Removal of Pb(II), Cr(III) and Cr(VI) from Aqueous Solutions Using Alum-Derived Water Treatment Sludge     

Ya-Feng Zhou  Richard John Haynes 《Water, air, and soil pollution》2011,215(1-4):631-643

The sorption of Pb(II), Cr(III) and Cr(VI) from aqueous solution using alum-derived water treatment sludge was investigated using the batch adsorption technique. Samples of sludge from two separate water treatment plants were used (one where alum was used alone and one where it was used in combination with activated C). The sorption characteristics of the two samples were generally very similar. Sorption isotherm data for all three ions fitted equally well to both Freundlich and Langmuir equations. Maximum sorption capacity and indices of sorption intensity both followed the order: Cr(III)?>?Pb(II)?>?Cr(VI). Kinetic data correlated well with a pseudo-second-order kinetic model suggesting the process involved was chemisorption. Sorption was pH-dependant with percentage sorption of Cr(III) and Pb(II) increasing from <30% to 100% between pH?3 and 6 whilst that of Cr(VI) declined greatly between pH?5 and 8. HNO₃ at a concentration of 0.1?M was effective at removing sorbed Cr(III) and Pb(II) from the sludge surfaces and regeneration was successful for eight sorption/removal cycles. It was concluded that water treatment sludge is a suitable material from which to develop a low-cost adsorbent for removal of Cr and Pb from wastewater streams.  相似文献   

Associations Between Dioxins/Furans and Dioxin-Like PCBs in Estuarine Sediment and Blue Crab     

Johan Liebens  Carl J. Mohrherr  Natalie K. Karouna-Renier  Richard A. Snyder  K. Ranga Rao 《Water, air, and soil pollution》2011,222(1-4):403-419

The objective of the present study was to evaluate the relationships between the quantity, toxicity, and compositional profile of dioxin/furan compounds (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in estuarine sediment and in the blue crab (Callinectes sapidus). Sediment and blue crab samples were collected in three small urban estuaries that are in relatively close proximity to each other. Results show that differences between PCDD/F and DL-PCB mass concentrations and total toxic equivalents (TEQ) toxicity in sediments of the three estuaries are reflected in those of the blue crab. TEQs are higher in the hepatopancreas of the crabs than in the sediment, but the concentration factor is inversely proportional to the TEQ in the sediments. Congener profiles in the crabs are systematically different from those in the sediments, and the difference is more pronounced for PCDD/Fs than for DL-PCBs, possibly due to differences in metabolization rates. Compared with sediment profiles, more lesser-chlorinated PCDD/Fs that have higher TEFs accumulate in crab hepatopancreas. This selective bioaccumulation of PCDD/Fs results in a TEQ augmentation in crab hepatopancreas compared with sediments. The bioaccumulation in the blue crab is also selective for PCDD/Fs over DL-PCBs.  相似文献   

Relationship of homestead food production with night blindness among children below 5 years of age in Bangladesh     

Campbell AA  Akhter N  Sun K  de Pee S  Kraemer K  Moench-Pfanner R  Rah JH  Badham J  Bloem MW  Semba RD 《Public health nutrition》2011,14(9):1627-1631

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Sociodemographic, health and lifestyle predictors of poor diets   总被引：1，自引：0，他引：1  

Harrington J  Fitzgerald AP  Layte R  Lutomski J  Molcho M  Perry IJ 《Public health nutrition》2011,14(12):2166-2175

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Allergenicity assessment of the papaya ringspot virus coat protein expressed in transgenic rainbow papaya     

Fermín G  Keith RC  Suzuki JY  Ferreira SA  Gaskill DA  Pitz KY  Manshardt RM  Gonsalves D  Tripathi S 《Journal of agricultural and food chemistry》2011,59(18):10006-10012

The virus-resistant, transgenic commercial papaya Rainbow and SunUp (Carica papaya L.) have been consumed locally in Hawaii and elsewhere in the mainland United States and Canada since their release to planters in Hawaii in 1998. These papaya are derived from transgenic papaya line 55-1 and carry the coat protein (CP) gene of papaya ringspot virus (PRSV). The PRSV CP was evaluated for potential allergenicity, an important component in assessing the safety of food derived from transgenic plants. The transgene PRSV CP sequence of Rainbow papaya did not exhibit greater than 35% amino acid sequence homology to known allergens, nor did it have a stretch of eight amino acids found in known allergens which are known common bioinformatic methods used for assessing similarity to allergen proteins. PRSV CP was also tested for stability in simulated gastric fluid and simulated intestinal fluid and under various heat treatments. The results showed that PRSV CP was degraded under conditions for which allergenic proteins relative to nonallergens are purported to be stable. The potential human intake of transgene-derived PRSV CP was assessed by measuring CP levels in Rainbow and SunUp along with estimating the fruit consumption rates and was compared to potential intake estimates of PRSV CP from naturally infected nontransgenic papaya. Following accepted allergenicity assessment criteria, our results show that the transgene-derived PRSV CP does not pose a risk of food allergy.  相似文献   

Planetary science. Price tags for planet missions force NASA to lower its sights     

Kerr RA 《Science (New York, N.Y.)》2011,331(6022):1254-1255

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Role of electrolyte abnormalities and unmeasured anions in the metabolic acid-base abnormalities in dogs with parvoviral enteritis     

Richard K. Burchell  Arnon Gal  Ryan Friedlein  Andrew L. Leisewitz 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(2):857-866

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A review of phosphorus homeostasis and the impact of different types and amounts of dietary phosphate on metabolism and renal health in cats     

Dottie Laflamme  Robert Backus  Scott Brown  Richard Butterwick  Gail Czarnecki-Maulden  Jonathan Elliott  Andrea Fascetti  David Polzin 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(6):2187-2196

Elevated concentrations of serum phosphate are linked with progression and increased case fatality rate in animals and humans with chronic kidney disease. Elevated concentrations of serum phosphate can be a risk factor for development of renal and cardiovascular diseases or osteoporosis in previously healthy people. In rodents, an excess intake of dietary phosphorus combined with an inverse dietary calcium : phosphorus ratio (<1 : 1) contributes to renal calcification. Renal injury also has occured in cats fed experimental diets supplemented with highly soluble phosphate salts, especially in diets with inverse calcium : phosphorus ratios. However, not all phosphorus sources contribute similarly to this effect. This review, which focuses on cats, summarizes the published evidence regarding phosphorus metabolism and homeostasis, including the relative impact of different dietary phosphorus sources, and their impact on the kidneys. No data currently shows that commercial cat foods induce renal injury. However, some diets contain high amounts of phosphorus relative to recommendations and some have inverse Ca : P ratios and so could increase the risk for development of kidney disease. While limiting the use of highly soluble phosphates appears to be important, there are insufficient data to support a specific upper limit for phosphate intake. This review also proposes areas where additional research is needed in order to strengthen conclusions and recommendations regarding dietary phosphorus for cats.  相似文献   

Effects of surgery on free and total 25 hydroxyvitamin D concentrations in dogs     

Dylan N. Clements  Gemma Bruce  John M. Ryan  Ian G. Handel  Ioannis L. Oikonomidis  Adam G. Gow  Helen Evans  Susan Campbell  Emma Hurst  Richard J. Mellanby 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(6):2617-2621

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Magnetization transfer and diffusion tensor imaging in dogs with intervertebral disk herniation     

Richard L. Shinn  Theresa E. Pancotto  Krystina L. Stadler  Stephen R. Werre  John H. Rossmeisl 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(6):2536-2544

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