. The projected value of the six macroalgae was increased by 45–77% (up to US$7700 ha � 1 yr � 1 ) through the extraction of protein prior to the conversion of the residual biomass to biocrude. This study highlights the importance of optimizing biomass productivities for high-energy fuels and targeting additional coproducts to increase value.
James R Elphick - One of the best experts on this subject based on the ideXlab platform.
-
chronic toxicity of chloride to Freshwater Species effects of hardness and implications for water quality guidelines
Environmental Toxicology and Chemistry, 2011Co-Authors: James R Elphick, Kelli D Bergh, Howard C BaileyAbstract:Toxicity tests using nine Freshwater Species (Ceriodaphnia dubia, Daphnia magna, Oncorhynchus mykiss, Pimephales promelas, Lumbriculus variegatus, Tubifex tubifex, Chironomus dilutus, Hyallela azteca, and Brachionus calyciflorus) were conducted to evaluate their sensitivity to chloride. Acute-to-chronic ratios (ACRs) from these tests indicate the ACR of 7.59 employed by the United States Environmental Protection Agency (U.S. EPA) in deriving its water quality guideline for chloride may be conservative; a revised ACR of 3.50 is presented here. The endpoints used to calculate the ACR included 24-h to 96-h median lethal concentrations (LC50s) for acute tests, and 48-h to 54-d inhibition concentration (ICx) values for growth or reproduction for chronic exposures. Data from the present chronic toxicity tests, and other investigators, were used to propose a water quality guideline for long-term exposure to chloride using a Species sensitivity distribution (SSD) approach. The 5th percentile from the SSD was calculated as 307 mg/L and proposed as the water quality guideline. Cladocerans were the most sensitive Species in the dataset. Ceriodaphnia dubia was used to evaluate the relationship between water hardness and sensitivity to chloride. A strong relationship was observed and was used to establish a hardness-related equation to modify the proposed water quality guideline on the basis of water hardness, resulting in values ranging from 64 mg/L chloride at 10 mg/L hardness to 388 mg/L chloride at 160 mg/L hardness (as CaCO3). These data suggest that current water quality guidelines for chloride may be overly conservative in water with moderate-to-high hardness, and may not be sufficiently protective under soft-water conditions. Environ. Toxicol. Chem. 2011;30:239–246. © 2010 SETAC
-
chronic toxicity of chloride to Freshwater Species effects of hardness and implications for water quality guidelines
Environmental Toxicology and Chemistry, 2011Co-Authors: James R Elphick, Kelli D Bergh, Howard C BaileyAbstract:Toxicity tests using nine Freshwater Species (Ceriodaphnia dubia, Daphnia magna, Oncorhynchus mykiss, Pimephales promelas, Lumbriculus variegatus, Tubifex tubifex, Chironomus dilutus, Hyallela azteca, and Brachionus calyciflorus) were conducted to evaluate their sensitivity to chloride. Acute-to-chronic ratios (ACRs) from these tests indicate the ACR of 7.59 employed by the United States Environmental Protection Agency (U.S. EPA) in deriving its water quality guideline for chloride may be conservative; a revised ACR of 3.50 is presented here. The endpoints used to calculate the ACR included 24-h to 96-h median lethal concentrations (LC50s) for acute tests, and 48-h to 54-d inhibition concentration (ICx) values for growth or reproduction for chronic exposures. Data from the present chronic toxicity tests, and other investigators, were used to propose a water quality guideline for long-term exposure to chloride using a Species sensitivity distribution (SSD) approach. The 5th percentile from the SSD was calculated as 307 mg/L and proposed as the water quality guideline. Cladocerans were the most sensitive Species in the dataset. Ceriodaphnia dubia was used to evaluate the relationship between water hardness and sensitivity to chloride. A strong relationship was observed and was used to establish a hardness-related equation to modify the proposed water quality guideline on the basis of water hardness, resulting in values ranging from 64 mg/L chloride at 10 mg/L hardness to 388 mg/L chloride at 160 mg/L hardness (as CaCO3). These data suggest that current water quality guidelines for chloride may be overly conservative in water with moderate-to-high hardness, and may not be sufficiently protective under soft-water conditions. Environ. Toxicol. Chem. 2011;30:239–246. © 2010 SETAC
Guoxiang Liu - One of the best experts on this subject based on the ideXlab platform.
-
cladophora rigida sp nov a new Freshwater Species within cladophoraceae ulvophyceae chlorophyta from china
Phycologia, 2021Co-Authors: Zhijuan Zhao, Huan Zhu, Jiaqing Wang, Benwen Liu, Guoxiang LiuAbstract:Cladophora is one of the most Species-rich and taxonomically challenging taxa of green algae. Recently, some samples of Freshwater filamentous algae were collected from Hubei, Yunnan and Guizhou Pr...
