Ultrafiltration of Blackwater for Marine Vessel Application.

摘要

The United States Army currently is investigating waste treatment technology for processing marine vessel wastewater. This has become necessary in order to satisfy Environmental Protection Agency marine discharge regulations. As an interim measure, the Army is installing collection, holding, and transfer tanks aboard their watercraft. Because of physical limitations, many of the collection, holding, and transfer tanks do not provide adequate holding capacity. Concentration is one method of extending holding tank capacity. A candidate system is ultrafiltration. Two manufacturers' ultrafiltration membranes were evaluated with blackwater. Half-inch (1.2 centimeter) tubular membrane configurations were investigated. Membrane TI was commercially available. Membrane TII was specially prepared for this evaluation using half-inch tubular supports. In order to satisfy Army maintainability and reliability requirements, no pretreatment, aeration or cleaning were provided for either membrane. Depressurization of the membranes overnight or over the weekend provided sufficient flux recovery that membrane cleaning was unnecessary. An economic comparison of the membranes could not be made because of the commercial nonavailability of the TII membrane. Although the power requirements of this membrane were approximately 15-fold less than membrane TI, the commercial price of TII will ultimately determine the tradeoff between the two membranes.