No description available.

No description available.

Cross-linked copolymers of acrylic acid (sodium acrylate) and acrylamide were synthesized by free radical polymerization. The copolymer hydrogel was studied for capture of copper ion from aqueous solution. Effects of macromolecular structure (i.e., content of the acrylic acid, the quantity of the carboxyl groups neutralized with sodium hydroxide, and the degree of cross-linking) on water-sorption and copper ion uptake were investigated. With an increase in the content of acrylic acid (sodium acrylate), the copper sulfate uptake increases, and water sorption decreases quickly and then slowly increases when the acrylic acid content is high enough. The copper ion uptake is accompanied with a release of sodium ions from the copolymer. Increasing the percentage of the carboxyl groups neutralized by sodium hydroxide will increase the uptake of copper sulfate and water. With an increase in the content of the cross-linking agent, both copper sulfate uptake and water sorption decrease. Even though valence of copper ion is two times that of sodium ion, the copper ions sorption and sodium ions release do not follow a simple ion exchange relation because of insertion of acrylamide co-monomers in macromolecular chain. When copper ions interact with carboxyl groups in the copolymer to form chelating complexes, the water sorption decreases substantially. An analysis of adsorption isotherm indicates that at relatively low concentrations of CuSO4 in water, the copper ion sorption into the copolymer follows the Langmuir model. The wide angle X-ray diffraction (WAXD) data reveal that the copper sulfate sorbed in the hydrogel is not in crystalline state.

Cross-linked copolymers of acrylic acid (sodium acrylate) and acrylamide were synthesized by free radical polymerization. The copolymer hydrogel was studied for capture of copper ion from aqueous solution. Effects of macromolecular structure (i.e., content of the acrylic acid, the quantity of the carboxyl groups neutralized with sodium hydroxide, and the degree of cross-linking) on water-sorption and copper ion uptake were investigated. With an increase in the content of acrylic acid (sodium acrylate), the copper sulfate uptake increases, and water sorption decreases quickly and then slowly increases when the acrylic acid content is high enough. The copper ion uptake is accompanied with a release of sodium ions from the copolymer. Increasing the percentage of the carboxyl groups neutralized by sodium hydroxide will increase the uptake of copper sulfate and water. With an increase in the content of the cross-linking agent, both copper sulfate uptake and water sorption decrease. Even though valence of copper ion is two times that of sodium ion, the copper ions sorption and sodium ions release do not follow a simple ion exchange relation because of insertion of acrylamide co-monomers in macromolecular chain. When copper ions interact with carboxyl groups in the copolymer to form chelating complexes, the water sorption decreases substantially. An analysis of adsorption isotherm indicates that at relatively low concentrations of CuSO4 in water, the copper ion sorption into the copolymer follows the Langmuir model. The wide angle X-ray diffraction (WAXD) data reveal that the copper sulfate sorbed in the hydrogel is not in crystalline state.

Estrogens produced by livestock can be released into soils when their manure is spread onto agricultural land. This is the first study to determine the sorption of a range of estrogens in a wide range of soils at the regional scale, including the sorption of the phytoestrogen equol which had never been previously studied. Sorption increased in the order of 17β-estradiol=estriol <estrone<equol in surface soils collected from 41 agricultural fields in Alberta and was significantly positively correlated with soil organic carbon content (SOC) for all estrogens. 17β-estradiol was further investigated and its mineralization in non-amended and manure-amended soils never exceeded 30% at 90 days, which suggest that even under optimum environmental conditions for mineralization, 17β-estradiol or its metabolites estrone and/or estriol appear to have a relatively long persistence in Alberta soils. Maximum 17β-estradiol mineralization was significantly positively correlated with sorption and hence increased in soils with greater SOC such as those used in this study with a long-term history of solid beef manure applications. Two ELISAs were developed using rabbit polyclonal antibodies for future field experiments and environmental monitoring. Of these, a developed 17β-estradiol+estrone+estriol ELISA could detect estriol in water from an edge of field experiment at concentrations as low as 1 ng mL-1.

No description available.

Estrogens produced by livestock can be released into soils when their manure is spread onto agricultural land. This is the first study to determine the sorption of a range of estrogens in a wide range of soils at the regional scale, including the sorption of the phytoestrogen equol which had never been previously studied. Sorption increased in the order of 17β-estradiol=estriol <estrone<equol in surface soils collected from 41 agricultural fields in Alberta and was significantly positively correlated with soil organic carbon content (SOC) for all estrogens. 17β-estradiol was further investigated and its mineralization in non-amended and manure-amended soils never exceeded 30% at 90 days, which suggest that even under optimum environmental conditions for mineralization, 17β-estradiol or its metabolites estrone and/or estriol appear to have a relatively long persistence in Alberta soils. Maximum 17β-estradiol mineralization was significantly positively correlated with sorption and hence increased in soils with greater SOC such as those used in this study with a long-term history of solid beef manure applications. Two ELISAs were developed using rabbit polyclonal antibodies for future field experiments and environmental monitoring. Of these, a developed 17β-estradiol+estrone+estriol ELISA could detect estriol in water from an edge of field experiment at concentrations as low as 1 ng mL-1.

Universiẗat, Diss., 1996--Hohenheim.

Stuttgart, Univ., Diss., 2001.

Zugl.: Tübingen, University, Diss., 2006.