ABSTRACT
As persistent and ubiquitous contaminants in water, iodinated X-ray contrast media (ICM) pose a non-negligible risk to the environment and human health. In this study, we investigated the adsorption behavior of two typical ICM compounds, iohexol (IOH) and amidotrizoic acid (DTZ), on magnetic activated carbon. Theoretical investigations, using density functional theory, identified the molecule structures and calculated the molecular diameters of IOH (1.68 nm) and DTZ (1.16 nm), which revealed that ICM could be adsorbed by mesopores and larger micropores. Therefore, magnetic activated carbon with a porous structure was prepared by the co-precipitation method to investigate the adsorption mechanism of IOH and DTZ. MAC--5 (magnetic activated carbon with a theoretical iron oxide content of 37%) showed the best adsorption ability for both IOH and DTZ, with maximum adsorption capacities of 86.05 and 43.00 mg g-1, respectively. Adsorption kinetics and isotherm models were applied to explore the mechanisms involved, and the effects of solution pH, initial concentration, temperature, ionic strength, and natural organic matter were also investigated. The pore filling effect, π-π stacking, hydrogen bonding, and electrostatic interaction, were found to be the main adsorption mechanisms. The co-adsorption data showed that competition may occur in ICM coexisting environments. Interestingly, the used MAC--5 could be successfully regenerated and its adsorption efficiency did not decrease significantly after five cycles, indicating that it is a promising adsorbent for ICM. The results from this study provide some new insights for the treatment of water containing ICM.
Subject(s)
Iohexol , Water Pollutants, Chemical , Adsorption , Charcoal/chemistry , Contrast Media/chemistry , Diatrizoate Meglumine , Humans , Hydrogen-Ion Concentration , Iohexol/chemistry , Kinetics , Water , Water Pollutants, Chemical/analysis , X-RaysABSTRACT
Infection cases of diphyllobothriid tapeworms are not much in the below teen-age group. We report a case of Diphyllobothrium nihonkaiense infection in a 13-year-old boy. He presented with severe fatigue, occasional abdominal pain at night time. He also had several episodes of tapeworm segment discharge in his stools. By his past history, he had frequently eaten raw fish including salmon and trout with his families. Numerous eggs of diphyllobothriid tapeworm were detected in the fecal examination. We introduced amidotrizoic acid as a cathartic agent through nasogastroduodenal tube and let nearly whole length (4.75 m) of D. nihonkaiense be excreted through his anus. After a single dose of praziquantel, the child's stool showed no further eggs, and his symptoms disappeared. The evacuated worm was identified as D. nihonkaiense by mitochondrial cox1 gene analysis. Here we report a successful extracorporeal worm extraction from an infection case of D. nihonkaiense by the injection of amidotrizoic acid.
Subject(s)
Antiparasitic Agents/therapeutic use , Diatrizoate Meglumine/therapeutic use , Diphyllobothriasis/drug therapy , Diphyllobothrium/drug effects , Diphyllobothrium/isolation & purification , Adolescent , Animals , Cyclooxygenase 1/genetics , Diphyllobothriasis/parasitology , Diphyllobothriasis/pathology , Diphyllobothrium/classification , Diphyllobothrium/genetics , Feces/parasitology , Humans , Male , Praziquantel/therapeutic use , Sequence Analysis, DNAABSTRACT
Infection cases of diphyllobothriid tapeworms are not much in the below teen-age group. We report a case of Diphyllobothrium nihonkaiense infection in a 13-year-old boy. He presented with severe fatigue, occasional abdominal pain at night time. He also had several episodes of tapeworm segment discharge in his stools. By his past history, he had frequently eaten raw fish including salmon and trout with his families. Numerous eggs of diphyllobothriid tapeworm were detected in the fecal examination. We introduced amidotrizoic acid as a cathartic agent through nasogastroduodenal tube and let nearly whole length (4.75 m) of D. nihonkaiense be excreted through his anus. After a single dose of praziquantel, the child's stool showed no further eggs, and his symptoms disappeared. The evacuated worm was identified as D. nihonkaiense by mitochondrial cox1 gene analysis. Here we report a successful extracorporeal worm extraction from an infection case of D. nihonkaiense by the injection of amidotrizoic acid.
