The invention relates generally to polymers and methods for using the polymers. In particular, the invention relates to polymers usable for, e.g., removing undesirable elements from aqueous solutions.
Water pollution is an existing and growing worldwide problem. For example, waste water issuing from waste treatment facilities, from the chlor-alkali industry, from the metal finishing industry, and from certain municipal landfills often presents a metal contamination problem. Similarly, the metal content of water exiting both or either of functional and abandoned mines is a significant environmental issue in geographical areas with a mining industry.
Different treatment technologies have been developed to remove either of or both dissolved and suspended metal ions from industrial waters and wastewaters. One common practice is to precipitate the bulk of the metal contaminant as its metal hydroxide. Metal ions such as copper and lead are easily precipitated in this way, but the minimum concentration that can be obtained is limited by the finite solubility of the metal hydroxide. The resulting effluent from the hydroxide precipitation may be treated with a metal scavenging agent to remove trace metal contaminants. The metal scavenging agents may be precipitants, adsorbents, or metal specific ion exchange resins. The metal scavenging agents may also be effective when added in the same step as the hydroxide precipitation. Exemplary compounds utilized as metal scavenging agents include sulfides, (thio)carbonates, alkyl dithiocarbamates, mercaptans, and polydithiocarbamates.
The prior art metal scavenging agents have various limitations. On the other hand, other undesirable elements such as selenium in aqueous solutions need also to be removed. There exists a need, therefore, for a new material to remove undesirable elements such as metals and/or metalloids (e.g., selenium) from aqueous solutions.
USPTO Backgrounds
USPTO Backgrounds