| 摘要 |
A particulate material suitable for the removal of heavy metals from an aqueous effluent comprises a finely ground solid encapsulated in a microporous shell of a polyvinyl chloride. The solid may be peat. The shell comprises a sufficient amount of polyvinyl chloride to utilize the adsorptive qualities of the peat while imparting structural integrity thereto. A process for making the particulate material comprises the steps of dissolving a polyvinyl chloride in an organic solvent therefor to produce a polymer solution, combining the polymer solution with a solid to produce a homogenous dispersion, forming droplets from the dispersion and contacting the droplets with water to precipitate out a particulate material comprising a finely ground solid encapsulated in a microporous shell of the polyvinyl chloride. The material may be modified after the solid is encapsulated, or the solid of the material may be modified before it is encapsulated. The material or the peat is modified with a calcium salt, such as calcium carbonate, or a sodium salt, such as sodium hydroxide. Raw peat which is modified with a calcium salt, preferably calcium carbonate, is also suitable for the removal of heavy metals from an aqueous effluent. |