-
ulvella tongshanensis ulvellaceae chlorophyta a new Freshwater Species from china and an emended morphological circumscription of the genus ulvella
Fottea, 2015Co-Authors: Huan Zhu, Frederik Leliaert, Zhijuan Zhao, Shuang Xia, Guoxiang LiuAbstract:A new Freshwater Species of Ulvella, Ulvella tongshanensis H. ZHU et G. LIU, is described from material collected from rocks under small waterfalls in Hubei Province, China. This unusual Species differs from other Species in the genus by the macroscopic and upright parenchymatous thalli, and by the particular habitat (most Ulvella Species occur in marine environments). Phylogenetic analyses of plastid encoded rbcL and tufA, and nuclear 18S rDNA sequences, pointed towards the generic placement of Ulvella tongshanensis and also showed a close relationship with two other Freshwater Species, Ulvella bullata (Jao) H. ZHU et G. LIU, comb. nov. and Ulvella prasina (Jao) H. ZHU et G. LIU, comb. nov. The latter two were previously placed in the genus Jaoa and are characterized by disc-shaped to vesicular morphology. Our study once again shows that traditionally used morphological characters are poor indicators for phylogenetic relatedness in morphologically simple algae like the Ulvellaceae. Thus, the morphological circumscription of the genus Ulvella is here expanded to include: (1) thalli that are uniseriate in basal and apical parts, and parenchymatous in the middle portion with distinct differentiation of an unbranched dorsal side and a ventral side developing many short branches, and (2) epibiotic or epilithic, disc-shaped to vesicular thalli with a di- or tristromatic structure.
Andrew J Harford - One of the best experts on this subject based on the ideXlab platform.
-
manganese toxicity to tropical Freshwater Species in low hardness water
Environmental Toxicology and Chemistry, 2015Co-Authors: Andrew J Harford, Thomas J Mooney, Melanie A Trenfield, Rick A Van DamAbstract:Elevated manganese (Mn) is a common contaminant issue for mine water discharges, and previous studies have reported that its toxicity is ameliorated by H+, Ca2+, and Mg2+ ions. In the present study, the toxicity of Mn was assessed in a high risk scenario, that is, the slightly acidic, soft waters of Magela Creek, Kakadu National Park, Northern Territory, Australia. Toxicity estimates were derived for 6 tropical Freshwater Species (Chlorella sp., Lemna aequinoctialis, Amerianna cumingi, Moinodaphnia macleayi, Hydra viridissima, and Mogurnda mogurnda). Low effect chronic inhibition concentration (IC10) and acute lethal concentration (LC05) values ranged between 140 μg L–1 and 80 000 μg L–1, with 3 of the Species tested (M. macleayi, A. cumingi, and H. viridissima) being more sensitive to Mn than all but 1 Species in the international literature (Hyalella azteca). A loss of Mn was observed on the final day for 2 of the H. viridissima toxicity tests, which may be a result of the complex speciation of Mn and biological oxidation. International data from toxicity tests conducted in natural water with a similar physicochemistry to Magela Creek water were combined with the present study's data to increase the sample size to produce a more reliable Species sensitivity distribution. A 99% protection guideline value of 73 μg L–1 (33−466 μg L–1) was derived; the low value of this guideline value reflects the higher toxicity of Mn in slightly acidic soft waters. Environ Toxicol Chem 2015;34:2856–2863. © 2015 Commonwealth of Australia.
-
toxicity of magnesium pulses to tropical Freshwater Species and the development of a duration based water quality guideline
Environmental Toxicology and Chemistry, 2013Co-Authors: Alicia C Hogan, Melanie A Trenfield, Andrew J HarfordAbstract:Six Freshwater Species (Chlorella sp., Lemna aequinoctialis, Amerianna cumingi, Hydra viridissima, Moinodaphnia macleayi, and Mogurnda mogurnda) were exposed to 4-h, 8-h, and 24-h Mg pulses in natural creek water. Magnesium toxicity to all Species increased with exposure duration; however, the extent of increase and the nature of the relationship differed greatly between Species. Based on median inhibitory concentrations (IC50s), and compared with continuous exposure data from a previous study, the increase in toxicity with increasing exposure duration from 4 h to continuous (72–144 h) ranged from approximately 2-fold for Chlorella sp. and H. viridissima to greater than 40-fold for A. cumingi. Moreover, the form of the relationship between Mg toxicity and duration ranged from linear or near-linear to exponential for different Species. The life-stage at which M. macleayi was exposed was important, with cladocerans pulsed at the onset of reproductive maturity being approximately 4 times more sensitive (based on IC50s) than younger than 6-h-old neonates. Species sensitivity distributions were constructed for the 4-h, 8-h, and 24-h pulse durations, from which 99% Species protection guideline values (95% confidence limits [CLs]) of 94 (6.4–1360) mg/L, 14 (0.5–384) mg/L, and 8.0 (0.5–144) mg/L Mg, respectively, were derived. These values were plotted against exposure duration (h) and polynomial interpolation used to derive a guideline value for any pulse duration within the range assessed. Environ Toxicol Chem 2013;32:1969–1980. © 2013 Commonwealth of Australia. Environmental Toxicology & Chemistry © 2013 SETAC
