Environmental impact studies of the disposal of polyacrylate polymers used in consumer products

A highly absorbent consumer-product, polyacrylate polymer material was tagged with 14C and used successfully to study the environmental fate of the disposal of up to 300 million pounds of such materials annually in wastewater plants and landfills. The environmental behavior of polymers used in diaper products was studied in an on-site wastewater plant, in flow columns, and in a horizontal flow tank containing sand. The polymer exhibited a highly mobile fraction of about 2–5% which was discharged in effluents during the passage of a few pore volumes. The remainder was highly retarded and retained along the flow path in the wastewater sludges, and near the source in the sand studies. The retention processes appeared irreversible for these media, and it is concluded that more conventional landfill soils would provide even greater retention of the polymer materials studied. Microbial decomposition effects on the migration of these polymers under landfill conditions was not studied. However, a series of such studies has been initiated using large lysimeters to simulate landfills to obtain such information. This evolution of data and perspective suggests that the environmental behavior of complex materials can be successfully studied using tagged materials to understand the public health implications of their disposal as they enter the marketplace rather than later when appropriate adjustments are difficult to make.